Need engine advice N A 598 cubic inch rebuild
 

My year came to an end with a bang. I have owned the boat for 3 season. At the end of the first two I did a compression and leak down test numbers were great. Boat ran great all summer. Last Saturday was probably the last time out. It broke an exhaust valve. the number 8 cylinder. Screwed up the head and piston maybe more just not that far in yet.
The engine as I know it N A 598cubic inch Dart Big M block Dart PRO 1 345 heads. Not sure on the crank and rods or pistons yet.
The plan have the block and crank checked first and the head repaired. I have contacted Midwest cylinder head about the damaged head they are sure they can fix the damage.
Any suggestion as to whom would be good to do the work in the Cincinnati area. I'm not opposed to driving if it requires someone further away.

Thanks
Tim

I'd get in touch with Eddie Young. You wont be sorry.

http://youngperformance.com/

Eddie would be a good guy to talk to - he is in Nashville, so probably about 4-5 hours away. You may want to call Bob Madara at Marine Kinetics, since he is in touch with a lot of marine engine builders, just to make sure there is not someone good right in your back yard. I think there are a few pro engine builders who post on these forums up in Michigan and the Chicago area who might even be a little closer. Good thing is that it happened at the end of the season, and you have plenty of time to figure out what happened, fix the damage, and make sure it doesn't happen again. The main thing is to carefully document the tear down with lots of notes and pictures to kind of perform a "post mortem" to help troubleshoot the failure. Try to figure out exactly what exhaust valves were in that engine - there can be many causes for it to drop a valve like that. Look carefully for signs of water from a leaking exhaust manifold. Sometimes it's not a bad idea to figure out who you want to do the rebuild, and then take the whole thing intact to them so that they can tear it down and figure out what happened. If you take them a pile of parts, it gets that much tougher to find the cause.

I had the same problem with my 598ci NA, only it was number 7 and dropped an intake valve. Had a big solid roller cam in, same heads, was a Merlin III block. Found that the valve springs were way light for the application, resulted in valve float and piston/valve contact. Ate two pistons, scored cylinder wall, bent pushrods, damaged one Jesel rocker. Upon rebuild we put a new block on it, Dart big M, changed to hydraulic roller, the heads were repairable. I estimate that we lost about 75hp going hydraulic but I have 100 hours of absolutely trouble free boating on it now.

I have read alot about Eddie on this site and certainly consider him or contact him if needed.

Who repaired the head? As mentioned I contacted Midwest cylinder head and sent them pic's. They said it is repairable. They will weld the damaged area and cnc machine the chamber back to original specs.

I'm definitely taking my time, no need to get in a hurry. I'm looking at all local builders first. It would be nice to be able to stop in and check on the progress if needed.
Two that I'm checking on now.
The Performance Clinic. Dayton Oh.
B E S. Tony Bischoff

BES bischoff
http://www.besracing.com/

or steve barker
Barker Machine & FAB

(513) 724-3288

2822 Jackson Pike, Batavia, OH

Wet or dry exhaust?

Wet C M I

Yes BES. My memory sucks

Duplicate post

that exaust is dry to the tip on that boat unless you changed things since you got it from me my friend

It dumps into the tail pipe not out side the boat. I always called these wet. I could be wrong???

ok soory to hear about youre probs best luck . what caused the valve to drop ? motor has relatively small lift cam in it . check them headers for leaks ...

I think it was just a part failure. The head of the valve came off bounced around in the cylinder. The head and piston took most of the damage . No bent push rods the stem was still straight. I just hope the block and crank are okay.

yea me too .

Can you post a picture of the valve

I can post a pic of the head and piston the valve head was never found. I guess it got burnt up an spit out.

Any clue what brand valves they are,

Check the intake manifold and the other bank of cylinders for the missing valve head. Them damn things have a habilt of traveling around in areas you wouldn't believe.

Link pic of the head I don't have pics of the piston with me.

http://i927.photobucket.com/albums/a...929_204943.jpg

Head
http://i927.photobucket.com/albums/a...G_00000805.jpg

Wow, what a mess, is the head cracked between the cylinders

Tried to figure that out. Internet search turned up nothing. C - BH 1201 on the stem. My memory is not real good and I do not have it with me so I think that was the number.

I don't think so. I have had a couple people look it over and said it is repairable. The area between the chambers is smashed the head gasket broke there. So they think the head lifted and slammed back down.

3rd chamber.....looks like this cylinder head has been in this rodeo before

Ferrea lists a PN 1201 for their 1.88 exhaust valves - not sure if they are inconel or superalloy, but $33 price indicates that they may be.

http://www.ferrea.com/Big-Block-Engine-Valves/p34231

FWIW, REV lists a CL 1201 as a Duramax inconel exhaust valve. Not sure if they interchange.

http://premiumparts.ee/work/rev-valves?lang=en

Yes it's refferred to as "dry to the tip", not the same as a traditional wet exhaust.

The ferrea super alloy is a great valve

Man that's an easy fix. Should have seen mine after I detonated it and bent the intake valve over... There was no combustion chamber valve seats nothing. Valve seats ended up in the other bank of the motor hanging valves open. Little welding couple seats valves and good as new. That's the nice thing about aluminum.

Cant tell from the pic, is the valve guide out of round/wore out?

dudnt i give you the build folder ? i just looked and cant find it here . . im sure its in that boat folder i gave you . all the specs on the motor n parts are in it ... let me know ill look around some more . valves are pbm if i recall , its been a while though

Rob I have all the information. Just have not looked at in a while.
Thanks
Tim

The heads are now bare I really didn't look at them. The guides are going to be replaced.

looks like a non iconel valve failure, but not sure what they were yet? are the ferrera Inconel or another metal? I use the manley now, never again taking a chance of that issue.

I know anything can fail but tons of guys told me they never saw a manley Inconel break so I went with them...whow knows if it's true or not, to me anything can break and will haha

Ferrea claims their "Super Alloy" exhaust valves can withstand up to 2400 degress, where I believe inconel is rated to 1800 degrees.

While I do agree that using a high temperature tolerant exhaust valve of their nature, is a necessity on a marine engine, that alone isnt enough to close the book on things. Cutting the valve seat width too narrow, can lead to valve overheating. The majority of heat from the valve, is transferred to the cylinder head, when the valve contacts the seat. Alot of shops, try to cut narrow seat widths, in an effort to improve air flow. While that may be true, you do not want to compromise exhaust valve cooling, by doing so in a marine application.Same goes for valve seat materials. Some are more tolerant to extreme temps better than others.

So, aside from using the inconel or ferrea super alloys, one must also have the proper valve seat widths, proper fuel mixture, no water contamination to the exhaust valves from a leaky header, manifold, or reversion, if you do not want this situation to happen.

Good info, I had Tom at Gellner do my heads last year so I hope I'm. Good lol he found all kinds of issues with the heads and fix everything I've had no problems cents which is nice

Good info, I had Tom at Gellner do my heads last year so I hope I'm. Good lol he found all kinds of issues with the heads and fix everything I've had no problems cents which is nice

This was a couple years ago when I got a fuel line clogged with **** from the gas tank Dominic go over said he has never seen inconel valve do that before thank god I had good valves![ coula been worseATTACH=CONFIG]531037[/ATTACH]