quote:

Originally posted by Mike Beck:
Stop wasting your time at the track and put it on a chassis dyno. Much easier and economical to work on it there.

Bingo!!!!

If I am reading correct. You have not tried changing the carb or the distributor? Is this correct?

Have any gaskets been changed? Intake gasket?

You said the engine was freshened, any possibility that the valves are not seating properly?

Quick question for the OP..
Does this car have an electric fuel pump or belt driven pump?
You say cracking and popping going down track......

I once had a belt driven pump that had a hard spot when you rotated it by hand without the belt, car was missing going down track and was down on mph... swapped pump out and it came right back to normal.
Just a thought...in case it's a possible thing to check.

quote:

Originally posted by Corky:
Quick question for the OP..
Does this car have an electric fuel pump or belt driven pump?
You say cracking and popping going down track......

I once had a belt driven pump that had a hard spot when you rotated it by hand without the belt, car was missing going down track and was down on mph... swapped pump out and it came right back to normal.
Just a thought...in case it's a possible thing to check.

Are you running any sort of inline filter? Seen many of those cause problems

I apologize if I've missed it, but as 329L suggested, have you tried a different coil? It's happened to me...and it was intermittent, which made it harder to find...

Tried a different carb today still the same problem. It is a belt driven pump.

Did you happen to make new fuel lines or replace any fuel related fittings? Reason for asking, some of this newer hose is very easy to make "flapper" when pushing the male portion of a AN fitting into the hose, therefore restricting flow. This wouldnt make any sense for being "heat related" but youve thrown alot of parts and still searching.
For the record I only suggested converter because several other parts had been tried or replaced and its an easy part to try, convertors can do weird things.
As far as rewiring, if its the original wiring, you really cant go wrong by rewiring, especially if its an 02, little expensive if done with all the new gadgets, may cure the problem and would be a nice update.
These little gremlins are a B$#&H!

Shane Carr

quote:

Originally posted by Sugar Shane:

As far as rewiring, if its the original wiring, you really cant go wrong by rewiring, especially if its an 02, little expensive if done with all the new gadgets, may cure the problem and would be a nice update.
These little gremlins are a B$#&H!

Agreed. No guarantees on wiring. Consider replacing the relay board if doing it.

Curious, what MSD ignition model are you presently using ?

Well you have tried all of the obvious so it is down to a small component (two step, chip) or wiring or a mechanical issue such as valve spring or damaged cam / lifters.

I always say check the cheap and simple things first before you start going off the deep end.
That is why I said change ignition box and a completely different carb first. Not because I did not think you can build a carb but because we are trying to narrow down problem. That did not resolve the issue.

At this point I would say do a compression test and a leakdown test to determine basic condition of motor and then let us know.

Also very likely you have a bad wire or ground some where and while they are not expensive they can be a pain to find. But before I start ripping out wiring I would determine basic condition of the motor just to get us an idea of the direction to look.

Well I have tried so many things on it I’m starting to think it may be something in the engine. This weekend it did it on every pass a total of 5. On Saturday I went 4.66@153 with my carb 1250 apd, put my uncles max speed 1250 on it and went 4:65@152. Got a friend that’s offered to put it in his car and see if it runs in his or not

Just a thought I am putting out there, based on my experience with my own car that I have owned and raced 20 years. Go ahead and rewire it. Even if you change nothing but wires and terminals. I am in the middle of doing this for the third time in said 20 years. Every 8 to 10 years my car starts acting crazy getting inconsistent and twice rewire has fixed it after checking and changing springs carbs, ignitions, etc. Just a thought.

quote:

Originally posted by jimmyc:
Well I have tried so many things on it I’m starting to think it may be something in the engine. This weekend it did it on every pass a total of 5. On Saturday I went 4.66@153 with my carb 1250 apd, put my uncles max speed 1250 on it and went 4:65@152. Got a friend that’s offered to put it in his car and see if it runs in his or not

That sounds like a lot of work but it will tell you if it is motor or wiring issue.

quote:

Originally posted by Curly1:

quote:

Originally posted by jimmyc:
Well I have tried so many things on it I’m starting to think it may be something in the engine. This weekend it did it on every pass a total of 5. On Saturday I went 4.66@153 with my carb 1250 apd, put my uncles max speed 1250 on it and went 4:65@152. Got a friend that’s offered to put it in his car and see if it runs in his or not

That sounds like a lot of work but it will tell you if it is motor or wiring issue.

Lot of work??? It takes 20-25 mins to pull a motor out of a dragster.. Just saying

Probably going to do it just to see. Hell it won’t take 3hrs total if that to be done

Put motor on a dyno then you can see what’s going on.

quote:

Originally posted by Sugar Shane:
For the record I only suggested converter because several other parts had been tried or replaced and its an easy part to try, convertors can do weird things.

as did I

What switch panel is in this car ?

quote:

Originally posted by 1320racer:

quote:

:
For the record I only suggested converter because several other parts had been tried or replaced and its an easy part to try, convertors can do weird things.

as did I

But you pounded your chest about it. Like a BABOON. I’d call you a monkey’s A$$ but it would be too mean to the monkey.

Usually putting the engine on a dyno goes for about $600 bills around here.

Can stick the pipe rack on a chassis dyno for $100-$150 for an hour or so, depending on the shop.

Either way, you are wasting your time and money testing at the track. Good luck. I fought with a distributor pickup module that randomly pulled a LOT of timing out at various times. Lots of frustration, but eventually found it. Brand new MSD distributor.

Summary of what the OP has told us...

quote:

Originally posted by jimmyc:
Was fine when I pulled the motor out last year for freshen up and made about 8 runs this year then started fluttering. Seem to me like it’s more above 6500 rpm.

• I’ve changed every piece of the msd except the distributor.
• Been over the wiring on the car also didn’t see anything there either
• Been through the valves 3 times now,
• had the carb apart nothing there either.
• New wires and plugs also.
• Tried a new battery to.
• valve springs are new.
• The master cut off switch has also been replaced
• I have changed the chips out to.
• It’s had new plug and wires also.
• crank trigger and all that has been swapped out to, even rewired from box to the eye.
• Rotor phased has been checked,
• cap button has been checked.
• disconnected alternator
• ohm coil wires and replaced coil
• swapped out ignition box
• swapped out converter
• swapped out carb



What I don’t really understand is the 1st pass I make that day it’s fine then it starts the next pass and continues on each pass. Like it’s got to get heat soaked to do it. It’s fine until it’s under a load up in the rpms.

next up swap out the engine and if that don't fix it, rewire the car and when that don't fix it, he'll change the tubing.