CPFITNESS

Definitely not drinking salt water, boat only launched in Hillsborough River here in Tampa since rebuild was done .

GLENAMY 242SS

I want to see what evil lurks beneath those pieces of iron junk pos heads. I would also seriously question anybody that told me this was a fresh rebuild, look at it. Sorry, just my .02

CPFITNESS

No need to be sorry. I saw the motor at various stages of the rebuild so it's not like I got bait and switched. I suppose the question is was it simply not re-assembled correctly.

​​​​​this is about 8-10 hours of runtime post rebuild. All of that was essentially troubleshooting
I get that you don't like the peanut port heads but let's be objective here for a second. These heads are what came on this motor from the factory so they should work. High performance? Maybe not, but as a simple basic functioning motor, they should work. So the question is, why didn't they and what exactly happened to my #1 cylinder which is the only one down on compression. Lastly, is it possible to literally round off every single camshaft love? Could not going above 3500 rpm be caused by the entire camshaft giving out and just not getting enough lift across a the cylinders? How would rounded loves impact compression testing? Only the #1 cylinder is coming up off.

CPFITNESS

Some pics of the heads prior to being reinstalled last December.

DrFeelgood

You can inspect the camshaft lobes without much difficulty. I see several in your pic that are not obviously rounded off, and several other lifters that are clearly coming up out of their bores indicating they are on the open part of a lobe.

I suppose if valves were not adjusted correctly (way too tight) or valvesprings were installed with way too much pressure, that could wear down a whole camshaft. Obviously lack of oil pressure too, but there'd be other evidence of that.

Griff

Maybe not saltwater, but that engine has been ingesting water. By the looks of the top of the intake manifold, it looks like it had water seeping as well.

CPFITNESS

Meh, I think some of that is from cleaning the bilge and just getting some water on the motor. There was a leaky tstat gasket at one point I believe as well.


We found at least part of our issue today. #1 intake valve is messed up. Pistons look great, cam seems fine sondears of having damaged that seem unfounded. With that said, it seems a bit strange that this one valve would keep the motor from revving up past 3500 but it's clearly messed up. I found a set of rectangle port 088 heads locally so since it's out and taken apart AGAIN I'm thinking of going with those. We do need to figure out why that valve began to tulip though. We did have an issue with the carb when we put it back together so I'm guessing eith the carb not acting right it could have leaned it and made it get hot enough to do the damage to the valve


somehow I didn't take pic of the head only of the cylinder underneath, I'll get some more pics tomorrow

SB

Tuliped valves typically from Detonation from lean or lower octane then needed, timing that is off, engine over heat….,.your engine has checked all those boxes.

CPFITNESS

welp, i am at wits end. I got the set of 088 rec port heads. Took them to machine shop they were cleaned up and pressure tested good. They were put on, motor went back into the boat, mechanic sea trialed said it was good. Took a couple pics one was of the garmin showing the boat doing 40mph at about 4200 RPM so I was more or less happy. I go and pick the boat up, take it to the ramp, fire her up, run it down the river, everything is going good. I slow down approaching a no wake zone where i was just going to turn around and head back and i pop the hatch and there is some light smoke. nothing that really concerned me because figuring the motor was just reinstalled there may have been some oil and grease burning off along with the fresh paint on the motor. What did concern me was a bit of a knocking sound that I dont recall hearing in the past but i didn't panic because i thought maybe with the new heads it was just some type of slightly different sound or maybe literally something just vibrating and physically banging in the bilge. I go to get her up on plane and she wouldn't go up past 2000 and then she stalled out. When she stalled, she slow cranked and almost didn't crank, kinda like a dead battery to the point that i flipped battery switch to both. She slow cranked but then again wouldn't go past 2000rpm. I idled all the way back up river listening to the knocking sound and am pretty much feeling confident that now we have the bottom end ****ed. I suppose i can hope it's something valve related again but this is way worse than what it did before. At least before it would go to 3000 rpm and do 30mph.

I f'in hate mercruiser. It seems to me like this is reversion that occured but I just dont get it, we have 3 " riser spacers which the boat didn't come with stock and our exhaust height is plenty high so i guess it oculd just be the dreaded reversion at idle? The motor was idling a bit on the low side in my opinion but not by much and this comp cams cam shaft is very similar to the 454 magnum cam. I am utterly disgusted at this point. I have $45k into this boat. Obviously hindsight being 20/20 I would have bought a 383 stroker crate motor from mercruiser with full warranty from the get go and i'd be in a much better spot. At this point probably going to list it as a project boat and hope to get 15k. Its really a nice boat, I put so much work into redoing everything and cleaning her up and making her nice. Someone can buy it for $15k, drop another 15k on a crate motor and have a like new pocket cruiser for 30k but I just dont think it makes sense for me to keep ****ing with it. The only though it s to somehow rebuild again and look into the 496 exhaust that keeps the water separate but I'm not sure if that is compatible with exhaust running out the y pipe through the bravo transom.