Exhaust manifolds corroded bad.-gctid381805

[Guest]

[img]/media/kunena/attachments/vb/685310=27659-sewing machine 027.jpg[/img] Hello everyone been awhile.I just removed my manifolds and risers and iwhat is the best way to clear all this corrosion.Can I soak them in muratic acid for a couple hours to eat the rust? I have never delt with these before thanks.Oh its a 5.7 volvo

[Guest]

Get new ones. You're never going to get the manifold to riser mating surfaces to seal properly, even with a new gasket. This will cause more expensive engine problems down the road due to water leakage into your cylinders.

[Guest]

+1. They're done. That flange looks like %^$#@. Much cheaper and easier to replace the exhaust stuff than an engine.

[bhawes]

Is that the mating flange that we're looking at, or a piece of the gasket between them? If it's the gasket, remove it all with a good scraper, and see what the mating surfaces look like. You don't say when they were last changed, but you do run in fresh water, so they should last awhile. If they are salvagable, a rad shop can clean them out for you you. If you don't have enough "meat" left between water passages, to make a good seal between the components, replace them as advised.

[Guest]

Great I work with a guy who owns a rad shop, does it on the side.This boat was run in brackish and salt water in Wash State on the coast most its life then engine blown and sat over 10 years.

Eng change in the 90,s at some point to a 3970010 vette block (had to look it up)I hope a marine rebuild I emailed the rebuilder today with the ser # on the rebuild tag on the block Hitech out of Spokane I hope they can give some info.

The guy I bought the boat from never changed the manifolds on his refit attempt but must have replaced the risers they look good. I have never backed the boat in the water yet still working on it.The mating surfaces are bareilly pitted .I just removed the manifolds and risers today then took the picture with gasket material and I think silver silicone on them.I will get them welded,xrayed,magnafluxed and hydro tested if its cheaper than new ones.Exhaust ports are all black from carbon and plugs all look good, no visible signs of water entering the cylinders that I can tell at this point.

I added a small amount of dextron ATF to each cyl and manually rotated the engine with a pipe wrench its been a long time since I fired her up about 2 years.

[Guest]

I was going to take mine to a radiator shop and was told by the shop to go by some muratic acid and soak them. All the crap would come out and it's the same method they would use.

Unfortunately I can't say for sure it will work as I still have the manifolds in the shed and never tried it but I see no reason not to give it a goes so long as the flanges are good and corrosion hasn't eaten them too much.:arr

[dmcb]

Well I knew it was a salt water boat. Fresh water use only wouldn't look like that in 30 years.

When run in salt, the rust process never stops even if it is moved to fresh water. You can slow it down but you can't stop it.

You are asking for expensive engine problems. I really suggest you replace them.

I think you know you may have a problem if your rebuild isn't marine. Cam, head gasket are among the difference in a marine engine.

Don't cut corners with those manifolds. They will fail and ruin your engine sooner or later.

Doug

[Guest]

There are no options with those risers and manifolds. They have to be replaced. It is just part of boat ownership. I got 10 years out of mine in salt water using Salt Away. Bottom line is that if you try and use those - you are going to have water intrusion into your cylinders and hydrolock your engine....I replaced mine on a Merc 5.0 liter - did the work myself, and it cost me 600 bucks.

[Guest]

Prairie Puffin wrote:


http://baylinerownersclub.org/media/... 027.jpg[/img] Hello everyone been awhile.I just removed my manifolds and risers and iwhat is the best way to clear all this corrosion.Can I soak them in muratic acid for a couple hours to eat the rust? I have never delt with these before thanks.Oh its a 5.7 volvo

Wow,That is a major project you are doing.My only question is about your gas tank. Are you replacing it? They usually develop leaks after 20 years or so and it is one hell of a job to do after the boat is all back together.On your manifolds, I had mine milled at the surface where they joined the risers and cleaned them myself. It all depends how they look after cleaning. It looks like you have fresh water cooling so the engine should be ok.Great jobCheers

[Guest]

If it was mine I would dump the old and buy new ones. You are risking your engine and a big bill if you reuse them and they fail, not a good plan. Pay a little up front or a whole lot later.

[Guest]

2859er wrote:
If it was mine I would dump the old and buy new ones. You are risking your engine and a big bill if you reuse them and they fail, not a good plan. Pay a little up front or a whole lot later.

+1 on this. One boat buck for new manifolds and risers vs six or possibly more boat bucks of you get water into the engine cylinders.

[Guest]

I know the right way is to replace them but my pockets are not very deep Looks like i'm getting new ones anyway.Just finished digging a ton of rust out of the manifolds some ports were even plugged off doesn't look good I know now what destroyed the fresh water pump.I will acid bath them anyway to see how they look I hope this darn motor is marine but I doubt it.

According to the engine shop here's the reply:

Warren......you have a....71-82.... 400 ford that was re-built with all new part and was bored out to 30 over pistons.

LOL OK ......OK?

[Guest]

check737 wrote:
Wow,

That is a major project you are doing.

My only question is about your gas tank. Are you replacing it? They usually develop leaks after 20 years or so and it is one hell of a job to do after the boat is all back together.

On your manifolds, I had mine milled at the surface where they joined the risers and cleaned them myself. It all depends how they look after cleaning. It looks like you have fresh water cooling so the engine should be ok.

Great job

Cheers

Thanks,the tank was 1/2 full at one time and there was no leaks or any damage on it just surface rust on base and the inside was very clean.I primed and painted it all new hardware fittings and just cross my fingers from here.

[Guest]

Prairie Puffin wrote:
Thanks,the tank was 1/2 full at one time and there was no leaks or any damage on it just surface rust on base and the inside was very clean.I primed and painted it all new hardware fittings and just cross my fingers from here.

Usually I'm viewing this forum at work so I can't see picture albums due to firewalls. I just went through the entire album, Very nice indeed. As you know the main leak source on those tanks were pitting corrosion on the bottom. So long as that wasn't an issue you should be good to go. Again nice work.:worth

[Guest]

You can use muriatic...I have with good success before. 1/2 hour soak.

then get a machine shop to freshen up the surfaces. You need these to seal. End of story.

Chay