Engine overheating

[plansea]

O K here goes. I recently purchased a 1974 F36. She is powewred by 280 hp Chryslers, FWC supplied by D55 Sherwood duel pump. I am losing cooling water at a very fast rate. I have steam in the exhaust, but no moisture in the oil, and nothing is pouring into the bilge. I had the heat exchanger tested for leaks and it is fine. Where is my coolant going?I have checked compresion and have one cylinder at about 85 lbs. all others between 120 -125. Could this be the problem? The riser on that bank is also much hotter. Please help I an pretty sure spring is right around the corner (hope) !Larry

[MTP]

me thinks head gasket perhaps.........damn boats

[plansea]

Many thanx, I suspected that also, just didn't want to pull it off without another opinion. Larry

[prowlersfish]

Get a radiator pressure tester , pull the plugs out and pressure test . see it you can see coolant coming out some where.Pull off the raw water hose of the heat-exchanger and see if coolant is getting into the raw water side do to a bad exchanger

as far as the riser getting hot that is a separate issue as they are raw water cooled may have a bad riser also

[Danny Bailey]

Are your exhaust manifolds fresh or salt water cooled? If freshwater cooled could be a rust-through allowing anti-freeze to leak into the exhaust. Also, a bad radiator cap will allow anti-freeze to blow out under heat / pressure. Are you getting any anti-freeze in the bilge? Or, a bad recirculating pump will leak under pressure and blow green water in the bilge. Many possibilities for losing cooling water. Get a friend to run her at high cruise speed while you look the engines over good with a flashlight. A pair of mickey mouse type hearing protectors will help.

[Rodman]

Are your exhaust manifolds fresh or salt water cooled? If freshwater cooled could be a rust-through allowing anti-freeze to leak into the exhaust. Also, a bad radiator cap will allow anti-freeze to blow out under heat / pressure. Are you getting any anti-freeze in the bilge? Or, a bad recirculating pump will leak under pressure and blow green water in the bilge. Many possibilities for losing cooling water. Get a friend to run her at high cruise speed while you look the engines over good with a flashlight. A pair of mickey mouse type hearing protectors will help.

I am glad my engine is raw water cooled. Do not have to worry about radiator.

[prowlersfish]

Are your exhaust manifolds fresh or salt water cooled? If freshwater cooled could be a rust-through allowing anti-freeze to leak into the exhaust. Also, a bad radiator cap will allow anti-freeze to blow out under heat / pressure. Are you getting any anti-freeze in the bilge? Or, a bad recirculating pump will leak under pressure and blow green water in the bilge. Many possibilities for losing cooling water. Get a friend to run her at high cruise speed while you look the engines over good with a flashlight. A pair of mickey mouse type hearing protectors will help.

I am glad my engine is raw water cooled. Do not have to worry about radiator.

radiator. ?

[foofer b]

Mickey mousse wears hearing protectors?

[Danny Bailey]

Sure. That's why he can still hear. If you spend much time right beside screaming boat engines (3,000 RPM or above) looking for a water leak, you'll soon be watching the TV ads for the stuff that stops tinnitus (a ringing in your ears caused by hearing loss). I worked about half my career around jet aircraft. I listened to the safety folks warnings and wore hearing protection. I can still hear....a lot off my former co-workers can't. Lowes has mickey mouse ears for about $15. I use them now in my mowing business.

[mr elevman]

i suffer from selective hearing just ask my wife. ear and eye protection is greatly recamended hot anti freeze in the eyes isnt cool

[foofer b]

I sit on a commercial ZTR lawn mower 4-6 hours a day and always wear HP. I prefer ear plugs though as they seem to give me better NR.

[prowlersfish]

Much safer just to use a pressure tester no ear plugs needed . no need to be around a running engine .

[plansea]

thanx again for all the comments and suggestions. I will do the pressure test tomorrow or Tues. and share the results. Exhaust manifolds and risers are raw water cooled. Mickey Mouse is kool! L:arry

[prowlersfish]

And you can where your Mickey Mouse ears when testing ,

[BeaconMarineBob]

Plansea, You are losing coolant out the exhaust or is being pumped out through a cylinder (s) do to a leaking head gasket, or the exhaust manifold cooling jacket is leaking into the exhaust. If it is leaking that bad you should be able to smell the antifreeze burning in the exhaust. On many 318 and 360 the exhaust manifolds were not part of the closed system. So check the plumbing first. That will help you narrow down the problem. Steam is not really a problem that is a long haul to the transom and the exhaust pipes get hot so they steam. Smell the steam at transome for antifreeze.

One cylinder at 85 psi is a very big problem. Compression should be between 125 and 150 on that Chrysler 360 and not more then 10 psi between cylinders. With low compression like that she has no power. With just one bad cylinder at 85 psi she will run like she has a bent shaft or prop.

If the engines are old it maybe time for a new set of heads or long blocks and re power her. If you are interested in new long blocks or bobtails give us a call we have several options as well as a set of 1992 low hour Crusader 350 bobtails a drop in fix for under $6500.00 for both A very sweet fix for your F 36.

Bob

Beacon Marine

609 713 4602