Those type camshafts are always the butt of forum jokes by all the gurus, but the fact is they work quite well.
Pushrod Length for Shaved Heads
- Thread starter 71GSSDemon
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I would say very close to 1 compression point.
So they would be approximately equal to taking 0.060" off the 452s? If so, wouldn't the better flow and the already existing hardened seat be the way to likely proceed?
I do appreciate all the info. Just asking questions before the work gets done.
It depends. If you somehow plan on taking advantage of the quench the closed chamber head can give, then no, IMO, the 452s would not do it. If your plan is to leave the pistons in the hole at TDC, then the 452s would be the better choice.
I would say for now the pistons will remain as is, which is about a mile down the hole. Someday something better, just trying to get it together and finish building the car. Then works new build bugs and maybe build something better.
Then I would use the 452s.
.0055 is about a cc, you'd be milling a long time to get any sort of gain with a 452, last time I cc'd one it was 90 cc's. I took .080 off of my trickflows and the pushrod with my new head gaskets are at maximum length for my rockers.
RRR,
Post #13. I have measured the plunger travel on a great many hyd lifters & it is exactly what I said it was. I milled a set of BB heads 0.120" & was able to use stock lifters, stock pushrods & stock rockers with a shim steel h/gasket & all worked without issue. If the lifters have been used, then they need to be compressed to get an accurate idea of how much adjustment they have.
Post #13. I have measured the plunger travel on a great many hyd lifters & it is exactly what I said it was. I milled a set of BB heads 0.120" & was able to use stock lifters, stock pushrods & stock rockers with a shim steel h/gasket & all worked without issue. If the lifters have been used, then they need to be compressed to get an accurate idea of how much adjustment they have.
Don't make me pull the toilet card.
Note this lifter test compressed the lifter 0.120" for purposes of the bleed down rate. Production lifters will bottom out in the 0.150-0.0180" range & can be adjusted anywhere in this range. These are FT lifters, not roller, which may be different.
If you want to raise the compression in a 70's 440 that most likely has the piston .156" below the deck milling the heads .060" is not worth the effort. You need to deck the block if you really want to make some real compression gains. I have done several write-ups in detail about doing this on the forum in the past. I've decked a lot of blocks .100" without issues.
Also you do not have to mill the intake face on the head or the intake manifold surface. When you deck the heads or the block it causes the intake to sit higher up on the heads (a good thing) since the top of the intake ports on the heads are curved at the opening. By raising the intake up on the head it allows you to high port the top port and straighten out the roof. The only thing that has to be done depending on how much mill the block deck or deck the heads is sometimes you have to elongate the intake manifold bolt holes just a touch.
Tom
Also you do not have to mill the intake face on the head or the intake manifold surface. When you deck the heads or the block it causes the intake to sit higher up on the heads (a good thing) since the top of the intake ports on the heads are curved at the opening. By raising the intake up on the head it allows you to high port the top port and straighten out the roof. The only thing that has to be done depending on how much mill the block deck or deck the heads is sometimes you have to elongate the intake manifold bolt holes just a touch.
Tom
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