I picked up my CJ manifold this morning from Mike (86merc) and had a few talks with how poor the final product casting looked. At that point and checking it out more, i decided to make this thread for pre and aft pics of when i clean up the runner outlets and smooth the valley at the intake mouth. I'll keep the thread updated with pics and like my last ported manifold thread will also provide dyno runs very soon. I may even have the chance to compare to a stock unit as mike also picked one up which be an awesome comparison. we will be doing a big manifold test once again coming up between a stock mani to boss to CJ to cleaned up CJ on his car this time to keep numbers consistent from gains. We also will have a few different FRPP throttle bodies to test. For now i just wanted to make a thread for before and after reworking purpose. :beer:
Drew
Prior to clean up
Started at the T body entrance by smoothing down any heavy cast lines.
One thing that i just caught as i was removing the runner gaskets is that there was a pretty good size casting lip that went above the actual manifold sealing surface. Would this of caused a problem with a vacuum leak from less pressure on the gasket, not likely, but didn't want to keep the manifold from sitting as flat as possible to the head. Took it off with a flat file across the runner flange and took off any debris left with some sand paper.
Before
After
Filled the opening void after sanding/scuffing the surface with motorcraft silicone. I choose it because it does flex slightly but is super strong and will not degrade from temps or oil/fuel contamination.
Cleaned up all the port opening as some of the casting look to of gotten shifted upon process. It created wall sides at the head flange with sharp walls that didnt line up. Also smoothed down the fuel injector housing with a lot less blend area.
Stock uncleaned port vs cleaned up port
All ports finished
Manifold done and ready to be bolted on :rockon:
Drew
Prior to clean up
Started at the T body entrance by smoothing down any heavy cast lines.
One thing that i just caught as i was removing the runner gaskets is that there was a pretty good size casting lip that went above the actual manifold sealing surface. Would this of caused a problem with a vacuum leak from less pressure on the gasket, not likely, but didn't want to keep the manifold from sitting as flat as possible to the head. Took it off with a flat file across the runner flange and took off any debris left with some sand paper.
Before
After
Filled the opening void after sanding/scuffing the surface with motorcraft silicone. I choose it because it does flex slightly but is super strong and will not degrade from temps or oil/fuel contamination.
Cleaned up all the port opening as some of the casting look to of gotten shifted upon process. It created wall sides at the head flange with sharp walls that didnt line up. Also smoothed down the fuel injector housing with a lot less blend area.
Stock uncleaned port vs cleaned up port
All ports finished
Manifold done and ready to be bolted on :rockon:
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