questions about engine rebuild

[mkgearhead]

Ok my son and I are about to start a full rebuild of his motor (1990 GS-T) and he has been reading about putting pistons out of a 2g 4g63 motor in his engine so my question is what is all needed to do this. is it just pistons or is it rods too, and on a side note he is running 12 Psi on 91 (highest oct. in colorado) will he have to drop his boost with the higher compression? Thanks for the help

 

[firefighter_637]

no you can still reuse the same rods but i would definately replace all the bearings and make sure your crankshaft still looks good and doesnt need to be resurfaced, in my opinion if you rebuild right you should be fine at 12 psi of boost but for security you could always get a cheap manual boost controller

 

[firefighter_637]

also while your at it i would replace your exhaust manifold with the 2g one too because they are stronger and higher flowing and much less prone to cracking

 

[mkgearhead]

Thanks for the input, as for the replace all the bearing and such he is planning on doing a full engine overhaul with all new parts (including the 2g manifold) again thanks for the input

 

[blackGSX2g]

Ok my son and I are about to start a full rebuild of his motor (1990 GS-T) and he has been reading about putting pistons out of a 2g 4g63 motor in his engine so my question is what is all needed to do this. is it just pistons or is it rods too, and on a side note he is running 12 Psi on 91 (highest oct. in colorado) will he have to drop his boost with the higher compression? Thanks for the help

Putting 2g pistons in your 1g would definately be a good idea...I upped my 2g ones from 8.5:1 to 9:1 and I felt a good throttle reponse and gas mileage difference (though the gas mileage could have something to do with it being a brand new motor).

I'd take your 1g rods in to be inspected to make sure they aren't warped or cracked...maybe have them magnafluxed/shotpeened. Something to look in to.

As for the actual fitment of the 2g pistons on the 1g rods, bring the measurements in the link to your machine shop or just tell them to:

Open up the wrist pin bore from 21mm to 22mm
and narrow the pin end of the rod .100'' to make it 1.040''

found here: http://hometown.aol.com/rcm1061/myhomepage/auto.html

 

[BUCK]

No way I'd go with 2G Pistons in Colorado & 91 Octane....

 

[blackGSX2g]

He said he was only running 12psi though...what about all the stock 2gs running around CO without any complaints?

I run 9:1 compression on stock boost levels at the moment with 93 here in MI, but have used 92 once with no problems.

 

[mkgearhead]

I think he has shyed away from the 2g pistons cause he found a rod and pistion kit that is for the 1g at 8.2 to 1 comp. so 91 pump gas at 12psi should be ok (his grandpa has a 03 SVT Lightning at around 11 or 12 Psi on pump gas so) i will let you guys know HP and Tq numbers after we are finished and will post timeslips sometime this summer thanks again for all the help

 

[mkgearhead]

Plans have changed. I gave him the motor out of my Talon for his birthday and bought a JDM engine,trans and transfer case for my Talon. 4 DSM's running at the same time!!! It's a miracle!!!