wrench_head943

Just built the engine, a ford 460 cobra engine with rewarder bbf exhaust, well yesterday i ran the engine for break in time on the cam and ran water through it durring break in time to cool the engine, the engine ran so strong, but after break in noticed that the oil was milkshake color. It is a wet exhaust system the the exhaust was throwing out a massive amount of water, my question is i saw alot of people saying how exhaust/headers can cause the milkshake. there was no gasket on the exhaust durring break in and the exhaust wasnt completely on only about 4 bolts of 8 holding on exhaust because it has to be removed to put in the boat. Im going to drain the oil and run dry exhaust now and completely bolt up the exhaust or headers this time, if you guys can give me some insight to why or how exhaust can cause a milkshake that would be great, i am kinda aware how exhaust creates a vacum and if theres water sitting there how it could cause that but if its something else that someone can tell me id appreciate it

Chris Sunkin

Oil really can't enter the engine's crankcase through the exhaust ports.

You may be thinking of another issue- reversion. Reversion occurs when radical camshafts cause the intake valve to remain open for an extended period of time, resulting in intake pulses pulling water from the risers on low and mid-performance manifolds. This causes cold water to splash the exhaust valve head which is really bad- but the water can't get past the piston. If it was enough quantity to milkshake the oil, it would have broken the piston & bent the rod.

On a new engine build, most likely the water is penetrating from an intake manifold gasket leak or possibly a head gasket leak.

ENFORCER24

Most rewarder headers are water injection , not jacketed , where the water gets injected directly into the exhaust tubes outside the cylinder heads , cant be safely run on I/O type boats cause they get very very hot (glowing red after extended run times)
rewarder did make a water jacketed header in the 80's and 90's , i know bacause i own a set , but with the age of the header it could have developed a leak into the cylinders , but as Chris said , if its e-nuff to milky the oil in just an hour or 2 , it would hydro lock a cylinder and bend a rod or break a crank shaft or both , more then likely either a head gasket or intake gasket seeping water into the oil
just my .02 , hope it helps

wrench_head943

yeah they are direct water cooled where you run water into them off the piece on the intake, and its a jet drive but inboard engine so i guess what your saying is there not going to work for the boat? yeah my buddy is building the engine and he put all the gaskets on and siliconed them to make sure it sealed but im guessing its coming from the head gasket or intake, the machine shop said the block was good but i dont think they pressure tested it, a freeze plug came out over the winter and made me wanna rebuild it. its hard to look for myself for cracks now that the whole engine has fresh powder coat on it.

ENFORCER24

The water injected headers are meant for jet boats , its fine as long as the engine is not enclosed and the exhaust doesnt go thru any fiberglass , most route above the transom
the popped out freeze plug probably should have been mentioned in the first post , knowing that it is suspect of freeze damage i would say that it could be cylender head or block crack that could be the culpret , but still could just be a gasket , its time to pressure test

Chris Sunkin

Coast Guard regulations require a water-jacketed exhaust for engines in a closed compartment. Dry headers, even water-injected, must exit over the transom.

Plug the inlet and outlet holes and pressurize the system with about 15PSI. If you use more, you'll definitely have leaks as you'll blow the gaskets out of it.

wrench_head943

damn so those headers are pointless since it was going to run thru hull and thats fiberglass that sucks guess i should have done research first before buying. and yeah only one freezeplug popped so i guess pressure test is the next step. thanks guys and i guess ill be getting rid of those headers and **** it maybe ill just buy a new boat

MESABALANCING

Make sure you drain the oil good and double check the filter for debriss the water in the oil can cause you alot more trouble it will wipe a cam out in a New York minute. Sorry to jump off the subject but I thought it would save trouble. Best of luck Sincerely Laz Mesa
www.mesaracingengines.com

wrench_head943

also theres a 545 cam in it i believe from erson so that may be causing some problems too

ENFORCER24

i dont know what you can get away with on cams before reversion , but i do know that Stainless marine makes adapters for the 460's so you can use 454 manifolds , and performance manifolds for BBC are ALOT easier to find then ford , if you go thru fiberglass , you want jacketed exhaust so you dont loose it all in a fire , or just stick to over the transom exhaust , you can get a set of over the transom headers on ebay for 300-400 bucks easy , for jacketed manifolds theres always a set of used ones floating around here for BBC for under a grand , thats wherethose adapters come into play