I'm running a heavily ported LT4 manifold on my Canfields. I am questioning whether the mounting surfaces are mating up properly. It's apparent that the intake is sucking oil from the valley, so the port floors aren't sealing up properly. How do I confirm that the intake manifold and cylinder heads are machined properly and line up exactly? Does anyone know the exact angle of the intake ports to the flat surface at the front of the engine block?

TIA.

 

Intake surface is 10* from head/block mounting face. Make sure there is enuf surface width to which the gasket can seal against.

Head mounting surfaces are 90* from one another, so front/rear surfaces would be at a 45*.

 

Why not check the top/bottom fit with feeler guages to see where you're at?

-Mindgame

 

One of my problems is that the intake and heads are so heavily ported that the sealing surfaces are almost non existent. I don't know how to fix that problem actually. My builder used a Felpro 1207 gasket but I don't think it seals nearly as well as the stock material gasket. I'm going to try an LT4 race gasket this time around if it lines up okay.

Mindgame, how do I mock up a feeler guage to measure the bottom of the port seal to the heads? The tops of the ports seal okay. I have tried spraying the top area with carb cleaner while the car is running and there is no change in RPM so it looks like it's sealing. When I look inside the ports of the heads it looks like it's pulling oil from the bottom. How do I get under there to check it out?

Thanks a lot guys.