Just recently had my 1964 409 (340HP) motor completely rebuilt. Rebuild included upgrade of the cam (just a little warmer, nothing radical) and a changeover to dual quads (Edelbrock) with Offenhauser jet hot-coated manifold made specifically for converting a 340HP motor to dual quads. No shortcuts were taken in the rebuild. Here's my problem: Motor has approximately 500 miles since rebuild and I continue "pushing" oil out the left side exhaust (1 quart per 100 miles) Solution offered by performance shop who rebuilt motor is that they are confident nothing went wrong during rebuild and all I need to do to eliminate the problem is change to 20W50 oil versus the 10W30 I'm using. I'm at a standstill and don't know what else to do other than change the oil and see, which doesn't seem to make much sense to me as a solution. Any and all help would be much appreciated.
Excessive oil consumption
- Thread starter dkieltyka
- Start date
I have seen this more than once. Has always been restriction in rear oil drain hole in cyl head. Pull valve cover, if you make a huge mess, then this would be the problem. Even heads that have been vatted can have this problem. Easy check though. If the hole is restricted, oil will pool above valves and overcome the seals. Try this and get back to us.
dunhamfield
Well Known Member
Mac hit the nail on the head.
Remove your intake manifold very carefully and read the gasket. Also look for oil in the intake port.
It is amazing how much oil can be sucked by a misaligned gasket.
I didnt believe it cause there was no sign of a vaccum leak and the engine ran puuuuuuurrrrrrrfect.
I replaced the intake manifold gasket and was very careful to not allow it to shift or slip while reinstalling the manifold.
I have no more smoke................
Remove your intake manifold very carefully and read the gasket. Also look for oil in the intake port.
It is amazing how much oil can be sucked by a misaligned gasket.
I didnt believe it cause there was no sign of a vaccum leak and the engine ran puuuuuuurrrrrrrfect.
I replaced the intake manifold gasket and was very careful to not allow it to shift or slip while reinstalling the manifold.
I have no more smoke................
I'm very thankful for all responses to my continuing "dilemma" - appreciate everyone's help. So far we've pulled the valve covers and everything was fine. The drain holes were clear right down to the oil pan. We also pulled the plugs and none seem to be fouling. Our next step will be to pull the intake manifold to "read" the gaskets and look for oil in the intake port. I'll let you know how I make out.
Well shoot, I didnt want to have to make this post, but it has to be done. The Offy intake does not have a shield to deflect oil from road draft tube opening. I assume you have pcv hooked up. You are pulling excessive oil from lifter valley and routing it into intake manifold. Aubrey has described his technique for fabricating a shield to the bottom of the intake. Since you have to pull intake anyway, now would be the time to add a shield. It was my thought that Offy would not make a product that had this problem, but it is indeed a problem. I solved the problem with 1 1/4 rubber expansion plug, but I have valve cover breathers, so this would not be an option for you. Recently models posted a pic. of an Offy that had a really nice looking shield. Never seen one before, maybe old production?? Aubrey never misses the oppurtunity to tell me , " I told you so." So , go ahead Aubrey and let me have it and lets get it over with. Aubrey, please re-describe your shield again for the benefit of this member.
Home made shield!
I had a puddle of oil under my car every time after i parked.
I have a offy 2x4 medium high rise intake on the 348.
There was no shield in place at the exit to the road draft tube so i made a shield myself (se attached pics). It must not be any fancy thing just a shield.
Mine is made of aluminum and sits on a couple of screw in studs with loctite.
I has worked great for me and I have no oil leak anymore.
Just mu input...........
I had a puddle of oil under my car every time after i parked.
I have a offy 2x4 medium high rise intake on the 348.
There was no shield in place at the exit to the road draft tube so i made a shield myself (se attached pics). It must not be any fancy thing just a shield.
Mine is made of aluminum and sits on a couple of screw in studs with loctite.
I has worked great for me and I have no oil leak anymore.
Just mu input...........
Attachments
Nice work, Swede...........