Editing Milling cylinder heads

==Overview== When the decks of the block or heads are milled to raise compression (usually the heads are milled to raise the CR), or to correct the [http://www.crankshaftcoalition.com/wiki/Quench '''quench measurement'''] (the block is milled for correcting quench), or to true the surfaces, often the intake flanges and the ends of the intake manifold (or the surfaces of the block, or a combination of them both) need to be milled to correct the port and bolt hole alignment. ==Mill the heads or the intake manifold?== It is better to keep all the modifications to the cylinder head or intake manifold- one or the other. Otherwise, the heads and intake become basically inseparable. On engines that show an amount to be removed from the ends in the table below, do a mock up ''before'' milling because in cases where the intake seals the lifter valley (like the SBC) there may be enough clearance without milling the ends. Always seal the ends using RTV whenever possible. On engines that use a separate valley cover, the ends need to be checked. ==How much to mill the decks== Whether milling the intake mounting surfaces is necessary and how much needs to be removed depends on the angles involved and how much material was removed from the decks. It should be taken into consideration that when the heads are milled, the [http://www.crankshaftcoalition.com/wiki/Valve_train_geometry '''valve train geometry'''] changes and [http://www.crankshaftcoalition.com/wiki/Valve_train_points_to_check piston to valve clearances] will be closer. While there are math formulas for this, the table below is quick and easy to use. {{Note1}}The figures below are used when ''flat milling'' the decks. <br> <table bgcolor="#eeeeee" border="2" cellpadding="1" width="98%"> <tr> <td align="center" width="200"><p align="center"><font color="black"><strong>Engine/Head Type</strong></font></p> </td> <td align="center" width="300"><p align="center"><font color="black"><strong>Amount in inches to reduce chamber volume by 1cc</strong></font></p> </td> <td align="center" width="300"><p align="center"><font color="black"><strong>Amount in inches to mill intake flanges for each 0.010 removed from heads or block</strong></font></p> </td> <td align="center" width="200"><p align="center"><font color="black"><strong>Amount in inches to mill intake ends for each 0.010 removed from heads or block</strong></font></p> </td> </tr> <tr> <td align="center" width="200">SBC 64cc chamber</td> <td align="center" width="200"><strong>0.0055</strong></td> <td align="center" width="200"><strong>0.0123</strong></td> <td align="center" width="200"><strong>0.0173</strong></td> </tr> <tr> <td align="center" width="200">SBC 76cc chamber</td> <td align="center" width="200"><strong>0.0059</strong></td> <td align="center" width="200"><strong>0.0123</strong></td> <td align="center" width="200"><strong>0.0173</strong></td> </tr> <tr> <td align="center" width="200">BBC 109cc closed chamber</td> <td align="center" width="200"><strong>0.0065</strong></td> <td align="center" width="200"><strong>0.0070</strong></td> <td align="center" width="200"><strong>0.0193</strong></td> </tr> <tr> <td align="center" width="200">BBC 118cc open chamber</td> <td align="center" width="200"><strong>0.0050</strong></td> <td align="center" width="200"><strong>0.0070</strong></td> <td align="center" width="200"><strong>0.0193</strong></td> </tr> <tr> <td align="center" width="200">Ford 1965-'77 289-302 engine</td> <td align="center" width="200"><strong>0.0060</strong></td> <td align="center" width="200"><strong>0.0100</strong></td> <td align="center" width="200"><strong>0.0143</strong></td> </tr> <tr> <td