Editing Vortec L31 cylinder head
Line 1: | Line 1: | ||
{{youcanedit}} | {{youcanedit}} | ||
==Overview== | ==Overview== | ||
− | The Chevrolet L31 5.7L Vortec cylinder head is the best | + | The Chevrolet L31 5.7L Vortec cylinder head is the best production head Chevy has made for the Gen I SBC engine to date. Because of this, it has become a very popular swap. |
− | The name "Vortec" can be confusing because GM used that name for their V6 and V8 truck engines as far back as | + | The name "Vortec" can be confusing because GM used that name for their V6 and V8 truck engines as far back as 1988. But the heads that are being referred to here are from trucks and SUVs produced from 1996-2002. |
They are made of cast iron, have 170cc nominal intake runners, and 64cc nominal combustion chamber volume (actual volumes may vary due to production tolerances and/or modifications done previously, so volumes, especially the combustion chamber volume, has to be determined by measuring, or "CC'ing" the chamber). | They are made of cast iron, have 170cc nominal intake runners, and 64cc nominal combustion chamber volume (actual volumes may vary due to production tolerances and/or modifications done previously, so volumes, especially the combustion chamber volume, has to be determined by measuring, or "CC'ing" the chamber). | ||
Line 12: | Line 12: | ||
* 1996-2002 Chevrolet Express/GMC Savana full-size vans | * 1996-2002 Chevrolet Express/GMC Savana full-size vans | ||
* 1996-1999 Chevrolet/GMC C/K full-size trucks | * 1996-1999 Chevrolet/GMC C/K full-size trucks | ||
− | * 1996-1999 Chevrolet Suburban/GMC Suburban full-size long wheelbase SUVs | + | * 1996-1999 Chevrolet Suburban/GMC Suburban full-size long-wheelbase SUVs |
− | * 1996-1999 Chevrolet Tahoe/GMC Yukon full-size short wheelbase SUVs | + | * 1996-1999 Chevrolet Tahoe/GMC Yukon full-size short-wheelbase SUVs |
* 1999-2000 Cadillac Escalade | * 1999-2000 Cadillac Escalade | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
==Vortec L31 5.7L head ID== | ==Vortec L31 5.7L head ID== | ||
− | The L31 5.7L Vortec casting numbers are ''' | + | The L31 5.7L Vortec casting numbers are '''12559062''' and '''10239906'''. |
{| | {| | ||
Line 59: | Line 25: | ||
==Technical specs== | ==Technical specs== | ||
− | * | + | *Valvespring Seat: 1.300” O.D., 0.850” I.D. |
− | *Valve Seals: | + | *Valve-guide Seals: Viton rubber positive seals, total 0.450” retainer-to-seal clearance |
− | + | ||
*Combustion Chamber Volume: 64 cc | *Combustion Chamber Volume: 64 cc | ||
*Heat Risers: No | *Heat Risers: No | ||
− | *Valve springs: Single | + | *Valve springs: Single wire with damper 1.235” O.D., 0.875” I.D. 75-pound seat pressure @ 1.700” installed height Coil-bind @ 1.150” |
− | + | *Rocker Arm Style: Self-Aligning | |
− | *Rocker Arm | + | |
*Intake Runner Volume: 170 cc | *Intake Runner Volume: 170 cc | ||
*Valve Diameter: I: 1.94”, E: 1.50” | *Valve Diameter: I: 1.94”, E: 1.50” | ||
*Casting Numbers: 10239906 and 12558062 | *Casting Numbers: 10239906 and 12558062 | ||
+ | *Max. Valve Lift: 0.420” which allows 0.030” retainer-to-seal | ||
*Rocker Stud: Press-in, 3/8” diameter | *Rocker Stud: Press-in, 3/8” diameter | ||
− | *Spark plug: 14 mm, | + | *Spark-plug Style: 14 mm, ¾ reach, tapered seat |
==Design limitations and modifications== | ==Design limitations and modifications== | ||
Line 87: | Line 52: | ||
==Flow rate of L31 Vortec heads== | ==Flow rate of L31 Vortec heads== | ||
− | {| style="color:black; cellpadding=" | + | {| style="color:black; cellpadding="5" cellspacing="0" border="1" bgcolor="#FFF8DC" |
− | !bgcolor="# | + | !bgcolor="#CCCCFF"|Lift (in.) !!bgcolor="#CCCCFF"|Intake (CFM) !!bgcolor="#CCCCFF"|Exhaust (CFM) |
|- | |- | ||
− | | align=" | + | | align="right" |0.100 || align="right" |70 || align="right" |49 |
− | + | ||
− | + | ||
|- | |- | ||
− | | align=" | + | | align="right" |0.200 || align="right" |139 || align="right" |105 |
− | + | ||
− | + | ||
|- | |- | ||
− | | align=" | + | | align="right" |0.300 || align="right" |190 || align="right" |137 |
− | | | + | |- |
− | | align=" | + | | align="right" |0.400 || align="right" |227 || align="right" |151 |
+ | |- | ||
+ | | align="right" |0.500 || align="right" |239 || align="right" |160 | ||
+ | |- | ||
+ | | align="right" |0.600 || align="right" |229 || align="right" |162 | ||
|- | |- | ||
|} | |} | ||
+ | |||
;'''Sources:''' | ;'''Sources:''' | ||
:Paul Shufelt, Chevy High Performance (Feb. 2001)<br> | :Paul Shufelt, Chevy High Performance (Feb. 2001)<br> | ||
Line 111: | Line 77: | ||
<td class="wbg-blacktext" align="center" valign="top"> </td> | <td class="wbg-blacktext" align="center" valign="top"> </td> | ||
− | <td | + | <td class="ltbluebg-blacktextbold-12px" colspan="3" align="center" valign="top">'''Intake Flow Comparison'''</td> |
− | <td | + | <td class="ltyellowbg-blacktext-12pxB" colspan="3" align="center" valign="top">'''Exhaust Flow Comparison'''</td></tr> |
<tr align="left" bgcolor="#CCCCFF" valign="top"> | <tr align="left" bgcolor="#CCCCFF" valign="top"> | ||
− | <td | + | <td class="ltorangebg-blacktext-14pxB" align="center" valign="top" width="92">'''Valve Lift'''</td> |
− | <td | + | <td class="oceanbluebg-blacktext" align="center" valign="top" width="92">'''GMPP'''<br> |
'''Fast Burn'''</td> | '''Fast Burn'''</td> | ||
− | <td | + | <td class="ltpinkPowderbg-bk12" align="center" valign="top" width="92">'''GM'''<br> |
'''Vortec L31'''</td> | '''Vortec L31'''</td> | ||
− | <td | + | <td class="msdbg-blacktext" align="center" nowrap="" valign="top" width="92">'''GM Stock'''<br>'''Iron 882'''</td> |
− | <td | + | <td class="oceanbluebg-blacktext" align="center" valign="top" width="92">'''GMPP'''<br> |
'''Fast Burn'''</td> | '''Fast Burn'''</td> | ||
− | <td | + | <td class="ltpinkPowderbg-bk12" align="center" valign="top" width="92">'''GM'''<br> |
'''Vortec L31'''</td> | '''Vortec L31'''</td> | ||
− | <td | + | <td class="msdbg-blacktext" align="center" valign="top" width="92">'''GM Stock'''<br> |
