I've been reading up on the olds 307's Currently purchasing a 1987 442, and also a 1987 Cutlass Salon. The Salon i wanna get better performance wise. In reading articles on this Engine it sas 7A Heads From the 87 307 Flow very poorly which basicually you can't build, add headers or any of that jazz. Just wondering if anyone wants to throw me some ideas?

Thanks Casey

Depends who you are talking to.


The sole purpose of the 307, was to make the Olds V8 meet EPA standards. The bore/stroke ratio and the cam/valve/port configurations, were designed to provide a power band consistent with that goal. Trans and final drive ratios, completed the combination.

Not hard to put it into the elevens if, it is your goal and, you want to spend the time and money. Easier to replace it with a larger version of the same engine, and make the necessary drivetrain changes to make that combo work efficiently.

Unless we know your goal, expectations, and intended use, along with your budget/skill/experience level, any further advice is pointless.

Give us what info you can, and we will go from there.

Norm

Hey, Just wanted to recommend this website I saw for 307 olds. Its
performanceolds307.tripod.com It has a a few mods that will help your engine.
With 7A heads it is actually not a good idea to add aftermarket intake or headers because of port mismatch. I added a turbo muffler a K&N on mine. It did improve. What I dont recommend for power is an ignition upgrade. The HEI is good for the 307 because the 307 runs at a low RPM.

Hi valley olds,

Welcome to TOC.


Checked it out. First thing I found, was the following.


In NHRA Superstock, there are a few 307 Oldsmobiles in the tens, using the same 307 heads and intakes that were being discussed above.

In Sportsman classes, a couple are in the nines. Rules allow them to adapt aftermarket manifolds if they choose to.



This one was running 10. 2s in Superstock, using a 305, at the time of the pic,


If you cannot post the quote accurately, do not post it at all.


Within the context of the actual quote, my answer stands.


Can't they be made to line up, by using normal port matching techniques?


By how much?


Since the same HEI can operate satisfactorily at 6K+, in a performance application, how is the "low RPM" of the 307 a factor?

Norm

88 Coupe wrote:In NHRA Superstock, there are a few 307 Oldsmobiles in the tens, using the same 307 heads and intakes that were being discussed above

This sounds pretty interesting, but will the engine last much with the weak mains?

88 Coupe wrote:
Can't they be made to line up, by using normal port matching techniques?

This, in a statement rather than an interrogative sentence, would have been a great answer for 442WMachine's post

88 Coupe wrote: By how much?

I dont really know by how much exactly. I installed the K&N first and felt a difference. After this I installed the turbo muffler and also felt a difference in acceleration (a little more than the K&N). When I upgraded the ignition though, I didnt feel any change in responce and accelearation.

88 Coupe wrote:Since the same HEI can operate satisfactorily at 6K+, in a performance application, how is the "low RPM" of the 307 a factor?

What I was trying to say is that it is not nessasary to upgrade the ignition because if it can operate good in high RPM applications, then it is enough for the low RPM 307

Considering the investment, and the cash difference between winning and losing, not to mention the fines for "oiling down" the strip, and the attendant PR problems with sponsors, spectators, and fellow competitors, I do not think they would be using a block with a "weak main web problem".

The "problem" is more about internet misinformation , and less about any actual weakness in the block design.

But that, would be another topic.


He did not make the statement, you did.

I asked the question, because I did not (and still do not) know the answer.


I washed my car this morning. Can't believe how much better it ran. I didn't measure the results, but it felt like a 10 HP increase, at least.


Clear enough.

I will add that, with few exceptions, HEI is more than adequate for all high performance Olds street engines, and ignition "upgrades" for any Olds V8 are a waste of money.

Norm

Coupe 88 said: The "problem" is more about internet misinformation , and less about any actual weakness in the block design

I guess this is true. I dont know, Ive always wanted to fix up my 307 but I hear nothing but bad things about it performance wise, weak block and mains, bad heads, etc... but you make a good point with that NHRA thing.

Coupe 88 said:He did not make the statement, you did.
I asked the question, because I did not (and still do not) know the answer.

Well he didn't make the statement but he did say, "In reading articles on this Engine it sas 7A Heads From the 87 307 Flow very poorly which basically you can't build, add headers or any of that jazz.
As for the question, sorry, I just thought you were trying to make me look like an idiot because porting does seem like a good choice and I had not thought of that. I dont really know if you can port it that much either but it sounds like a great alternative to getting the 5A heads (oldsmobiles are pretty scarse down here).

Coupe 88 wrote: Can't believe how much better it ran. I didn't measure the results, but it felt like a 10 HP increase, at least.

Well for you to feel a difference in the first place it did give you a pretty good chunk of horsepower because if you just get one by the time it gets to the rear wheels you lose it. So I guess, the K&N gave me 7-10 hp and the muffler gave me 10-15 hp

As I said previously:

The accuracy of the information, "depends who you are talking to".


I responded to what he actually said. Nothing more, nothing less.


What made you think that?


From a car wash?


If you do a "Google" search, you will find "documentation" that will back up that claim.

Again: It depends who you are talking to.

Norm

88 coupe wrote: From a car wash?

I meant from anything in general. If you actually feel the difference in acceleration you freed up a couple of horses.


88 Coupe said: What made you think that?

Ususally when someone speaks sarcastically (to make someone else look stupid) they answer to a question or statement in question form.

Do we take that as a yes?


How was my question sarcastic?

Norm

So, 442 WMachines from this we can basically conclude that the K&N and the muffler help give a few horses, if you dont modify your head you cant directly bolt on hedders and aftermarket intakes, you have no need to modify your HEI distributor, and you can get other suggestions at performanceolds307.tripod.com. Im done with this thread I helped with what I could and adding more posts would be a waste of my and the reader's time.

In the absence of any hard data to support your (not our) conclusion, your gains are in your imagination.

During previous discussions on the same subject, we have been calling it, "the placebo effect".


The spelling of "Hedders" indicates you are talking about the Hedman brand name, as all other manufacturers use the correct generic term, headers.

http://www.hedman.com/pages/hedmanmain.html

Why does Hedman show P/N 58070 for a 307 "G" body if the product will not fit that application?


As you have already stated, you do not know that.


An increase in compression and/or a change in cam timing, would certainly need to be compensated for, by a change in the advance curve.

Why wouldn't that be a modification to the HEI?


At the risk of repeating myself:


And that was only his opening statement.


There are several of those readers, who are interested in knowing how to read nonexistent sarcasm into my posts.

If you cannot answer the question, just say so.

Norm

Hey, I know this is an old post but I just wanted to say that I replaced all my vacuum lines with new ones and it did help. My roommates said that my car now runs like a "normal" car (before it was really really slow). So this might be something you could consider doing. I ended up using around 18 feet of vacuum hose.

This is an old thread. It is about 307 heads.


OK. Obviously, you had a vacuum leak.

Your vacuum leak, has nothing to do with 307 heads.

Norm

actually, somebody told me that older cars with the original vacuum lines tend to have vacuum leaks because of all the heat exposure by the engine which causes small cracks in the hoses. So, if no one replaced lines in the last 20 years they will be kind of cracked.