Riser to Manifold Pitting and Graphite Gaskets

[SilentSeven]

Purdy!

[core-rider]

Update, after calling 15 shops, and waiting in line for my parts to get worked on for 3 weeks, finally got these milled and ready to go back on. Thanks for everyones' help/insight here.

I do want to note, they only milled 20 thousandths on each side. In order for my bolts to not bottom out, I had to add 2 extra washers (less gasket). Not sure if this was a flaw in fabrication on my manifolds, and could explain the seepage & pitting around water jackets after only 300 hours. Hopefully this helps anyone else who has similar issues.

For you to contact that many shops and most all of them say they can't do cast iron I'd have to say they just simply didn't want your work, but didn't want to say it that way. Cast iron is used in most engine parts including blocks and heads even on newer engines. For a shop to not be able to mill cast iron... how are they even a machine shop!?!

I have to think you have another issue going on if they only milled 0.0020" on both surfaces or 0.0040" total. I bet that gasket is thicker than 0.0040". For sure those washers are! Are those bind holes in the lower manifold? It's hard to tell from the pics, but I thought they went through into the water jacket meaning they should never bottom out.

[stag15]

For you to contact that many shops and most all of them say they can't do cast iron I'd have to say they just simply didn't want your work, but didn't want to say it that way. Cast iron is used in most engine parts including blocks and heads even on newer engines. For a shop to not be able to mill cast iron... how are they even a machine shop!?!

I have to think you have another issue going on if they only milled 0.0020" on both surfaces or 0.0040" total. I bet that gasket is thicker than 0.0040". For sure those washers are! Are those bind holes in the lower manifold? It's hard to tell from the pics, but I thought they went through into the water jacket meaning they should never bottom out.

core-rider Only a handful of the shops wouldn't do cast iron (more fabrication than engine machining), but the automotive shops I called did. Many of the automotive places didn't want my work, or claimed they didn't have the bracket necessary to do non-automotive work, or said they would charge me more than what a new set would cost.

I have a solid thread bottom on my lower manifolds (pic attached). Agree, the machining is not enough to make up 2 new washers worth of play. Second washer is probably just insurance, but it would be really close to bottoming out without at least 1 extra washer, i.e. the two manifolds are loose without gasket fully torqued. Likely cause to the pitting/seepage after only 300 hrs. Again, hopes this helps someone else out as it seems these manifolds are notorious for seepage (hence the rebuild kits and multiple posts on the topic), and something to check for before simply slapping a new gasket on.

[Aaren22]

How much did they charge you to mill those down?

[stag15]

Aaren22 $80/surface, so $320 total. Not sure if this was a good deal or not given no one else would even bid the work. With Summer fast approaching, I went for it (cheaper than a new set). Glad I did as the mating surfaces went together much easier, whereas before there was a visible gap between riser/lower without the gasket.