'''Iron 882'''</td></tr> | '''Iron 882'''</td></tr> | ||
<tr align="left" bgcolor="#FFF8DC" valign="top"> | <tr align="left" bgcolor="#FFF8DC" valign="top"> | ||
− | <td | + | <td class="ltorangebg-blacktext-12px" align="center" valign="top">0.050”</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">30</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">40</td> |
<td class="wbg-blacktext" align="center" valign="top">39</td> | <td class="wbg-blacktext" align="center" valign="top">39</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">23</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">25</td> |
<td class="wbg-blacktext" align="center" valign="top">34</td></tr> | <td class="wbg-blacktext" align="center" valign="top">34</td></tr> | ||
<tr align="left" bgcolor="#FFF8DC" valign="top"> | <tr align="left" bgcolor="#FFF8DC" valign="top"> | ||
<td class="ltorangebg-blacktext-12px" align="center" valign="top">0.100”</td> | <td class="ltorangebg-blacktext-12px" align="center" valign="top">0.100”</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">61</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">70</td> |
<td class="wbg-blacktext" align="center" valign="top">70</td> | <td class="wbg-blacktext" align="center" valign="top">70</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">53</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">48</td> |
<td class="wbg-blacktext" align="center" valign="top">58</td></tr> | <td class="wbg-blacktext" align="center" valign="top">58</td></tr> | ||
<tr align="left" bgcolor="#FFF8DC" valign="top"> | <tr align="left" bgcolor="#FFF8DC" valign="top"> | ||
<td class="ltorangebg-blacktext-12px" align="center" valign="top">0.200”</td> | <td class="ltorangebg-blacktext-12px" align="center" valign="top">0.200”</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">126</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">139</td> |
<td class="wbg-blacktext" align="center" valign="top">125</td> | <td class="wbg-blacktext" align="center" valign="top">125</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">107</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">101</td> |
<td class="wbg-blacktext" align="center" valign="top">108</td></tr> | <td class="wbg-blacktext" align="center" valign="top">108</td></tr> | ||
<tr align="left" bgcolor="#FFF8DC" valign="top"> | <tr align="left" bgcolor="#FFF8DC" valign="top"> | ||
<td class="ltorangebg-blacktext-12px" align="center" valign="top">0.300”</td> | <td class="ltorangebg-blacktext-12px" align="center" valign="top">0.300”</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">180</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">190</td> |
<td class="wbg-blacktext" align="center" valign="top">175</td> | <td class="wbg-blacktext" align="center" valign="top">175</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">140</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">121</td> |
<td class="wbg-blacktext" align="center" valign="top">135</td></tr> | <td class="wbg-blacktext" align="center" valign="top">135</td></tr> | ||
<tr align="left" bgcolor="#FFF8DC" valign="top"> | <tr align="left" bgcolor="#FFF8DC" valign="top"> | ||
<td class="ltorangebg-blacktext-12px" align="center" valign="top">0.400”</td> | <td class="ltorangebg-blacktext-12px" align="center" valign="top">0.400”</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">221</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">227</td> |
<td class="wbg-blacktext" align="center" valign="top">204</td> | <td class="wbg-blacktext" align="center" valign="top">204</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">167</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">140</td> |
<td class="wbg-blacktext" align="center" valign="top">141</td></tr> | <td class="wbg-blacktext" align="center" valign="top">141</td></tr> | ||
<tr align="left" bgcolor="#FFF8DC" valign="top"> | <tr align="left" bgcolor="#FFF8DC" valign="top"> | ||
<td class="ltorangebg-blacktext-12px" align="center" valign="top">0.500”</td> | <td class="ltorangebg-blacktext-12px" align="center" valign="top">0.500”</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">243</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">239</td> |
<td class="wbg-blacktext" align="center" valign="top">205</td> | <td class="wbg-blacktext" align="center" valign="top">205</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">178</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">147</td> |
<td class="wbg-blacktext" align="center" valign="top">142</td></tr> | <td class="wbg-blacktext" align="center" valign="top">142</td></tr> | ||
<tr align="left" bgcolor="#FFF8DC" valign="top"> | <tr align="left" bgcolor="#FFF8DC" valign="top"> | ||
<td class="ltorangebg-blacktext-12px" align="center" valign="top">0.600”</td> | <td class="ltorangebg-blacktext-12px" align="center" valign="top">0.600”</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">238</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">229</td> |
<td class="wbg-blacktext" align="center" valign="top">206</td> | <td class="wbg-blacktext" align="center" valign="top">206</td> | ||
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">184</td> |
− | <td | + | <td class="wbg-blacktext" align="center" valign="top">151</td> |
<td class="wbg-blacktext" align="center" valign="top">142</td></tr> | <td class="wbg-blacktext" align="center" valign="top">142</td></tr> | ||
<tr class="wbg-blacktext" align="left" valign="top"> | <tr class="wbg-blacktext" align="left" valign="top"> | ||
<td class="wbg-blacktext" colspan="7" align="left" valign="top"><span class="wbg-blacktext-12pxB">'''Note''':</span> Vortec L31 and Stock Iron 882 flow data where obtained from Car Craft Magazine’s Web site in their Technical Articles section. The Fast Burn (new version) flow data is Chevrolet’s data.</td></tr></table><br> | <td class="wbg-blacktext" colspan="7" align="left" valign="top"><span class="wbg-blacktext-12pxB">'''Note''':</span> Vortec L31 and Stock Iron 882 flow data where obtained from Car Craft Magazine’s Web site in their Technical Articles section. The Fast Burn (new version) flow data is Chevrolet’s data.</td></tr></table><br> | ||
