noise problems at high rpm

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Barracuda_v8

Barracuda_v8

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hello!
I have problems with my engine, a mopar 408. In first gear it works up to 6000rpm then it starts popping in the exhaust, in 2nd gear it will go to 5300rpm then it starts popping. First i thought it was the the lifters that pumped up so the valves were floating, but it was not. Then i saw that the spark plugs where a bit whiter than it should be so I changed jets in the carburetor, didn´t work. So now I think it is a electrical problem. Can it be the coil that is broken, although the sparkplugs looks good? or anything else??
 
Check the pick up in the distributor.
This is where the points use to be in the distributor.
I had a mopar performance unit start hitting in this area before and did the same kind of high rpm miss firing that you have.
Look for damage in this area.
 
T67POWER said:
Check the pick up in the distributor.
This is where the points use to be in the distributor.
I had a mopar performance unit start hitting in this area before and did the same kind of high rpm miss firing that you have.
Look for damage in this area.
Click to expand...

Okey i will look into that. but what did you do about it?
thanks Daniel
 
T67POWER said:
Check the pick up in the distributor.
This is where the points use to be in the distributor.
I had a mopar performance unit start hitting in this area before and did the same kind of high rpm miss firing that you have.
Look for damage in this area.
Click to expand...

I have a mallory unlite distributor, it is optical. the mopar performance unit is magnetic. but maybe it is the lamp in my ditributor that doesnt work under high pressure?
 
I'd agree, it sounds like it may be fuel starvation since it cuts out sooner in higher gears. You're probably emptying the carburetor fuel bowls at high rpm and need a new fuel filter, bigger fuel pump, or bigger fuel lines.

Tell us about your combo...at least the engine and fuel system.
 
Unfortunatly a standard fuel tank to a holley hp150 pump( will work up to 900hp). 8An line with a moroso inline fuel filter holley regulator barry grant 750 carburetor. The engine is stroker 408 with 450hp. 10:6 compresion. Performer rpm intake, ported j heads, tti headers, the cam:231 237 0,50 duration 560 lift.
 
73Scamp318 said:
I'd agree, it sounds like it may be fuel starvation since it cuts out sooner in higher gears. You're probably emptying the carburetor fuel bowls at high rpm and need a new fuel filter, bigger fuel pump, or bigger fuel lines.

Tell us about your combo...at least the engine and fuel system.
Click to expand...

Unfortunatly a standard fuel tank to a holley hp150 pump( will work up to 900hp). 8An line with a moroso inline fuel filter holley regulator barry grant 750 carburetor. The engine is stroker 408 with 450hp. 10:6 compresion. Performer rpm intake, ported j heads, tti headers, the cam:231 237 0,50 duration 560 lift.
 
are you getting full throttle? not that uncomon that the pedal hits the carpet before the throtleblades are fully opened,closing the powervalves and leaing out.
 
thought of another thing. maybe i have to high timing. but i haven´t herad any knocks. where should it be? I set mine on 36 degres.
 
hade about the same problem twice

first it was fuel stavation cause by a bad sending unit in the fuel tank

the second time it spark plug wire that made induction in higher rpm range
reroute the spark plug wire and made a big improvement after that I went with taylor 10.4 wire problem solve
 
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