GRAND PRIX Possible 3.8 V6 Replacement

[43grandprix]

My '82 Grand Prix's original 4.1L V6 engine apparently was replaced before I purchased it. The car's odometer was not working when I got it, so not sure how many miles are on her, but it does say 101,623 now. A mechanic figured out that the current engine is a 3.8V6 as when he was going to replace one of the cooling system hoses the 4.1 one didn't fit. The car has a DualJut carb instead of the 4-BBL that came with the 4.1.

Don't drive the Grand Prix much and it doesn't seem to use oil or have any blue or white smoke coming out of the tailpipe (thank goodness!). Of course, don't know how many miles the 3.8 has on it. Am wondering if I should have the engine compression checked and spark plugs looked at to determine the true condition of the engine? The factory A/C drive belt is missing as the compressor clutch pulley scrapes against the compressor, so that must have needed replaced long ago. Need to have A/C as the heat really bothers me.

My question to everyone is depending on the compression test etc., should I replace the 3.8 V6 will another one (to keep the factory A/C, radiator (which has been replaced), current accessories i.e. alternator etc.) or put a 350 in with an Edelbrock 4-BBL carb.? If the engine needs replaced, then the automatic transmission would probably need to replaced as well especially if a V8 is installed. The torque converter seal is leaking and needs replaced for the tune of $500 I'm told. Don't know what rear end the car has. I plan on keeping the car forever, so want to make it more reliable. It's not left me stranded so far, but so don't want that to happen.

The plan is to make the car a "street version" of Richard Petty's G-Body Grand Prix, as I saw him win the '83 Winston 500 in person at Talladega Speedway on May 1, 1983! The interior would stay stock. The paint job would look like Richard's. My budget is limited, so can't go "wild" on modifications, etc. I don't mind the V6, but don't know if the 3.8V6 is "bullet-proof" or not.

Thanks.

Maggie Ann

 

[565bbchevy]

I would be the first in line to say swap it and make more power but it appears your little V6 probably runs OK so it would probably would be worth the effort to verify it's condition.
Engine swaps can get very expensive especially if you are on a budget, I would move forward with what you have, the 3.8 is definitely not bulletproof but if it is in good condition and you are in no hurry to get anywhere it can last.
For the AC I would probably replace the compressor and also go with the newer style condenser if it is original and replace anything that is questionable in the system including o-rings and the orifice tube and convert to 134A and get it charged.

 

[CaliWagon83]

Hi Maggie Ann. There are nearly as many opinions on this subject as there are members on this forum. The good thing about G-Bodies is they have plenty of room under the hood, so your engine options are virtually unlimited.

Obviously, the stock 3.8 V-6 doesn’t have much power, but if that’s not a major issue for you, they’re generally pretty reliable engines otherwise. You might want to consider changing over to a throttle body EFI system, as that will give you much better cold-start performance and generally smoother drivability.

 

[43grandprix]

I would be the first in line to say swap it and make more power but it appears your little V6 probably runs OK so it would probably would be worth the effort to verify it's condition.
Engine swaps can get very expensive especially if you are on a budget, I would move forward with what you have, the 3.8 is definitely not bulletproof but if it is in good condition and you are in no hurry to get anywhere it can last.
For the AC I would probably replace the compressor and also go with the newer style condenser if it is original and replace anything that is questionable in the system including o-rings and the orifice tube and convert to 134A and get it charged.

Thanks for your quick reply. Yes, I realize that engine swaps can eat up one's wallet quickly. My beloved '73 Dodge Charger's 400 engine was overhauled years ago and it cost me $2,000! With machine shops being few and far between now, overhauling an engine would not be cost effective. Used to work in the local Chrysler/Plymouth dealership as the Parts/Service Manager, so know which MoPar engines are bulletproof, but I'm not versed on which GM engines are except for the Chevy 350.

Yes, the current V6 seems to run ok. The water pump, radiator, spark plug wires and plugs, cooling system hoses, rear main seal have been replaced since I've owned it since October 2005. When the rear main seal was replaced, they discovered that the crank bearings were worn, so those had to be replaced as well. The car used Pennzoil 10W30 before I bought it, so have stayed with it, even though I absolutely detest Pennzoil! The A/C drive belt was gone when I bought the car, so am sure almost everything in the system needs replaced! Can a V8 be installed (or even a newer V6?) and use some of the original A/C system parts if they're still good? Wouldn't mind having dual exhaust, but since my budget is limited, I just want a powerplant that reliable and decent gas mileage. Will be driving a lot of country roads with the car. Thanks for your input! Very much appreciated!