+ | {{!}} It's unknown at this time why there's a discrepancy in the exhaust flow of the Vortec heads between the two tables. | ||
− | ==Upgrading and | + | ==Upgrading and Compatibility== |
− | The L31 Vortec head | + | The L31 Vortec head will bolt directly onto Gen 1 small block Chevrolets. They will also obviously work on L31 engines (sometimes referred to as Gen1+). They are not compatible with Gen2 (LT1 or LT4) engines. They are also not compatible with any of the current LS engines. |
There are some inherent costs associated in swapping from 1995-back heads to the L31 Vortec heads. Here is a list of items to be purchased and/or labor associated with the upgrade: | There are some inherent costs associated in swapping from 1995-back heads to the L31 Vortec heads. Here is a list of items to be purchased and/or labor associated with the upgrade: | ||
* L31 heads | * L31 heads | ||
− | * Springs if the cam has a valve lift over about 0. | + | * Springs if the cam has a valve lift over about 0.420" |
− | * | + | * Center bolt style valve covers if the heads used previously were perimeter style |
− | ** Note: [http://www.crankshaftcoalition.com/wiki/Vortec_L31_cylinder_head#Small_port_Vortec_head_p.2Fn_25534351_.28bare.29_and_p.2Fn_25534421_.28assembled.29 GMPP small and large port Vortec heads] and other aftermarket Vortec heads accept either perimeter or center bolt valve covers | + | [[File:Vortec valve-rocker.jpg|thumb|right|300px|Self aligning stamped steel rockers]] |
− | *Self aligning rocker arms | + | ** Note: [http://www.crankshaftcoalition.com/wiki/Vortec_L31_cylinder_head#Small_port_Vortec_head_p.2Fn_25534351_.28bare.29_and_p.2Fn_25534421_.28assembled.29 GMPP small and large port Vortec heads] and other aftermarket Vortec heads accept either perimeter or center bolt valve covers |
− | * Valve cover gaskets | + | *Self aligning rocker arms |
− | * Vortec specific intake manifold. While some aftermarket heads have both 12 and 8 bolt intake bolt patterns, the height of the Vortec ports require a tall, "raised port" type early intake manifold (along with porting/port work to the intake manifold and/or head), to even come close to fitting correctly | + | * Valve cover gaskets |
+ | * Vortec specific intake manifold. While some aftermarket heads have both 12 and 8 bolt intake bolt patterns, the height of the Vortec ports require a tall, "raised port" type early intake manifold (along with porting/port work to the intake manifold and/or head), to even come close to fitting correctly | ||
* Vortec specific intake manifold gasket | * Vortec specific intake manifold gasket | ||
* Vortec specific intake manifold bolts | * Vortec specific intake manifold bolts | ||
− | * Head bolts (required only if the original head bolts are either missing or unusable for some reason | + | * Head bolts (required only if the original head bolts are either missing or unusable for some reason) |
* Head gaskets ([http://www.crankshaftcoalition.com/wiki/Head_gasket#Re-using_head_gaskets generally required] any time heads are re-installed) | * Head gaskets ([http://www.crankshaftcoalition.com/wiki/Head_gasket#Re-using_head_gaskets generally required] any time heads are re-installed) | ||
* Machining valve guide boss or the use of different retainers and springs, or ghetto grinding the stock retainers, etc., to work with a camshaft having somewhere around 0.450" or more valve lift. | * Machining valve guide boss or the use of different retainers and springs, or ghetto grinding the stock retainers, etc., to work with a camshaft having somewhere around 0.450" or more valve lift. | ||
Line 210: | Line 178: | ||
Unlike previous SBC valves, Vortec valves have just one groove for the keepers instead of two grooves (earlier valves had one groove for the keepers, the second (lower) groove was for the oil control O-ring); Vortec heads use a positive-type valve stem oil seal and do not use the tin oil shield seen for years on SBC heads, nor do Vortec heads use exhaust valve rotators. | Unlike previous SBC valves, Vortec valves have just one groove for the keepers instead of two grooves (earlier valves had one groove for the keepers, the second (lower) groove was for the oil control O-ring); Vortec heads use a positive-type valve stem oil seal and do not use the tin oil shield seen for years on SBC heads, nor do Vortec heads use exhaust valve rotators. | ||
− | Another difference between Vortec valves and the earlier non self aligning head valves is the tip length. Earlier valves are 0.250" on both intake and exhaust valves. Self aligning head intake valves have a 0.260" groove-to-tip length, exhaust valves use a 0.289" groove-to-tip length | + | Another difference between Vortec valves and the earlier non self aligning head valves is the tip length. Earlier valves are 0.250" on both intake and exhaust valves. Self aligning head intake valves have a 0.260" groove-to-tip length, exhaust valves use a 0.289" groove-to-tip length. |
==Valve springs, retainers and locks== | ==Valve springs, retainers and locks== | ||
[[File:Vortec beehive.jpg|thumb|left|300px|Straight wound spring, Left; Beehive spring, right]] | [[File:Vortec beehive.jpg|thumb|left|300px|Straight wound spring, Left; Beehive spring, right]] | ||
<br style="clear:both"/> | <br style="clear:both"/> | ||
− | The stock Vortec valve springs are single wound without a damper and are 1.250" diameter. The damping is done by the spring ID (. | + | The stock Vortec valve springs are single wound without a damper and are 1.250" diameter. The damping is done by the spring ID (.880") being a close fit to the guide boss OD (0.845"); this damps the spring without the added cost of an inner flat wound damper seen on the Gen 1 SBC throughout its production. If you have aftermarket springs designed for the earlier heads, you must remove the inner damper because the damper ID will be too small to fit over the guide boss without it being cut smaller. If the boss is cut smaller, a damper should be used. |
