big block won't rev
Melting Slicks
Joined: Sep 2007
Posts: 2,429
Likes: 0
From: Tucson AZ
Sasha, I have a different though for you to check out. If you have brutal low end torque and it runs strong when cold but it just hits a wall at @ 4000rpm. Your timing chain is off by 1 tooth. I had a worn timing chain jump and that sucker ran like a duramax on steriods up to 3000rpm than nothing. Good Luck
PS if it was a fuel pressure issue it would surge. IMHO
PS if it was a fuel pressure issue it would surge. IMHOBINGO, I was looking for this to see if anyone posted this suggestion.
Folks, I think we have a winner right here.
If valves were to tight you'd get a reaction from the carb. If they were too loose, you'd hear them.
Let us know what you find????
Tank
Racer
Joined: Sep 2007
Posts: 286
Likes: 0
From: Pensacola Fla
Rev limited
Just a question,just a thought,this car does not have a rev limiter intalled such as a MSD 6 AL box has were you can change your rev limiting by plugging in different chips of different values.Again just a thought.
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
The engine would bounce off the rev limiter. Like a miss fire
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
Over the years we all have been their scratching are heads saying "Man its won't rev but it sure has some torque or Man it rune like a raped aped after 4000 RPMs"
Melting Slicks
Joined: Sep 2007
Posts: 2,429
Likes: 0
From: Tucson AZ
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
I never had that problem...but when I lashed my valves tight, it took forever to rev to 6K and strained to rev to 6.5K...when I loosened the lash by .002, all was well...
Thread Starter
Heel & Toe
Joined: Dec 2008
Posts: 17
Likes: 0
LOOKS LIKE IT MAY HAVE BEEN THE TIMING!
I want to thank everyone for there advice. Had my neighbor come over and I set the total advance to 35 @ 3000 RPM. i then checked it with the vacuum pluged in and it goes up to maybe 44. We took it for a ride and it definatly revs better, i got it to 4500. I also notiiced a slight miss now and found my number one plugwire melted on the headers and arcing. bought new wires and the miss is gone, sounds good, but it has been raining here and I can't go do a speed run.
I will update everyone when I get a chance to run it.
I want to thank everyone for there advice. Had my neighbor come over and I set the total advance to 35 @ 3000 RPM. i then checked it with the vacuum pluged in and it goes up to maybe 44. We took it for a ride and it definatly revs better, i got it to 4500. I also notiiced a slight miss now and found my number one plugwire melted on the headers and arcing. bought new wires and the miss is gone, sounds good, but it has been raining here and I can't go do a speed run.
I will update everyone when I get a chance to run it.
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Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
All concentrating on timing, weather it is just not advanced enough or even one tooth off on the timing chain, but are you sure that the secondaries on your carb are working ?
4000 RPM under load is about when they should add their fuel.
Could be no fuel at all or even simply not opening up .
Just an idea .
Good luck. Gunther
All concentrating on timing, weather it is just not advanced enough or even one tooth off on the timing chain, but are you sure that the secondaries on your carb are working ?
4000 RPM under load is about when they should add their fuel.
Could be no fuel at all or even simply not opening up .
Just an idea .
Good luck. Gunther
Racer
Joined: Aug 2005
Posts: 347
Likes: 0
From: Pace FL
Hi
All concentrating on timing, weather it is just not advanced enough or even one tooth off on the timing chain, but are you sure that the secondaries on your carb are working ?
4000 RPM under load is about when they should add their fuel.
Could be no fuel at all or even simply not opening up .
Just an idea .
Good luck. Gunther
All concentrating on timing, weather it is just not advanced enough or even one tooth off on the timing chain, but are you sure that the secondaries on your carb are working ?
4000 RPM under load is about when they should add their fuel.
Could be no fuel at all or even simply not opening up .
Just an idea .
Good luck. Gunther
A small leak in the seconday diaphram can be part of it as well. Ensure the secondary linkage opens smoothly all the way with it NOT running and then check the diaphragm if you still don't have a strong 5000+ rpm. Good luck,
Scott
Drifting
Joined: Oct 2005
Posts: 1,527
Likes: 148
From: East London/SW Essex UK
My L36 ran up to 4500 and that was it. Added headers, low restriction mufflers, Torker 2, Holley 750 DP, MSD, timing 36 degree total all-in at 2200 rpm - it was now really sharp and would rev up to 4500 rpm
OK so it would build-up under protest to 5100 rpm - but it just ran harsh. Came to the conclusion it was well past its sell by date and that the cam was a bit 'soft'.
What a difference with my new 489 the extra 1500 rpm makes
OK so it would build-up under protest to 5100 rpm - but it just ran harsh. Came to the conclusion it was well past its sell by date and that the cam was a bit 'soft'.
What a difference with my new 489 the extra 1500 rpm makes
Thread Starter
Heel & Toe
Joined: Dec 2008
Posts: 17
Likes: 0
My L36 ran up to 4500 and that was it. Added headers, low restriction mufflers, Torker 2, Holley 750 DP, MSD, timing 36 degree total all-in at 2200 rpm - it was now really sharp and would rev up to 4500 rpm
OK so it would build-up under protest to 5100 rpm - but it just ran harsh. Came to the conclusion it was well past its sell by date and that the cam was a bit 'soft'.
What a difference with my new 489 the extra 1500 rpm makes
OK so it would build-up under protest to 5100 rpm - but it just ran harsh. Came to the conclusion it was well past its sell by date and that the cam was a bit 'soft'.
What a difference with my new 489 the extra 1500 rpm makesis the 489 the cam you put in it?