Pressure Relief Valve tube broken

[chrome72]

First time poster and learning a ton.

Recently purchased a 1992 Honda Nighthawk 750 which was in pieces. Attempted to get motor in the bike frame but it got stuck at a weird angle. Ended up having to take off the housing cap where the oil pump resides to get engine out. I ended up breaking a piece/tube that holds the pressure relief valve in the process.

I took the service manual page that shows what I am talking about and a picture of the aftermath.

Did I totally just destroy the engine? Or is the actual housing cap (aka the very bottom of the engine) and the remaining piece that holds the relief valve enough to have a working engine?

Appreciate any advice,

 

[amc49]

That looks like a pretty serious f/u there bucko...............

 

[chrome72]

Did I break part #5, the oil pump assembly from this schematic

The oil pump assembly looks like this part from ebay but I don't see the double tubes where my red line starts in my original image.

 

[amc49]

Can't say as you show no pics of damage there. Pump is off to the side. You have broken part of the main crankcase, the lower half, but the upper and lower halves are matched parts, you can't get one by itself. (You can but it would be a mistake as bad as the breakage you did.)

You have to have that relief valve in place and sealed or the engine will never develop proper oil pressure and tear up in short order.

 

[chrome72]

If the crankcase is matched and its a bad idea to get a non matched lower half, what are my options?

New engine?
Weld the pieces back together? I saw people use JB Weld in engines.

Really appreciate your knowledge.

 

[dan1951]

If the broken piece fits back together like a glove no distortions in the break it could be tig welded back together by a professional welder useing a piece of metal dowel same size as the tube inside to prevent heat distortion. Use a very minute amount of JB weld on the fine crack inside where the tube and o-ring resides to prevent leakage might be worth a try see what a welding shops opinion would be just a thought, Good luck with it.

 

[dirtdigger]

You would have to find a very good tig welder. With how thin the spot that is broken and the quality of cast aluminum it would be very difficult to get it to weld reliably. The aluminum they use in the cases is not the best and can be a pain to weld. Best option would be to look for a different motor or set of cases. Look around for a good welding shop and take the case to them and let them look at it, if they are hesitant then I would just look for some cases and forget the welding. If it was just a crack in the case I would say no problem let them weld it up but beings it is a critical engine oil gallery I wouldn't chance it. imho

 

[amc49]

X2, not a low load section of the motor there, the passage has to seal full oil pressure. You can forget JB epoxy there. A GOOD welder CAN do it but we all know how hard it is to find anything truly good anymore, never mind all the people who will tell you they are.

 

[chrome72]

This is great, thanks everyone.

If I am looking for a complete engine case, can anyone point me to a site that shows what this looks like for my reference? I searched on Ebay but not quite sure what I am looking for and what constitutes an engine case.

Happy new year!

 

[dirtdigger]

I think you need to look for a complete motor. Its not something simple to just swap out, its a complete teardown, then you will have to do some measuring for bearing clearances etc.

 

[amc49]

X2 to that, buying cases alone with damage like already exhibited thus far means you may well not like all the work you are about to put upon yourself. Not saying you are not capable but playing the odds of most people. You are saying you can set up and build an entire new engine there. Those skills don't just lie around waiting to be picked up off the floor. Your not recognizing how serious the break was screams don't do that.

I suggest finding a running engine too. If new cases then myriad pieces have to be refitted to those new cases, the measuring previously mentioned. Some of it has to be VERY exact, a mistake and kablooey again.

 

[chrome72]

Got a welder who works on bikes said he can weld the piece back together and should not have any issues. If for some reason that doesn't work, I am on the hunt for a new engine. Thanks for all the input. Got a rolling chassis now so just need a working engine to put in it.