− | The stock springs are not suited for high performance use or for lifts above about 0. | + | The stock springs are not suited for high performance use or for lifts above about 0.420" using stock retainers. There are several replacements for the stock springs, among the best is the beehive spring and retainer combination from Comp Cams, originally designed for the LS engine series. |
*'''[http://www.compcams.com/WhatsNew/NewsDetails.aspx?ListHistoryID=164462240 p/n 26915]'''- 105 pounds at 1.8" installed height; open pressure 293 lbs. at 1.2"; coil bind at 1.100"; spring rate 313 lbs./in.; bottom OD 1.290" | *'''[http://www.compcams.com/WhatsNew/NewsDetails.aspx?ListHistoryID=164462240 p/n 26915]'''- 105 pounds at 1.8" installed height; open pressure 293 lbs. at 1.2"; coil bind at 1.100"; spring rate 313 lbs./in.; bottom OD 1.290" | ||
− | *'''[http://www.compcams.com/WhatsNew/NewsDetails.aspx?ListHistoryID=1166393320 p/n 26918]'''- 125 pounds at 1.8" installed height; open pressure 367 pounds at 1.15"; coil bind 1.100"; spring rate 372 lbs./in.; | + | *'''[http://www.compcams.com/WhatsNew/NewsDetails.aspx?ListHistoryID=1166393320 p/n 26918]'''- 125 pounds at 1.8" installed height; open pressure 367 pounds at 1.15"; coil bind 1.100"; spring rate 372 lbs./in.; bottom OD 1.310" |
− | {{Note1}}The p/ | + | {{Note1}}The p/n26918 springs were udated, Check w/Comp Cams to be sure the specs are correct. |
*'''[http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=26981-16&Category_Code= p/n 26981]'''- 110 pounds at 1.70" installed height; open pressure 292 lbs. at 1.175"; coil bind 1.115"; spring rate 347 lb./in.; bottom OD 1.240" | *'''[http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=26981-16&Category_Code= p/n 26981]'''- 110 pounds at 1.70" installed height; open pressure 292 lbs. at 1.175"; coil bind 1.115"; spring rate 347 lb./in.; bottom OD 1.240" | ||
Line 230: | Line 198: | ||
On the other end of the cost scale is the use of inexpensive "Z-28/LT-1" springs (or any spring with a ~1.70" installed height and a 1.25" OD) with the damper removed along with the stock retainers that have had some of the bottom ground off to provide more clearance (sometimes referred to as the "ghetto grind"). This will allow more lift (in the area of 0.500") without changing the guide boss height or diameter. | On the other end of the cost scale is the use of inexpensive "Z-28/LT-1" springs (or any spring with a ~1.70" installed height and a 1.25" OD) with the damper removed along with the stock retainers that have had some of the bottom ground off to provide more clearance (sometimes referred to as the "ghetto grind"). This will allow more lift (in the area of 0.500") without changing the guide boss height or diameter. | ||
− | Chevrolet recommends using the [http://www.summitracing.com/parts/crn-10309-1 Crane Cam p/n 10309-1] drop-in valve spring/retainer kit which is good for | + | Chevrolet recommends using the [http://www.summitracing.com/parts/crn-10309-1 Crane Cam p/n 10309-1] drop-in valve spring/retainer kit which is good for .550” lift (this allows about 0.025" between the retainer and seal) with no machining. The spring rate for this spring is 409 lb/in and has a 0.870" ID. |
When retaining the factory boss and seals, be sure the valve seals are driven on all the way. You need to check that they are before installing this kit. Use a 3/8” drive 1/2” socket and a soft mallet to gently drive the seals fully home. | When retaining the factory boss and seals, be sure the valve seals are driven on all the way. You need to check that they are before installing this kit. Use a 3/8” drive 1/2” socket and a soft mallet to gently drive the seals fully home. | ||
Line 236: | Line 204: | ||
*[http://www.thirdgen.org/techboard/tech-general-engine/542295-ls6-valvetrain-vortec-heads.html LS6 Valvetrain on vortec heads] | *[http://www.thirdgen.org/techboard/tech-general-engine/542295-ls6-valvetrain-vortec-heads.html LS6 Valvetrain on vortec heads] | ||
*[http://www.thirdgen.org/techboard/tech-general-engine/562935-rework-vortec-heads.html Vortec valvetrain mods] | *[http://www.thirdgen.org/techboard/tech-general-engine/562935-rework-vortec-heads.html Vortec valvetrain mods] | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
===Locks=== | ===Locks=== | ||
− | + | If self aligning rockers are used they can sometimes come into contact with the locks. Using a lock like the Edelbrock p/n 9615 can help. This 7 degree lock is 0.050" lower than a regular lock. | |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
===Spring seat=== | ===Spring seat=== | ||
− | + | Use reduced hex head bolts or 12 point fasteners to give more clearance if a larger seat like for a 1.44" OD spring is used. Use caution if making the seat larger, there have been a few warnings about cracks developing on heads with enlarged seats. | |
==Valve guide boss== | ==Valve guide boss== | ||
[[File:900 guide boss1.jpg|thumb|450px|left|Stock Vortec boss is 0.845"OD]] | [[File:900 guide boss1.jpg|thumb|450px|left|Stock Vortec boss is 0.845"OD]] | ||
− | For performance use, often the guide boss will be shortened to allow more lift without retainer to seal clearance problems. Along with that, the guide boss OD can be machined down from 0. | + | For performance use, often the guide boss will be shortened to allow more lift without retainer to seal clearance problems. Along with that, the guide boss OD can be machined down from 0.845" to a smaller common diameter, like .785" of the original Gen1 SBC heads, so aftermarket springs (double or with dampers) can be used. At the same time the boss can be machined from .555" to use a commonly available positive seal like 0.530". |
<br style="clear:both"/> | <br style="clear:both"/> | ||
+ | ===Valve guide boss modification=== | ||
[[File:VORTEC GUIDE BOSS MODIFIED.jpg|thumb|250px|Before (right) and after]] | [[File:VORTEC GUIDE BOSS MODIFIED.jpg|thumb|250px|Before (right) and after]] | ||
