Ummm...Araldite in a cylinder port?

[cardiffrob]

Well, the alloy cylinderhead on my Morris Minor has been hacked about by various previous owners and the round ports have been cut square at some point. My hope is that some kind soul can give me reassurance that Araldite or JB-Weld might be a suitable material for sleeving down the port to match the original size. (Welding content photo attached) I used JB on an intake manifold for the same reason and it held up perfectly but a head is a bit different. Pleeeeease don't ask me to weld it!

 

[cardiffrob]

I know Araldite used to be used in the old Austin Seven engines where, in theory, the engine never gets above about 120 degrees. That's the theory, not the practice. JB Weld is something different, material-wise?

 

[Digger6135]

Bellzona molecular metal would have done it.

Digger6135

 

[BrokenBiker]

i used JB weld to plug a hole in the rocker cover of the megane when what i assume was a pressure release safety bolt blew out...it has been in there 18 motnhs and the car has got really hot a few times during that time and its still ok...dont think i would use it for this application though

 

[dobbslc]

I think the tuning boys use something called Devcon for ports.

 

[brightspark]

I think the tuning boys use something called Devcon for ports.

good stuff but belzona slightly better

 

[BrokenBiker]

I think the tuning boys use something called Devcon for ports.

I used that while I was working in Essex making battery boxes for f16 jets...iirc it's titanium impregnated paste that hardens like glass. Think it also comes in aluminium flavour too

 

[optima21]

I'd go for JB weld, you need the standard version though as its good for 250C. in the words of Blue Peter, here's a head I did about 7 years ago and its still going strong. the larger tubes of JB weld are called Industroweld

roughed out for the JB weld to bond to

fill the ports with jb weld (and a finished port)

and a couple views of the port throat

 

[Tinbasherdan]

Belzona is where it's at, unfortunately it's also devastatingly expensive, or at least it was when we were using it

 

[brightspark]

as usual I-scored a pack for nothing

 

[CompoSimmonite]

In 1970's mate stripped the spark plug thread on his Yamaha YDS6 250 so he Araldited it in place. Worked fine for over year until bike sold. Meant head had to be removed to clean plug though !
I'd be tempted to change manifold shape to match ports rather than the other way round in this instance.

 

[PhillipM]

Used to just mix a decent epoxy with some graphite or microbead filler and use that when I was doing port work on cylinder heads, works fine so long as you prep the surface properly.

Obviously not for exhaust ports mind...

 

[cardiffrob]

Thanks, everyone. JB looks to be my 'winner' for the day. I had thought about changing the port shapes to suit the head but there isn't enough meat on the manifold backplate to play with if you want the standard (larger) Morris studs. If I went larger on the ports then I'd need to make stepped studs and that would be a pain in the butthole.
I'll be JB'ing a short ali sleeve into the port to bring it back to the standard size and shape. Strangely, the previous owner had not enlarged the port all the way in so after an inch it suddenly steps back to the original bore. I'll try to get some photos in the morning.
Cheers!

 

[sardine]

I had a big bucket of ceramic epoxy that they use on quarry rock crushing machines, I was well chuffed and couldn't wait to use it, I went away from home for a couple of weeks, and when I came back it had all leaked out a crack in the bottom.

 

[Chris Stevens]

Well, the alloy cylinderhead on my Morris Minor has been hacked about by various previous owners and the round ports have been cut square at some point. My hope is that some kind soul can give me reassurance that Araldite or JB-Weld might be a suitable material for sleeving down the port to match the original size. (Welding content photo attached) I used JB on an intake manifold for the same reason and it held up perfectly but a head is a bit different. Pleeeeease don't ask me to weld it!

View attachment 78298

Devcon titanium putty is what I use for cylinder heads, and never had a single problem. But as long as the ports still have reasonable wall thickness, is there any real need to reshape them? I would guess the rectangular shape isnt going to flow that great, but not going to make any enormous amount of difference if its a road engine though. If the numpty with grinder has only got at the port mouths its not difficult for anyone with a pencil torch to weld them up properly, as while epoxy is fine on crossflow heads, not sure how well it would stand up to the extra heat of an A series? I would suggest leaving well alone unless port is breaking into the pushrod tunnels.

 

[HMB]

I think the tuning boys use something called Devcon for ports.

Devcon indeed but it ain't cheap

 

[cardiffrob]

Chris. Do A-series engines run hotter than a crossflow design, then? Not sure I follow. Also, it isn't actually an A-series although not a great difference. The ports have thick walls which permitted the grinding-out down about 1.5 inches where it suddenly steps back in by perhaps 3mm? The 'filler material' would be to hold the sleeve in place rather than to form the wall of the port. JB ordered from Ebay last night so I'll crack on with that plan.
Photos coming when it gets lighter.

 

[cardiffrob]

Original round hole bored out square for the Morris manifold and then opened out again for a larger round tube at some point in its' life.

Top one was a Ford 100E manifold with round ports that has had an extra tube welded to the inner face of the flange and slips into the port. Middle is my new one and the bottom nasty is the original design with unbalanced lengths, tight turn and a hotspot on the intake. Yuk!

 

[cardiffrob]

Thanks, PDG. That makes sense. Whilst the water keeps it down to near boiling point round the chamber I can see that the area near the exhausts will be hotter.

 

[Chris Stevens]

Chris. Do A-series engines run hotter than a crossflow design, then? Not sure I follow. Also, it isn't actually an A-series although not a great difference. The ports have thick walls which permitted the grinding-out down about 1.5 inches where it suddenly steps back in by perhaps 3mm? The 'filler material' would be to hold the sleeve in place rather than to form the wall of the port. JB ordered from Ebay last night so I'll crack on with that plan.
Photos coming when it gets lighter.

A series intake and exhaust ports on same side, and inlet port runner will get a lot hotter than crossflow head. I would say if you decide to use JB weld failure is pretty likely, as it doesnt seem to have much metallic content, and not going to stand up to heat as well as Devcon. If that was my head I would either grind away the step, or repair properly with welding. Bearing in mind the bodge job thats been done on it, if you not run motor then crack testing would be well worth doing.