Riser to Manifold Pitting and Graphite Gaskets

[stag15]

I had some weeping at the riser gasket, so decided to install new gaskets. After taking apart and cleaning the gasket surfaces, I noticed some pitting specifically around the exhaust ports (pictures attached). Question for this community, is this okay with the graphite gaskets? The graphite gaskets are pretty thick, much thicker than any of the deformations, so I assume that it will create a mechanical barrier that molds in and around any of these deformations. Also, I went to a machine shop, but they said they won't mill cast iron...so that leaves that option out.

[NautiqueJeff]

I think you'll be fine. I'd just install everything and go with it.

[stag15]

Thank you, Jeff. That's what I thought. Haven't owned a ski boat in over 10 years, so figured I would give the experts an ask.

[SilentSeven]

What Jeff said. If I was doing the assembly on my boat...I might add some RTV high temp type sealant as a bit of an extra insurance policy.

https://www.amazon.com/Permatex-8187.../dp/B0002UEOPA

[stag15]

Silent Seven, I bought some...curious if I should or shouldn't add that with these graphite gaskets? I feel like the graphite is a mechanical bond, whereas a sealant is more of a chemical bond? I have seen a lot of posts say no sealant with these graphite gaskets.

[Smindustries]

I think you're on the right track with just putting it back together.

Liquid gasket materials are used with graphite quite often in cars. If you decide to go that route, I encourage you to place the Permatex into the nearest trash can and use Hondabond. It is the best liquid gasket sealant on the planet, bar none.

https://www.amazon.com/Hondabond-Hig.../dp/B006YTTV4W

[gary s]

You went to the wrong shop. Engine builders mill cast heads and blocks all the time. And I have never had a car with graphite gaskets and water cooled exhausts so no comment there. But it's your boat, you do what you want, what could possibly go wrong. I got this new manifold from PCM- when I questioned them they said don't use it and paid shipping both ways.

[SilentSeven]

Silent Seven, I bought some...curious if I should or shouldn't add that with these graphite gaskets? I feel like the graphite is a mechanical bond, whereas a sealant is more of a chemical bond? I have seen a lot of posts say no sealant with these graphite gaskets.

Maybe I am misinformed? I saw the pitting on the cast iron risers and my reaction was to add a very light film of high temp sealer to mitigate the pitting. If the graphite gaskets mitigate pitting by design, then that would be the way to go....

I've assembled a lot of engines but maybe better to listen to others here....

Sent from my Pixel 3a using Tapatalk

[stag15]

Gary, called three machine shops today (one is a professional race car motor builder), no one will machine cast iron? Also called a few placed in the oilfield/industrial district of town, no luck. Was hoping to go this route for cheap insurance before putting back together.

SilentSeven, read a few car/hotrod forums, they all say no sealant with graphite gaskets? Seems like cheap insurance, and given graphite being inert, not sure what harm a sealant would do? Anyone else have luck installing these graphite gaskets with a gasket maker?

[SilentSeven]

Honestly, I don't think you can go wrong either way. You have some pitting but it's not terrible. And it appears the graphite gaskets are supposed to cover some pitting.

In the end, these are risers and not too hard to access. If you have a do over, it's not the biggest deal.

If it was mine, I'd button it up without any machining and maybe add a thin layer of sealant. This is a low pressure application and I think you'll be fine either way.

Sent from my Pixel 3a using Tapatalk

[stag15]

SilentSeven That is the route I am leaning towards. Have 5 more machines shops I am going to try first, and one yesterday that was a "maybe". If no success there, I will go back to putting them together. Spring weather is already here, want to get these back together asap!

[gary s]

How do these "machine" shops deck a block or make sure a head is straight?

https://www.youtube.com/watch?v=80wgpPjGBx4

[stag15]

gary s I called 7 places today. Only 3 would do cast iron, and 2 of those said I was too small of a customer for them to take my business. The one company that will take my business is waiting on a part.

[Stevemo14]

Are you calling engine shops? All the engine shops i have dealt with when I had the old 6.Blow Diesel dealt with cast iron. I had to have the heads and the block both trued 2x.

[stag15]

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.