− | In order to fit one of the commonly available smaller diameter positive type valve stem oil seals, the tops of the guide boss needs to be turned down. To fit springs with a smaller ID like double | + | In order to fit one of the commonly available smaller diameter positive type valve stem oil seals, the tops of the guide boss needs to be turned down. To fit springs with a smaller ID like double or those with a damper, the guide boss needs to be modified by shortening and decreasing the OD of the boss. |
<br style="clear:both"/> | <br style="clear:both"/> | ||
===Tooling=== | ===Tooling=== | ||
[[File:Tool.jpg|thumb|450px|Comp tooling]] | [[File:Tool.jpg|thumb|450px|Comp tooling]] | ||
− | Crane | + | Crane and Comp Cams sell cutters to machine the guide boss diameter using a hand drill. The arbor and cutters should be used with valve guides that are in good condition because the arbor uses the guide to locate the cutters. |
− | + | Some Comp Cams part numbers: | |
− | * | + | *4718- spring seat cutter, 1.440" OD |
− | * | + | *4726- valve guide cutter, 0.530" OD |
− | * | + | *4732- 11/32" arbor for cutting tools |
− | + | ||
− | + | ||
<br style="clear:both"/> | <br style="clear:both"/> | ||
;From an article by editor Jeff Smith: | ;From an article by editor Jeff Smith: | ||
− | <blockquote>The Comp Cams cutter increases the spring-seat diameter while simultaneously reducing the outside diameter ( | + | <blockquote>The Comp Cams cutter increases the spring-seat diameter while simultaneously reducing the outside diameter (od) of the guide boss. The Crane tool also cuts the valve-guide-seal diameter at the same time. Comp sells a separate tool that cuts a new guide seal and reduces the guide height to create additional retainer-to-seal clearance. Both cutters machine the top of the guide down to a 0.530-inch diameter, which is the standard size for positive-type aftermarket seals. This requires purchasing new valve-guide seals, since the factory uses a 0.560-inch guide to locate the seals. Another way to go is to have a machine shop cut the guide boss diameter to around 0.760 inch and reduce the seal height and use either the Crane H-11 tool steel spring (PN 99846) or the Comp spring (PN 981). |
</blockquote> | </blockquote> | ||
==Rocker arm studs== | ==Rocker arm studs== | ||
− | Production L31 Vortec heads come with pressed in 3/8" studs. For high performance and/or solid lifter applications, screw in studs are highly recommended. The pressed studs can be pinned, but this is a stop-gap measure that should be done only in cases where the spring pressures/engine RPM/lobe intensity will not be excessive and/or the budget is limited. Otherwise use ARP screw in studs or their equivalent. | + | Production L31 Vortec heads come with pressed in 3/8" studs. For high performance and/or solid lifter applications, screw in studs are highly recommended. The pressed studs can be pinned, but this is a stop-gap measure that should be done only in cases where the spring pressures/engine RPM/lobe intensity will not be excessive and/or the budget is limited. Otherwise use ARP screw in studs or their equivalent. If not using guide plates, non shouldered studs can be used instead of studs having shoulders and a hex for tightening (this type of stud is tightened by "double nutting"). Screw in studs having a hex may require the stud bosses to be machined shorter to compensate for the hex. |
− | + | ===Guide plates=== | |
+ | Guide plates can also be installed at this time if desired. Consider Isky adjustable guide plates. Using guide plates will require the stud bosses to be machined shorter to compensate for the thickness of the plates and the hex on the stud. While home builders have successfully installed screw in studs without specialized equipment, unless the builder is well versed in doing this type of work, i.e. drilling straight, correctly located holes and tapping them, this is better left to a professional machinist/machine shop. At the least, a fixture to guide the drill bit and tap should be used. | ||
− | + | <br> | |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
{{Note1}}If using guide plates, non self aligning rockers need to be used. If guide plates are not used, self aligning rockers MUST be used. | {{Note1}}If using guide plates, non self aligning rockers need to be used. If guide plates are not used, self aligning rockers MUST be used. | ||
− | |||
− | |||
==Exhaust valve seats== | ==Exhaust valve seats== | ||
Line 331: | Line 258: | ||
==Pushrod guide holes== | ==Pushrod guide holes== | ||
− | [[File:Vortec head p-rod hole enlargement.jpg|thumb|Vortec head enlarging pushrod hole]]Vortec heads have a 7/16" round pushrod hole in the head; earlier non self aligning rocker arm equipped heads have a 7/16" x 11/32" | + | [[File:Vortec head p-rod hole enlargement.jpg|thumb|Vortec head enlarging pushrod hole]]Vortec heads have a 7/16" round pushrod hole in the head; earlier non self aligning rocker arm equipped heads have a 7/16" x 11/32" ovoid hole in them. |
===So what this means is three things:=== | ===So what this means is three things:=== | ||
Line 369: | Line 296: | ||
====Large port Vortec flow chart==== | ====Large port Vortec flow chart==== | ||
− | <table border=" | + | <table table border="2" cellpadding="2" cellspacing="0"><tr valign="top" tr bgcolor="#FFF8DC"><td colspan="2"><center>INTAKE</center></td><td colspan="2"><center>EXHAUST</center></td></tr><tr valign="top" tr bgcolor="#FFF8DC"><td>Lift (in.)</td><td> CFM </td><td>Lift (in.)</td><td> CFM </td></tr><tr valign="top"><td>0.200</td><td>128.6</td><td>0.200</td><td>100.8</td></tr><tr valign="top"><td>0.300</td><td>188.4</td><td>0.300</td><td>138.6</td></tr><tr valign="top"><td>0.400</td><td>234.8</td><td>0.400</td><td>154.4</td></tr><tr valign="top"><td>0.500</td><td>257.2</td><td>0.500</td><td>152.5</td></tr><tr valign="top"><td>0.600</td><td>263.2</td><td>0.600</td><td>163.8</td></tr><tr valign="top"><td>0.700</td><td>269.1</td><td>0.700</td><td>167.0</td></tr></table> |
