Tweaking an 87 Olds 307 - opinions?
- Thread starter skryla
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I'm confused. Are we still talking 307 or have we moved on to 350's?
Skryla unless you want to keep the original engine in your car just to have the original engine, you really should go with a 350. How about a 403? Either way a 350 build to run on the computer is going to pale in comparison to your BTR built engine and going with a 307 will just be that much worse. I know you're not looking to match your BTR engine but if the performance of your 307/350 is too big of a huge dropoff, you're going to be left wanting more.
With that said, would you please state your performance goals ( 1/4 mile ET's and mph ) and not focus on horsepower numbers? Some people have such ridiculous notions on what HP they assume is needed to reach a certain goal and many times they are WAY off. Maybe you're one of those guys? If you are we can cure you!
I wasn't joking before when I mentioned you should get my 350. It was specifically built to run on the computer which it did. It's spunky and fun to drive but isn't anything that's going to throw you back in the seat and suck your eyeballs into your skull. I have real world performance numbers to back up what it can do ( high 13's ) and it has tons more left on the table if you want more. It's priced to sell. I don't have a long term place to store it so I just want it gone. You will not find a better deal.
P.S. 350 heads on a 307 will not work. The valves will be shrouded due to the small 307 bore size. Yes they will bolt on and work, but they won't give you any more performance. This is info from those in the past who did it or wanted to do it ( before just moving on to a 350... ).
Skryla unless you want to keep the original engine in your car just to have the original engine, you really should go with a 350. How about a 403? Either way a 350 build to run on the computer is going to pale in comparison to your BTR built engine and going with a 307 will just be that much worse. I know you're not looking to match your BTR engine but if the performance of your 307/350 is too big of a huge dropoff, you're going to be left wanting more.
With that said, would you please state your performance goals ( 1/4 mile ET's and mph ) and not focus on horsepower numbers? Some people have such ridiculous notions on what HP they assume is needed to reach a certain goal and many times they are WAY off. Maybe you're one of those guys? If you are we can cure you!
I wasn't joking before when I mentioned you should get my 350. It was specifically built to run on the computer which it did. It's spunky and fun to drive but isn't anything that's going to throw you back in the seat and suck your eyeballs into your skull. I have real world performance numbers to back up what it can do ( high 13's ) and it has tons more left on the table if you want more. It's priced to sell. I don't have a long term place to store it so I just want it gone. You will not find a better deal.
P.S. 350 heads on a 307 will not work. The valves will be shrouded due to the small 307 bore size. Yes they will bolt on and work, but they won't give you any more performance. This is info from those in the past who did it or wanted to do it ( before just moving on to a 350... ).
DoubleV said:
Sorry DoubleV. Yes we have moved on. I drive my wife nuts how quickly I change subjects. An idea in my mind is like "flubber" (for those of you old enough to appreciate the Robin Williams movie reference).
I have resolved myself to the fact that I am now building an Olds 350.
BTW, I PM'd you about your engine.
DoubleV's engine sounds like a good plan. The 307 is a great motor for what it is, but what it is doesn't sound like what you want.
My two cents on the computer, I'd ditch it. It's my understanding that it's primary function is to improve emissions, and I personally wouldn't waste any time on it. This isn't to knock the guys who have kept it, and I know there are 350s and even 403s that are running it. Also, in my situation I was going with a 455 in an original V6 car, TH350 non-lockup trans, and no AC, so HEI was a no-brainer for me. The only concern I guess would be, is the computer able to properly command a larger engine with it's factory program and assumptions, and if not, what needs to be done to make a 350 run right with the computer? My feeling is that to address this properly, a certain not-insignificant amount of time and re-engineering would need to go into it, and this is time that could better be spent on retrofitting HEI. Just my opinion.
My two cents on the computer, I'd ditch it. It's my understanding that it's primary function is to improve emissions, and I personally wouldn't waste any time on it. This isn't to knock the guys who have kept it, and I know there are 350s and even 403s that are running it. Also, in my situation I was going with a 455 in an original V6 car, TH350 non-lockup trans, and no AC, so HEI was a no-brainer for me. The only concern I guess would be, is the computer able to properly command a larger engine with it's factory program and assumptions, and if not, what needs to be done to make a 350 run right with the computer? My feeling is that to address this properly, a certain not-insignificant amount of time and re-engineering would need to go into it, and this is time that could better be spent on retrofitting HEI. Just my opinion.
