AQ271 Full System HX install questions

[Scott Danforth]

Ok, so now the boat is in Florida with me. I have to clean all the road grime out/off the boat as well as take care of a few things prior to dropping it in the water.

one of the things that I will be doing is installing a heat exchanger. I contemplated a half system, already went the thought process of a V104 SJE kit, however there is no overhead capacity in the HX according to San Juan.

A custom HX would be required. So I called my former employer down here and am now looking at a custom HX,
however going to go with a full system since I would rather just replace risers than complete exhaust manifolds Having a custom 5 x 22 4-pass system built. It will have some room for tweaking the motor a bit more.

here is the dilemma. From what I can tell, the VP risers for the 80-93 V8's did not have a boss for plumbing the HX seawater discharge to. A block-off plate will be easy (have access to laser and plenty of 316L)

Is there an aftermarket riser that has a boss cast in place for plumbing? The Osco manifolds appear to have a thicker flange that may work, however I would like to find a set of risers that have a boss specifically for the purpose of plumbing.

CMI's are still a thought, however that will have to wait until spring.

 

[Don S]

Re: AQ271 Full System HX install questions

Can't help you with the riser question, but don't forget about the thermostat housing. The one for the half system is different than full system. You need some extra opening.

 

[Scott Danforth]

Re: AQ271 Full System HX install questions

Agreed, was going to use the current T-stat housing from the sea-water cooled setup, leave the manifolds plumbed the way they are to the T-stat housing discharge, however pull the warm coolant from the rear of the manifolds and tie back into the HX at the same point as the discharge from the thermostat. that should keep the manifold coolant constantly circulating and the block t-stat controlled. I will need to run a vent line to the top of the manifolds to prevent an air pocket. I still have to come up with the right sized surge tank / deaeration tank (10% draw down, 7% expansion) May end up making one.

 

[Scott Danforth]

Re: AQ271 Full System HX install questions

ok, so I have a heat exchanger, a plan for both a full system or a half system. it will depend on what I find when I pull the manifolds back off to machine the ports. if there isnt enough room for adequate water flow, then I will go half system with a neutra-salt injection system. if there is enough room in the castings, then I will go full system.

I am also waiting from CMI for the flow rate capacity of their E-top's

 

[Scott Danforth]

Re: AQ271 Full System HX install questions

Went with half system installation for a few reasons:
e-tops would have too much restriction running glycol thru them
and I wanted to go boating this weekend and couldnt wait for the other parts to show up.

HX installed.

issues to attend to:
need to re-tap the threads on the lower block drains. Starboard side has a bad lead thread and had to force the plug in. it drips a bit.
using the anti-freeze jug currently as the overflow tank. need to pick up a cheap plastic overflow tank
going to install a neutra-salt injector for keeping the HX and exhaust manifolds as good as can be.

however engine quickly warms up to 160 and stays there.

 

[captmello]

Re: AQ271 Full System HX install questions

In the past, I've seen posts saying that adding a closed cooling system in a used engine was not a good idea. The reason was that sediment in the used engine would clog the heat exchanger. Clearly you're not a novice. What is your take on this?

Boating this weekend??? I'm jealous.

 

[Scott Danforth]

Re: AQ271 Full System HX install questions

since I had the motor out, not much sediment in the engine as most of it was on the floor when I had the heads off and pulled the pan to put the high volume pump on. plus, you have to flush the block as part of any HX installation on a used motor.