HT413
Semi Pro Bowler
Good God. Lol I fixed it thanks.Man..looks like auto correct did a number on ya haha!
Good God. Lol I fixed it thanks.Man..looks like auto correct did a number on ya haha!
Thanks good to know. Thats why I really want to learn, plan and then build this engine.Reboot always remember that "bigger is better" really only pertains to cubic inches. Big cams,headers always sound & "talk" good, but matching everything up good works better on the street for good drivability.
Ok so i measured the piston height this evening. And I got an average of .149 inches below the deck. and the bore diameter at 4.30 but there is a bit of a chamfer at the top.
What compression would I be at if I used the 452 heads? I know gasket thickness comes in to play as well but whats a ball park?
Wallace has you at 8.01:1 with 0.020 steel shim gaskets w/ 4.38 gasket bore, assuming flat tops.
http://www.wallaceracing.com/cr_test2.php
If your block has not been rebuilt and has the stock late 440 pistons you'll find them way down the hole just use a machinist rule or dial caliper - no need to be exact
let us know if the stock shim gaskets or were they thick aftermarket gaskets
don't worry about cam numbers yet
Stock bore is 4.320" How do the cylinders look, smooth, scratched?
Compression is right around 8.0:1 with the open chamber 88-89cc heads.
If the short block is in decent shape to be used as is, I would look at small chamber aftermarket heads. I think the Brodix B-1 B/S is about the smallest chamber head at 65cc (9.59:1 compression with 0.020" head gasket), but it is also one of the most expensive too. The old '67 915 heads I think are around 72(9.06:1) to 75cc(8.85:1), but somewhat hard to find. Edelbrock has a few different versions of 75cc heads (E-street, RPM, Victor.)
Indy EZ, 440-1, SR are also 75cc. Trick Flow are 78cc(8.66:1)
If you need to rebuild the short block, then put good flat top pistons in it that are near zero deck height. A piston compression height (pin center to piston top) of about 2.060" should put the piston about 0.022" below deck of a unmilled 10.725" tall block.
Many KB/ICON pistons are 2.067" (0.015" below deck, so easy to mill block for zero deck height.) ROSS pistons are 2.065" (0.017"), SRP pistons 2.062" (0.019"), Sealed power 2355 2.061"(0.021"), JE pistons 2.058"(0.024")
What is the final goal? Have you considered a Gen III Hemi? If you want EFI, serpentine belt drive, modern A/C, and such, the Gen III might be an option. I scored a nice 2008 6.1 SRT engine with NAG trans and all the accessories, wiring harness and computer for $4,000. I will likely drop another $2,000+ into converting the harness and re-program the computer, or maybe just go aftermarket EFI computer (maybe try a Holley Dominator EFI?)
To get my compression closer to 9 to 1 whats my best option?
A) Do i want to plan on smaller aftermarket heads? What about a full top end kits? or are those too generic?
or
B) Do i put new pistons in and then rework the factory heads?
I feel like Im chasing my tail.
How achievable are my goals?
Keith Black 236 gives 10:1
their ICON IC836 step dish has 12cc dish and gives 9.3 and a bit less if you open up around the valves with 452 heads
https://www.uempistons.com/index.ph...id=249&zenid=ae1a52b19c9f7433857d8f1bab42d9a6
this piston actually works best for a wedge head and 10:1 80 cc head
Hyper - Cast KB363.STD 16 Chrysler 440 Chrysler 6.735 rod -9.9cc step dome - discontinued pm clearance
but think about the heads first
or instead of just doing pistons you can think of a stroker kit
there is no easy answer with a late 440 but measure twice- cut once
Use the wallace calculator linked to above
If you use the 2.060 flat top pistons you are essentially building a 6 pack compression type motor- advertised at 11:1 It's actually not usually that much- learn to use the calculator
67 heads- find any 4bbl 67 (imperial- new yorker)- where are U and I'll give U a set but not a bargain once you figure in new seats, guides, valves
I may have a set with seats and guides but you still end up with 906 style ports - which are tricky to port- I do run them on a couple of motors - that I built 30 years ago
BUT unless you get a piston with a reverse dish you will still have a combustion chamber that sucks
That is the problem. If you dump money into the short block, you still have to deal with the stock heads. If the short block can be used, I would put the money in the aftermarket heads. Better flow is more power no matter the compression ratio, not to mention lighter weight, cooler running (no exhaust crossover), better combustion chambers and spark plug location, hardened seats, better valve guides, larger stainless steel valves, and the new springs, retainers, locks, and spring seats.
The lower compression may cost you some low end torque, but a higher stall converter can solve that issue.
This path also works if you decide to build the short block later, or even stroke it. You can then pick pistons for the compression ratio you want with the heads.
Use the wallace calculator linked to above
If you use the 2.060 flat top pistons you are essentially building a 6 pack compression type motor- advertised at 11:1 It's actually not usually that much- learn to use the calculator
67 heads- find any 4bbl 67 (imperial- new yorker)- where are U and I'll give U a set but not a bargain once you figure in new seats, guides, valves
I may have a set with seats and guides but you still end up with 906 style ports - which are tricky to port- I do run them on a couple of motors - that I built 30 years ago
BUT unless you get a piston with a reverse dish you will still have a combustion chamber that sucks
" I would put the money in the aftermarket heads. Better flow is more power no matter the compression ratio, not to mention lighter weight, cooler running (no exhaust crossover), better combustion chambers and spark plug location, hardened seats, better valve guides, larger stainless steel valves, and the new springs, retainers, locks, and spring seats."
All true but if you leave the pistons down the hole your combustion chamber (including what's in the block still sucks
good points rebootej but with his OD he is not going to want a loose converter- I guess if he has lock up he can make it work
I mentioned the higher compression height, but the flat top pistons with 84cc heads and 0.040' head gasket is only about 10:1 compression. You can also get D-dish pistons with the higher compression height to lower the compression ratio, and have good quench with a closed chamber head.
I was going through these thoughts with my '73 Jensen interceptor 440 engine. The heads need rebuilt, and I have some B-1 B/S heads on the shelf, and I thought about putting those on the engine, but the short block is going to need to be-built too, so I just went straight to a 505" stroker (27cc dish piston, about 10:1 compression) with Trick flow heads and threw the budget out the window. It sure gets to be chasing your tail trying to do this cheaply. Usually end up doing it twice when trying to do it cheap?
Found some local 915 heads. He had them origally listed as 415. Would these be worth picking up or would it be better to get aftermarket aluminum heads?
https://chico.craigslist.org/pts/6263791487.html