Exhaust manifold removal

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bcassedy
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Re: Exhaust manifold removal

Postby bcassedy » Fri Apr 26, 2019 3:07 pm

Since you have the manifold removed and it's loaded with rust you could try Jeff's process of "rodding them out". I'm not sure of the process tho I suspect it entails using a stout screwdriver(?) to carefully dig out / scrape surfaces of the rust in all passages in the manifold. This might prevent you from having to purchase new ones. It may not be necessary but sand / soda blasting would ensure you got all the rust.

Jeff, am I off base here?

Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only

ddependo
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Re: Exhaust manifold removal

Postby ddependo » Fri Apr 26, 2019 4:14 pm

I taken mine to a radiator shop. Have them acid dipped or whatever they use.
Wayne
1973 32 express fly bridge
Chattanooga
"Southern Lady"

jralbert
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Re: Exhaust manifold removal

Postby jralbert » Fri Apr 26, 2019 4:44 pm

As some here know I am not an engineer mechanic you name it guy (Jeff will issue the correct verdict) but I am pretty sure if enough rust has accumulated to clog a manifold and/or riser, it came from the inner surfaces of those parts. Meaning, that the parts have been compromised, thinned out and subject to more easily burst. (and, yeah, if one is bad, the others of the same age may be just as bad also).
I guess one could knock all around with a hammer to see if there is a "breakthrough". Maybe, there are other ways to test soundness I'm not familiar with.
But if the manifold is of a certain age, having served well to this point, would it not be smart to ditch it? Call it insurance.
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

Fastjeff
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Re: Exhaust manifold removal

Postby Fastjeff » Mon Apr 29, 2019 7:19 am

Joel is an honorary engineer of good standing.

Careful knocking of cast iron with a ball peen hammer can indicate wall thickness, but plan on replacement anyhow.

You could block off the water passages and pressure test it, but... (See above.)

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

barkleydave
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Re: Exhaust manifold removal

Postby barkleydave » Sun May 05, 2019 7:35 pm

For reliability replace them all.... I know it hurts... but welcome to boating!

Mine are fine but dreading when it is time. I no longer can do that kind of work so Ouch.... at the mercy of the marina.

I have dreams of new crate engines with closed cooling !
1987 Marinette 29 FB Sedan
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain

Fastjeff
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Re: Exhaust manifold removal

Postby Fastjeff » Mon May 06, 2019 5:47 am

Good advice. Getting water in can wreck the motor on start up.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

legendlc
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Re: Exhaust manifold removal

Postby legendlc » Mon May 13, 2019 2:17 pm

Okay here goes the noob questions. I am trying to determine the water path through the exhaust. I have the manifold log style that has the water flows from the top not the front plate. Then it runs the length of the manifold and the next part is the spacer that has the water jacket blocked so water exits the top of the manifold i assume? downstream from the spacer with no water carrying ability is the lower elbow that is at a roughly 90 Degree up angle. This has a water inlet/outlet hose connection on each side and the water jacket is open. Then the upper swivel elbow that has the water jacket on the end mating to the lower elbow and the other end has a insert and outer cast portion. Here is the question...does water flow between the cast portion and the exhaust insert/portion? I am trying to replace mine and t is roughly half open and water flows between them but the other half is closed and it doesn't seem like rust etc i cannot rod it out scrape it out or drill it out. I am looking online and have seen used ones that look totally sealed between the exhaust and cast portion where the exhaust bellows connect and all the new ones for sale do not show pictures of that end. I wasn't sure if there were different options for closed cooling or raw cooling or if they should be 100% open all around or partially etc. Any advice will be appreciated.
1978 37 Double Cabin
Lake Cumberland KY

jralbert
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Re: Exhaust manifold removal

Postby jralbert » Mon May 13, 2019 3:53 pm

I'm trying to attach the Chrysler engine manual I saved. Engine cooling flow systems are described on pps 5-8. Maybe you'll be able to make better sense out of them than I can and I hope the info attached in this pdf is helpful (note- after writing this, I could view the file, at least part of it, good luck): [UPDATE NOTE: the manual was aboard my former 1988 boat so it may have been current, say, circa 1987. The notes in the manual were made by the original owner]
Attachments
ChryslerEngine.pdf
(1.43 MiB) Downloaded 114 times
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

EWRice
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Re: Exhaust manifold removal

Postby EWRice » Tue May 14, 2019 11:32 am

Be carefull with chrysler service manuals unless they are the latest edition. I have an original (around 1985ish) and there are more pages of updates and tsb than the original manual. There are at least 10 pages of tsb on the early cooling systems alone.
Muskegon Lake
1972 32' Express flybridge
"AL13"
Twin 318s
On board air & prime 920
1963 Thompson Super Sea Lancer
Graymarine 327
1961 Alumacraft 12'
'55 10hp Johnson

legendlc
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Re: Exhaust manifold removal

Postby legendlc » Tue May 14, 2019 12:02 pm

Oh boy lol It is very confusing for certain. I was looking this morning and found several examples of the log style manifold with the lower elbow and upper swivel risers (like I have) and the upper swivel riser had 1 water inlet coming into it and the lower elbow had a hose not sure if in or out. Mine has no water lines connected to the upper swivel riser but two on the lower elbow. I am not sure what is correct. Sounds like a call to marysville marine or something to see if the PO had the hoses correct. Appreciate the help and the manual I will keep digging.
1978 37 Double Cabin
Lake Cumberland KY