SAE Net horsepower and torque ratings (not crankshaft I don't think, but not at the wheels, either):
1987 non-HO 307
140 hp @ 3200 RPM
255 ft-lbs @ 2000 RPM
1987 HO 307
180 hp @ 3200 RPM
255 ft-lbs @ 2000 RPM
1972 350 2-bbl single exhaust
160 hp @ 4000 RPM
275 ft-lbs @ 2400 RPM
1972 350 4-bbl single exhaust
180 hp @ 4000 RPM
275 ft-lbs @ 2800 RPM
1972 350 2-bbl dual exhaust (really not sure on this one)
180 hp @ ? RPM
280 ft-lbs @ ? RPM
1972 350 4-bbl dual exhaust
200 hp @ 4800 (?) RPM
300 ft-lbs @ 3200 (?) RPM
1987 non-HO 307
140 hp @ 3200 RPM
255 ft-lbs @ 2000 RPM
1987 HO 307
180 hp @ 3200 RPM
255 ft-lbs @ 2000 RPM
1972 350 2-bbl single exhaust
160 hp @ 4000 RPM
275 ft-lbs @ 2400 RPM
1972 350 4-bbl single exhaust
180 hp @ 4000 RPM
275 ft-lbs @ 2800 RPM
1972 350 2-bbl dual exhaust (really not sure on this one)
180 hp @ ? RPM
280 ft-lbs @ ? RPM
1972 350 4-bbl dual exhaust
200 hp @ 4800 (?) RPM
300 ft-lbs @ 3200 (?) RPM
King_V said:
The 86-87 307 HO's were only 170 hp. The earlier non swirlport 307 HO's were 180 and supposedly a hair less torque too. The earlier non HO 307's were 150 hp. So basically, both versions of the ealier 307's were rated at 10 hp more than the later versions were.
I'm curious what TBI might be able to do to 'wake up' an old 307. I found an article where a guy adapted some TBI equipment off of a 78 seville I believe it was onto his 307 and made decent gains in torque. I can't seem to find the article anywhere. I'm surprised nobody else has tried adapting tbi onto a 307 on this board, not the roller rocker motors but perhaps the flat tappet would actually perform better being pushed by electronics. perhaps with a lot of tuning it could even support a small turbo - but thats probably getting carried away. The build im vaguely imagining right here is above my skill level - but I suspect all these parts could be assembled off of various make/model donor cars for just a few hundred dollars from a junkyard. The typhoon 4.3L used mitsubishi turbochargers for example.
pencero said:
The '75-'79 Seville was an Olds 350, not a 307, and it was fuel injected from the factory. The 307 was a pretty well wrung out engine for what it was, which wasn't much in terms of performance. Every once in a while, someone comes along and talks about "maybe this could be done with the 307", I think I've seen a turbo project somewhere... Sure, a 307 with a turbo or two would probably make decent power. But it's SO easy to just drop in a 350 or a 403 or a 455, where you're STARTING with 200+ horsepower, rather than working up to it. And this isn't to denigrate the 307, it's a fine, reliable motor. Some of my best Olds memories were with 307 cars, but they aren't memories related to speed or winning races. Just my opinion.
I understand why it's kind of a waste of time to mess with a 307 and end up spending more than just copping a different smallblock. From a business perspective someone could stand to make a reasonable profit if they found a way to push the 307 a little harder, called china and reproduced the set of obsolete parts / obsolete technology they had used to achieve these gains and sold it as a 'kit'. Admittedly the 307 is becoming so obsolete now it would serve better as a backup generator to a small hunting cabin than be rebuilt for a use in a car these days lol
pencero said:
Ha ha I wouldn't have put it so starkly, but yeah, unless you're going for originality, or you have a decent-running car, or you want to do some sort of experiment for the betterment of the 307 legend, hunting cabin duty is pretty good work for a 307. There are NOT that many Oldsmobile guys out there compared to Chevy, not by a long shot. I had been immersed in Oldsmobile for so long, I had developed this impression that Oldsmobile had a decent following among the general car crowd. In fact, there are probably 100x more guys building Chevy engines than there are guys building Oldsmobile engines. That's not to say that us Olds guys aren't a dedicated and loyal bunch, we generally are, there just aren't that many of us. I'm surprised that there's ANYTHING out there for Oldsmobile, when there's such a huge Chevy market.
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