Dirthead

Checkmate454, I have internal flappers in my tips not on the rear. I also though that they might be causing the problem. I had asked my Lighting exhaust manufacturer, CP Performance, and Comp Cams and they said that they would not be the problem. I guess I will have to take their word, but it sure looks like a potential problem to me.

Actually Lighting even took it a step further. They sent me a pair of Shotguns from drewmarine.com. These are to help with the reversion but in my case they have not. If you have never seen a set of shotguns, they are a flapper that is spring loaded in the closed position and only open at higher RPM's. If the though of the water hipping your flappers were true, the shotguns would only make the problem worse, not better because they are harder for the exhaust pressure to open than regular rubber flappers. Thanks for the comments. Let me know what you find out.

PatriYacht

Dirthead, you said in your first post that you never get water in your oil when the diverter is closed and the exhaust is thru the prop. If that is true then it is a reversion problem. The solutions for this problem are less cam or dump water farther backin the exhaust. Raising the idle speed is also helpful. You said several times that you were idling at low speeds, 500-800 rpm. That could cause a problem. Try to idle at 800 rpm even when in gear.

baronbob

I just installed a procharger and I had the very same problem and I fixed it. Here is a little background on the stock exhaust you initally refrenced. A buddy ran his Merc, noticed over temp. and imediately shut down. He ended up with water in his cylinders. He contacted Merc and they said that through the hub exhaust will suck back sea water if the engine is shut down quickly W/O a chance to cool down. I know this does not apply to your new install but listen on as I have an idea for you and just wanted to pass on that story to help you seperate the two problems. First the intake gasket. When I installed my Procharger they insisted on drilling three 1/4" holes in the thermostat. I thought about why and here is what I have come up with. With the circulation pump gone the sea water pump pressure gets in the motor. The pressure can get quite high. High enough to blow an intake manifold gasket. When the engine is cold the thermostat is closed and therefore the exhaust water cant come out of the thermostat housing, builds pressure and blows the gasket. I can't explain the 160 vs 140 experience. If your circulation pump is goneand you do have a thermostat you need to relieve the thermostat. I suggest you pull the intake, Put in a new, GOOD gasket, and make your first run with out a thermostat. Hopefully their will not be any water in your oil. Then dril 3 1/4" holes in your thermostat. If you dont get up to temp running then get another thermostat and only dril 2 holes. Be warned that I blew my gasket plugging two of the three holes while trying to get my engine temp up. Two 1/4" holes kept my intake gasket alive and allowed 140deg running hard. If you want to talk on the phone. Bob @ 530 587 4700

Vinny P

DirtHead,
I will let you know what happens. I plan on testing again tomorrow.

blue thunder

I had milkshake in sb engine last year. Pressure tested everything. Was running mild comp cams with 111lsa and 51* overlap. I didn't think cams were the problem because one engine was ok. Over the winter I went to a little more cam. Now comp cam 278/292 564/567 on 112lsa 61* overlap. Before removing old cams I degreed them just for fun. I found the engine that was getting milkshake had valve timing retarded 4*. The other engine was right on. I didn't connect all the dots until I fired both engines this spring and now both had milkshakes with the 61* overlap. Well enough is enough so I invented these inserts (pic) that convert my exhaust to full dry. No more milkshake for me. Sounds awesome too.

Also, I hate to be the bearer of bad new dirthead, but chance are that ticking is a wiped lobe on those comp cams. I went through 3 cams on my port engine this spring and had to rerebuild that engine one time due to metal in the oil. The lifters were soft. The last cam had a different design lifter which looked much better than the first two. These are my last comp cams cams. They absolutely suck and have cost me gobs of time and money.

BT

blue thunder

One thing I did last year that cleaned up about 80% of the milkshake in the sb engine was add pcv valves. Not a complete fix but it helped clean the oil and got me through the season. To find out if you wiped a lobe cut open the oil filter and use a magnet to look for metal.

BT

Dirthead

Blue Thunder. How did the PVC type valve breathers help over the traditional style breathers?

blue thunder

When the oil gets hot the water vaporizes and causes the atmosphere inside the engine to get humid. That is what creates the scummy creamed cheese and rust. With a passive ventilation system (stock breathers) the turns of air inside the engine are almost stagnate. With a positive vent system (pcv) the turns of air is significantly higher causing the humid air to be evacuated and dryer air drawn in.

BT

Vinny P

So much for the CMI headers solving my problem. They helped but did not completly eliminate all the reversion. Removing the rubber flappers from the tips didn't do anything to help. I am going to full dry tails. The plus side is that now I can upgrade the cam without being limited by reversion.

Dirthead

CHeckmate,

Sorry to hear that about the CMI's. This weekend I did a few things. I had the cam degreed and I think the engine builder said that it was retarded 3 de and it is supposed to be advanced 4 degrees. I would think that having the cam retarded 7 degrees would be one possible problem. I went ahead and replaced the intake and head gaskets just to make sure all was OK. They looked good with no signs of being blown, however the head gaskets had moisture on both the top and bottom side of the gaskets. The seals around each cylinder were good with no signs of water getting by the seals but other areas that are not sealed had this moister. I never noticed water coming from the heads to the outside of the block, and would have thought that I would have Sean water seeping out of here if it did. Any thoughts?