Blown Head Gasket??
 

I think I know the answer to this, but I thought I'd throw it out there to see if I may be missing something....

525SC...Last run of last year, developed a miss...figured a fouled plug...put it away for the winter. Spring time, fresh plugs fire it up...miss still there, maybe a bit of stale fuel. Fresh fuel, fire it up, miss still there. All plug wires check out good. Ok...Soooo, I do a compression check.

#1-125, #3-125, #5-125, #7-125

#2-125, #4-125, #6-000:mad:, #8-60:mad:

It appears that I have at least a blown head gasket between 6 & 8. Unless I'm missing something, & it could be something else, it looks like my boating season just got a bit shorter.

Any input on this will be greatly appreciated.
I plan on pulling the top end down on Friday, hopefully it will be nothing more than a head gasket.

If the plugs looked fine ,kind of. then i say head gasket.
If not ,,i say reversion ,,water . How does the oil look.
#6+8 are most likely the first ones !:eek:

There was no water in the oil...
I really am thinking positive....Head Gasket....Head Gasket...:eek:
Thanks...

**

Reversion will cause low or no compression?
I had always thought it to be water intrusion thru the valves, & down past the rings into the oil. I'm not seeing how this would cause a compression problem.
Perhaps I've misunderstood the whole reversion problem. I've also heard that reversion was checked thru a "leak-down" test, not a compression test.

It would cause the valves to pit and corrode and not seal.

0 is really bad. Even with a blown head gasket, I would expect to see some compression.

No reason to try and guess. Might as well just pull the head.

Reversion has a hard time getting in supercharged motors.
We have seen somthing like this before we have two customers blocks in shop now head gasket went first then burnt block between cyl, on the supercharged motor customer did not notice boost went down because it was making up for leak in gasket but the flame travel transfered between cyl and burnt block!
I hope this is not the case but supercharger makes up for some loss of cyl!!!
Good luck keep us posted.
Thumper

do a leak down, zero is bad, just went thru same thing leak down showed 30percent had water in cyl was reversion i think. pressured block heads and intake held 15#30 mins so if it was a head gasket it would had leaked then.

check the valves as well and if they have not been changed in a while time for new valve springs as well

With those compression numbers, I'd just pull the intake and heads and take a look. Might be a good time to do a valve job while it's apart.

Been there... this was the result. Destroyed the block too.:eek:

Those pictures look painful :eek:...
I do hope that is not my problem.
I will tear into it tomorrow evening.

Thanks for all the input.

How many hours did your engine have on it when this happened? Thanks Scott

The engine has 256 hrs.

I started tearing it down last nite, I removed the header, & I did notice, what appears to be a small (3/8") hair line crack. It's at the bottom of the flange, where the the weld is. Both 6 & 8 show signs of water being in the combustion chamber, but I will know the whole story tonight when I get the head off. I hope this is something that just happened, & I've caught it before it destroys something.
I'm calling CMI this morning, hopefully they will be able to repair the header. It looks like it is very repairable, but looks can be deceiving :eek:...

Do you boat in saltwater?

head gasket
 

Biggus,
Thats the painful picture I was talking about we could put a quarter in one of the blocks damage !!!
Hard to tell how long it ran that way but must have been some time.
Hope its not the case for rangerrick63
Thumper

a couple of things to look out for... if water has been in those holes since last season, you are almost certainly looking at sticking the rings in those pistons . when you get the heads off you need to make a fixture and leak those two holes down individually before you have to have the heads off a second time. also.. it will often rust a valve in the guide and it will hang open slightly and you will see what you are seeing now...
brush research makes little mini valve guide hones that clean and refinish the guides beautifully and theyre cheap.

Got the head off...
#6 bent exhaust valve...
#6 & #8, signs of water in the combustion chamber, but it doesn't look like it's been for long.
It looks like I got lucky this time...
Would the water cause the bent valve?

I've called CMI to arrange to ship my headers to them to be tested & repaired. Hopefully I can get them out to them next week.

Heads are going to the machine shop in the morning for a valve job, springs, & most likely, valves.

