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Gen 3 v8 Lifter Bank Angle? |
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Ken_Parkman
AMC Addicted Joined: Jun/04/2009 Location: Ontario Status: Offline Points: 1815 |
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Farna, sorry, but the lifter angle is important. A change in angle will change the cam timing events; the effect doubled in crankshaft degrees.
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bobsterfl
AMC Nut Joined: Jun/18/2009 Location: Orlando, Fl Status: Offline Points: 260 |
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According to classicoldsmobile.com "Oldsmobile engines from 1964 onward originally used a 45 degree cam bank angle (CBA). This angle is formed by the intersection between the cam centerline and perpendicular lifter centerline. By 1968, all Olds engines were using a 39 degree CBA. In the years between, 39 degrees was used mainly on blocks found in Toronado's, and 45 degrees was being used everywhere else. The CBA also affects the pushrod hole angle in the heads. 45 degree blocks used 45 degree heads and the same for 39 degree blocks and heads. If swapping heads between 45 and 39 degree blocks, you must watch for pushrod interference at the bottom of the head. To put 45 degree heads on a (455) 39 degree block, you have to bore the push rod holes to .562" i.d. Applies to "A" heads and some "B" heads. Angle Lifter Notes 45 0.842" All 330's. Non-Toro D-block 425's, B-block 400? ['65 442]. 39 0.921" E and G block 400's, '66-7 Toronado 425's. Some '66-7 non-Toro blocks. Late 307's? 39 0.842" Most Olds engines 1968 and up. [exception: late 307's?]
There's 2 kinds of 425's: Toro and Non-Toro. There's a BIG SIGNIFICANT
difference:
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Bobsterfl
1970 BBO Javelin 390 - Torqueflight |
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6PakBee
Supporter of TheAMCForum Charter Member Joined: Jul/01/2007 Location: North Dakota Status: Offline Points: 5454 |
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I'm glad I never got into Oldsmobile. That just gave me a headache.
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Roger Gazur
1969 'B' Scheme SC/Rambler 1970 RWB 4-spd Machine 1970 Sonic Silver auto AMX All project cars. Forum Cockroach |
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19611 |
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Ken_Parkman -- I understand that the angle makes a difference, but if everything is designed to work together at whatever the angle is then it shouldn't matter. Using the Olds example above, you can't use a cam made for a 39 degree lifter angle in a block made for a 45 degree lifter angle. That's obvious, you have to use a cam and rocker designed for the angle being used. Pushrods and valves are likely the same -- but of course have to be the correct length and size for the application, just no special design.
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Frank Swygert
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6762 |
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farna, there is formula(s) for this. You may get the timing "peak event" at the correct location but with the angles being off, the slope of crankshaft stroke vs the camshaft "stroke"/slope will be slightly different. Your approaching slope of the camshaft would have to be different then the receding slope if you were to have an even event curve to match the crankshaft event.
Very much doubt those old engines would put that much work into this type of grind. It would take a computer programmed grinder to get this correct. The further the angles are off the bigger the difference. If your running in the 10's of a second, likely this is were it would be seen. On a street engine, likely not even noticeable. |
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Steve_P
AMC Addicted Charter Member Joined: Jun/28/2007 Status: Offline Points: 3760 |
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I thought it'd be understood that I meant that the lifter bores are 90* to each other, like the cylinders- without my typing it out. Really weird about the Mopar lifter bores not at 90* |
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