Check my work-Chime in please

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You are correct, sir,, and thanks for taking the time to lay it all out for everyone. I was trying to separate out the positive above-deck and negative below-deck displacements to enter separately in to a calculation. But, in the end, it does not matter if they are entered separately in 2 places, or combined in 1 place. The net effect is the same. Good to know, thanks for clarifying. My motor books used the method I used and they are Mopar books.

Doing it both ways (with an estimate of the above deck dome volume at TDC), I ended up with 9.64 SCR and 8.14 DCR. If DR thinks that is a bit too much, a .039" head gasket yields a 9.34 SCR and a 7.89 DCR. I can be happy with the 8.14 DCR and I already own the .028 head gaskets I want to use.This is using the advertised intake closing angle for the cam, which Lunati measures at .006" valve lift. So the only question is what calculator is better: using advertised closure angles or estimating off of .050" lift angles.

You could deck the block or heads at this point DR, or try to find steel shim head gaskets to get it up, but you're gonna find it to be pretty good at these numbers. Somebody tell me this little motor is going to run like the 283 chebby I build when I was a kid with the Duntov cam and 10:1 pistons:) Focus on the things like piston-to-valve clearance and consistent piston deck heights and piston-to-deck clearances and such.
OK, I am clear on about everything and of course I know about clay checking piston to valve clearance. I am happy to do it if it really needs to be done, so the question, is it necessary or just a "peace of mind" thing?
 
OK...."This little motor is going to run like the 283 chebby you built when you was a kid with the Duntov cam and 10:1 pistons" Glad I could help......LOL

Clay? If you have done this combo before and know the cam lift and pistons won't hit, then it is just peace of mind. But I personally would not put together a new combo without checking. Last time I did this, I mocked up the compressed head gasket thickness with some old gasket bits, put some very, very light hardware store springs on the pair of valves on a cylinder (so light that they did not compress the pistons in the lifters), and the lifters and pushrods in place for that cylinder. I rotated the engine a few degrees at a time in the overlap region for that cylinder and pushed the valves by hand down each time to get an idea of the piston-to-valve clearance.

And piston-to-head clearance? Read the recent thread on the pistons kissing the heads....
 
To all who contributed to this conversation you have my utmost gratitude. I feel every post was beneficial to me and my build! I will do the valve/piston clearance test for peace of mind, just need to figure out the head gasket thickness thing. I do feel like I have been to school and am better prepared for the next one! Just waiting for RRR to give his stamp of approval and I am off and building motor as/is:prayer:
Thanks again all, DR:rock:
 
Ok, my cam is in the engine and degreed in where it is supposed to me. My double row comp timing set seems to have a little more chain slack than I would like but--------. I am now ready to check piston to valve clearance but am a little unclear on how to do it. My heads are together with valve springs decked and installed. I was thinking installing the left head and putting lifters & pushrods in #1 only, installing head and spinning it with clay on top of the piston. I get a little hazy after that. Dont want to bend anything! Could use a little good FABO advice here, the search didnt turn up anything definitive.
TIA to all, DR:coffee2:
 
That is basically it, DR. Go slow 'just in case' but you really should be OK; your lift is not radical as I recall. Do you have the correct final pushrod that you will use? If not, you are going to have to use something close and compensate the measured clearance number by the amount they are off, multiplied by the rocker ratio.

One thing you have be careful with is the empty hydraulic lifter's pistons being compressed way down in the lifter body if you are using the actual valve springs. This will result in the valves not opening as far as they actually will once the lifters are pumped up. If you could remove the valve springs on #1 and put in some very light springs (from the hardware store), then that issue would mostly go away and the caly is not needed. But if you don't have access to an 'off-the-head' valve spring compressor, then you are going to have work with the actual springs as installed.

With the actual springs, measure to see how far the lifter pistons are compressed down into the lifter body from the retainer clip when the valves are near max lift. Then subtract the amount of lifter preload you expect from that measurement; multiply the resulting number by the rocker ratio and you will have the amount of 'missing valve lift' in this test. Subtract that from the clay thickness left after a cycle to get the actual clearance......clear as mud !? LOL

Alternately, pump 2 lifters up with oil (submerge in a can of oil and pump the piston 'til it becomes solid). Use these on #1 and check during the test to see if they stay pumped up to the top. Now your resulting piston-to-valve clearance will be too tight, by your final lifter preload distance times the rocker ratio.

Light temporary valve springs sure make life easier.... or solid lifters. Hope the above helps
 
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