loses power 3500 rpm - 5000 rpm

[Steelrat]

The motor's power is intermittent. It will run fine for days or hours then loses power between 3500 - 5000rpm. Then the issue goes away for a while :confused:
Build
Engine is a .040 over 400 small block
Block is decked and drilled for steam holes
Scat 9000 crank
Scat forged 4130 5.700" Rods, ARP 8740 Bolts
Mahle pistons 10:44 compression
Competition valve train
Crane gold roller rockers
Competition Cam 284xe.
AFR 210 Heads.
Hogged out RPM Air Gap Manifold
Custom 950 Pro Series Carb
I have:
checked for burnt plug wires - none
checked rev limiter setting - is at 6000 - this type-
https://static1.pt-content.com/images/pt/2010/04/msd83645_w-1.jpg
Timing is 10 -12 base - total of 32
Checked for cracked distributor - no cracks or issues.

Is my timing too conservative, maybe go with 18-24 initial with 36-38 total.
Thoughts?

[Pro Stock]

36 degrees would probably be better but is not the cause of your problem.

[Gitter Dun]

could be a number of things, but I would probably start with fuel delivery. Check the fuel filter.

[Steelrat]

I changed my fuel log , it was about 20% blocked with crud, and I adjusted timing to 36-38 total. Made a difference...temporarily.

So took it to the shop for diagnosis. Found the timing was fluttering all over the place. Part of he mechanical advance mechanism had broke loose at the press on part of the dist shaft. It had like 40 degrees play in it . In addition to this my oil pressure has been dropping.
Last week:
1000 rpm idle - 10-12
2500 rpm- 35-40
3000rpm- 50-55

This week
0- 5 at 1000rpm idle.
18 lbs at 2500
2500 at 4000.
So if the timing was winging that far, could this have taken out a rod bearing on the mains, and explain the oil pressure slowly going down?

Car is parked and going no where.
Thanks.

[Gitter Dun]

I changed my fuel log , it was about 20% blocked with crud, and I adjusted timing to 36-38 total. Made a difference...temporarily.

So took it to the shop for diagnosis. Found the timing was fluttering all over the place. Part of he mechanical advance mechanism had broke loose at the press on part of the dist shaft. It had like 40 degrees play in it . In addition to this my oil pressure has been dropping.
Last week:
1000 rpm idle - 10-12
2500 rpm- 35-40
3000rpm- 50-55

This week
0- 5 at 1000rpm idle.
18 lbs at 2500
2500 at 4000.
So if the timing was winging that far, could this have taken out a rod bearing on the mains, and explain the oil pressure slowly going down?

Car is parked and going no where.
Thanks.

Is that all, LOL:hammer: HMMM.. oil pressure loss...Did the pick up fall off....happened to me before.

[Steelrat]

Did the pick up fall off....happened to me before.

Going to drain the oil Monday and whack the oil pan or fish through drain plug with coat hanger to see if the pick up is laying in the pan. Eliminate that at least. :confused: