Help - 496 Tripower burning oil
Thread Starter
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
Help - 496 Tripower burning oil
So, been fighting with my 1500 mile, 496 tripower setup.
Drove it to work today and noticed increasing amounts of gray/blue smoke coming from the sidepipes at idle and when I revved the engine. Got home and checked oil. 1+ quart done in less than 100 miles.
Step 1. Pulled plugs. 6 of 8 look good. #4 was oil fouled and #1 was badly oil fouled. Thank god for MSD 6A box.
Step 2. Quick compression check. #4 first, 200 PSI, #2 as a control, 190 PSI, #1 180 PSI. Battery was starting to get weaker I am sure as I went along. This was good news since I had bounced the tach off the 6k rev limiter in 2nd gear this past weekend.
Step 3. Pulled carbs off. Found a lot of dirty, oily gas in the lower part of the dual plane intake. I can attribute the gas to the accelerator pump getting worked as I removed the carbs (all three of my carbs have accelerator pumps (Holley 4782, 4783 mechanical Six Pack carbs)). Also found a piece of what looks like gasket material in the manifold under the front carb.
Tomorrow after the car cools down, I am going to drain the radiator and pull the intake manifold.
Heads are Dr. J Airwolf 305's which are heavily ported Edelbrock RPM heads. The intake ports are matched to a Mr. Gasket 107 which measures 1.85 x 2.16 port size. I am using a 3937795 oval port tripower manifold with some light porting. I am wondering if I am getting a good seal at the bottom of the port and that the gasket is getting sucked into the port causing a massive oil leak. I did not want to get a rectangular port manifold and deal with epoxy etc to do the port match but I am wondering if the oval port is not deep enough to seal well.
Here are some pics:
Mr. Gasket 107:
Oval port manifold:
Rect port:
I was trying to avoid this:
And this:
I really want to stick with the tripower setup for now with all the $$$ I have invested. I am thinking of selling everthing that I have right now and getting the FB Thottlebodies EFI tripower setup. They use a reworked Edelbrock dual quad manifold so it should have more meat to seal the bottom edge. Oh, and want to stay under the stock '75 hood.
Thoughts? Ideas?
Drove it to work today and noticed increasing amounts of gray/blue smoke coming from the sidepipes at idle and when I revved the engine. Got home and checked oil. 1+ quart done in less than 100 miles.
Step 1. Pulled plugs. 6 of 8 look good. #4 was oil fouled and #1 was badly oil fouled. Thank god for MSD 6A box.
Step 2. Quick compression check. #4 first, 200 PSI, #2 as a control, 190 PSI, #1 180 PSI. Battery was starting to get weaker I am sure as I went along. This was good news since I had bounced the tach off the 6k rev limiter in 2nd gear this past weekend.
Step 3. Pulled carbs off. Found a lot of dirty, oily gas in the lower part of the dual plane intake. I can attribute the gas to the accelerator pump getting worked as I removed the carbs (all three of my carbs have accelerator pumps (Holley 4782, 4783 mechanical Six Pack carbs)). Also found a piece of what looks like gasket material in the manifold under the front carb.
Tomorrow after the car cools down, I am going to drain the radiator and pull the intake manifold.
Heads are Dr. J Airwolf 305's which are heavily ported Edelbrock RPM heads. The intake ports are matched to a Mr. Gasket 107 which measures 1.85 x 2.16 port size. I am using a 3937795 oval port tripower manifold with some light porting. I am wondering if I am getting a good seal at the bottom of the port and that the gasket is getting sucked into the port causing a massive oil leak. I did not want to get a rectangular port manifold and deal with epoxy etc to do the port match but I am wondering if the oval port is not deep enough to seal well.
Here are some pics:
Mr. Gasket 107:
Oval port manifold:
Rect port:
I was trying to avoid this:
And this:
I really want to stick with the tripower setup for now with all the $$$ I have invested. I am thinking of selling everthing that I have right now and getting the FB Thottlebodies EFI tripower setup. They use a reworked Edelbrock dual quad manifold so it should have more meat to seal the bottom edge. Oh, and want to stay under the stock '75 hood.
Thoughts? Ideas?
Race Director
Joined: May 2006
Posts: 18,740
Likes: 2,583
I'm not clear on something, you state you are using a version of Edlerock RPM heads but they make both oval and rectangular. Your intake is oval, your gasket is square, so what are the heads, if not oval how is this supposed to work?
Le Mans Master
Joined: Dec 2006
Posts: 5,557
Likes: 9
From: Oquirrh Mountains
St. Jude Donor '09
Are these the gaskets you used or the MRG 107's? If so, that's you're problem. The embossed areas of the blue gaskets are designed to seal against the surface of a regular GM oval port head. The "roval" ports on the edelbrock heads are bigger than the embossed area and will result in a leak at the corners since there's nothing to seal against - that's why you're sucking oil.
Notice the rubber embossed areas on these gaskets are MUCH bigger than the embossed areas of the blue gaskets in your pictures. These are Mr Gasket 5827 intake gaskets for reference. Edelbrock also makes a similar gasket with rubber embossed areas around the ports. I would give these a shot.
Notice the rubber embossed areas on these gaskets are MUCH bigger than the embossed areas of the blue gaskets in your pictures. These are Mr Gasket 5827 intake gaskets for reference. Edelbrock also makes a similar gasket with rubber embossed areas around the ports. I would give these a shot.
Last edited by Ben Lurkin; Apr 26, 2013 at 01:20 AM.
Thread Starter
Race Director
Joined: Jun 2000
Posts: 10,046
Likes: 675
From: FL
Ben, I actually used the 5287 on the last intake swap. When I pulled them, the manifold surfaces were slick with oil. I will either use the 107 or the 117 which is thicker when I reassemble. Right now I am trying to decide if I want to stick with oval port tripower or find a rect port manifold. Maybe efi.