− | == | + | '''[[Vortec_L31_cylinder_head#Upgrading and Compatibility|Return to above]]''' |
− | + | ||
+ | ==Vortec specific intake manifolds== | ||
+ | The L30 5.0L and L31 5.7L Vortec engines never came with a carb; they all used EFI so did not need a heat crossover port in the heads. GMPP and the aftermarket sell various carburetor and TBI intakes to fit the Vortec heads, though, so using a carb or TBI with Vortec heads is easy and some Vortec intakes have the provision to run coolant through the plenum area to provide intake heat. | ||
+ | |||
+ | Vortec heads use an intake manifold having 8 instead of 12 bolts. Also, Vortec intake ports are taller than earlier SBC heads. That means earlier intakes will not match up to the Vortec ports; there's not enough metal above the port (except on "raised port" aftermarket intakes) to allow the head and intake port to match up. An early intake would need at least 0.325" of material above the intake port opening to have any chance of sealing, and that doesn't take the difference in the port width/location. Because of these differences, a Vortec-specific intake must be used. | ||
+ | |||
+ | ;Chevrolet says<nowiki>:</nowiki> | ||
+ | <blockquote> | ||
+ | Do not try to modify either the heads or the intake manifold to try to make the Vortec heads match up to a standard 12-bolt intake manifold. The ports will not match up. You must use a Vortec style intake manifold with any Vortec style cylinder head. | ||
+ | </blockquote> | ||
+ | |||
+ | Due to issues with aftermarket Vortec intake manifold gaskets deteriorating for no apparent reason, it is suggested to use a Fel-Pro gasket p/n Q1255, or equivalent. | ||
{| | {| | ||
Line 378: | Line 316: | ||
|} | |} | ||
{| | {| | ||
− | |[[File:Gmpp vortec tbi intake.jpg|thumb|center|420px|TBI intake p/n 12496821 from GMPP | + | |[[File:Gmpp vortec tbi intake.jpg|thumb|center|420px|TBI intake p/n 12496821 from GMPP]] |
|[[File:12366573 - GMPP Vortec dual plane intake manifold.jpg|thumb|center|270px|Dual plane GMPP intake p/n 12366573]] | |[[File:12366573 - GMPP Vortec dual plane intake manifold.jpg|thumb|center|270px|Dual plane GMPP intake p/n 12366573]] | ||
|[[File:Gmpp 12496822 open plenum.jpg|thumb|center|420px|GMPP p/n 12496822 open plenum intake]] | |[[File:Gmpp 12496822 open plenum.jpg|thumb|center|420px|GMPP p/n 12496822 open plenum intake]] | ||
Line 386: | Line 324: | ||
The shape of a Vortec combustion chamber requires a domed piston designed for it if domed pistons are needed. If a small chamber SBC domed piston is used with a Vortec head, the piston could hit if it isn't clearanced. | The shape of a Vortec combustion chamber requires a domed piston designed for it if domed pistons are needed. If a small chamber SBC domed piston is used with a Vortec head, the piston could hit if it isn't clearanced. | ||
− | Off the shelf domed pistons are available | + | Off the shelf domed pistons are available form Keith Black and others that will work with Vortec combustion chambers without needing any extra work. |
[[File:Vortec dome piston long rod.jpg|350px|left|thumb|KB domed piston for the Vortec head. This example uses a long rod]] <br style="clear:both"/> | [[File:Vortec dome piston long rod.jpg|350px|left|thumb|KB domed piston for the Vortec head. This example uses a long rod]] <br style="clear:both"/> | ||
− | While using a domed piston in a SBC engine is generally avoided, there may be certain circumstances that require their use. One such example is the large port Bow Tie Vortec head; it can only be milled to about 51 cc. This will give about 12:1 CR using flat top pistons. So if a higher CR is required | + | While using a domed piston in a SBC engine is generally avoided, there may be certain circumstances that require their use. One such example is the large port Bow Tie Vortec head; it can only be milled to about 51 cc. This will give about 12:1 CR using flat top pistons. So if a higher CR is required, domed pistons must be used unless the chambers are welded and machined smaller. An engine built with ''unported'' large port Bow Tie heads (FASCAR (Florida Association of Stock Car Racing rules) made over [http://www.chevyhiperformance.com/techarticles/148_0506_gm_bow_tie_vortec_small_block_engine/viewall.html 630 HP/500 ft/lb torque] with 12:1 CR. |
− | + | See the discussion page for more. | |
==Recommended spark plugs== | ==Recommended spark plugs== | ||
The exact heat range depends on several factors. This is a guide that will get you in the ballpark. Carefully assess the heat range before settling on a plug for your particular combination. | The exact heat range depends on several factors. This is a guide that will get you in the ballpark. Carefully assess the heat range before settling on a plug for your particular combination. | ||
− | * AC Delco | + | * AC Delco Rapid Fire Spark Plugs R44LTS |
− | * AC Delco | + | * AC Delco Rapid Fire Spark Plugs MR43LTS |
* AC Delco Rapidfire No 3 Spark Plug | * AC Delco Rapidfire No 3 Spark Plug | ||
− | * | + | * ACCEL P526S U-Groove “SHORTY” Double Platinum (approximately 3/16″ shorter than AC R44LTS) |
− | * | + | * ACCEL 516 |
* Autolite 26 | * Autolite 26 | ||
* Autolite 104 | * Autolite 104 | ||
Line 407: | Line 345: | ||
* Bosch HR10BX | * Bosch HR10BX | ||
* Bosch HR9DC | * Bosch HR9DC | ||
− | |||
− | |||
==Vortec water bypass== | ==Vortec water bypass== | ||
8[http://www.hotrodders.com/forum/thermostat-bypass-vortec-conversion-161468.html#post1581704 Thermostat bypass] Hotrodders forum thread | 8[http://www.hotrodders.com/forum/thermostat-bypass-vortec-conversion-161468.html#post1581704 Thermostat bypass] Hotrodders forum thread | ||
− | |||
− | |||
==Optional GMPP Vortec parts== | ==Optional GMPP Vortec parts== | ||
Line 419: | Line 353: | ||
<table align="center" border="1" cellpadding="1" cellspacing="0" width="660"> | <table align="center" border="1" cellpadding="1" cellspacing="0" width="660"> | ||
− | <tr class=" | + | <tr class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" align="center" valign="top"> |
