3rdgen Fbody with 3500 heads

[95crackedhead]

why would running that higher 11.5:1 compression be inadvisable in a daily driver setup?

[ForcedFirebird]

why would running that higher 11.5:1 compression be inadvisable in a daily driver setup?

Possible detonation on pump gas would be the main reason. With the proper cam, the CR could come down to acceptable levels.

[95crackedhead]

i.e. a cam that has enough lift so that at lower rpms there would be less cylinder pressure?

[ForcedFirebird]

i.e. a cam that has enough lift so that at lower rpms there would be less cylinder pressure?

The valve can stay open longer to allow some of the compression to escape.

[sharkey]

a long duration cam will decrease the dynamic compression of the engine.

with 3500 heads on a 3.4l, 11.5:1 compression, it should be fine on premium with some good tuning.

[ForcedFirebird]

a long duration cam will decrease the dynamic compression of the engine.

with 3500 heads on a 3.4l, 11.5:1 compression, it should be fine on premium with some good tuning.

According to the CR calculator here, 3500 heads and 3.4 pistons should get 11.16:1. Mine will be less because of removing a little material in the chambers.

[95crackedhead]

forced, what will you be doing for fuel tuning? megasquirt?

[ForcedFirebird]

forced, what will you be doing for fuel tuning? megasquirt?

Yep , so isn't Sharkey.

[ForcedFirebird]

Finally the short block is here! Cyl walls look good, and still have the factory x hatches. Refresh this puppy, and I should be ready to go (after some elbow grease and paint, of course).

I just can't believe how much more rust is on this block than the 3.1, but that's the difference between NY and FL . Thnaks Ninty4Three4 for the good hookup, this was less than buying an engine local - including delivery - and I know his car was running fine when it was removed.

[johnnymossville]

Forced, what figures did you use to calculate the CR to get 11.16:1? When I use the CR calculator here with the specs that they have for the 3.4 pistons and the 3500 heads (I have them as 32.4 cc chambers) I keep coming up with11.56:1. I like your figures (11.16:1) as this is a more streetable CR, and a little chamber smoothing would even lower figure a bit.

[ForcedFirebird]

Forced, what figures did you use to calculate the CR to get 11.16:1? When I use the CR calculator here with the specs that they have for the 3.4 pistons and the 3500 heads (I have them as 32.4 cc chambers) I keep coming up with11.56:1. I like your figures (11.16:1) as this is a more streetable CR, and a little chamber smoothing would even lower figure a bit.

Did you use the .060" compressed height head gaskets with a 3.80" fire ring (gasket bore) for the 3500? Since I bought the gasket kit set, these are what I came up with. Also the chambers are getting modified a little bit, so I should be below 11:1 with the Camaro pistons.

EDIT: Your right! I must have entered something wrong. I came up with 11.5:1 this time.

[johnnymossville]

Cool, I just didn't know if I was doing something wrong. That should give you more N/A power. lol

[ForcedFirebird]

Are the flat hyd lifters in the 3.4 the same height as the hyd rollers in the 3500's? Now that I know I need to use the 3500 rockers and don't have adjustment, they have to be exact, correct? I have a set of pushrods from a 95 3400, and would be very happy to know they'll work. Rather not wait until final assy to get pushrod length.

[Superdave]

they are different height, you'll need custom pushrods.

If you feel like risking it, the measurements for the FWD "Hybrids" have been posted before but i guess it's best to measure with the propper tool.

[IsaacHayes]

IIRC pushrod length didn't change only hardened ones for the early ones that used guides, but I could be wrong. No idea on the lifters. So the 1.7 rockers didn't work out? But you have different block than a 3400 so that might be different... Not sure of the stock cam in the rwd 3.4