Cracked my valve train.. can I JB weld?
 

I'm putting things together after I changed my head gasket... everything is going great then bam, I cracked this part while tightening these screws. I pulled the valve train to do work on the head. So I had a couple questions. Any ideas why this happened? And can I JB weld where it cracked? I googled this question and got mixed results. I've looked for just the part I cracked, but it seems like I have to buy the entire assembly.

Car is a 1996 Honda Civic Coupe EX. The crack is towards the bottom of the pic... can't miss it.

https://i.imgur.com/hYDgrdr.jpg

Re: Cracked my valve train.. can I JB weld?
 

404

Re: Cracked my valve train.. can I JB weld?
 

Re: Cracked my valve train.. can I JB weld?
 

I dont see a crack, but no you can not put jb weld on the rocker assembly

Re: Cracked my valve train.. can I JB weld?
 

scroll to the bottom of the pic. hard to miss, lol. OP- that is now officially a paperweight.

Re: Cracked my valve train.. can I JB weld?
 

I wonder what causes it to break like that. Makes it look weak.

Re: Cracked my valve train.. can I JB weld?
 

Re: Cracked my valve train.. can I JB weld?
 

Wtf it's broken completely off

I was looking for a hairline crack

Yeah that's garbage.

Re: Cracked my valve train.. can I JB weld?
 

You need another complete head. You cannot just replace the end cap where the dizzy mounts. The cam journals are unique and line bored in each head specifically.

Re: Cracked my valve train.. can I JB weld?
 

Is it possible to put a new valve train on and get it line bored?

I know it's not worth it, I just know it should be possible to line bore it true.

But a new used head should be no more than $100.

Re: Cracked my valve train.. can I JB weld?
 

best guess, the tightening sequence wasn't followed. can you confirm?

since it's trash anyway you could try JB Weld or an aluminum specific casting repair epoxy. Devcon is one of them but it's hard to find in small quantities. due to the location of the break, most of the stresses will be taken by the fasteners anyway. on top of that, older non-vtec engines had this as a separate piece. see...
https://cimg2.ibsrv.net/gimg/honda-t...ba9ccd8549.jpg

if you do attempt it, everything needs to be very clean and oil-free. follow package instructions and bolt down and torque to spec (and per the sequence) to let it cure in place. it may not work, but this will likely give the best chance of success.

otherwise... new or good used head. :beer:

Re: Cracked my valve train.. can I JB weld?
 

I would try putting it together as two pieces, which as @hondamark said, is how the non-VTECs are made. The part at the very end really just provides a place to mount the distributor, it isn't under much stress. Worst case you'll need a new head, which is where you are now.

It's important to make sure the dowel pins are going into their holes properly as you turn the large bolts to bring down the cam caps.

Re: Cracked my valve train.. can I JB weld?
 

Re: Cracked my valve train.. can I JB weld?
 

Its possible to line bore that but is it worth it vs a replacement head.

Re: Cracked my valve train.. can I JB weld?
 

NO...that thing is done. Time for a new one.

Re: Cracked my valve train.. can I JB weld?
 

If I do try to epoxy this and run it, is there anything else I can cause more damage to if the repair doesn't work? I don't want to cause more harm when I can just buy this for $80...

https://www.ebay.com/itm/96-00-CiViC...~1AL:rk:1:pf:0

Re: Cracked my valve train.. can I JB weld?
 

heat

Re: Cracked my valve train.. can I JB weld?
 

Yes, it is possible to repair this head, but you would have to be emotionally attached to it because the fix would likely be more expensive than a good used core. Re-line honing the cam journals would require a replacement part for the damaged one, cutting a few thousandths off all of the caps in the cam bridge, re-installing the cam caps and torquing them down, line honing the cam journals to factory spec, re-assembling the head completely and then re-installing the head on the block. Since the centerline of the camshaft will now be closer to the crankshaft, one would have to either install an adjustable cam gear to advance the cam slightly for proper operation (and potentially create a fix to increase the tension on the timing belt since there will be additional slack in the whole system), or to increase the head gasket thickness to counter the cam centerline change... although this may drop the compression ever so slightly.

Again, a LOT of work and expense just to fix it... did I mention "replace the head" ?!? :)

Re: Cracked my valve train.. can I JB weld?
 

Maybe you fix it IF the head has had a ton of money already dumped into it... CNC port work... a 5-angle racing valve job... replacement valve seats that sit proud to reduce valve shrouding... something well beyond stock. It just doesn't make sense to do this to a factory stock head.

Re: Cracked my valve train.. can I JB weld?
 

replace no matter what. learn a lesson of derp and move on

Re: Cracked my valve train.. can I JB weld?
 

Last question guys.. for this project. This bolt marked with the red arrow. It just keeps turning and doesn't seem to tighten. I'm all nervous now after I screwed up. All the other bolts are torqued. Just keep turning it? What is this bolt for?

https://imgur.com/sIZn9K7

https://i.imgur.com/sIZn9K7.jpg

Re: Cracked my valve train.. can I JB weld?
 

That bolt holds the rocker/valve assembly. It's not a head stud. HS are at the bottom/lower section of the cylinder head.

Re: Cracked my valve train.. can I JB weld?
 

Re: Cracked my valve train.. can I JB weld?
 

Run it, that is not a critical dimension. The cam cams are all doweled and still connected. That broken off piece ONLY supports the distributor and o-ring seal. NBD. Bolt it all down including the broken off piece just remove any loose pieces.

Edit: Oh wait, that is the oil supply galley broken off just under that bolt with the green colored head. She is junk.

Re: Cracked my valve train.. can I JB weld?
 

The threaded hole for that is likely reamed out. You can get thread inserts for it but I would replace the head if I were you. You can find a good reman head on eBay for under $300.