− | <td class=" | + | <td class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" colspan="2" tr bgcolor="#FFF8DC" align="center" valign="top">'''Intake Manifolds For Vortec Heads'''</td> |
− | + | ||
− | + | ||
</tr> | </tr> | ||
− | <tr class=" | + | <tr class="ltbluebg-blacktextbold-12px" tr bgcolor="#FFF8DC" align="center" valign="top"> |
− | <td class=" | + | <td class="ltbluebg-blacktextbold-12px" align="center" valign="top">P/N</td> |
+ | |||
+ | <td class="ltbluebg-blacktextbold-12px" align="center" valign="top">Option</td> | ||
</tr> | </tr> | ||
Line 509: | Line 443: | ||
<td class="wbg-blacktext" align="center" valign="top">12496820</td> | <td class="wbg-blacktext" align="center" valign="top">12496820</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top"> | + | <td class="wbg-blacktext" align="center" valign="top">GM EGR Style, For Dual Pattern Style Carb’s</td> |
</tr> | </tr> | ||
Line 517: | Line 451: | ||
<td class="wbg-blacktext" align="center" valign="top">12366573</td> | <td class="wbg-blacktext" align="center" valign="top">12366573</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">GM RPM Style, | + | <td class="wbg-blacktext" align="center" valign="top">GM RPM Style, Square Pattern Carb.</td> |
</tr> | </tr> | ||
Line 525: | Line 459: | ||
<td class="wbg-blacktext" align="center" valign="top">12496821</td> | <td class="wbg-blacktext" align="center" valign="top">12496821</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">GM TBI | + | <td class="wbg-blacktext" align="center" valign="top">GM TBI With EGR |
</td> | </td> | ||
Line 552: | Line 486: | ||
<td class="wbg-blacktext" align="center" valign="top">Edelbrock Performer RPM Pro-Flo EFI <b></b>.</td> | <td class="wbg-blacktext" align="center" valign="top">Edelbrock Performer RPM Pro-Flo EFI <b></b>.</td> | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
</tr> | </tr> | ||
Line 570: | Line 496: | ||
</td> | </td> | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
</tr> | </tr> | ||
Line 607: | Line 501: | ||
<tr class="ltyellowbg-blacktext-12pxB" align="center" valign="top"> | <tr class="ltyellowbg-blacktext-12pxB" align="center" valign="top"> | ||
− | <td class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" colspan="2" align="center" valign="top">'''Rocker Arms | + | <td class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" colspan="2" align="center" valign="top">'''Rocker Arms For Vortec Heads'''</td> |
</tr> | </tr> | ||
Line 615: | Line 509: | ||
<td class="wbg-blacktext" align="center" valign="top">12495490</td> | <td class="wbg-blacktext" align="center" valign="top">12495490</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">GM Rocker Arms, 1.5 Ratio, Stamped Steel, Self-Aligning</td> | + | <td class="wbg-blacktext" align="center" valign="top">GM Rocker Arms, 1.5 Ratio, Stamped Steel, Self-Aligning Style</td> |
</tr> | </tr> | ||
Line 695: | Line 589: | ||
<div class="wbg-blacktext-12pxB" align="center">There are hundreds of cams suitable for use with the Vortec head.</div> | <div class="wbg-blacktext-12pxB" align="center">There are hundreds of cams suitable for use with the Vortec head.</div> | ||
− | <span class="wbg-blacktext-12pxB">Example:</span> 12-235-2 Comp Cam Extreme 4 X 4, flat tappet cam, lift I .447”, E .462”, duration @ .050” 210 | + | <span class="wbg-blacktext-12pxB">Example:</span> 12-235-2 Comp Cam Extreme 4 X 4, flat tappet cam, lift I .447”, E .462”, duration @ .050” 210 I, 218 E. |
− | Strong low end and mid range torque. Excellent cam for | + | Strong low end and mid range torque. Excellent cam for R.V., and pickups when changing to the Vortec heads.<br> |
− | <span class="wbg-blacktext-12pxB">Note:</span> Valve spring change is required | + | <span class="wbg-blacktext-12pxB">Note:</span> Valve spring change is required with this cam.</td> |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
</tr> | </tr> | ||
Line 715: | Line 599: | ||
<tr class="ltyellowbg-blacktext-12pxB" align="center" valign="top"> | <tr class="ltyellowbg-blacktext-12pxB" align="center" valign="top"> | ||
− | <td class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" colspan="2" align="center" valign="top">'''Valve | + | <td class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" colspan="2" align="center" valign="top">'''Valve Covers For Vortec Heads'''</td> |
</tr> | </tr> | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
<tr class="wbg-blacktext" align="center" valign="top"> | <tr class="wbg-blacktext" align="center" valign="top"> | ||
− | <td class="wbg-blacktext" align="center" valign="top"> | + | <td class="wbg-blacktext" align="center" valign="top">12355350</td> |
− | <td class="wbg-blacktext" align="center" valign="top"> | + | <td class="wbg-blacktext" align="center" valign="top">GM Chrome With Red Bow Tie In Center</td> |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
</tr> | </tr> | ||
Line 747: | Line 613: | ||
<tr class="wbg-blacktext" align="center" valign="top"> | <tr class="wbg-blacktext" align="center" valign="top"> | ||
− | <td class="wbg-blacktext" align="center" valign="top"> | + | <td class="wbg-blacktext" align="center" valign="top">SCTZVC</td> |
− | <td class="wbg-blacktext" align="center" valign="top"> | + | <td class="wbg-blacktext" align="center" valign="top">New “Take Off” ZZ-4 Black Valve Covers (When Available)</td> |
</tr> | </tr> | ||
Line 757: | Line 623: | ||
<td class="wbg-blacktext" align="center" valign="top">24502540</td> | <td class="wbg-blacktext" align="center" valign="top">24502540</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">Valve Cover Adapter, | + | <td class="wbg-blacktext" align="center" valign="top">Valve Cover Adapter, Converts Center Bolt To Outside Bolt</td> |
</tr> | </tr> | ||
Line 765: | Line 631: | ||
<td class="wbg-blacktext" align="center" valign="top">10046089</td> | <td class="wbg-blacktext" align="center" valign="top">10046089</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">Center Bolt Valve Cover Gaskets </td> | + | <td class="wbg-blacktext" align="center" valign="top">Center Bolt Valve Cover Gaskets (price is for one gasket)</td> |
