Need help with heads street car proformance
June 22nd, 2017, 11:22 PM
#1
Registered User
Thread Starter
Join Date: Jun 2017
Posts: 6
Need help with heads street car proformance
Hi everybody new to the forum I have a 1987 Oldsmobile Cutlass with a 72 Oldsmobile 350 I recently had the motor rebuilt I had everything upgrade next stage up from stock the block was Cut & Board the heads that came the motor we're 7 heads when I install the motor it had a Bad Head and i installed number 8 heads and forgot put the 7 heads back on when I got the motor rebuilt I know the number 8 head where cut and valves had work done to them so my question is is the motor going to be a beater with no horsepower it has a mild cam Edelbrock high RPM intake 700 CFM Edelbrock carb new HEI distributor 2400 Stoll turbo350 trans 373 rear I don't know how I forgot to put the seven heads back on but everybody makes mistakes so what do you think the horsepower rating would be this is my first classical car p.s I'm guessing there number 8 heads because it has a big 8 on the head
June 23rd, 2017, 05:06 AM
#2
Connoisseur d'Junque
Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
I can't ask you rhetorically if you even know what a period is, as you have used one — ONE — in "p.s", so I won't.
Instead, I'll ask you whether you know what a comma is.
I will try to decode your paragraph-long sentence (is it even a sentence if it doesn't end with a period?) as best I can.
It sounds as though you had machine work done on your engine, but you assembled it yourself, rather than having it rebuilt by someone else. In the course of the work, you "had everything upgrade next stage up from stock," and I really have no idea what this means.
To what specifications did you have the machine work done?
You say it was bored? How much?
What about other parts? What pistons were used? Was any work done on the crank? How about the connecting rods? The valvetrain?
You say it has a "mild cam." Which one?
You say it was "Cut." Cut where? Do you mean that it was decked (had the head mating surfaces of the block milled), or that the mating surfaces of the heads themselves were milled, or both, or something else?
You say, "when I install the motor it had a Bad Head." What do you mean? What is a "Bad Head"? Which head was "Bad" - the #7 or the #8?
You say that you forgot to put the #7 heads back on the engine - Did the #7 heads have machine work done to them? If so, what? How about the #8 heads?
We have no way of guessing what the output of your engine would be without this information.
Also, there is no need to post identical threads in different places - all this will do is complicate the responses and confuse people.
Please provide additional information, so that we have some glimmer of hope of being able to answer your question.
And, please, watch this video before responding. Thank you.
Welcome to ClassicOlds.
- Eric
Instead, I'll ask you whether you know what a comma is.
I will try to decode your paragraph-long sentence (is it even a sentence if it doesn't end with a period?) as best I can.
It sounds as though you had machine work done on your engine, but you assembled it yourself, rather than having it rebuilt by someone else. In the course of the work, you "had everything upgrade next stage up from stock," and I really have no idea what this means.
To what specifications did you have the machine work done?
You say it was bored? How much?
What about other parts? What pistons were used? Was any work done on the crank? How about the connecting rods? The valvetrain?
You say it has a "mild cam." Which one?
You say it was "Cut." Cut where? Do you mean that it was decked (had the head mating surfaces of the block milled), or that the mating surfaces of the heads themselves were milled, or both, or something else?
You say, "when I install the motor it had a Bad Head." What do you mean? What is a "Bad Head"? Which head was "Bad" - the #7 or the #8?
You say that you forgot to put the #7 heads back on the engine - Did the #7 heads have machine work done to them? If so, what? How about the #8 heads?
We have no way of guessing what the output of your engine would be without this information.
Also, there is no need to post identical threads in different places - all this will do is complicate the responses and confuse people.
Please provide additional information, so that we have some glimmer of hope of being able to answer your question.
And, please, watch this video before responding. Thank you.
Welcome to ClassicOlds.
- Eric
June 23rd, 2017, 10:32 PM
#7
Registered User
Join Date: Feb 2013
Location: Phoenix, AZ
Posts: 13,738
Aye caramba. It's really hard to decipher much from what you posted.
Aftermarket cast pistons typically have huge dishes and are short on compression height, so 7.x:1 compression ratio is possible. 7 heads have about 68 cc chambers and 8 heads have larger 79 cc chambers, which would make the compression ratio issue much worse. Low compression ratio means the engine can easily be overcammed. Top this engine off with an RPM intake manifold that is designed for high performance and you have a drastic mismatch of components that may make a power level on par with a 60s era VW Beetle.
Aftermarket cast pistons typically have huge dishes and are short on compression height, so 7.x:1 compression ratio is possible. 7 heads have about 68 cc chambers and 8 heads have larger 79 cc chambers, which would make the compression ratio issue much worse. Low compression ratio means the engine can easily be overcammed. Top this engine off with an RPM intake manifold that is designed for high performance and you have a drastic mismatch of components that may make a power level on par with a 60s era VW Beetle.
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