Field Expedient Engineering: JB Weld Porsche Cylinder Head Repair

Murilee Martin
by Murilee Martin
field expedient engineering jb weld porsche cylinder head repair

When your 1980 Porsche 924 craps out minutes after the start of its first race and you’re in rural Texas, parts might be a little hard to find. You won’t get far with a blown head gasket and big ol’ notches burned in the head itself. But, damn, the clock keeps ticking! The Moose Knuckles team called every junkyard within 500 miles, but nobody had any 924 (or Audi 100) cylinder heads. In fact, nobody had ever heard of them furrin thangs.

The Moose Knuckles were able to find a head gasket a few hours’ drive away, but they came up with exactly bupkis on the head. But then one of the guys remembered the fine print on the JB Weld package: Repairs Engine Blocks. Block, head, what’s the difference?

Picking up some JB Weld and JB Kwik, the Moose Knucks got right to work. Sure, combustion-chamber temperatures get higher than the JB Weld-rated 500 degrees F, but we’ve seen such repairs work in the past… on cast-iron heads. What will happen with an aluminum head?

Fill in the holes with that magical gray stuff, sand it down, and slap the head back on the engine. Take the car on the track. Return behind the tow truck. Repeat. Endlessly.

Because the track exit at MSR comes before the transponder loop, and the Moose Knuckles’ Porsche never managed a full lap under its own power, all those laps that ended on the hook didn’t count. Official race results counted the car as a DNS. On the bright side, the Moose Knuckles took home the I Got Screwed award.

Just so you don’t think JB Weld repairs always fail at LeMons races, here’s a JB-patched E30 oil pan from the same race. The car wiped out, bottoming the pan and cracking the hell out of it. Thanks to a generous application of metal-filled epoxy, the car finished the race.

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  • Panzerfaust Panzerfaust on Apr 29, 2011

    I've seen J-B weld used to repair VW vanagon crank case. Heat really wasn't an issue-except when the owner would use his Coleman catalytic heater to warm the engine up in the winter so it would start.

  • John Horner John Horner on Apr 30, 2011

    JB Weld to patch up an oil pan? Sure. JB Weld to fix a head .... never had a chance. JB Weld can't take the mechanical stresses or temperature. Didn't anyone at the track have a TIG welding set up? That could have worked.

    • Panzerfaust Panzerfaust on May 01, 2011

      Probably because a good portable TIG welder costs 3 times as much as any of the cars do. As I posted above, welding an aluminum head in the field is an iffy proposition. First it has to be of an alloy that can be welded, second the contamination from years of fuel, oil, coolant and other grime creates such porosity that you can't get much of a bead at all, or you have a weld fails almost immediately. But it would certainly be worth a try if the head was scrap anyway.

  • CEastwood I could have bought one of these if I had the cash in 76 for $1000 white , red interior , 3 speed stick with whitewalls/ wire hubcaps - it was mint and gone a day after I saw it . But the real catch that got away was an all original 69 green Camaro RS convertible 327 4 speed with 46K on the clock for 1800 that I saw a few months earlier . Young and poor was not a fun place to be !
  • KOKing I'm in an emissions check only state, and I'd trade that away for a safety check all day.
  • Bd2 The hybrid powertrain in the Sportage and Tucson are the ones to get.H/K should discontinue the base NA 2.5L powertrain and just build more of the hybrid.In the future, maybe offer a 2nd, more powerful hybrid (the hybrid 2.5) which will first arrive with the next Telluride/Palisade.Kia also needs to redo the front fascia for the Sportage's refresh.
  • The Oracle I say let the clunkers stay on the roads.
  • Jpolicke Twenty-three grand for a basket case? And it has '66 wheel covers and gas cap so who knows what else isn't original?