resurfacing ports on 6.5TD Turbo Exhaust manifold

[john8662]

Building up a few 6.5's here lately. A couple for myself, and a 6.5 for a customer.

Seems that a lot of the manifolds I've pulled off core engines or out of the truck they need to go back into aren't in good shape on the ports themselves.

I know the manifolds don't require gaskets, so the mating surfaces on the manifolds need to be good, as well as the heads. I've tried gaskets. Felpro let me down hard core on a set, the both failed in short order. I am very reluctant to use gaskets again.

I have a very talented machinist that I do business with that I presented this issue to. He'd be interested in doing it. But, he doesn't want to make a jig for the mill unless there is some interest besides me. I'd still have to come up with a big chunk of metal for the jig.

Anyone enounter this?

Still checking on making some copper gaskets though as a plan B.

J

[DennisG01]

John, I'm not sure if this completely answers your question, but...

When Ronnie built my engine, I kept the manifolds as I was having them ceramic coated. Ron said to make the mani mounting surface true as he will make sure the block is true. I took the mani's to a local machine shop (actually the back room to a local NAPA store) and he simply put them on a large belt sander. Haven't noticed any leaks to date.

[Robyn]

John
I had the same iisue with a set of manifolds.

What I did was to bolt the manifold down with the surface that contacts the head on the table.

I then lightly touched the surfaces that the bolts contact with a spotfacer and made them all the same height (at least the end ones

Next I turned up a couple round pieces with a hole though them and made them identical length.

Flip the manifold over and use the stand off's and a couple bolts to clamp the manifold down.

I then used a multi insert fly cutter and took a very light cut across the manifold contact surface that I could get to between the bolt heads used to hold the manifold.

I then carefully switched one end bolt out at a time to allow the last little portion to be cut.

As long as you keep the settings all the same and dont move stuff, it will do a fine job.

I think I ended up taking off about .030" to clean the surface good enough to be useable again.

Worked great and cost little to make the fixture.

The thing just has to be stable is all and square with the table/cutter

Indicating the original surface is not a bad plan either.

This is what I did to save a set of manifolds.

Missy

[Kennedy]

I wouldn't even consider doing one of these without taking a cut on the manifold faces.

Setup time will definitely be the hard part, but not overly complicated. What Robyn describes is what I'd suggest adding that making adjustable stand offs would be best. You wouldn't necessarily need a jig or to spot face the outer bolt face. The stand offs would slide in the slots on the mill table.

I have a local guy who does this type of stuff for me. He's quite a wiz with stuff like this and makeshift clamping etc. You should have seen the apparatus we had set up to do my LB7 Y bridge intake...

[JeepSJ]

Yep, I remember when mine showed up (bought them from a salvage yard that used to advertise here) and they were visibly twisted. My local machine shop trued them up.

[phantom309]

First set i did i did it the old fashioned way with a flat bastid file,.
second set i used my buds flwheel surfacer for a few minutes,.

Nick

[racer55]

flywheel or surface grinder is the way to go.