I really appreciate all the input on this...The knowledge on OSO never fails to impress me:drink:

Is there any pitting on the valve stems???? Thats what happened to mine when Gils leaked. The water could cause a bent valve. Better a valve than a connecting rod.

Is the vale bent or tulip'd ? when they bend its more of a problem where it came in contact with something between it and the piston. Water could do this bit it usually tulips the valve and then it takes out the piston or it will drop the head off the valve and do real damage. These are problems that I have seem in my past.

Thumper, it did not take long at all for that damage to occur. It was a Procharged 502, (my buddies boat) the more you reved it, the more boost it made. I was driving, he was the passenger. We were racing a Velocity and I had it strung out to 5600 or so (9 lbs) He yelled watch the tach, I yelled that's what the rev-limiter is for. He reached into his pocket and yelled "here's the chip".... :eek: It made noises like a Jake Brake seconds after!

Kurt

if i had to guess, i would suggest as i mentioned earlier, yours did what mine did... got a little water in the exhast port and rusted the valve to the guide and the next time you started it a piston closed it for you. that push rod is going to be bent as well... i've got 20 bucks that says the rings in that piston are stuck as well...

Further examination, valve is not bent but stuck...stevesxm is correct, it appears the valve had some rust on it, & when I started the engine, it basically, jammed itself in the guide.
I did check the push rod, & it is not bent.
The cylinders show no sign of rust at or around the piston, of course I can't see the ring grooves. I have no movement of the piston in the cylinder, but correct me if I wrong, if the rings were stuck, wouldn't I be able to "wiggle" the piston in the cylinder? Is there any other way of knowing without actually pulling the piston? If I were to manufacture a flat plate, bolt it to the top of the cyl, & put some air into it, should it hold... basically a leak down test, if so, how much air (10 - 15 lbs?), & how long should it take to bleed off?
After removing the second head, I noticed #5 & #7 exhaust ports have some rust in them, but #1, & #3 show just black. Perhaps I am catching something very early that could've been quite disastorous in the near future...

If the rings are stuck to the piston it won't move around in the bore.

Not to steel this thread ,,,, but this is funny ,,,
"here is the chip" .LMAO !!:grinser010:

Cool story Kurt !!

you don't have to take my advice... but if i were standing where you are, i would make the fixture i described earlier and just leak down all of the cylinders. use 100 psi and just watch the gage. the good ones will be 8 to 15 % , the bad ones will be very obviously bad. if the rings are stuck in the pistons ( which i would be very surprised if they aren't, it is a very easy fix right now . if you try to slide with it and they are stuck, it will chew up those bores in fairly short order, not to mention run bad and fill up the oil with fuel. it's an absolute piece of cake to get the pan off and brush hone the bores w/ 240 and put a fresh set of rings in it if it needs them. all i did to get the stuck rings out of my pistons was to warm the pistons with a propane torch and then soak them in an inch of wd 40.. three or four goes like that and they freed right up.

all im saying is that you have gone this far and the gasket set alone is a couple hundred bucks not to mention all the screwing around... why do it twice ?

I agree with stevesxm 100 % .

Also wholly hell WHERES THE REV CHIP. DONT LET HIM HOLD THE TRANSOM PLUG:eek:
Thumper

The issue I have is with 6 & 8 also. It appears that the valves bent slightly. It was not an over winter freeze up because it has not been rotated this year, just pulled the heads because there was a miss. I'm worried I have a reversion issue also.

I wanted to give a quick up-date on my motor issue...
I did end up pulling the whole engine out, & discovered #8 rings were in-fact, stuck. So, I mangaed to get them removed with no damage to the piston. I replaced the rings, & bearings, got the heads worked, they checked out good, so I had them worked. I got them back, back on the engine, & in the boat by the next day. I had it running on Tues. wrapped it on on Wed, & on the road to Georgia on Thurs. We boated all weekend on Lake Nottely, boat ran fantastic. I even managed to run out of gas...So, I got that out of the way.
I really appreciate the advice on the stuck piston rings...You were right on...
Thanks & I definitely owe you a beer....or two...:drink: