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19donziz29
05-26-2010, 11:06 AM
Well thanks to those that helped me try and figure out why I lost power in one motor and had a funny noise coming from it. Well it was the last run of the trip for me from the tie up back to jametown when I heard a quick popping noise. I took it off plane immediately and after comparing engine sound back at the dock we still weren't sure what it could be. Well I got it home and tore it apart and I found a blown head gasket, no cylinder pressure in number 4 and 6. I wish the head gasket was my only issue, It did some damage to the Head and Block. I'll attach some pictures. I'm glad it was at the end of the AOTH trip, but what sucks is it's the beginning of the season! Not even sure if this is repairable.

mrfixxall
05-26-2010, 12:30 PM
Bummer!! i feel for ya!

matt, with cylinder @ TDC does the piston reside higher then the burnt surface of the block? you could have the block zero decked, the down fall doing that is that motor will be stronger then the other motor..I have only seen this happen to 502's and they can be welded back up but removing the deck material would be a better choice if theirs enough their..

just a suggestion,you may want to look into the other engine as well before it happens to it to..,,maybe have them both zero decked and good arp head bolts or i like using arp studs..gm head bolts have a tendency of loosing their strength it a motor has been over heater or even getting close to it..

19donziz29
05-26-2010, 12:44 PM
Yeah the other head and the other motor will be taken apart before I think of running it again. I'll check the pistons position at the top. I'm not sure if it leaned out or what the issue was to cause this.

mrfixxall
05-26-2010, 01:11 PM
matt, did the intake bolts come out real easy? they have a tendency of coming loose. when i install intakes on the vortec engines i use a the white Teflon thread sealer and premix it with blue loctite then wire wheel all the bolts then apply my mix then torque them to spec..no more bolts coming loose..what i don't like is seeing all the oil in the cylinder # 4 does the top of the piston on that cylinder look like it was melted around the edges? that a indication of detonation and or chitty fuel..if it was lein your intake valve would be tuliped and a white color.

farmer tx
05-26-2010, 06:50 PM
Matt, There doesn't look like much thread in the upper head bolt hole between the two cylinders.

BUIZILLA
05-26-2010, 09:04 PM
pic 4 shows detonation on piston deck at 1-2 on the clock
pic 2 shows piston or some material on valve face of exhaust valve on right side of pick.. which is the same hole as the suspect eroded piston

scored wall on the other middle slug could be a broke or stuck ring, if those are hyper pistons > the ring gap is too tight and they butted

z33donzi
05-27-2010, 09:09 AM
hey matt i have another head off my old 330 hp heres my cell 270-899-0229 let me know if i can help

FISHIN SUCKS
05-28-2010, 05:55 AM
Hey Matt, talked to your Pops last night. Let me know if you want the block and head nickel welded, my guy can do it if there is enough nickel in the castings to weld to. I think my port motor looked the same if not a little worse than what your pix show. Have not had a problem with mine since, cost me $400 two years ago, should be close to that today. let me know,

tom

Team Jefe
05-28-2010, 08:08 AM
Matt - welding on a casting is tricky....doable as Tom can attest, but the metallurgical comp. of the head has to be right. Generally have to to use GTAW (aka "TIG" or "Heliarc"). Me, I would do it, but also have a backup Just In Case.

One thing to remember is, once weleded...your boat will be just a little slower that other similarly Z29's with whom you may run.....again, as Tom can attest:lookaroun:

19donziz29
05-28-2010, 09:36 AM
Thanks guys! Yeah Tom I will be keeping in touch on this. What I need to do first is pull the other motor apart and make sure i'm not running into the same issue. Tom let me drive that 28zx I'll run it faster than Z-Mans! Your alternators are probably crying with all those lights and loading up pulling horsepower away like crazy, :nilly: Maybe I'll just put in some 383 strokers and run with the zx crowd!

ITTLFLI
05-28-2010, 11:54 AM
Maybe I'll just put in some 383 strokers and run with the zx crowd!

:eek::pimp:

FISHIN SUCKS
05-29-2010, 08:27 AM
Thanks guys! Yeah Tom I will be keeping in touch on this. What I need to do first is pull the other motor apart and make sure i'm not running into the same issue. Tom let me drive that 28zx I'll run it faster than Z-Mans! Your alternators are probably crying with all those lights and loading up pulling horsepower away like crazy, :nilly: Maybe I'll just put in some 383 strokers and run with the zx crowd!
ha ha, just let me know what you want me to do my brutha:wink:!!!

gcarter
05-29-2010, 10:00 AM
My dad welded a bunch of heads and blocks for me when I was much younger.
Takes a real technician.
Choose carefully. With that being said there's absolute nothing wrong w/it.