</tr> | </tr> | ||
Line 775: | Line 641: | ||
<td class="wbg-blacktext" align="center" valign="top"> | <td class="wbg-blacktext" align="center" valign="top"> | ||
− | Holley | + | Holley Custom, Cast Aluminum, Ball-Milled Top, Valve Covers. The rigid 1-piece aluminum castings combine strength and light weight in a design that provides a tight gasket seal while also acting to reduce valve train noise. |
</td> | </td> | ||
Line 787: | Line 653: | ||
<td class="wbg-blacktext" align="center" valign="top"> | <td class="wbg-blacktext" align="center" valign="top"> | ||
− | Holley | + | Holley Custom, Cast Aluminum, Polished Flat Top, Valve Covers. The rigid 1-pc aluminum castings combine strength and |
+ | |||
+ | light weight in a design that provides a tight gasket seal while also acting to reduce valve train noise. | ||
</td> | </td> | ||
Line 799: | Line 667: | ||
<td class="wbg-blacktext" align="center" valign="top"> | <td class="wbg-blacktext" align="center" valign="top"> | ||
− | + | MR Gasket, 1987-up SBC, center hold down, baffled. Included: 2 covers, 1 oil fill cap, 2 PCV/breather grommets.) | |
</td> | </td> | ||
+ | |||
+ | </tr> | ||
+ | |||
+ | <tr class="ltyellowbg-blacktext-12pxB" align="center" valign="top"> | ||
+ | |||
+ | <td class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" colspan="2" align="center" valign="top">'''Valve Springs For Vortec Heads'''</td> | ||
+ | |||
+ | </tr> | ||
+ | |||
+ | <tr class="wbg-blacktext" align="center" valign="top"> | ||
+ | |||
+ | <td class="wbg-blacktext" align="center" valign="top">10309-1</td> | ||
+ | |||
+ | <td class="wbg-blacktext" align="center" valign="top">Crane Cams valve spring and retainer kit. (drop-in springs with no machine work needed)</td> | ||
+ | |||
+ | </tr> | ||
+ | |||
+ | <tr class="wbg-blacktext" align="center" valign="top"> | ||
+ | |||
+ | <td class="wbg-blacktext" colspan="2" align="center" valign="top">Labor to set installed height and assemble springs and retainers. $40.00</td> | ||
</tr> | </tr> | ||
Line 815: | Line 703: | ||
<td class="wbg-blacktext" align="center" valign="top">10105117</td> | <td class="wbg-blacktext" align="center" valign="top">10105117</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">GM Composition Head Gasket, | + | <td class="wbg-blacktext" align="center" valign="top">GM Composition Head Gasket, .028” thick compressed. (price is for one gasket)</td> |
</tr> | </tr> | ||
Line 823: | Line 711: | ||
<td class="wbg-blacktext" align="center" valign="top">12557236</td> | <td class="wbg-blacktext" align="center" valign="top">12557236</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">GM Composition Head Gasket, | + | <td class="wbg-blacktext" align="center" valign="top">GM Composition Head Gasket, .051” thick compressed. (price is for one gasket)</td> |
</tr> | </tr> | ||
Line 831: | Line 719: | ||
<td class="wbg-blacktext" align="center" valign="top">1094</td> | <td class="wbg-blacktext" align="center" valign="top">1094</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">Fel-Pro Head Gasket, | + | <td class="wbg-blacktext" align="center" valign="top">Fel-Pro Head Gasket, .015” thick compressed. (price is for one gasket)</td> |
</tr> | </tr> | ||
− | < | + | <tr class="ltyellowbg-blacktext-12pxB" align="center" valign="top"> |
− | < | + | <td class="ltyellowbg-blacktext-12pxB" tr bgcolor="#FFF8DC" colspan="2" align="center" valign="top">'''Intake Gaskets For Vortec Heads'''</td> |
− | <td class=" | + | </tr> |
+ | |||
+ | <tr class="wbg-blacktext" align="center" valign="top"> | ||
+ | |||
+ | <td class="wbg-blacktext" align="center" valign="top">89017465</td> | ||
+ | |||
+ | <td class="wbg-blacktext" align="center" valign="top">GM Intake Gasket. [Old P/N 12529094]</td> | ||
+ | |||
+ | </tr> | ||
+ | |||
+ | <tr class="wbg-blacktext" align="center" valign="top"> | ||
+ | |||
+ | <td class="wbg-blacktext" align="center" valign="top">1255</td> | ||
− | <td class=" | + | <td class="wbg-blacktext" align="center" valign="top">Fel-Pro Intake Gasket.</td> |
</tr> | </tr> | ||
Line 871: | Line 771: | ||
<td class="wbg-blacktext" align="center" valign="top">25164641</td> | <td class="wbg-blacktext" align="center" valign="top">25164641</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">#3, | + | <td class="wbg-blacktext" align="center" valign="top">#3, rapid fire style, set of 8</td> |
</tr> | </tr> | ||
Line 879: | Line 779: | ||
<td class="wbg-blacktext" align="center" valign="top">P526S</td> | <td class="wbg-blacktext" align="center" valign="top">P526S</td> | ||
− | <td class="wbg-blacktext" align="center" valign="top">Accel U-Groove | + | <td class="wbg-blacktext" align="center" valign="top">Accel U-Groove “SHORTY” Double Platinum Header Plugs approximately 3/16" shorter then R44LTS plugs, set of 8 </td> |
</tr> | </tr> | ||
Line 978: | Line 878: | ||
==Links== | ==Links== | ||
− | *[http://www.nastyz28.com/forum/showthread.php?t=56505 Vortec Cylinder Heads: The Definitive Guide] | + | * Nasty Z28.com forum thread, [http://www.nastyz28.com/forum/showthread.php?t=56505 Vortec Cylinder Heads: The Definitive Guide] |
* [http://www.chevyhiperformance.com/howto/97458/index.html Iron Vortec Head All the Details You Need to Know] from the February, 2009 issue of ''Chevy High Performance''. | * [http://www.chevyhiperformance.com/howto/97458/index.html Iron Vortec Head All the Details You Need to Know] from the February, 2009 issue of ''Chevy High Performance''. | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
==Resources== | ==Resources== | ||
* [[Valve train points to check]] | * [[Valve train points to check]] | ||
− | * [[Quench]] | + | *[[Quench]] |
− | + | ||
− | + | ||
[[Category:Engine]] | [[Category:Engine]] | ||
[[Category:GM]] | [[Category:GM]] | ||
[[Category:Cylinder head]] | [[Category:Cylinder head]] | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− |