3500 crank

[El_Diablo]

can someone please figure out the compression of the setup joseph proposed on the last page, im really interested in doing something like that but dont have the mathmatical know how to figure it out

[bszopi]

IF I did the math right...

[El_Diablo]

holy shit.... someone was off, lol

[ForcedFirebird]

IF I did the math right...

You used the stock bore/stroke for the 3400's? this number would be lower with 32.4cc chambers on the 3500 heads, and the 3500 gaskets have a 3.8" bore.

[bszopi]

Hmm... That's wierd. AHHH... I figured out what's wrong. I copied and pasted only 2 columns instead of all 3, so the stock values are showing up. Hold on, lemme see if I can recreate the numbers I had last night....

And yes, I used 3400 values for the combustion chamber volume and piston volume. Using the 32.4cc volume for the heads, the CR drops down to 11.33:1. I'm not sure of the stock piston dish(dome) volume for a 3500, so that may change things as well.

[bszopi]

Thought about this more while taking a shower, and figured out I screwed up the piston deck clearance (went out .075" instead of in). So, with that said, how about these numbers....

And with going with the 3500 heads, it yields 8.12:1.

Now, this assumes that a 3500 piston staying in the block 0.0065", unlike the 3100 where it comes out of the block 0.020". If we use that number, with the 3500 heads, CR is 8.53:1, and with the 3400 heads, it comes out to 9.14:1.

There was a reason I put a big IF at the beginning of my original post.

[zofo61]

So with all that said...........is the general opinion that the only thing we are changing on the 3500 is using the 3400 rods on an offset crank?

[El_Diablo]

wow... so really that makes a boosted setup almost perfect now because i can use the .250 offset grind, a small journal sbc rod at 5.7 inches (yes, i know they need to be modified) and all that i would really have to get custom made are a set of forged pistons which would allow me to knock the compression even lower (if i even wanted to) and move the ring land down a bit for huge boost

[zofo61]

Considering this is the way to go for boost, how would the electronics play in with the 3400 out and the 3500 in as far as PCM and crank trigger....has anyone looked into that?

[bszopi]

Using the 3500 crank, you will need the external trigger sold by the 60V6 store. Theoretically (ok, Joseph has actually done it), you could just fab a new 7x trigger to replace the 52x trigger wheel currently on the crank, then shim the sensor out. The 3400 PCM shoul be able to control it no problem then.

[El_Diablo]

any pcm should be able to control it as long as you have a way to change the fuel and spark trim


i think i just figured out the bottom end of my build

[zofo61]

any pcm should be able to control it as long as you have a way to change the fuel and spark trim


i think i just figured out the bottom end of my build

I am just making it as easy as possible and if I can keep my harness and PCM .............thats pretty easy......................

[El_Diablo]

the engine just wants fuel and air, it doesn't car who or whats controling it as long as its within its parameters, give it enough fuel and air and it'll run on anything, the pcm is the picky one... you have to satisfy all of its sensors or it'll f' you over every time

[kwhauck]

wow... so really that makes a boosted setup almost perfect now because i can use the .250 offset grind, a small journal sbc rod at 5.7 inches (yes, i know they need to be modified) and all that i would really have to get custom made are a set of forged pistons which would allow me to knock the compression even lower (if i even wanted to) and move the ring land down a bit for huge boost

Are you planning on using the 3500 block or 3400 block? I mean this helps me out but i'm wondering what kind of compression i will get with the 3400 block SBC rods at 5.7, and the offset grind before i send the crank off to be machined? Any help, anybody?

[MidnightriderZ24]

im wondering the same. im deciding on using the 3500 crank with 3400 heads.