engine help needed
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engine help needed
Hi bought my first project with an older sbf. I have a 302 with D80e heads. It had a dual quad setup on it that I removed to go back to single carb. I put a edelbrock performer 302 intake on. Now it won't run under 2500rpm unless I continue to pump the accelerator. It was after this I realized it had those heads which I believe are 351w heads????? Is that intake my problem or will it work with those? Any help is appreciated. Thanks
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Your D8OE is from 1978. Even if those are 351w heads, that usually leads to even lower compression on a 289/302 due to the larger combustion chambers. The trade off was a little compression for the bigger valves. Better answers exist these days. But I digress....
What has been done to it or is it OEM from waaay back? (in which case, have you done a compression check?)
What else do you know about the short block? Cam, pistons, etc.
Having said that, that manifold, a straight Performer, right?, should work just fine on that motor.
What size and type of carb?
Does this manifold line up and bolt down correctly? Do you have any vacuum leaks?
What has been done to it or is it OEM from waaay back? (in which case, have you done a compression check?)
What else do you know about the short block? Cam, pistons, etc.
Having said that, that manifold, a straight Performer, right?, should work just fine on that motor.
What size and type of carb?
Does this manifold line up and bolt down correctly? Do you have any vacuum leaks?
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The Carb i have on is a Edelbrock 600. It came off a running engine last week. The intake bolted on fine without issue. I had my brother hold the gas at a consistant RPM and i sprayed carb cleaner around the whole intake and noticed no pick up in RPM. I just am not sure why it wont run now when it did run with the dual quad setup a few short weeks ago. I am unsure about any of the motor work. I was told it was a 331 when i bought it. I have no reason do doubt the guy he was a familly friend but has since passed. I am new to these engines and have only built mopar and chevrolet engines. That is why i was concerned when i found out about the heads. If they should work with that intake atleast that gets me in a new direction. And the compression seemed fine all about 130 psi. Enough to run anyways.
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Joined: Jun 2006
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From: Ottawa, Ontario
D8OE are smog heads with massive combustion chambers(69cc) and small valves(1.78/1.45") and it doesn't matter what motor they came off the exact same head was used on both 302s and 351s.
These heads will affect performance negatively but the motor should still run correctly so your problem is most likely the carb(needs a cleaning or jetting) or ignition timing.
These heads will affect performance negatively but the motor should still run correctly so your problem is most likely the carb(needs a cleaning or jetting) or ignition timing.
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Joined: Aug 2002
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From: Southern California
I had a friend years ago who installed the dual quad setup on the exact engine you have...with a cam (around 180 duration/just under 500 lift......of course it was too much for the engine for a street driver.....he was hurting for money and didn't want to spend the time to tune the carbs......I suggested buying a couple of adapters and installing 2- 350 cfm holley 2V's......with very little tuning, it idled & ran great (very strong performer up to 5500 rpm...sold the quads and put a few coins in his pockets.....just an option....
Hotshot
Joined: May 2003
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From: south louisiana
D8OE are smog heads with massive combustion chambers(69cc) and small valves(1.78/1.45") and it doesn't matter what motor they came off the exact same head was used on both 302s and 351s.
These heads will affect performance negatively but the motor should still run correctly so your problem is most likely the carb(needs a cleaning or jetting) or ignition timing.
These heads will affect performance negatively but the motor should still run correctly so your problem is most likely the carb(needs a cleaning or jetting) or ignition timing.
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Joined: Dec 2012
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From: Whitewater, CO
Tis, sorta hard to tell, from your thread, but, I assume that all you did was pull the intake and put a dif one on?
My top 2 guesses are ignition timing...or a vacuum leak (my first choice). It could be underneath the intake. Put your hand over the top of the carb, when running and see if that helps. That induces a richer mixture and compensates for a vacuum leak.
Turn your dizzy, when the motor is running and see what happens.
The issue about the heads is smoke (it clouds the issue) and I agree w/the others..taint your problem.
My top 2 guesses are ignition timing...or a vacuum leak (my first choice). It could be underneath the intake. Put your hand over the top of the carb, when running and see if that helps. That induces a richer mixture and compensates for a vacuum leak.
Turn your dizzy, when the motor is running and see what happens.
The issue about the heads is smoke (it clouds the issue) and I agree w/the others..taint your problem.
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