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lm 318 plumbing issues...

politicallycorrectcraft

politicallycorrectcraft

Member
Ok, We've sorted out the riser gaskets. Thanks again Jeff. Now we are working out where the plumbing should go on our new engine. According to the osco book,Since my engine will sit at downward angle I should feed the exhaust manifolds from the the underside in the rear of the manifolds. This will push water forward in the lower part up to the front of the manifold and up and out via the copper tubes. This will require me to add a nipple in rear port in the manifold and add block of plates on the front of the manifolds. I have two sets of manifolds and all the hardware required. It is evident to me by the rust on the front of the manifolds that it was getting a lot hotter up there and was not cooling properly. So my question is how to run hoses to the back of the manifolds. The current setup has two hoses coming from the topside of the thermostat running the front plates of the manifolds. should I run hoses from the thermostat to the rear of the manifolds? Seems like a weird bend for the hoses. Does anybody have any pics of a setup feeding the manifolds from the underside in the rear?
correctcraft 088.jpg
 
Well, if you don't solve it soon, it's just a matter of time before I get behind another one. I'll take pics for you.
 
I had gone through the post. I thought that how a head gasket is laid out. It is very possible that the head gasket is leaking between a coolant passage and an oil passage, no a cylinder. This would account for good performance and water only in the oil, not the cylinder. Oil would not get into the coolant because the pressure is higher in the coolant.
I would like to thank the members of the forum for promoting the post.
 
I'm gonna get beat up for this, but...

Previous owner removed the FWC from my 360s and went to RWC. In doing so, he simply ran the water IN at the top, front of the manifolds. Worked fine but--after working on them one day--I goofed and left out one of the copper tubes. The manifolds now cooled even better, so they are ALL gone now.

OSCO tech rep said "That'll never work!" But it does--confirmed by an infrared temp gun.

Jeff
 
PCC is using a single pocket/impeller pump..the picture from the manual, is for a dual pocket/impeller pump. I have the identical set up on my engines, one impeller for the engine, one for the oil cooler & manifolds
 
Pete, don't you think that the dual pocket pump makes for a more complicated system? I don't see why a single pump wouldn't work when the plumbing is correct for a single pump.
My preference is the crankshaft pumps by either Johnson, Jabsco or Sherwood. Any of these offer two volumes... small pump and large pump determined by the thickness of the impeller.
No belt, no belt drive side load on bearings, no pump removal required in order to change the impeller, etc.
But not all applications allow for one.

Question:
Are any of you Chrysler guys able to use the crankshaft pumps????
 
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There is no front engine circulating pump on these Chryslers (mine anyhow has none) so maybe that is why there is the dual pocket pumps. I am sure there is a way to convert to single tho, just takes some plumbing work.

Rear pocket is pump -> oil cooler -> in exhaust manifolds aft end -> out exhaust pipe.
Front pocket is pump -> thermostat housing -> block -> heads -> intake -> back to thermo housing -> out via exhaust risers or back to intake side of pump via that crazy brass 4 way connector in the bilge..
 
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Guess I hadn't consider Raw Water cooled, so I can understand that! Sort of like the old Jet Pump drive engines.
Very difficult to control and maintain engine temperature for varying loads.

But when we do a closed cooling system, you must have the engine circulating pump in place.
 
Rick...It sounds more complicated than it actually is, all I really have is 2 separate cooling systems, one for exhaust & oil cooling, one for the motor. My older engines have no circulating pumps on them, later models do & they have the single pocket pump, as for being crank driven?? not in the older engines,I have seen a fairly modern Volvo ( GM 350) with one & a friends 1976 Coronet has them too ( Volvo again) I was wondering about switching to electric??
 
Pete, the electric sea water pump poses a problem.
Whether belt, gear (as in some Diesel applications) counter-shaft or crankshaft driven, Seawater Pumps are typically Engine RPM driven as to maintain the correct flow/volume for any given engine speed.........., of which includes the exhaust cooling demands.
 
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