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LM318 Cooling System

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Jeff H

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I have restored twin 1978 LM 318 raw water cooled inboard engines. The original raw water plumbing was incomplete. I have fabricated a new fiberglass T connecting the single pocket pump, circulation pump & thermostat housing. I would like to know if the plumbing I have installed is similar to the original cooling system? The service manual/bulletins fail to illustrate this topic. Thanks for any info!
 

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Hey Jeff – you weren’t afraid of the blue paint huh?!?!

The plumbing appears to be correct……but I’m sure someone else will confirm. I tried to compare to a picture of my motor but, as you can see, the factory configuration was a bit of an oddball…..with water running into the tail end of the exhaust.

BogdenZ ("Buehler Jet" on the old forum format)
 

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The water can come in the back like that IF you have the copper tubes and IF their opening is in the front.

Jeff
 
Those motors look nice!I got FWC and wondering if I need the copper tubes, when I took the old BARR marine manifold off it didnt have it .Its a V-drive so? fastjeff,yours is straight drive right?I read the osco report but its throwin me for a loop

Who do you guys recommend for Intake manifold gaskets?
 
If those are OSCO manifolds, and you're putting the water in from the rear, then you need the copper tubes (open in front) to circulate the water properly. If not, the water will short-circuit out the back and you''ll fry the front of the manifolds. Alternately, you can put the water in the front of the manifolds without the copper tubes, and let it flow through and out the back--mine are done that way.

Any good intake gasket will work, but DO NOT leave out the little metal plates.

Jeff
 
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Thanks for the updates. I ran both on the shop floor at length at a high idle & it appears that the water is traveling from the raw pump through the top of the thermostat housing and directly to & out the exhaust. Does not appear to be sufficient water flow up through thermostat/housing. Temp. at thermostat area is 135-140 & near 200 at intake manifold cross-over; exhaust outlet water is cold. Is this normal with this cooling system not under a load?

Jeff
 
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Jeff H - I'm a little suspicious about how the fabricated T's might be impacting the flow......especially the t-stat housing. The design may be more conducive to directing flow to the exhaust manifolds and not enough to the intake.

It might be worth asking some board members to post pictures of the fronts of their RWC engines. Mine wouldn't be much help because of that rear-of-the-manifold set up.
 
This forum setup is dissapointing but anyho

Jeff h how bout some touch up on that alternator pulley bolt
Bogdenz Jet where do I get those fine braided cooling lines?
FastJeff -got the copper tube and my water comes in the rear(flywheel)lowest point and exits pullley side(front) that tube seems to be not needed as if I put it in the water will mostly shoot out without cooling
 
On a normal (non-Vee drive) installation, the water either comes in the front and goes out the back (without the copper tubes) OR the wter comes in low from the back, flows forward, enters the openings on the copper tubes, then out the back.

Jeff
 
Greasemonkey - you can find those braids at most auto parts stores. I think I got mine at Pep Boys. It's just the braiding itself......which slides over your existing hose. The primary reason I bought it is becuase my old hose was in good shape but looked really bad (paint, etc.).

Fastjeff - after rereading my previous post, I could have phrased it better. What I was questioning was whether the design of the two fabricated T's is getting proper flow through the intake (evacuating it). Although I'm struggling to compare Jeff's picture to a mental snapshot of my set up, I wonder if the T at the pump could be counteracting flow out of the intake (which may already be weak because of the design of the piece over the t-stat).

I suppose the obviuos question could also be asked.....is the t-stat working properly.
 
Fastjeff-I know its fun messin with the new guy and I would enjoy it as well!U never aswered bout the Napa hat.Was that a micheal Waltrip edition or Ruetimann or truex?

Andrew -you have to log in evertime you click something and pictures arent full size and already up

I like the old format where I hang out with my fellow mopar muscle heads and not those outties

Just easier to post and navigate

This format is causing our fearless leader to give suspect advice on copper tubes ,U see hes got a straight shaft and I got a vee drive his timing chain is where my flywheel supposed to be,No whatta mean

When Fastjeff aint happy the plugs aint firin on all cylinders
 
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