align="center" width="200">Ford 1969-'77 351W engine</td> <td align="center" width="200"><strong>0.0055</strong></td> <td align="center" width="200"><strong>0.0100</strong></td> <td align="center" width="200"><strong>0.0143</strong></td> </tr> <tr> <td align="center" width="200">Ford 1978-up 302/5.0L/351W engines except 86 5.0 HO</td> <td align="center" width="200"><strong>0.0045</strong></td> <td align="center" width="200"><strong>0.0100</strong></td> <td align="center" width="200"><strong>0.0143</strong></td> </tr> <tr> <td align="center" width="200">Ford 351C engine</td> <td align="center" width="200"><strong>0.0050</strong></td> <td align="center" width="200"><strong>0.0100</strong></td> <td align="center" width="200"><strong>0.0143</strong></td> </tr> <tr> <td align="center" width="200">Ford 385 Series with quench-type head</td> <td align="center" width="200"><p align="center"><strong>.0050</strong></p> </td> <td align="center" width="200"><strong>0.0100</strong></td> <td align="center" width="200"><strong>0.0143</strong></td> </tr> <tr> <td align="center" width="200">Ford 385 Series with open chamber head</td> <td align="center" width="200"><p align="center"><strong>.0030</strong></p> </td> <td align="center" width="200"><strong>0.0100</strong></td> <td align="center" width="200"><strong>0.0143</strong></td> </tr> <tr> <td align="center" width="200">Chrysler 273, 318ci "LA" engine with 57-61cc chamber</td> <td align="center" width="200"><strong>0.0053</strong></td> <td align="center" width="200"><strong>0.0095</strong></td> <td align="center" width="200"><strong>0.0144</strong></td> </tr> <tr> <td align="center" width="200">Chrysler 340-360ci "LA" engine with 63-71cc chamber</td> <td align="center" width="200"><strong>0.0048</strong></td> <td align="center" width="200"><strong>0.0095</strong></td> <td align="center" width="200"><strong>0.0144</strong></td> </tr> <tr> <td align="center" width="200">Chrysler B/RB engine with 66.5cc or 73.5cc chamber</td> <td align="center" width="200"><strong>0.0062</strong></td> <td align="center" width="200"><strong>0.0123</strong></td> <td align="center" width="200"><strong>Not required</strong></td> </tr> <tr> <td align="center" width="200">Chrysler B/RB engine with 79/81/83cc chamber</td> <td align="center" width="200"><strong>0.0042</strong></td> <td align="center" width="200"><strong>0.0123</strong></td> <td align="center" width="200"><strong>Not required</strong></td> </tr> <tr> <td align="center" width="200">Chrysler B/RB Max Wedge engine with 81 or 86cc chamber</td> <td align="center" width="200"><strong>0.0050</strong></td> <td align="center" width="200"><strong>0.0120</strong></td> <td align="center" width="200"><strong>0.0170</strong></td> </tr> <tr> <td align="center" width="200">Olds 403-455 Big Block engines</td> <td align="center" width="200"><strong>.0050</strong></td> <td align="center" width="200"><strong>.0130</strong></td> <td align="center" width="200"><strong>.0169</strong></td> </tr> <tr> <td align="center" width="200">Olds 350 Small Block engine </td> <td align="center" width="200"><strong>.0060</strong></td> <td align="center" width="200"><strong>.0130</strong></td> <td align="center" width="200"><strong>.0169</strong></td> </tr> <tr> <td align="center" width="200">Pontiac 1965-'67</td> <td align="center" width="200"><strong>0.0061</strong></td> <td align="center" width="200"><strong>0.0061</strong></td> <td align="center" width="200"><strong>Not required</strong></td> </tr> <tr> <td align="center" width="200">Pontiac 1968-'70</td> <td align="center" width="200"><strong>0.0052</strong></td> <td align="center" width="200"><strong>0.0052</strong></td> <td