I've put together practically every type of engine imaginable (340's, 440's, stroker 440's, Kawasaki 2 stroke, Briggs and Stratton...), But this current one has got me scratching my head and I'm wondering if anyone has any opinions.
Details:
472 Hemi (build 1.5 years ago with about 2000 miles on it)
Aluminum MP (old style) heads
Single 4 barrel Mopar intake
9.5 comp (Same pistons as the crate motor-Wisco?)
Moly rings, low tension oil rings
This thing has given me fits all year. I finally got it to run great, but in my opinion it's using too much oil (I haven't got an exact figure, but a good guess would be a quart every 500-800 miles. It seems to vary) I've never built an engine that used this much oil.
I dynoed the engine when it was build. It made 605HP and didn't show any signs of trouble. I used the old Rotella T and EOS to break it in.
After a while I notice the engine would ping a little going up a hill in fourth and was also seeing an thin oily-carbon film in the left tail pipe and and mostly carbon in the right. I also noticed that when you first start it up, the left tail pipe would show some exhaust (very slight but noticable, whitish grey like condesation, mostly out of the left side in pulses like it's from 1 or two cylinders. After 5 minutes of running the smoke is barely visible). This was after switching to Joe Gibb 10W30 Hotrod oil.
I pulled the intake and found it was leaking. Resealed using a .060 Mopar gasket and permatex No 2, lowered the timing to where we had it on the dyno (31 total). I replaced the oil with GTX Diesel 15/40 (SL/CI rated. Engine ran a lot better, no more pinging. The oily film seemed to go away, but later re-appeared.
I did the intake again with a Mr. Gasket gasket set and used Hylomar blue on both sides of the gasket.
The film/slight smoking persists. I did a leak down and got 3-6% on all cylinders. A couple of the plugs (1,4 and 6) seemed darker but there did not seem to be wet oil on them (a bit on the threads and the at the weld on the ground strap but none on the tips). The plugs have never fouled out (NGK FR5).
I pulled the breather and PCV off and there are only slight intermittent wisps of smoke out of the valve covers when the engine is running and warmed up. I also changed the left bank valve seals.
The engine runs awesome other than the oil dissappearing. There is no great cloud of smoke following me around. Some suggest there must be an intake/head mismatch.
I really don't want to pull this thing and rip it apart, but if I have to I will. I just can't see it being the oil rings being bad or not broken in.
I know I sealed the head studs that bolt into the bottom of the intake ports and the intake bolts are torqued as per the manual. I do have eagle rods in this and there is .035" gap between the rods. The oil pressure is at
70psi@2500 rpm and 40psi at idle (1000 rpm). I can't see it being the PCV as both tail pipes would show the same thing (PCV connected to carb).
I'm stumpped. Any other opinions?