I'm at a loss for the flat line at 2k (without stumbling). Most rev limiters that I've bumped up against still have some rpm fluctuation as it kills cylinder sparks.

Anyhow, here's a few more random thoughts:
[1] Back to basics again, verify your timing marks are consistent with cylinder #1 TDC.
[2] Try replacing the magnetic pickup/trigger in the duraspark distributor. Perhaps the trigger is "missing" at higher rpms and is simulating a rev limiter.
[3] Better yet, try swapping with a conventional points distributor/coil system to see if the problem remains.
[4] Try opening the throttle at the carb. Once the engine tops out at 2k rpm, press the accelerator pump manualloy to see if the engine speed increases. If it does, it would indicate fuel starvation. What carb are you running, btw?

 

I doubt its fuel related...I mean it worth checking...but fuel delivery just doesnt fit in this case...if it were that lean it would surge, pop, lean out and die at WOT....It wouldn't rev up nice and wouldn't rev down with out throwing a fit either.

I just cant picture how this thing can run great and not build rpm at WOT no load....


Dude I want video of this...I want you to get it to idle then grab the throttle linkage and pull it to WOT and hold it there while you record what happens... and record a slow gradual transition to wot as well as rapid..

-Gun

 

hey gun, fwiw vacuum advance dizzys still have mechanical advances in them as well

 

all of them do or just this brand?

I got rid of my vac advance so long ago I dont remember what it looked like inside

 

yeah i know what you mean. a video would be a huge help here. a video with a vacuum gauge hooked up doubly so.

it's possible that the valves are all screwed up and it's getting enough fuel/air for idle but it runs out at 2500. I've never heard of an engine that runs "great" until 2500.

 

The crazy thing is its no load...20% throttle should be enough to get it to rev dangerously high...

 

well... i know my accel rebuilt duraspark II dizzy has both - pretty sure they all do.

 

You said in a previous post that it sounded like it had a load on it like it was in drive.

You could have a trans problem and it may be using all that power in the torque convertor just like you were power brakeing it aganst the convertors stall speed.

Try this, you say it revs to around 2000 rpm, bring it up to about 1800 for a minute or 2 and see if the cooling lines to the trans get real hot. Also check the temp of the convertor if either are very hot you have a trans problem.

 

Thats a great idea but wouldn't that cause the engine to die?

a 1500 TC powerbrake should cause the engine to stall / die at about 1500 rpm right?

-Gun

 

Do you have a drive shaft in the car right now?? The reason I ask is that if the shift lever on the trans was hit and forced out of normal position it is possiable it is no longer indexed with the shift valve in the valve body.



What can then happen is the shift valve can be in drive or reverse but the park lever is in park. This would load the engine just like you had it in drive and held the car back with the brakes.



If you have a driveshaft in the car you can usualy feel the car move either foward or reverse when the engine is first started til the park pall catches it.


If it sounds like it's making power it's got to be going somewere