Crazy exhaust question

[HotKetchup]

OK this apparently is an odd question because I can't find anything relating to it anywhere - but I have my exhaust manifolds (log style) off my 5.7L OMC, theyre still in pretty good shape and was wondering if after I clean the rust off the inside of the water jacket with a rust removing agent like CLR or the like, is there any type of pour-in liner I can apply to the water jacket? Even a high quality hi heat enamel paint?? Fill it up the pour it out leaving theh inside coated & protected?

 

[Joshua Nichols]

Re: Crazy exhaust question

Nope not that I have heard of... Buy new manifolds if they are rusted out...

 

[wire2]

Re: Crazy exhaust question

There's a couple of products that will work well IF you get the surface super clean first. GE makes an air dry paint called glyptal. Racers use it on inner engine surfaces to smooth the sand casting irregularities, which allows oil to flow faster.
Two part epoxy paint will also do the trick.

But as I mentioned, the surface must be very clean. One way is to pour a cup of silica sand into the passages, seal the openings with cardboard and duct tape, then mechanically rotate it slowly for an hour or more. Remove the tape, pour the sand (and rust) out, flush with alcohol, blow it out, and let it dry overnight. Then reseal all but 1 opening, pour the paint in, seal that opening, and turn it several times by hand to distribute the paint. Open 1 seal, pour excess paint out, let it air dry for 12 hours.

 

[HotKetchup]

Re: Crazy exhaust question

Cool I figured there had to be SOMETHING out there for this application. NO theyre not rusted out theres plenty of life left in em. Im a jet engine mechanic by trade and ive been "programmed" to stop and prevent rust of any kind at all costs. In an application like this however its the nature of the beast.

 

[HT32BSX115]

Re: Crazy exhaust question

Cool I figured there had to be SOMETHING out there for this application. NO theyre not rusted out theres plenty of life left in em. Im a jet engine mechanic by trade and ive been "programmed" to stop and prevent rust of any kind at all costs. In an application like this however its the nature of the beast.

If you want to permanently prevent rust, install closed cooling.

If your manifolds are rusty inside and the walls are getting thin, replace them. While they'll last for years running in NON-salt water, they do eventually rust out.

The problem with exhaust manifolds and risers is that there's no way to determine when they'll rust through. It happens quicker in salt, MUCH SLOWER in fresh. (my last fresh-water manifolds lasted more than 20 years and I didn't do ANYTHING special to them)

If they rust through at the wrong time (like when you put it away for the winter) you'll have water in cyls that had open exhaust valves when the engine stopped turning.

If you have old manifolds and risers it's better to just replace them on a time basis instead of after they destroy your otherwise 'ok' engine.


ymmv.......


Rick

 

[Bondo]

Re: Crazy exhaust question

Cool I figured there had to be SOMETHING out there for this application.

Ayuh,... And ANYTHING you use in the water passages will peel off, 'n Clog the passages...

If there Was something that worked, it would be commonly used, 'n there Ain't...
It's the nature of the beast...

 

[cr2k]

Re: Crazy exhaust question

Closed cooling will not prevent rust in the exhaust manifolds. If you want NO rust then spend $3500 and get stainless manifolds.

 

[HotKetchup]

Re: Crazy exhaust question

Yes yes thats what I figured . Can someone lend me $3500??

 

[HT32BSX115]

Re: Crazy exhaust question

Closed cooling will not prevent rust in the exhaust manifolds. If you want NO rust then spend $3500 and get stainless manifolds.

Yeah....but they'll last so long that it won't matter.......