Originally Posted By: Hokiefyd
Originally Posted By: eljefino
Yup but the 307 in those is SLOOOW. And didn't they have carbs until 1990?
Yes, the Olds 307 was carbureted until the very end. It was the last of a long line of Oldsmobile small block V-8 engines. Many Oldsophiles belived that it held many advantages over the Chevy small block, but GM simply dropped development of the Olds version after about 1985. The last version of the 307, in 1985, had an aluminum intake manifold, roller cam followers, and a very smooth operation. It had a computer-controlled Rochester Quadrajet carburetor. I had a 1984 version of this engine; it had the aluminum intake, but sliding cam followers. It also had a computer-controlled Qjet. Interesting little animals.
And you can repair the Northstar engine quite easily, even while still in the vehicle (although removing the powertrain cradle does make the job easier). The only proper repair is to install Timeserts into the block. Not Helicoils, but Timeserts. There are tons of improperly repaired engines out there and that's half of the reason this motor gets a bad rep. Most of them are long-lasting anyway. I had a '97 that was in the family from almost new at 39k miles until about 190k miles. The engine was never opened up; the transmission fluid was never even drained. It's a tough powertrain. Some of them do have issues, but a skilled mechanic can have it back on the road, with a permanent Timesert fix, for about a grand. If you can pick up a used one for a song, you can have a bulletproof runner for not a lot of money.
I had the '83 307 with an iron intake. I'm glad it was because the heater control valve disintegrated and I had to remove threaded section from the intake by breaking it up. I might have dinged up the threads on an aluminum intake.
I also had to replace the HEI control module a time or two.
The 307 was sllloooowww but the rotating and reciprocating parts inside the engine seemed pretty durable.
The only thing I would add to your post on the Northstar is to do the starter with a good quality unit while you are in there. When the starter goes out, you are pulling the intake manifold off. Might as well be done while the heads are off.
The HT-4100s made my former employer a LOT of money. They were bad engines across the board. Long block was the most common remedy. Premium Long Block cost us about $900 and then he marked that up 50% + labor.
The 4.5 had a few improvements. Fewer cam bearing failures and the webbing in the block had been strengthened, but they persisted in pulling the aluminum threads out of the block.
The 4.9 isn't bad. But when I say it "isn't bad" I don't mean to imply that it is good. Just that they were less likely to suffer the earlier failures. They still failed and failed far more often than the Ford 302 or 4.6 in a Town Car or Chrysler 3.3 in a New Yorker.
Originally Posted By: eljefino
Yup but the 307 in those is SLOOOW. And didn't they have carbs until 1990?
Yes, the Olds 307 was carbureted until the very end. It was the last of a long line of Oldsmobile small block V-8 engines. Many Oldsophiles belived that it held many advantages over the Chevy small block, but GM simply dropped development of the Olds version after about 1985. The last version of the 307, in 1985, had an aluminum intake manifold, roller cam followers, and a very smooth operation. It had a computer-controlled Rochester Quadrajet carburetor. I had a 1984 version of this engine; it had the aluminum intake, but sliding cam followers. It also had a computer-controlled Qjet. Interesting little animals.
And you can repair the Northstar engine quite easily, even while still in the vehicle (although removing the powertrain cradle does make the job easier). The only proper repair is to install Timeserts into the block. Not Helicoils, but Timeserts. There are tons of improperly repaired engines out there and that's half of the reason this motor gets a bad rep. Most of them are long-lasting anyway. I had a '97 that was in the family from almost new at 39k miles until about 190k miles. The engine was never opened up; the transmission fluid was never even drained. It's a tough powertrain. Some of them do have issues, but a skilled mechanic can have it back on the road, with a permanent Timesert fix, for about a grand. If you can pick up a used one for a song, you can have a bulletproof runner for not a lot of money.
I had the '83 307 with an iron intake. I'm glad it was because the heater control valve disintegrated and I had to remove threaded section from the intake by breaking it up. I might have dinged up the threads on an aluminum intake.
I also had to replace the HEI control module a time or two.
The 307 was sllloooowww but the rotating and reciprocating parts inside the engine seemed pretty durable.
The only thing I would add to your post on the Northstar is to do the starter with a good quality unit while you are in there. When the starter goes out, you are pulling the intake manifold off. Might as well be done while the heads are off.
The HT-4100s made my former employer a LOT of money. They were bad engines across the board. Long block was the most common remedy. Premium Long Block cost us about $900 and then he marked that up 50% + labor.
The 4.5 had a few improvements. Fewer cam bearing failures and the webbing in the block had been strengthened, but they persisted in pulling the aluminum threads out of the block.
The 4.9 isn't bad. But when I say it "isn't bad" I don't mean to imply that it is good. Just that they were less likely to suffer the earlier failures. They still failed and failed far more often than the Ford 302 or 4.6 in a Town Car or Chrysler 3.3 in a New Yorker.
