Even though my oil pressure sensor wasn't even tight (Helms says 13lbf-ft), I cracked my block. Stupid pipe threads and their conical base... Stupid me...

Here's a picture. The crack goes through to the threads.



Seems like this happens often (example: https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/jb-weld-cracked-block-2881341/)

How much do I need to tear down the engine in order to have this welded? Do I need to strip down to a bare block? I just torqued my head on...

 

So, am I fucked?

Is the casting too impregnated with oil?

I've called Suja1, iLL Garage, and One6. I've got a lead on a bike shop that I can call and ask and I might get the names of a few more places through people I know but, I'm running out of leads.

 

onesixx huh....https://honda-tech.com/forums/drag-racing-36/8-50-slower-roll-cage-junk-3133351/

I know welding cast aluminum is a bitch and the aluminum need's to be preheated. So I would say for a proper repair you need to strip it down.

But is there any way around it? That sensor is for the oil light that is in your cluster no feedback to your ecu at all. Only comes on when below 5psi anyway.

Maybe plug it the best you can with liquid Teflon and run an oil sandwich with a greddy oil gauge.

What kind of build? NA? Turbo?

 

mine actually broke the whole top piece offoff, i ended up tapping it as far as i could and put a npt plug in it as far as it would go in and use a GE sandwich plate for my pressure sensor. Worked good

 

i fixed one almost a year ago for a guy on his b16 block. he put jb weld on his so i had to grind all of it away and then i went in and hacked off up till where the crack was no more. drilled and tapped some round stock with that bsh 28 tap or whatever the hell it is cause its not 1/8" npt and welded it on and all was good. u just gotta clean it real good and use non chlorinated brake clean. just let it dry first so any residual that went into any cracks or hiding sports doesnt ignite when ur welding. bottom line is it can be done as long as the person knows what they are doing.


mike

 

have you talked to RCautoworks?

 

That is actually quite easy to a good welder. I would take a carbide bit, and just clean that metal up as good as I could without hacking too much other stuff up. Then I wouldn't even worry about pre-heating the entire block. Just run a quick capping bead. Shouldn't be too hard for a local welder........if they know what they are doing. Might need to get your car to them, but they should be able to do it with the motor in the car even. Ask around. If you were around me, I would do it for you anyway.

 

Thanks for the suggestions everyone. A friend of mine helped me find someone who'd be willing to attempt the repair.

I think the current plan is to make a bung and tap it with an 1/8"-28 BSPT tap. Then weld the bung to the face of the sensor plug area all the way around its circumference then lay a cap weld across the crack.

I just need to research what filler rod to use and what aluminium alloy the bung should be made of. If you have experience and no what material should be used, I'd appreciate you weighing in. Otherwise, I'll try and post up my research results for future reference.

 

The friend I have that's helping me out sent a few progress pictures last night and I figured I'd share.

He's cleaned up around the crack and made a bung to weld to the existing extrusion.









More to the point of the question that this thread was created for, preparation so far has consisted of stripping the paint and grinding the face of the extrusion. I don't believe the base of the crack has been drilled (definitely not based on these pictures) and I don't know if they're preheating the block. I'll update when I find out more.

 

I've done this repair, exactly how op's is cracked. I cut with carbide, preheated and tried to "bake" the oil out of the aluminum, to no avail. It was a bitch. Once you add heat into the workpiece, oil will get pulled into it and contaminate it no matter how much you try to clean it. Not a fun repair at all. I built up aluminum and retapped it. Doable, but not easy by any means. Welding bungs on a used valvecover is babyshit compared to this area. Hopefully you don't have to chase that crack into the pipe plug above it. that was what happened to the block I was repairing. Looks easy, but isn't.

 

It looks like they were able to repair it. I've posted pictures in my build thread: https://honda-tech.com/forums/showpo...&postcount=354

and I'll repost some of them here.

Drilling to interrupt crack propagation:


Capping the weld:


Welding on the tapped bung:


Second view of bung:


I haven't seen it in person yet as it's about 2 hours away but I'll be picking it up this weekend. It looks like a good weld and I've got my fingers crossed that it'll be successful. I'll repost after I get the engine running to let everyone know if I have a leak.

 

If he was able to weld it why the bung why not just chase the threads?

 

Primarily because the rotating assembly is still in the block and I didn't want to worry about metal shavings from chasing the threads finding their way in there.

 

Looks good. Glad you got it repaired!

 

you cover the tap in grease and back it out to clean off the chips, I'm so glad I have a third gen and the entire thing just unbolts from the block if I needed to do repairs, they should have stayed with that design

 

Looks good man, glad you were able to get it repaired. Just FYI I would recommend putting the brass T-fitting on the firewall instead of screwing it directly onto the block. With the increased length of the bung, there is an even bigger moment created by hanging weight off the back of the block.

 

Thanks for the tip but there's no brass t-fitting. Just the sensor for the dummy light. I'm not running an oil pressure gauge.