Gas and Power 1985 Grand Prix 3.8 V6

[GBody-J]

Good morning G body forum I am new to the group. I have a 1985 Grand Prix 3.8 V6 I just did a full tune up, I replaced the distributor and and rebuilt the carb. My questions may sound remedial but please bare with me. What can I do to my G-Body to help it run better in the summer? What can I do to boost the speed of my car that will not cost me alot of money? Should I use regular gas and add an octane booster or just use premium gas? Should I repalce the radiator with a full aluminum 3 row radiator?

Thanks,
Jaime aka GBODY-J

 

[lilbowtie]

Jaime
It's a 3.8 (I believe110 HP) and probably has 2.73 gears at best so it is what it is - a 19 second car. It's designed to run on regular. I would leave well enough alone and if you want to go faster work on a set-up on the side.

 

[Speedy94c]

Depends on if you want top end speed or quick out of the hole speed. If out of the hole speed is what your after then I would suggest changing gears in the rearend.

 

[TURNA]

Like the others said

Save your money build an engine on the side.

As much as I would want a Pontiac engine in a Pontiac the cheapest route would be a 350 Chevy.

A good engine would be this

https://www.summitracing.com/parts/nal-10067353/overview/

Its cheap and a great foundation for upgrades in the future

If you look around you can find it a couple of bucks cheaper

 

[olds307 and 403]

Actually a good running Buick 350 is a direct and the cheapest swap, if you can find one. The Buick 3.8, your motor and the 350 and 455 V8's have oiling issues, most issues are due to front cover wear. I would add 2" or 2.25" dual exhaust, a 2004R trans, if drive on the highway a lot and 3.42 or 3.73 gears in your rear end. The exhaust and rear gears especially will improve acceleration a lot.

 

[84slow]

Like the others said

Save your money build an engine on the side.

As much as I would want a Pontiac engine in a Pontiac the cheapest route would be a 350 Chevy.

A good engine would be this

https://www.summitracing.com/parts/nal-10067353/overview/

Its cheap and a great foundation for upgrades in the future

If you look around you can find it a couple of bucks cheaper

Exactly what he said.. I got the same motor but I do have a 350 on the side I'm building but for the mean while I put a pair of headers I got the local Kijiji "craigslist" and ran true duals instead of the setup we got with the crossover tube. Opened it up noticable on power all through out... It's just not worth dumping cash in it.. and as far as gears it's not worth it because we are a 3 speed transmission.. image what it would feel like with gears probably high revs on nice cruises

 

[MrSony]

I agree with olds307, especially having done it myself. Easiest swap hands down. V6 out, V8 in. If you can find a good shape, RUNNING Buick 350, that will be the cheapest and most direct swap. I'd recommend a 75-80 engine. One, more plentiful. Two, they have the stronger capscrew rods. 68-75 (75 was a changeover year) have slightly weaker and less desirable stud/nut rods. And stay away from the 68-69 engines. They oil through the rockers instead of the pushrods. No parts from 70 to 80 are compatible and they use taller lifters and it's just a pita. All the wiring, the transmission (if you want to use the TH200 that's probably in there, I advise not), engine mounts, front accessories, water pump, fuel pump ALL interchange. You could even plop the computer BS on it if you wanted, but it'd take some creativity. The 3.8, 350 and 455 don't have oiling issues, more of a design flaw. They have external oil pumps housed in the timing cover behind the oil filter. The steel gears in there will, over time, wear away at the aluminum housing. Housings are pretty cheap for what they are (200 bucks for a brand new blueprinted cover from TA Performance. Cover, oil pump, thrust plate and adjustable pressure regulator, and a neoprene front seal instead of having to deal with rope).
TA also sells cam bearings with the oiling holes in a better location and oilling groves on the backside of the bearing to help with flow. They make downpipes to connect to manifolds for dual exhaust, and offer a 2.5 inch mandrel bent dual exhaust kit for 350$ for our cars. Plus, Buicks just sound wicked.

<--My car.
Word of advice; DON'T FORGET THE OIL GALLEY PLUGS. :I TA again makes screw in plugs if you tap the holes for threads.

If you want a motor to build, Buick, Olds, or Pontiac stuff by nature is more expensive than SBC stuff. It just is. But not many people can say they have a g body, and didn't swap a SBC in it. If you just want a motor to drop in and go, find a nice Buick 350. Easy way to identify, dizzy in the front at an angle. Just like your V6. Will also have a big "350" cast into the back if the intake. Get a 350 buick, slap a TA Stage 1 aluminum intake, BUICK quadrajet (I prefer the 17058241 myself), comp 268 cam kit, and away you go. Buick 350s are everywhere for under 500 bucks.

 

[TURNA]

Come on guys look at the big picture here.

Buy a 35 Plus year old engine that will cost him 3 times as much to rebuild or update than a brand new 350 Chevy with a warranty?

If he had the money, then he just go Pontiac.

 

[olds307 and 403]

Only if he can find a Buick 350 he can hear run and stick an oil pressure gauge on it. They are pretty rare up here compared to the US, only have seen on in person that I worked on in a shop, was supposedly a US car.