How long should a rebuild last?

[blowbye]

I'm new here guys but I need your help.
Had my 460 "professionally" rebuilt last year and after less than 10 hours its hanging on the hoist in my garage. Again.
This was a complete rebuild after I found some water in the oil. Engine shop tore it down and said it was a blown head gasket. Did a complete tear down and re-build with turned crank, new cam, bored 30 over, pistons, rings, bearings, valve job etc. etc.I have the CJ heads,CJ intake, Dooley 10 qt. pan, ford truck rods and football bolts, 750 Holley. Engine reved to 5000 rpm against a soft touch rev limiter with a 5000 chip.
Turning an A impeller in a JE pump with Place Diverter in a CVX-20.
It simply stopped while at revs. Back at the garage drained the oil and found 10 quarts of oil mixed evenly with about 10 quarts of water. Shouldn't a gasket set last longer than 10 hours? Whats fair here? Need your input. Should I jump on this shop?

[HammerDown]

There could be several reasons...to much pressure caused by the Jet (could) blow out the Head Gasket if things arnt flat. Did your shop Deck the Heads and Block for true flat? Did you assemble the motor...torque the Heads correctly?
The list could go on...but I would check for true flat Heads and Block...and check to see how much pressure is in that motor...this can be dome with a guage at the Intake Manifold.
With my Bassets and Rex Thermostat Bypass...and 2 dumps out the back VS most jets have one...I'm seeing less than 9 psi of water pressure.

[blowbye]

They supposedly decked the heads and block (with a torque plate) and we discussed the torque sequence on the heads before they put the motor together. Since my first post I have pulled the motor apart and found some real problems. In taking the water pump cover and timing cover off I found the same problem as Rampager discussed some time ago. A corroded section of the timing cover about an inch square in size. And the backing plate between the timing cover and the water inlet cover did not have the two inside bolts installed that attach the plate to the timing cover. All the outside circle of bolts were there but not the two inside ones. I guess water could under pressure get between the plate and the timing cover and get in the pan that way. Also found the skirt of piston in cylinder number two in pieces in the pan. And rust everywhere. In the intake ports, floor of the intake manifold and in the bores of the cylinders. Thanks for your thoughts on the pressure issue. Do you think they could give out in such a short time? So much for boating this year.

[quiet riot]

I'd be inclined to take good notes on what you found and take it back to the engine builder to have them rectify the situation. I've got 11 years on my 351w ford without a problem and I've dumped about 400lbs of N2O through it too. I haven't had any experience with water blowing by from the jet pressure on fords, but have seen it on other motors and had to install regulators.
jd

[quiet riot]

oh yeah, I'd put a chip in the msd that is about 400 rpm above the point that the motor normally runs at when well loaded at full throttle, you don't want to be kissing the rev limiter all the time at full throttle, just when the pump unloads or something breaks.
jd

[Danhercules]

I am only a year inot jets, but, it seems like my Ford 460 dose not like the pump pressure obove 4.5k I will get water in the oil obove that. I keep my gate closed, but i am gonna get a pressure reg, in the offseason so I can open my valve all the way. Jsut my .02

[blowbye]

Thanks guys for the thoughts on my engine problem. Been in the garage taking the motor apart and it is toast. Found pieces of piston skirts in the pan and when I pulled the heads found 4 broken pistons and the block cracked in bore number 6. Crack about 3 inches long with a two inch long "T" at the top. All the bearings wiped and rust everywhere. I guess it hydrauliced from all the water. Could that pressure have caused the pistons to break up? Don't know a lot about this and have never had an engine come apart like this. Aside from the shattered skirt the other three had quarter sized chunks out of the top edges. Heads, intake manifold and Dooley pan all look great though. Look for them soon on E-bay. No message icon for "screwed". But there should be. Now if I can just find a BBC lying around.
"By the time you think you might have been screwed.... you have been."

[HOSS]

Well if your gonna sell the heads you may be breaking it off in someone. I was going to suggest that the problem you are describing seems to be a crack and that you should spend the 60 ucks on having them magnafluxed.

[blowbye]

You're right Hoss and I don't want to pass on the "feeling". Fact is they were supposed to have been magnafluxed at the time of the rebuild. No more than ten hours on them since. Up here in the Great White the cold winters are a real problem with frozen engines but this boat sits in a heated garage all winter so it wouldn't have been the cold. And when you see how small the crack in the cylinder wall is it's hard to believe all that water could get in so fast. But I was just really P.O.'d when I made the E-bay comment. You know 10 hours in the boat this year after all the time and money invested.....
Enjoy the rest of your powered week-end everybody. My brother-in-law is coming over to take us sailing. Can things get any worse????

[AZKC]

I got about 10 hours out of my first one and 2 hours out of the second :mad: I'm going to blow the next one up while I'm setting the timing smile_sp

[superV]

blowbye:
I'm new here guys but I need your help.
Had my 460 "professionally" rebuilt last year and after less than 10 hours its hanging on the hoist in my garage. Again.
This was a complete rebuild after I found some water in the oil. Engine shop tore it down and said it was a blown head gasket. Did a complete tear down and re-build with turned crank, new cam, bored 30 over, pistons, rings, bearings, valve job etc. etc.I have the CJ heads,CJ intake, Dooley 10 qt. pan, ford truck rods and football bolts, 750 Holley. Engine reved to 5000 rpm against a soft touch rev limiter with a 5000 chip.
Turning an A impeller in a JE pump with Place Diverter in a CVX-20.
It simply stopped while at revs. Back at the garage drained the oil and found 10 quarts of oil mixed evenly with about 10 quarts of water. Shouldn't a gasket set last longer than 10 hours? Whats fair here? Need your input. Should I jump on this shop? Hey sorry to hear of your misfortune. I have the exact same set up as you in my 1977 CVX 20. And I also had the same thing happen. These boats have a real problem with hydro locking due to the way the Ex. comes out above the pump and that area being confined and the lack of rise in the ex. also due to confined engine compartment. I have spent all week putting mine back together.
And may be able to really help you give me a call if you like @ 314-368-2808.
Regards,
Josh

[blowbye]

Josh that would be great. I'll give you a call tonight (Tuesday) around 8pm. your coast time.
Ron.

[blowbye]

Hey Josh,
Just read your "Rookie" post. Maybe I should hold off on that "PLEASE HELP ME, WTF" phone call for a few days. On my CVX we cut out those plywood panels that some genius designer put in the boat to strengthen? the structure. Made screwing with the motor a lot easier.
Good luck.

[superV]

blowbye:
Hey Josh,
Just read your "Rookie" post. Maybe I should hold off on that "PLEASE HELP ME, WTF" phone call for a few days. On my CVX we cut out those plywood panels that some genius designer put in the boat to strengthen? the structure. Made screwing with the motor a lot easier.
Good luck. Don't trust me ! :D wink Its all good but you should really take a close look at your ex. and make sure you flaps are in perfect working order.BTW I would have liked to cut those out on boat my to but it is to clean to do so IMO.I will say for it being such a small eng. compartment I had no problem Bolting up. It was only about an 1hr job to do the bell housing and motor mounts. wink BTW im all ears on any info you may have for me on the boat what kind of #s are getting and RPM? Is your pump stock? W/B