Do any of the major piston companies make an off-the-shelf piston with a compression height around 1.68-1.69 for the 4.05 bore? All the piston combinations I can find for building a 390 with a 428 crank will have the pistons sticking out of the top of the hole or too far down in the hole (quench > .06).

I know Ratsmoker talked about putting together a list of all the off-the-shelf pistons for FEs. Did that ever get posted anywhere?

Thanks,
Bob

 

The 390 truck pistons are the ones you want. As per where, I'd say Napa.

 

I have heard this as well on both forums. That a 390 low compression truck piston is the same as the 410 car piston.

-Scouder

 

Will these work?

http://www.fastengineparts.com/sub_c...hp?mid=2&id=39

 

Yep I think the 381P are they ones you want. They are cast, so no forced induction or nitrous.

 

Yeah those would work. With a steel shim gasket (.018) you could get the quench space under .06. As I mentioned above, I was looking for a piston with a 1.68 or 1.69 compression height. My guess is they only exist in custom piston land ($$$).

Thanks

 

Go to napa and ask 'em for '66 410 pistons. They should have the correct compression height, but ask 'em just to make sure.

 

I used the Sealed Power .030 over 390 low compression pistons with a 1UB 428 CJ crank and C7AE rods in my 416 FE. It yeilded just over 1.6 compression height, and around 10.1 to 1 compression.

 

on that site the 410 piston is the exact same as the 390 piston. The 410 piston should have a different compression height due to the longer stroke.

 

The 390 low compression truck piston actually IS the 410 piston. When I tore down my D4TE 390 truck motor it had pistons that actually said "410" on them. Ford used a 410 piston in the truck motors to lower the compression. As I said above, that piston will be just what you arev looking for with a 428 crank in a 390.
Paul G.

 

What is the dish and eyebrow volume on the 381P pistons? Based on the dimensions given on the link above, I estimate it is around 12 cc (9cc dish with 3cc for eyebrows).

The 381P pistons will work for a 410 build up, but they have a 1.66 compression height. This will leave the piston top approximately .032" down in the hole. Add in a .041" thick head gasket and you have a .073" quench space. Most modern engine builders recommend that the quench space be kept below .06" to avoid detonation. I am not sure how critical being at .073" would be, but since I estimate the compression would be up around 9.8:1 with 68 cc chambers, you could have some detonation issues. You could go with a steel shim head gasket which would cut quench down to .053" (perfect), but your compression with 68 cc heads will increase to around 10.4:1 (pretty high for iron heads).

It works out a little better with 71 cc heads. 9.5:1 with a .041" head gasket and 10:1 using the .02" steel shim gasket. Same quench as above for both obviously.

My problem is I already own and want to use some early 1960 small chambered heads (C0AE-D; around 60 cc) with the big intake and exhaust. My compression with those pistons and a steel shim would be up around 11.4:1. Way too high. I am still looking, but I will probably stick with a 3.78 stroke and use the Silvolite 1130 pistons and a steel shim for .052" quench and 9.86:1 compression. This is where I want to be for both these numbers. Not sure I can do it with a 3.98" stroke without having custom pistons made and that would mean another $500 or so.

 

I used that exact piston set for my 390/410 conversion. The description is wrong for the compression. The stock replacement should be 10.5:1 i beleive