Turbo vs. 3400/3500

[carbon]

I have a 3400 sitting on my garage floor begging me to do something with it... I am curious which would be better for a forced induction application, the stock 3400 top end, possibly ported, or the 3500 top end?

I had read somewhere that the 3400 upper intake does a better job at getting equal flow all around where the 3500 upper, while flowing more, doesn't do as well at equal flow. Is it significant enough to be concerned or is there some benefit to using the 3500 other than flow?

Also, with the 3500 heads decreasing compression a little with stock 3400 pistons, I was thinking that using the heads and lower intake from the 3500 but with the 3400 upper would be the way to go... but I am just not sure.

Also what would be a recommended size turbo to use for a middle of the road build for say 250-275HP at the crank on a 3400? I am not interested in setting the world on fire but I would like more oomph than the stock 185HP.

One more question... is the stock cam O.K. for forced induction or is there a significantly better profile one for forced induction? This would most likely be a staged process with getting the 3400 running N/A first and then adding the turbo at a later date. But I would like to have the engine set up for that upgrade.

[robertisaar]

the stock cam isn't that bad... but you might as well use the 3500 parts from the heads on up, they're overall pretty damn good.

as far as turbos, a T61 is a decent size for a 3400 and with about 9psi, it should make 275 HP... i'm sure there are other choices, but find something for a good price and we'll see how well it fares.

http://www.squirrelpf.com/turbocalc/index.php?version=4&target_peak_power=275&engine_disp=3.4&engine_disp_factor=0&target_af=12&bfsc=0.51&max_ic_loss=1.7&rpm_redline=6000&rpm_peak_power=5200&rpm_max_boost=3800&rpm_min_boost=3000&vol_1=89&vol_2=93&vol_3=90&vol_4=87&vol_1=89&vol_2=93&vol_3=90&vol_4=87&intake_temp_1=90&intake_temp_2=120&intake_temp_3=135&intake_temp_4=140&turbo_n=1&map_sel0=68

thats the map with a 3400 and a T61 assuming 1.7psi loss from an intercooler

[carbon]

Thats a great turbo calc... thanks.

Right now I am looking to get all the info I can.

[IsaacHayes]

Stock cam works well with boost. Of course there is always room for improvement though.

3500 intake will work great, has more plenum volume. I'd use it over 3400. You can put one on a 3400 LIM. Or do the whole 3500 top end on the 3400. Loner had a turbo on a 3400 with 3500 top end (minus UIM) and a cam and ran 12's with an automatic corsica and blew up all his trans he kept putting in there... lol

3400 with a turbo will be good. Throw a cam on later and you're really moving. I heard the 3500 top end is better for NA and a ported 3400 top end is best for boost but I don't know for sure on that. 3500 def makes more power N/A and has great velocity.

3500 UIM though should be beneficial either way.

[carbon]

Any other opinions?