Diamond forged 3400 pistons now available

[SappySE107]

http://wot-tech.com/shop/all/forged-3400-pistons/prod_186.html

These are a full floating piston, and are available in "off the shelf" pricing for .020, .040, and .060" overbore, in 9.5 10.5 and 11.5:1 compression. Stock, .010, .030, and .050" overbore is 39.99 more and any compression change (based on stock 28.6cc 3400 heads) is 159.99 more. If we we get a group order of 6 sets on a different compression ratio, I can give a discount on those since they are considered custom.

Rings are available as well for 89.99 in standard, or 164.99 for a NAPIER 2nd ring version set, meant for nitrous or heavy boost.

[IsaacHayes]

Sweet, so even with 3500 heads just choose the 11.5:1 option and you still have good 11:1 or so compression. Too bad stock is $40 more but oh well.

[SappySE107]

no its 10.8:1 with 3500 heads. You need 11.7:1 to get 11:1.

[IsaacHayes]

Oh, I was thinking it was 9.1:1 with 3500 heads on a 3400. Didn't know it was .7. I've heard varying things. Well 10.8 is still respectable and would allow you to run a little less rowdy cam and less chance for knock for a street driven car. Not sure $160 is worth it to go up to 11:5 with that setup for a street car.

Hmm getting the 10.5 with that setup would get you 9.8 which is what the 3500 is stock. So one could go that route if the 3500 block was too much of a pain over using the 3400 block.

[SappySE107]

It is 9.6:1 stock and 9.1:1 with 3500 heads. If you had 11.5:1 compression with stock 3400 heads, it will be 10.8:1 with 3500 heads.

[IsaacHayes]

Right the 3400 is 9.6:1 but isn't the 3500 9.8:1 stock?

Hmm I'm not understanding how it all works apparently, cause how does a 3400 9.6:1 go to 9.1:1 (.5) with 3500 heads, but a 3400 with 11.5:1 then put on 3500 heads goes to 10.8:1 (.7) ? I guess I need to look at the formulas for how you calculate this stuff.

[SappySE107]

Yeah, its not static, its dynamic. I am using the calculations in dynomation based on all the measurements for bore/stroke, gasket thickness and bore, piston heigh and dish, and cylinder head area.

[stewartfn18]

so if im reading this right, stock 3500 heads on stock 3400 pistons will bring the cr to 9.1:1. what exactly does that do? i know a lower cr is better for boost, but im going N/A with the 1393 grind cam, the old one. what exactly will this do?

[robertisaar]

so if im reading this right, stock 3500 heads on stock 3400 pistons will bring the cr to 9.1:1. what exactly does that do? i know a lower cr is better for boost, but im going N/A with the 1393 grind cam, the old one. what exactly will this do?

dropping the compression lowers power, but also reduces the chance of detonation

[SappySE107]

The 3500 heads still improve power over 3400 heads, even with the compression loss. You could increase compression with pistons and see even better gains.

[robertisaar]

true, but with all other factors being the same, less compression equals less power... the 3500 heads are just that good.

[Lilchief]

Will these work in a 3.4 block ?

[SappySE107]

Yes, its the same bore for a 3.4, 3400, and 3.4 DOHC. They stick out of the block .020" and are based on the 3400 engine.

[geldartb]

Ben could you give me some advice here.
which would be more beneficial with my setup going with a set that gave me the 10.8.1 or going with the set that would give me the 11.5.1.

i got the rwd 3.4 pistons i was gonna use but if i can get these i would rather use these. with the rwd pistons i would end up with a 11.5.1

i got the following
3500 top end
tog headers 1357 cam
65mm tb

[SappySE107]

Its about 5hp difference from 10.8:1 and 11.5:1 on your setup according to dynomation. I don't know that 5 crank hp would be enough to make me want to keep stock cast pistons over a forged of these quality.