gofast53

Have an ASP .46 in a 41"vee hull and previous owner has modified it for crankcase cooling. There is an extra plate with two nipples (inlet and outlet) attached which is screwed on (and sealed with silicon) with the crank case cover to the back of the motor. As the crank cover recesses in by attaching the extra plate with nipples you have quite a large chamber area which can be circulated with water.
Does anyone know if this is a common mod and is it really required, or would the standard water cooled head be sufficient?.

Have had motor running and head temps (taken from around glow plug) are between 140 -150 F. Reason I am asking is that I have just purchased a new ASP .61 to upgrade my vee hull with and was wondering whether I should do the same mod to it as has been done to the .46. Hull is quite deep and has very little air cooling.

Tim Wiltse-RCU

I have never heard of it before!

LAter,
Tim

BB Modss

Id really like to a see a picture of this. Iv done so many mods that look cool but have no use, this engine is just a must have in my collection.

BB Modss

I sent you a privet message CARIMALI

gofast53

Mod is very simple, if you look at the back of the engine, the crank case (which is held onto the engine block with 4 screws) recesses inwards to the crankcase. All you do is make a thin plate the exact shape of the crank cover, drill two holes and thread in a couple of nipples (one for inlet water tube other for outlet tube) a distance apart. Remove crank cover screws and place manufactured plate onto crank cover (smear silicon between plates close to edge) and tighten screws.
My .46 engine block is kept cool during running, at this stage not sure what affect it has on motor performance which is why I started this post to find out from other members their thoughts.
Works well in my case as my hull is quite deep and has very little air circulation, but will do some further testing on temps with crank cooler connected and then disconnected to see what differences or advantages there are.
I have seen magazine pictures of some older marine engines where this mod is standard during production by the manufacturer.

jetpack

My Feedback: (1)

OS MAX used to have that same feature on its marine versions. Its primary function is to cool the intake charge cooler than air tempurature. It does draw some heat out of the lower portion of the case.

The benifit is debatable due to the intake charge is already chilled from acceleration, so what is colder? Water tempurature or the intake charge?

Marine engines are water cooled exactly where the heat is produced, and can be regulated. A marine engine would need to have an insufficient cooling head to call in the need for a cooler crankcase.

Personally, i wouldnt use one...you want some heat in the case to maintain its dimenional stability.

The OPTIMUM would be to have the ENTIRE case the same tempurature...not one end cold and the other hot. Some marines engine are so well cooled its hard to keep the proper heat IN them.

BB Modss

I agree Jetpack, I do use restrictor's in some of my bigger engines to get my headtemp up to the correct temp.

jetpack

My Feedback: (1)

I think more benifit would be gained by using a water cooled exhaust manifold to keep that half of the engine near the same temp as the blank side of the block to prevent egg shape expansion.

Square Nozzle

My Feedback: (1)

Cooling the crankcase is not necessary. It is already cooled by the incoming fuel charge (air and primarily methanol). The place to take the heat out is the head and the exhaust header.