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Author Topic:   Losing power, then blaaaahhh
MThershey
Dirt Full Roller

Total posts: 36
posted July 18, 2005 06:42 AM  
Ford 351w with hei ignition. Car starts off great, then loses power steadily until about 10 laps in it just goes blaaaaahh. After a couple of slow laps, it kicks back in again with decent power. The ignition box is new, plugs are new. Could it be the coil fading? Any other ideas?

J3
Dirt Maniac

Total posts: 188
posted July 18, 2005 08:58 AM  
quote:
Originally posted by MThershey:
Ford 351w with hei ignition. Car starts off great, then loses power steadily until about 10 laps in it just goes blaaaaahh. After a couple of slow laps, it kicks back in again with decent power. The ignition box is new, plugs are new. Could it be the coil fading? Any other ideas?

Yes, coil could be getting to hot. Try replacing it and maybe even moving it farther away from a heat source. Are you running an alt? If so, sounds like it could be cutting in and out and not charging right. I have had that happen as well. It would stop charging and batt would get weak. Then it would start again. Check alt output. Not just at low R's, but high R's as well. Mine worked fine when below 2000, but over 2K it stopped charging for some reason.

Also, what carb and jets are you running. If fuel pump cant keep up, it could be just taking that long to **** her dry and starts flopping due to lack of food.

MThershey
Dirt Full Roller

Total posts: 36
posted July 18, 2005 10:06 AM  
No alternator, carb is Motorcraft 2bbl with 62's. We had 64's and it ran a little rich.

J3
Dirt Maniac

Total posts: 188
posted July 18, 2005 10:45 AM  
quote:
Originally posted by MThershey:
No alternator, carb is Motorcraft 2bbl with 62's. We had 64's and it ran a little rich.

Then I would change coil first. If problem continues, I would look at ignition box. Just because it is new doesn't mean it isn't bad. What kind of ignition, stock or aftermarket? If it is stock ignition box, make sure you are using the one with the blue gouromet, not the yellow. Yellow is bad.

Steve Dupree
Dirt Freak

Total posts: 316
posted July 19, 2005 04:15 AM  
Sounds more like a coil or fuel i am putting in my knew motor and noticed yesterday that they make two different fuel pumps for these 351w. The new one i just put on new motor was alot smaller around and had a smaller inlet hole also i think i will put the one from my old motor on. Also if you are going to try a new coil you might think of getting a new distributer with the coil in the top like the chevy dist. We really like ours. We paid 210.00 for the one we run on the race car but they make some others that are 99.00 and i just put one of those on a motor i built for a friend and it seems to be great also. Also if your rules allow you and you get that motor running drop me a line i build 2100 series carbs and ours are running 90 jets and they hall. Just drop me a line and i will send you a pic of a few. If you email drop me a line at geminikid1@yahoo.com Hope you get er going.

sc1 racing
Dirt Freak

Total posts: 419
posted July 19, 2005 08:55 AM  
how is the temp doing? ussally a fuel problem will show on the temp gauge. also could be in distributer itself. is it locked, vacum advance? also timming will cause a simular problem. ussally if timming is off it will slow down every lap when temp changes. 4 years ago was the first time i locked my distributer, and could have kicked myself for not doing it years ago..

also on fuel alot of people think if they smell fuel out of the exhaust that it is running rich, and most read the plugs wrong. id also up the jets..what do you have to loose?

MThershey
Dirt Full Roller

Total posts: 36
posted July 20, 2005 07:22 AM  
The engine runs at about 210 during the race. The dist. is locked. I just had an experienced engine guy look at the plugs after the heat race and he said they looked good. We also just timed it to 36.

roche314
Dirt Roller

Total posts: 18
posted July 20, 2005 09:34 AM  
sc1,
How do fuel problems show up on temp gauge? Lean/rich too hot/cold?

Jesterondirt
Dirt Full Roller

Total posts: 56
posted July 20, 2005 06:27 PM  
plug wires could possibly be arching to the headers/manifolds when it heats up.

sc1 racing
Dirt Freak

Total posts: 419
posted July 21, 2005 10:21 AM  
if a car is lean it will heat up almost every lap..if to rich will over heat under low speeds.

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