marinus_

Last year I purchased a 1989 caprice station wagon with a 307 olds engine in it. The car is in excellent shape and has just over 100,000 miles on it. The main reason for purchasing this vehicle is for our camping vehicle and to pull our tent trailer. I really wanted an Oldsmobile wagon but had a hard time finding one in decent shape for the right price so I settled for a Chevy with an Olds engine in it.

I have had a few problems with it overheating this summer and have already replaced the thermostat, radiator cap, rad hoses, clutch fan as well as flushing the cooling system and adding a transmission cooler. We went on another camping trip pulling the trailer and drove for about 2.5 hours each way without any overheating.
My issue is that this engine is not what I had expected as far as power goes. I had trouble climbing any hills and it is very sluggish pulling away from a stop sign. (especially when it is warm)
I had it to the shop several times and they made several adjustments trying to get it to run better but did not make much difference at all.
It may be that this engine will never have the power that I am looking for and I may have to change the engine out to something with more horsepower.

My question is.... Is there anything that I can do to the 307 to increase the horsepower without sinking too much money into it? If not, what would you guys suggest for a replacement engine? Keeping in mind that I still have to get the emissions test done every two years.

I am thinking of going to a 350 because that would probably be the most economical choice.

Any advice would be greatly appreciated.

Thanks,
Rene

Oldsmaniac

The 307 is tired, has choked exhaust and prob a tired quadrajet carb. You also have, most likely, a weak rear gear ratio. The 403 Olds engine is a smallblock and will bolt in smoothly. The Olds 350 is another good choice. Get a fresh engine, run true duals with dual catalytic converters and you should be set.

agtw31

the 307 is a transportation engine,nothing more.

after 100k,the valve springs,cam and lifters start going away

have your heads overhauled,new timing chain,cam and lifters,and it will wake the 307 up.

not like a 350,but better than before.

joe_padavano

OK, it IS a 307, so perhaps you need to modify your expectations.

Seriously, I have two of these cars, an 84 Custom Cruiser and an 86 Caprice. The 84 has the flat tappet 307 with the 5A heads. The 86 has the roller cam 307 with the 7A heads. The 84 is noticeably stronger than the 86 according to my butt dyno. This may be partly attributable to the different 307s and it is likely attributable to different rear axle ratios, though I have not checked the ratio in the 84 (the 86 has a 2.73 axle).

I don't know if you are subject to emissions testing where you live, but an engine swap will NOT be emissions legal. If you install a 350 or 403, it can be made to look like the 307 and you will likely be passed (since emissions test technicians really don't check casting numbers), but there's no guarantee.

marinus_

I honestly didn't know what to expect from the 307 and didn't so much research on it before I bought the car.

We are subject to emissions testing here but apparently it is O.K. to swap the engine as long as the new one maintains or exceeds the original emissions test standards. I guess that means that I would have to put in a newer engine and keep the pollution control stuff intact.
My thought is to maybe purchase a donor vehicle with a decent engine and have it e-tested before I remove it from the car to see if it passes the test.
I do really like the car but if it can't do what I need then I might have to look into selling it and getting an older one in decent shape that doesn't need to get tested. Cars that are manufactured prior to 1988 are exempt here in Ontario. (at least until they decide to change the rules again) It is not easy to find a decent wagon without a whole lot of rust up here.

marinus_

I already had the exhaust replaced and the carb was rebuilt just before I bought the car. Do you know if I can use the same computer controlled carburetor on the Olds 350 or a 403? I would need to keep the emissions intact in order to pass the e-test that has to be done every two years as well.

joe_padavano

The problem is that the 307 was the only Olds V8 available in that year. The 350 and 403 went out of production in 1980 and 1979, respectively. As I said, you can retrofit these engines to LOOK like a 307 (including using the CCC system) and you're unlikely to be caught by a test tech, but there is a non-zero risk that the car will be failed.

The electronic Qjet in the CCC system uses conventional secondary metering rods. You can swap the rods for those appropriate for the larger engine (and file the stop on the air valve so it opens a full 90 deg). The primary side is computer controlled, and you really would want a new PROM to alter the metering, but you can probably get it close enough through adjustment. The biggest problem is that the ignition advance is totally controlled by the computer and the only way to alter the advance curve is with a new PROM.

wolfman98

Or you could move to the maritimes and put whatever motor you want in it. this is where they send all the clunkers from that cash for clunkers program.