formula31

That cam on a 110 lobe sep is a reversion risk. I run a flat 224, 232 on 114 and Im real close. If you have the cam card, post the rest of the numbers.

If your one head is air locked it would get hot real fast and cause the valves to stick in the guides or a host of other problems. You may need to run a water line from the water passage at the rear of the intake that is typically blocked off to the water passage at the front of the intake on each side. You will need to have it machine, drilled and tapped. I would put the circ pump back on first.

team Tickfaw

complete cam specs from cam card- duration @50-intake 223/exhaust 231
lobe lift-intake .3088/exh. .3233
lobe seperation 110
seat duration @ 006 intake 280/exh.288
gross valve lift intake.525/ exh.550
valve lash hot intake .000/ exh .000
degree intake lobe to 108 ATDC
seat timing int @.050 BTDC 5.5 ABDC 37.5
seat timing exh @.050 BBDC 49.5 ATDC 1.5
Alot of these numbers I really dont understand but I specificaly asked cam rep about reversion and this is what was recommended. I also belive I got the same cam specs off this forum. If I will have a reversion problem, what can I do other than replace brand new cams?

formula31

It depends on your risers. I have the real short low ones used for the silent choice call magnum choice. If you have the full height risers you might be ok.

Im not a cam expert by any means. It appears that even though your lobe seperation is closer, this cam is a lot faster (ramp) than mine. Do you have the timing numbers at .004 (SAE J604) or .006?

PatriYacht

I doubt if the cam is going to cause any problems. It has less duration and less lift than the cam used in the 454-400hp Cyclone. The Cyclone used those old log style manifolds with a very small, short riser. It certanly isn't causing any overheating problems. I read on another thread that water flow in Merc engines is biased toward one exhaust manifold anyway. If there is a shortage of water, it's going to show up in the manifold that normally gets the least water.

rackster

Sounds like you don't have enough water pressure to "force" enough water through both exhausts to keep them cool. Without any water pump, the water travels the path of least resistance, which is not equal to each exhaust manifold. If you have a water pressure gauge, what was the pressure? I would look there before I started looking for "major" problems. Eliminate the "easy" possibilities first.

PatriYacht

I agree. Always eliminate the simple things first.

Dave_N

You could try temporarily restricting (pinching off) the supply hose to the cooler side to see if the warmer side cools off. Might help you determine if it is just a flow issue.

Dave

team Tickfaw

First sorry it took me awhile to get back with anyone, been mardi gras on the river. Had to ride with someone though. On the cam specs that was all that was written on the card so dont know any more about it. I do have the tall risers on the exhaust and they also have these cone -like plates installed between the riser and manifold that I belive is supposed to help on reversion. Does not however have internal flappers. Previous owner removed them and installed slip in baffels and retained the rubber flappers on the outside.
Have thought alot on the high temps and feel that water flow has alot to do with it. Did not think about pinching off the line to other side to see if it made it cooler.
On the cam, was this a bad choice for a cam? What hp can I expect with this combo?
One other thing, It appears to have a lifter that does not want to pump up. First fired engine it started ticking then progressivly got worse, guess oil was getting hot making it worse. Called cam manufacture and explaned problem, suggested re-adjusting valves. Did this and helped some but still hear ticking. Said to pull them out and they would replace the set. All valve train new before starting engine. Would this cause black soot in the exhaust? After running for short period to trouble shoot noticed alot of soot on transom and outdrive where soot was mixing with water. Thanks for all of ya'll help.

formula31

I cant answer on the cam selection, its quite a bit different than mine but it looks like it has much less overlap even with the 110 seperation. Your duration at .006 is much less than mine. just a quess. If youve got the tall risers you are probably fine. The cone shaped things keep any condensation that develops on the walls of the pipes after you shut down from dripping down into the exhaust port.

DO NOT replace just the lifters. It will likely kill the cam. It been my experience and a lot of people agree that the cam and lifters have to be broken in as a set. Im very worried that the cam manufacturer would even suggest this.

The soot is probably carb setup, most likely overjetted. Needs to be setup properly at all speeds.

formula31

Oh, and if you dont know about cam breakin, make sure you follow the rules on that. It may be too late.

Proper breakin lube and Gm EOS in with a 30 wt dino oil.
NO Idling or cranking.
20-30 minutes at 2000-2500 rpm. Then avoid as much idling as possible for another half hr or so.
Change oil and stick with dino for a while.

I have run into a bad lifter on my last purchase. I caught it while setting them before I ever fired it so I got lucky.