3500 Top End Swap Complete

[AaronGTR]

The 3400 stroke is supposed to be 84mm which is actually 3.307" and using those numbers in the calculator I came up with 8.94:1 compression with stock heads and 9.1:1 with the milling. So .36 drop in compression... not as bad as it sounds at first, but still not great if looking for NA power. Add a cam to that baby to make use of the improved flow.

[SappySE107]

I used metric originally and I always screw up the 3.331 for 3.31 (probably rounded). If the quench wasn't setup so well id say go with the iron head gaskets but thats .020 thinner and would leave about .010 quench. Not good:P

Id take the flow increase over the compression but ideal would be to go with the iron head pistons and get the compression much higher for NA.

[farmerz24]

now all we have to do is get the 3500 crank working in the 3400, offset grind the journals some and maybe we can get up to 3.6 - 3.7 L.

what do you guys think?

[onefastV6]

Add a cam to that baby to make use of the improved flow.

I would like to add a cam, but unfortunately that won't happen for atleast another year.

As for the compression decrease, I found a few calculators that came out with a loss of 1% of the total HP going from a 9.6 to a 9:1 compression ratio. So for example assume the engine made 200 HP with 9.6:1 compression the HP with a 9:1 compression ratio would be 198 for a loss of 2 HP.

If that is the case then the manifolds and heads easily make up for that 2 HP loss.

[Syn]

now all we have to do is get the 3500 crank working in the 3400, offset grind the journals some and maybe we can get up to 3.6 - 3.7 L.

what do you guys think?

don't see it happening

[AaronGTR]

now all we have to do is get the 3500 crank working in the 3400, offset grind the journals some and maybe we can get up to 3.6 - 3.7 L.

what do you guys think?

Why? The 3500 crank is the same stroke as the 3400. The increase in displacement on the 3500 is from the bore diameter. Read the rest of the thread please.

[bszopi]

The 3500 stroke may be the same, but the rod journals are much larger. Therefore, as he stated, you could get the journals offset ground to the size of the 3400 journals and therefore gain some stroke, thus making a larger displacement possible.

Please read the rest of the 3500 threads please... :P

[farmerz24]

now the question i guess is how much can we offset grind to increase stroke? .1 .2 litres?

i had been speaking with my local buddy V6ho on this topic and according to him due to the constrcution of the crank it may not be possible to offset grind. i guess someone will have to try this and see.

[Syn]

now the question i guess is how much can we offset grind to increase stroke? .1 .2 litres?

i had been speaking with my local buddy V6ho on this topic and according to him due to the constrcution of the crank it may not be possible to offset grind. i guess someone will have to try this and see.

its been discussed alot in another thread i read it last night

[El_Diablo]

do you know the thread and what forum its on? this would help alot

[FallenZ24]

The 3500 stroke may be the same, but the rod journals are much larger. Therefore, as he stated, you could get the journals offset ground to the size of the 3400 journals and therefore gain some stroke, thus making a larger displacement possible.

Please read the rest of the 3500 threads please... :P

Is it even possible to increase the stroke of the 3400? Don't the pistons come proud of the block already?

Anyways, Its good to hear that you finished the swap. Hopefully you can get it tuned out and on a dyno. I'd like to see the gains.

-Joseph

[Guest]

Is it even possible to increase the stroke of the 3400? Don't the pistons come proud of the block already?

Yes they do. What's your point?

[AaronGTR]

Is it even possible to increase the stroke of the 3400? Don't the pistons come proud of the block already?

Whats proud of the block mean?



Anyway, yes the pistons do come just slightly past the surface of the block. If you increase the stroke you also get shorter rods, at least thats whats normally done. You shorten the rod length the same amount you increased the stroke and the piston stays at the same height at TDC but goes down further at the bottom so it pulls in more air. And there you have it, a "stroker" motor.

[EspanolaGuitarista]

Congratulations...

What is KR? Is that squish area?

[Guest]

Is it even possible to increase the stroke of the 3400? Don't the pistons come proud of the block already?

Whats proud of the block mean?



Anyway, yes the pistons do come just slightly past the surface of the block. If you increase the stroke you also get shorter rods, at least thats whats normally done. You shorten the rod length the same amount you increased the stroke and the piston stays at the same height at TDC but goes down further at the bottom so it pulls in more air. And there you have it, a "stroker" motor.

Proud = past (in this case), the pistons come proud of the block, meaning they come past the deck surface.

I have never heard of anyone using shorter rods in a stroker motor, in fact they usually wouldn't work, due to the simple fact that at BDC the distance between the piston skirt and the rod journal is increased over a shorter stroke design, so decreasing the length of the rod will make the crank counter weights smash the piston skirts.
The pin hight (compression hight) is usually changed to off set the grind and no, it's not by the same amount of stroke increase, it's by half that. Simple geometry here.