I have quite similar problem with my recently installed heads & cam, low power. I'll list my engine info & what I have found (not much
Here is complete specs for my engine:
- 351W .060 -78 block + "std .060 pistons"
- Performer RPM 1.90/1.60 60cc heads (new style)
- Roller rockers
- Crane Powermax 272 hyd. cam (@.050 216/228 )
- Performer 351W intake manifold
- Carter 625 carb
- Accel 300+ ignition box
- Pertronics Ignitor
- dual 2-1/4 exhaust with H-pipe
- original iron exhaust manifolds (this is no good, I know..)
- compression is bit low but it should be 9:1 or just little bit lower..
I know my car (Ranchero -78 ) is heavy and rear 2.73 is not best for acceleration but after heads & cam about all I got is that the engine spins much higher than before but I don't feel much power increase.
I have been experimenting with ignition and it seems that engine likes lots of advance, 20 initial & about 42 or more max. Due starting problems with 20* initial, I have settled down with just 12 degrees, and I have soft springs in the distributor.
Cranking cylinder pressures are quite similar before head & cam swap, about 155-160 PSI, and idle vacuum is now 16" with no vacuum advance. I had it on 18" when I had 20 degrees initial. (before head&cam 19-21" )
Next step is to put larger jets in the carb and see if it makes difference..
I can't even do burnout with my only pulling wheel now, I can't all be depending on those junk exhaust manifolds, right?
[ This Message was edited by: Jogi on 6/28/04 6:59pm ]