My 3100 build :)

[bkaab]

I'm currently rebuilding my 3100 in my 96 GP and putting some new performance parts into it and replacing the gaskets.

I am going to swap over to a 3400 topend gasket matched porting, Pistons, and Rod bearings. Deleted the cat right before the car broke.

Anyway I think I remember reading that if ya swap over to a different piston that came in an older a 3.1v6 (RWD I think?)that it will raise compression. Also remember reading that there was exhaust manifolds that come on different 60*v6 that flowed much better then stock. Any one have more info on these?


The tear down.








Old Rear head


Old Front head


Thanks,
Andrew B.

[bob442]

your answer should lie in the CR calculator on this site for what compression ratio you will yield, and manifolds from a 3500 flow the best

[Superdave]

pistons for a 3.1 Camaro (gen 1) will yield either 11.4:1 with the .040 headgaskets, or 10.72:1 with the 3100's .060 headgaskets.


Save your old 3100 pistons, someone who is building a N/A Gen 2 engine might want them. 9.8:1 with .060 gaskets, that's a good jump from 8.9:1

[TGP37]

your answer should lie in the CR calculator on this site for what compression ratio you will yield, and manifolds from a 3500 flow the best

Remember, on a 3100 you can use 3400 heads, but not 3500 heads. On a 3400 block, you can use 3500 heads.

I don't know if 3500 intake mani's will fit 3400 heads? Something to check into. Unless you were referring the exhuast mani for the 3500.

If you got the money, consult with Ben and he'll know what the best top end will be.



edit: It almost looks like cyl 1 & 3 were getting steamed. And that would be the rear passanger side. I suppose the coolant leak may have been around there.

How are your cylinder walls? Probably need a good honing when you swap those pistons.


And might I suggest, since your down there soon, put in a crank scraper as well. Helps reduce parasitic drag on the crank.

[bkaab]

So these are the pistons I am looking for correct

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Piston-Individual---Standard-Sealed-Power_3716880-P_2185_R|GRPENGPAMS_____

What car should the 3500 exhaust manifolds be off?

[robert 1980]

I have a nice 3400 top end if you need one?60xxx miles and everything you'll need heads intakes rockers.
Im selling it cheap too=) make offers?

[carbon]

You can use the 3500 upper on a 3100/3400 large port lower or vice verse, but the lower intakes are not interchangeable between the heads.

[bkaab]

Engine is out

[robert 1980]

Cool looks good for it's age=) Good luck with the build.Car is in nice shape too.Don't see to many of them anymore.

[bkaab]

Got my 1st new performance parts 3400 Top end. Going to do some home porting and paint it all.

[bkaab]

Well I got the block all torn down to just the crank. That will come out soon also. Looks like the piston skirts were dragging pretty bad on some cylinders. The engine had a pretty nasty piston slap knock before I tore it down. Take a look at the pics. Do ya think I need to bore it over?











So here's some pic's thus far.




and where my other coolant leak was

[zinX11]

Looks like at least a good hone job on a CK10 or equivalent is in order, over-boring if the cylinders show too much wear/taper. That's not something you can eyeball, but if you're buying pistons, might as well bore it the minimum it will clean-up at and can still get a piston to fit. Then you know you'll have a good sealing, quiet engine. Good machine work is worth every penny.

Mike

[TGP37]

How bad was the ridge? Did it needed reamed out?

I always believed the ridge was directly proportional to the cylinder wall wear. If the ridge needed reaming, I would bore the cylinders. If not, I guess it is okay to just hone.

But that has been a personal understanding......I could be wrong.


I fit were me, I'd have them bored considering the visual inspection.

[bkaab]

Whats the difference in the pistons for a TGP and a 3100? Would the ones for a TGP be better for a boosted application?
I have a little bigger cam to go in but its flat tappet. Do I just use the older 3.1 non roller hydraulic lifters then?
And 1 more question about rocker arms. What is the 1996 3100 rocker arm ratio? 1.5 or 1.6?

Sorry for all the questions. Just trying to learn. In the 3800 world its much more straight forward.

[bszopi]

When you ask about differences between pistons, are you asking for like compression ratio?

As far as the rockers go, all 3x00 engines have 1.6 ratio rockers stock.