Cylinder head repair?

[71Scamper]

Here's the scoop:

I have a set of X heads that has been worked over big time. I have a ton of time and money into these. I converted my block over to roller cam and had to have the pushrod tubes drilled at a slight angle to clearance for the new pushrod angle. The problem I have is, the bit poked through the intake runners on a few ports. I plan on this being a street/strip car, more so on the street side. I was thinking of having the ports brazed and smoothed back out, but I was told by an old timer that there's a good chance the casting will crack from the heat. How about that Splash Zone epoxy? Will it hold up? I'm so pissed right now I'm ready to give up on this project. Help.................

 

[torkflight]

they can crack if you don't heat them up and cool them down slow enough, I have used epoxy on several heads and never had an issue. can't remember what I used though, it was a two part mix, got it from a shop that does head porting

 

[RustyRatRod]

Why not use copper pipe and tube them?

 

[roccodart440]

My iron heads were fixed with epoxy. Never had an issue.

 

[moper]

I think it's the same stuff - called Z-Spar? Yes - mix it carefully, prep the surface well and it should be fine.

 

[jimjimjimmy]

what i did was i used brass tubes an then i used epoxy in the broken cast and smothed it out it sealed up real nice and very easy to do .

 

[71Scamper]

Why not use copper pipe and tube them?

what i did was i used brass tubes an then i used epoxy in the broken cast and smothed it out it sealed up real nice and very easy to do .

Rusty and Jim, the problem with this setup is that the holes are no longer straight. The machinist redrilled the holes at a 20 degree angle from the original holes. I used this info for the mod: http://www.allpar.com/mopar/LA-V8-engine-head-swaps.html

I think it's the same stuff - called Z-Spar? Yes - mix it carefully, prep the surface well and it should be fine.

Yes, Z-Spar I believe is the manufacturer. Is this stuff runny like JB weld or does it have a formable consistency? Also, what about a backfire? will the epoxy withstand it or just blow out?

 

[jimjimjimmy]

Rusty and Jim, the problem with this setup is that the holes are no longer straight. The machinist redrilled the holes at a 20 degree angle from the original holes. I used this info for the mod: http://www.allpar.com/mopar/LA-V8-engine-head-swaps.html



Yes, Z-Spar I believe is the manufacturer. Is this stuff runny like JB weld or does it have a formable consistency? Also, what about a backfire? will the epoxy withstand it or just blow out?

unless i am mistaken if you ran a bit through there why cant it be tubed what am i missing here . thanks and good luck .

 

[jimjimjimmy]

unless i am mistaken if you ran a bit through there why cant it be tubed what am i missing here . thanks and good luck .

see your problem now from the article pics . i broke through a 308 intake runner while porting years ago into a waterjacket i think and used epoxy that was 15 years ago it is still running . i forget the name but the dodge dealer used it to fix the axel bering case on the k car i think when the bering spun in the case it was good stuff .

 

[whitepunkonnitro]

It's not structural and it's not stressed, zero chance of it cracking out if you hit it with a quick weld.
I'd stitch the holes closed, grind them smooth, and then give them a swipe of JB or other good epoxy to seal up any pin holes.
Done it like that more times than I can count, and never had any problems.

 

[moper]

Once it dries it's good although I've heard you need to do more if you're running alcohol. It's been a while but from memory it's stiffer than JB Weld. More like a putty than a liquid but not "dry". It's not quite a putty, but close...lol. I was doing port roofs so I'd set up the head in a position that didn't allow for much movement. It's ok for it to be thick - you just remove the rest during shaping.

 

[71Scamper]

see your problem now from the article pics . i broke through a 308 intake runner while porting years ago into a waterjacket i think and used epoxy that was 15 years ago it is still running . i forget the name but the dodge dealer used it to fix the axel bering case on the k car i think when the bering spun in the case it was good stuff .

What kind of epoxy are you using? The reason I ask is because after looking at a bunch of engine machinist forums people have been saying either the Z-spar stuff or the Devcon stuff is the best. I'm wondering whats stronger.

Once it dries it's good although I've heard you need to do more if you're running alcohol. It's been a while but from memory it's stiffer than JB Weld. More like a putty than a liquid but not "dry". It's not quite a putty, but close...lol. I was doing port roofs so I'd set up the head in a position that didn't allow for much movement. It's ok for it to be thick - you just remove the rest during shaping.

Thanks Moper. Ya I heard you need to top coat if running alky, otherwise it will eat through the epoxy.

 

[roccodart440]

Talk to any reputable engine builder that uses epoxy to get the name of a decent epoxy to use.

From what I've read Z-Spar, or moroso A+B. http://www.goodson.com/

 

[moper]

The Moros A+B is also good - and I think stiffer when you apply it. But I've only used the Zspar. Reason I mention the coating is my fuel in CT has 10% ethanol. That will eat the epoxy out a lot faster. I have not done it - my stuff was race use and racing fuels years ago - but you may want to consider it. It's basically just an acrylic urethane clear coat. Gasoline will also eat through that but it takes a much longer time. Down side is it goes on after the port is shaped - you can't work that surface at all once it's applied.

 

[jimjimjimmy]

What kind of epoxy are you using? The reason I ask is because after looking at a bunch of engine machinist forums people have been saying either the Z-spar stuff or the Devcon stuff is the best. I'm wondering whats stronger.



Thanks Moper. Ya I heard you need to top coat if running alky, otherwise it will eat through the epoxy.

i will ask my friend tomorrow he knows what it was be i think it was z-spar .

 

[71Scamper]

The Moros A+B is also good - and I think stiffer when you apply it. But I've only used the Zspar. Reason I mention the coating is my fuel in CT has 10% ethanol. That will eat the epoxy out a lot faster. I have not done it - my stuff was race use and racing fuels years ago - but you may want to consider it. It's basically just an acrylic urethane clear coat. Gasoline will also eat through that but it takes a much longer time. Down side is it goes on after the port is shaped - you can't work that surface at all once it's applied.

Ahh your right! We have 10% here also. I'll have to top coat it then.

i will ask my friend tomorrow he knows what it was be i think it was z-spar .

Thanks Jim!