No power above 3500

norwmustang

New Member

May 12, 2003

15

0

0

Fredrikstad,Norway

Mar 1, 2006

#1

• Mar 1, 2006

• #1

My setup is

66 289

comp cams Magnum 280 0,512 lift

Twisted wedge heads with trick flow rocker arms 9,8 comp ratio

Performer rpm intake

Holley street avenger 670

Petronix ignitor with matching coil

Is my setup ok?

It has a fairly good low end but over 3500 almost nothing happens. It will easely go to 6000+ but with no power.

What could be wrong?

 

S

Sicarius428

Active Member

Jan 6, 2004

2,085

5

49

Mar 1, 2006

#2

• Mar 1, 2006

• #2

Possibly a fuel issue. Check your pump or fuel filter. How are your plugs?
Kevin

 

jdowen2

New Member

Dec 18, 2005

48

0

0

Mesa, Az

Mar 2, 2006

#3

• Mar 2, 2006

• #3

Need a bit more information. Does the car rev up to redline in neutral? Does it do the same thing in every gear? My first guess is the carb. Are the secondaries opening? New fuel filter? Fuel line size?

 

rbohm

Founding Member

Apr 12, 2002

6,698

550

204

tucson,az

Mar 2, 2006

#4

• Mar 2, 2006

• #4

first make sure your initial timing is set between 10 and 14 btdc with the vacuum advance disconnected and plugged.

second makesure that your total timing is between 36 and 40 degrees at around 3000 rpm.

the next thing is to make sure you have good fuel pressure, you should have 5-7 psi at the carb, and it should not drop at higher rpm.

once these are set, then we need to determine if you have a rich or lean condition. make a hard run, topping out 1st will do fine, and shut the engine off right away. then pull the plugs(assuming fresh plugs at the start of this test) and check them. if they are black and sooty, then you have a very rich condition, and you need to lean the jets down about 4 sizes to start. if the plugs are white, then richen the jets up about 4 sizes.

after all that, you need to check for restrictions in the exhaust system.

 

302 coupe

Founding Member

Mar 2, 2000

1,952

3

36

Macon, Ga.

Mar 3, 2006

#5

• Mar 3, 2006

• #5

yeah, a monkey probably crammed a banana in your tailpipe.


I agree with the others, its either a timing or fuel issue.

 

norwmustang

New Member

May 12, 2003

15

0

0

Fredrikstad,Norway

Mar 4, 2006

#6

• Mar 4, 2006

• #6

Thanx for all the input.

The timing is set to approx 37 @ 3000
It will rev easely to 6500 in neutral.
And it will go to 6000+ in first and 2nd.Not been able to try it in drive because it's winter here in Norway. But it has no power above 3500 but it will go up to red line.

The car has stock fuel lines and pump.

I have now ordered a 130 gph fuel pump and a pressure regulator,i will also change the fuel line to 3/8.

Should that be enough for my combo?

Kent

 

rbohm

Founding Member

Apr 12, 2002

6,698

550

204

tucson,az

Mar 4, 2006

#7

• Mar 4, 2006

• #7

302 coupe said:

yeah, a monkey probably crammed a banana in your tailpipe.

Click to expand...

yeah, dont be fallin for the banana in the tailpipe!

 

2nd Mustang

Founding Member

Feb 24, 2002

2,488

0

46

Southern California

Mar 4, 2006

#8

• Mar 4, 2006

• #8

All good points above, but I'll throw in a really bad example that I had. Hope it's not what you're going through. I had an engine shop rebuild an engine once. It idled really well, good torque in lower gears (4-speed manual) but just about died in fourth gear on the freeway. It would barely do 40 mph in the slow lane. I checked all the usual, etc. One odd thing was it was dropping oil out of the crankshaft cover. Took it back twice to the shop and they kept saying nothing was wrong. They obviously didn't take it out on a road test. I had a second shop tear the engine down and check. The first shop had installed the wrong size crankshaft bearings!

Good luck.

 

69Rcode_Mach1

Active Member

Apr 20, 2004

1,473

1

37

Salt Lake City, Utah

Mar 4, 2006

#9

• Mar 4, 2006

• #9

Oil pressure could also be another culprit. Make sure to check that out as well.

 

norwmustang

New Member

May 12, 2003

15

0

0

Fredrikstad,Norway

Mar 5, 2006

#10

• Mar 5, 2006

• #10

Maybe i have an oil pressure issue also
Because when i have about 2800 revs on the highway my oil pressure is good, but when i increase to about 3000 it will drop to zero.According to the original oil pressure guage. I have thought that it was just a faulty gauge.

I have installed a dakota digital instrument panel some weeks ago,i can check if the same happens with the oil pressure.


When i changed the oil pan on the car a while ago. i took apart one bearing on the chrankshaft,it had some wear on the bearing and crank. I saw that the bearing was 0,30 oversize. Is this the maximum?