Does this sound correct ?
Thread Starter
|
Senior User
Joined: Aug 2004
Posts: 498
Likes: 0
Does this sound correct ?
i have a 352 with a holley 500cmf 2 bl on the stock 2bl intake, dual exaust, i have recurved the distro getting 8* in the distro for 16* total i have it set up to et a total mec advance of 36* in at 2600 rpm. my fuel pressuere reads 4.5 lbs running at idle and 4.9 at 2600. I have a 8.5 power valve, heres wher it et's interesting, I am running #76 mainjets, It runs good i ave a gob of low end tq, and can pull the large hill near my home in overdrive with no problem. it is smooth and responsive up to about 3000 rpm and start's to fall on it's face, no problem realy cause with the overdrive I cruse at 70mph at 2150 rpm.
does this sound correct? 76 jets sre pretty large, and the CMF is probaly to much for the manifold, do I have just a realy good breathing motor, or is it poss I have a vacum leak somwhere ? Vacume is staday at idle at 18 lbs, like I said it has a lot of tq, want to break the tires loose when I let in the clutch. but gas milage is like 8mpg .
oh it's in a 1966 F100 with 3.54 rear and 3 speed overdrive trany.
what do you guy's think ?
does this sound correct? 76 jets sre pretty large, and the CMF is probaly to much for the manifold, do I have just a realy good breathing motor, or is it poss I have a vacum leak somwhere ? Vacume is staday at idle at 18 lbs, like I said it has a lot of tq, want to break the tires loose when I let in the clutch. but gas milage is like 8mpg .
oh it's in a 1966 F100 with 3.54 rear and 3 speed overdrive trany.
what do you guy's think ?
Thread Starter
|
Senior User
Joined: Aug 2004
Posts: 498
Likes: 0
Yes I bought it new in a box, it had #74 jets and a 4.5 power valve from the factory, I had to up jet as it was running to lean ( reading the plugs ) now the color is light brown, befor it was white. It's a holley holley not a ford Holley.
Post Fiend
Joined: Mar 2004
Posts: 6,056
Likes: 8
From: Union, Washington
The jets are not enough bigger to cause a real problem and anyway they only limit actual fuel flow at or near WOT. I knew it was a Holley, Ford never had a 500 CFM Holley on any of their engines. The carb should handle the engine to about 5000 rpm. I don't think the carb is your problem unless you have a vacuum leak, 18 for this engine isn't all that great. I assume this is a points dist. and if you are running regular fuel 36 degrees is a little much. I back down to 30 to 32 degrees. Check the dwell as if its wrong it can cause this problem. A bad coil can cause this also or even a condensor. Try running a jumper wire from the battery to the + side of the coil (the terminal the dist. is NOT connected to. This will give you full spark that the system is capable of. If it cures it you have a ignition problem.
Thread Starter
|
Senior User
Joined: Aug 2004
Posts: 498
Likes: 0
Thanks for the reply, I run midgrade fuel 89 oct, The ing is a pertronic's unit with a MSD blaster2 coil.Spark is fat and blue, So 18 is not good vacum at Idle ? could this this mayby indacate a vacum leak ? i have sprayed around the edges of the intake with carb cleaner and watched the tach and have seen no change in RPM, is it poss to have an internal vacum leak of some kind ?
Lead Driver
Joined: Apr 2001
Posts: 6,175
Likes: 21
From: Texas
vacuum sounds good to me.
The fuel pressure seems a little low (but I'm used to looking at electric pump numbers now). Have you checked to see if the fuel pressure drops off after spinning the engine fast for a while? Check the fuel filter and plumbing for any restrictions.
I realize I run a very different setup, but it sounds a bit like a fuel starvation I was just troubleshooting, especially if it's running as good as you say on the bottem end.
The fuel pressure seems a little low (but I'm used to looking at electric pump numbers now). Have you checked to see if the fuel pressure drops off after spinning the engine fast for a while? Check the fuel filter and plumbing for any restrictions.
I realize I run a very different setup, but it sounds a bit like a fuel starvation I was just troubleshooting, especially if it's running as good as you say on the bottem end.
