Not what you are thinking! I was looking for the cylinder stroke length for our 3.1L V6's. Can anyone tell me what it is?

thanks!

dale

 

3.31"

 

Ok, thanks for that information! so the stroke is 3.31" and the connecting rod is 6 inches? Does that sound about right to you?

 

yes 6" rods...

though I am looking at going n past you lee...
the highest ratio I can get, an machine 350(5.7") down to fit.

I am aiming for 6-7:1 ratio. I am also looking at a nice '04E

 

stock connecting rods are 5.7", if you want better connecting rods then you should get 6", but this will also require you to get custom pistons (around $450 from ross racing)

Socialdeviant, LONGER connecting rods are better, which is why i went with 6"ers from Crower.

The ones i got are rated up to 500hp and dont weigh alot (reduces strain on the crankshaft at high rpms)

the ones i got have to be machines just like V8 rods, but i only had to pay for 6 not 8. (they are made for the 90 degree V6, which uses V8 connecting rods)

 

I have been able to find little info on the boreXStroke of the engine(3.1)

Just a question though...

Did you tell ross about the longer stroke you were doing? and did they compensate the pin height on the piston for that?
If so, damn son, I am going to the same set up as you next spring... Well not the same, I want a lower Comp ratio...

I already have a full blown project going on now. Nothing like a full custom MPI intake, header, Cough- Turbo(-Big turbo 60-1) and everything that goes along with MPI going on another car.

 

yeah, you have to tell them you are using 6" rods or else they would probably think you are using 5.7" rods.

Also, my CR is 8.3:1... which is very low as is. (most turbocharged people like to use 8.5:1 pistons) I am going to use a T04, with a .8 A/R exaust rating. After many many hours of looking at formula's and compressor maps, i have decided that Twin turbos on these engines is not worth it.

The main principle for using Twin Turbos would be to get the fastest spool up speed possible, which you would need to use 2 small turbos. The one of the smallest and most redily available turbos they make are T25's with .43 A/R. Using this turbo would be 100% fine if you wanted a max boost pressure of around 13psi because they would spool up at around 2500rpm even on our engine.

Using a T25 with 0.63 A/R rating would be ideal because it would spin up at around 3200 rpm on an engine with low VE (volumetric efficiency, which is not very good on our engines because we only have 2 valves per cylinder, but you could overcome this with a custom ground cam.) But you would still hit a max boost pressure of about 16psi.

Going for the next step up to a T25 with .89 A/R would cause major turbo lag on a Twin turbo setup, but would not even be very good on a Single turbo setup.

So, like i said earlier, i spent alot of time looking at compressor maps and the such, doing my homework. And in the end it will run awsome.

I decided on a T04 with a .8 A/R Dual flange Exaust design and 0.6 Compressor A/R which will allow for both decent spool up. (3000rpm) and a max boost pressure of well above 26psi. I even ordered it last night.

BTW, its probably going to be pretty hard to get past 20psi on these blocks with a non steel ringed head gasket... (i cant find one) So in the end, the only thing that may be limiting you is the heads gasket lol.

 

My other turbo car is 8:1 stock, and I am lowering that to mid 7's

 

why so low?

if its detonating i highly doubt the pistons are at fault.

You probably need a larger intercooler or better electronics. Not new pistons.

 

No, no detonation, I am looking at going from the 14-17 PSI to into the 20's.
And with the lower static ratio, I can do it alot more safely.

 

Actually for this engine I chose an '04E/48. That should be creating boost around the 2K BAND.

The other car, is turbo from the factory, I am just uprading a 12A with a super 60.
The rest of the stuff is to get the most from the turbo.

 

Now, don;t any of you go coping me!

Bore 3.54 (.040 over with rebuild)
Stroke 3.31
Gasket .035
Height .0001
Dish -31.3

Ratio.... BULLSEYE 7:1

HE HE, refund check is spent early this year...

damnit... that freggin .040 over screwed it all up... did not do that right... of well, it will be close to this anyway.

 

Hey, can you tell me how you figured out the Cr to be 7:1? Here's what I've got and maybe you could tell me what mine should be
with a bore of 3.534 (yes 30 over)and .015 off the deck. My problem is that I built the engine and installed a bigger cam and now I have less lower end torque. I just found out that it is because of the change in the dynamic compression ratio as a result of the bigger bore,larger cam, and 1.6RR.

thanks

 

go to www.rosspistons.com click on calculator and figure it...

I used a generic .035 head gasket thickness.

With same number as mine, but with the deck height changed... Tadaaaaaaa...

roughly a -.5 CC dished piston.
but you can run flat tops at 7.04:1

 

Can anyone tell me what our combustion chamber CC's are?

 

Look at abpve post, but that is also taking into account the 6" rod...
hold that for a second, I messed some numbers up...
with 5.7" rods, you will need a -65CC dish.
With 6" rods -73CC

 

For in deph info on the 60*V6, go to This site

The combustion chamber size (in the head to be specific) is 48cc, from the info I have found, some say up to 52cc.

Stock Iron head gasket thickness is .040" installed, aluminium head gasket .060".

Rod length won't effect comppresion ratio, as long as the pin hight in the piston has been changed, the length of rod, changes the the velocity of the piston and dwell time at TDC and BDC, which will change how much pressue is built in the chamber during the dwell time, there is a fine balance between too little and too much. An engine builder I trust and holds class records for his class, plus class champion last year, uses a 1.6 rod ratio, a stock 3.1 with stock rods, etc, has a rod ratio of 1.72, while a stock 2.8 has a rod ratio of 1.9, which some builders would say is a perfect ratio, but each engine is a little different, it seems when it comes to what rod ratio will work best.

Keep us up to date on the 6" rod, as far as I know your are the first to actually install a 6" rod in a 60*V6, there has been lots of talk about it though.

 

52cc, but you can remove the "lip" thing in the CC to get like 56cc's if you want to lower your compression a little.

 

Yep. that's what I did. I removed the lip and around the exhaust valve to free up air flow. Man has this reduced my CR, doing the formulas it's down to about 6:1. Which has really screwed up my VE tables and spark. I've got to get a chip burned to adjust for it!