Manifold & Elbow Replacement

[Tranquilo]

So I just replaced my Manifold and elbow on my LM318 with a Barr manifold and OSCAR elbow (I had to source it locally because shipping was delayed)

Surprisingly, it was really easy. I hope the other side is as easy. After inspection of the old one, I think it probably could have gone awhile longer but the elbow is definitely shot.

Question to the Chrysler Universe:

Do I need a circulating pipe / copper sleeve in the manifold if I have a raw water system? I looked at the Barr instructions that came with the manifold and it says that my setup (water comes in at the front of the manifold - exits the rear & recirculates to the oil cooler and second pocket of the pump) does not get it "or the warranty is voided.

Simple enough

BUT my existing manifold has the sleeve in it and it is a Chrysler manifold (says "Chrysler" on the side)

The guy at the Marine Supply shop said only if you have fresh water cooling.

I put it all together so it would suck if I needed one but I don't want to start it up until I get some feedback from the folks here who know what they are talking about

FOR ANYONE LOOKING TO DO A MANIFOLD CHANGE: Its easy to do, heavy and dirty but manageable. If the boat is in storage for the winter, pull it and try to take it apart so see if the manifold is still good. The elbows die first.

If you are in the water like me: Get the whole assembly, put it together first, then yank the old one. I'm in salt water so this will be needed every few years. I'll have the old ones inspected and if they are good, boil them and keep them as spares.

I'll post photos later - got to get to the store for hoses before they close for the holiday.

Merry Christmas!

D

[Fastjeff]

D:

I accidentally left out that copper tube and that side ran as cool as the other side. (Water comes in the front with my setup.) I intentionally left the tubes out from then on, and all four manifolds ran nice and cool for years.

Jeff

PS: In attaching the risers/ elbows, I STRONGLY recommend a THIN coat of silicone on both sides of all gaskets. OSCO and Barr say never to do this, but I find it's absolutely necessary to prevent water leaks.

[Tranquilo]

Perfect!

I read one of your old posts on another forum and did just that. I'll fire it up today and see what happens!

Thanks again

[Tranquilo]

Still running about 5 to 20 degrees hotter after idling but the port side manifold temps seem to go anywhere from 100 to 125, where the other side runs 95 to 110. This is after idling for about an hour.

The port side also gives off more exhaust smoke - this is likely more steam because its a bit hotter. I also installed my new Edelbrock 1409 carb. It starts up like my car now

Oil cooler was also cleaned out, new hoses as well. Strainer clear. I can't tell if that manifold is getting the same water flow as the other but its closer to the pump (dual pocket) with shorter hoses, so I thought it would get more.

I'm likely traumatized and paranoid about this issue because it's overheated 3 times in the last 6 months and I don't want to make a habit out of it

[Fastjeff]

There has to be a restriction in the hotter side--that's why the other side is running cooler (it's hogging more of the water). I suggest running the motor with the hose going to the manifolds removed--one at a time. Compare the two water flows, which SHOULD be similar.

Jeff

PS: The flow at idle is minimal so don't worry about creating a mess.