 

[43grandprix]

Hi Maggie Ann. There are nearly as many opinions on this subject as there are members on this forum. The good thing about G-Bodies is they have plenty of room under the hood, so your engine options are virtually unlimited.

Obviously, the stock 3.8 V-6 doesn’t have much power, but if that’s not a major issue for you, they’re generally pretty reliable engines otherwise. You might want to consider changing over to a throttle body EFI system, as that will give you much better cold-start performance and generally smoother drivability.

Thanks for your quick reply! Of course, I don't know what "vintage" the 3.8 is, so not sure how reliable it really is. When I got the car, the rear main seal leaked a quart of oil a month the former owner said! I had the seal replaced and the shop discovered that the crank main bearings were worn, so they needed replaced as well! The engine uses Pennzoil 10W30 oil, so that bothers me as well. I detest Pennzoil and have for years! I wouldn't mind having a bit more power, but I'm not a racer or like going real fast. I start to get very nervous going over 70 mph and grip the steering wheel even tighter!

Am concerned how much longer the current DualJet carb. is going to last before it would need overhauled and if you could even find someone to do that and find an overhaul kit! The car isn't driven a lot as it's at the family farm and sometimes it's been hard to start (could be from old gas). How much is a throttle body EFI system kit? Since I've owned a '93 Chevy Pickup and now a 2000 GMC Sierra Pickup with EFI, I'm sold on that system. Right now, I have to let the car warm up about five minutes before I can get it off fast idle. Both choke pull offs have been replaced on the DualJet. I'd never seen any carb with TWO choke pulloffs and think that's a Mickey Mouse system and would just cause more headache! Thanks so much for the advice and suggestions!

 

[565bbchevy]

but I'm not versed on which GM engines are except for the Chevy 350.

You can get a new crate 350 SBC's with a warranty starting at under $2000 but you would still need all of the brackets, mounts and accessories etc. if you needed AC parts you would just get them for a 83' Monte with a 305

 

[43grandprix]

You can get a new crate 350 SBC's with a warranty starting at under $2000 but you would still need all of the brackets, mounts and accessories etc. if you needed AC parts you would just get them for a 83' Monte with a 305

565bbchevy, thanks for the advice. Which crate SBC 350 would you suggest? A GM one or one from Summit Racing or JEGS? Would the brackets, mounts, accessories and A/C parts be available as a kit from Summit, JEGS, or some other vendor like Mike's Montes? So the A/C parts for an '82 GP with a 350 Chevy engine are the same as the '83 Monte Carlo with a 305? That's good to know, as I wouldn't have any idea what fits what. Have you had good luck with any of these crate engines? Of course, I'd need a long block. Really don't need an engine with all the flashy chrome, as I just need the basics with my limited budget. Thanks again.

 

[565bbchevy]

You might be able to find a good running donor car that you can take the drivetrain out of but both Jegs and Summit sell GM crate engines and far as brackets you could possibly find them locally and get everything or post in the wanted section on here if you decide to go this route.
Many people are swapping from SBC to LS so they might part out their brackets cheap.
There is also a GM serpentine kit that includes everything for just over $900, you can see how quickly money goes into this swap when you are starting from scratch.

 

[MrSony]

Easiest thing to drop in is a BUICK 350 and a short shaft Th350 transmission.
I've done it twice. 3.8/4.1 out, 350 Buick in. Same wires, mounts, starter, everything. 455 fits as well, with some minor engine mount mods.
You can use the front accessory brackets off the 3.8/4.1 on the 350 as well.

if money is no object and you want to be like everyone and their grandma, go SBC. I'd go a pontiac 400 myself in a GP.

 

[Onehit]

Sony beat me to it...As a 3.8 owner I would have gone that way a long time ago if I know better. This forum wasn't around and the interwebs was in its infancy. Find a buick 350 and build it while the 3.8 serves its purpose. If its not broke don't fix it