align="center" width="200"><strong>Not required</strong></td> </tr> <tr> <td align="center" width="200">Pontiac 1971-'79</td> <td align="center" width="200"><strong>0.0047</strong></td> <td align="center" width="200"><strong>0.0047</strong></td> <td align="center" width="200"><strong>Not required</strong></td> </tr></table> <br><br> ==Intake flange angles== For those who would prefer to calculate it for themselves, the table below gives the intake flange angles. The amounts shown are how much difference there is from 90 degrees between the flange and deck. The flange angles listed below may be used with the following formula: ;Amount to be removed from intake flange = .707 ÷ (SIN (45 - intake face angle)) <br> <table bgcolor="#eeeeee" border="2" cellpadding="1" width="98%"> <tr valign="TOP"><td colspan="5" align="center"><b>Common V8 intake flange angles </b></td></tr> <tr><td><b>Make</b></td><td><b>Engine</b></td><td><b>Displacement</b></td><td align="center"><b>Intake flange angle</b></td></tr> <tr valign="TOP"><td>Chevrolet</td><td>SB 1955-up</td><td>262, 265, 267, 283, 302, 305, 307, 327, 350, 400</td><td align="center">'''10°'''</td></tr> <tr valign="TOP"><td rowspan="7">Chrysler</td><td>“LA” 1964-up</td><td>273, 318, 340, 360</td><td align="center">'''-3°'''</td></tr> <tr valign="TOP"><td>“B/RB” 1958-'78</td><td>350, 361, 383, 400, 413, 426W, 440</td><td align="center">'''10°'''</td></tr> <tr valign="TOP"><td>Mopar Hemi 1964-'71</td><td>426</td><td align="center">'''-13°'''</td></tr> <tr valign="TOP"><td>Chrysler Hemi 1951-'58</td><td>331, 354, 392</td><td rowspan="3" align="center">'''25°'''</td></tr> <tr valign="TOP"><td>DeSoto Hemi 1952-'57</td><td>276, 291, 330, 341, 345</td></tr> <tr valign="TOP"><td nowrap="">Dodge Hemi &amp; Poly 1953-'58</td><td>241, 259, 270, 315, 325</td></tr> <tr valign="TOP"><td>Poly “A” 1956-'67</td><td>277, 301, 303, 318, 326</td><td align="center">'''10°'''</td></tr> <tr valign="TOP"><td rowspan="3">Ford</td><td>SB 1962-up</td><td>221, 260, 289, 302, 351, 400</td><td rowspan="3" align="center">'''0°'''</td></tr> <tr valign="TOP"><td>FE 1958-'76</td><td>332, 352, 390, 406, 410, 427, 428</td></tr> <tr valign="TOP"><td>385 Series 1968-'97</td><td>370, 385, 429, 460</td></tr> <tr valign="TOP"><td rowspan="2">Oldsmobile</td><td>1949-'63 “Rocket”</td><td>303, 324, 371, 394</td><td align="center">'''20°'''</td></tr> <tr valign="TOP"><td>1964-up (late)</td><td>260, 307, 330, 350, 400, 403, 425, 455</td><td align="center">'''0°'''</td></tr> <tr valign="TOP"><td rowspan="2">Pontiac</td><td>1955-'79</td><td>265, 287, 301, 316, 347, 326, 350, 370, 389, 400, 421, 428, 455</td><td align="center">'''0°'''</td></tr> </table> ==Another way to calculate the amount to remove== In cases where the head in question isn't listed or the list cannot be accessed, the amount of material to remove from the cylinder head deck to reach a specific volume can be found by using a graduated burette or even a syringe. Assuming the target chamber volume is known, a burette or syringe can be used to dispense that amount of fluid into the chamber. Then measure down to the surface of the fluid and that will be the amount of material that needs to be removed from the deck. Using a fluid other than water will make this easier, since water has a relatively high surface tension. Mineral spirits or rubbing alcohol with a drop or two of food coloring works well for this. ==Resources== *[[Valve train points to check]] *[[Head gasket]] *[[Dynamic compression ratio]] <br><br> {{newarticle1}} [[Category:Engine]] [[Category: Cylinder head]]

| Editing help (opens in new window)

• Template:Newarticle1 (edit)
• Template:Note1 (edit)
• Template:Rounded (edit)