Engine falls off above 5000 rpms

[ullose2]

I have a 350 with holley alum. heads, a lunati voodoo cam, 750 double pumper, MSD 6A box, Blaster 2 coil, Pro-billet dist. 8.5mm super conductor wires, and then engine just falls off from 5000 rpms on up. It feels and sounds like the motor is hitting a rev limiter or something, but i dont have one. i talked to the MSD tech guys and they said to make sure that the green and purple wires on my box arent routed near anything, and to make sure my timing isnt fluctuating at the higher RPMs. Also, it only does this under load. When its in neutral it revs just fine. I am going right now to look into this, but i was going to see if you guys had any thoughts or past experiences with something like this. thanks alot.

heath

[68sixspeed]

Valve float? Just a thought, but what are you using for springs?

[ullose2]

I thought about valve float but it doesnt feel like that, plus I got the springs recomended by lunati for that cam. I am gonna check this other stuff first and if worse comes to worse I geuss i will have to look into that.

[69muscle]

could be a fuel problem if not valve springs

[Vegas69]

Jetting may be your issue.

[DeltaT]

I would do a fuel volume test - see how long it takes for your fuel system - after the regulator - takes to fill a 5 gallon jug up to the 1 gallon line. 5000 is too low to have valve springs floating since you specced the ones Lunati recommended - if they sent the right ones.\

Jim

[ullose2]

Sorry for the delayed reply. I dont know how i could do the fuel volume test b/c i have a mech. pump. Is there some other way to make sure the pump is up to the task. I think its supposed to be a 190 GPH pump, and I have the regulator set to 6 psi. Also, if it helps with diagnosis if I run it slowly up to and past 5000 it seems to do a little better, but I was thinkin this was because the drop in power was less noticeable because I wasnt in the throttle too much. Dang this is confusing.

I think the jet sizes i am running right now are 82 in both the secondaries and primaries. I thought this would be alittle much, but sense the engine was running lean before the rebuild and making less power, i would take it up 2 sizes and hopefully start rich and bring back down.

[ullose2]

Sorry for the delayed reply. I dont know how i could do the fuel volume test b/c i have a mech. pump. Is there some other way to make sure the pump is up to the task. I think its supposed to be a 190 GPH pump, and I have the regulator set to 6 psi. Also, if it helps with diagnosis if I run it slowly up to and past 5000 it seems to do a little better, but I was thinkin this was because the drop in power was less noticeable because I wasnt in the throttle too much. Dang this is confusing.

I think the jet sizes i am running right now are 82 in both the secondaries and primaries. I thought this would be alittle much, but sense the engine was running lean before the rebuild and making less power, i would take it up 2 sizes and hopefully start rich and bring back down.

[ullose2]

Sorry for the delayed reply. I dont know how i could do the fuel volume test b/c i have a mech. pump. Is there some other way to make sure the pump is up to the task. I think its supposed to be a 190 GPH pump, and I have the regulator set to 6 psi. Also, if it helps with diagnosis if I run it slowly up to and past 5000 it seems to do a little better, but I was thinkin this was because the drop in power was less noticeable because I wasnt in the throttle too much. Dang this is confusing.

I think the jet sizes i am running right now are 82 in both the secondaries and primaries. I thought this would be alittle much, but sense the engine was running lean before the rebuild and making less power, i would take it up 2 sizes and hopefully start rich and bring back down.

[ullose2]

Sorry for the delayed reply. I dont know how i could do the fuel volume test b/c i have a mech. pump. Is there some other way to make sure the pump is up to the task. I think its supposed to be a 190 GPH pump, and I have the regulator set to 6 psi. Also, if it helps with diagnosis if I run it slowly up to and past 5000 it seems to do a little better, but I was thinkin this was because the drop in power was less noticeable because I wasnt in the throttle too much. Dang this is confusing.

I think the jet sizes i am running right now are 82 in both the secondaries and primaries. I thought this would be alittle much, but sense the engine was running lean before the rebuild and making less power, i would take it up 2 sizes and hopefully start rich and bring back down.