Sooo... My car caught on fire...

[vtgti]

Was out tuning my car tonight. Just came off a hard pull through all 5 gears. Heard a "pa-ting", and smelled some oil, and then the cabin filled with smoke.

Pulled off, popped the hood and saw flames by my turbo and manifold. Didn't have my fire extinguisher in the car (buddy borrowed it from mine for his rally car for a race), started throwing dirt on it but couldn't get any dirt where it needed to be so I started blowing on it and I guess I've for a pretty decent lung capacity as I blew the fire out.

No real damage as that entire area us covered with gold heat resistant foil.

Towed it back to my shop to figure out what happened. Ended up that the header bolt on the second cyl back came out and oil poured from within the head out through the bolt hole onto the cherry hot header. It isn't supposed to be a through joke but either they were tapped extra deep or something, but two of the cyls have holes to the bolt area.

I'm researching some super high temp thread sealant to hold the bolts in. Manifold bolts never like to stay tight as they are anyways because of the heat cycling, but I can't gave this happen again.

[EuroPhreak07]

Pics?

[epmedia]

Loctite "red" is good for sealing, locking and 500F. Not sure how hot those particular threads get... Those studs should be "sorta" snug all the way down, oh wait - did you say "bolts"? When you say "bolts", did you mean studs? Good thing you put that fire out and did not melt any fuel lies

[Unique320]

I had a header stud come out while driving once. I was cruising a looked in my rear view and for about 500 feet behind me was solid smoke. I stopped, the cabin filled with smoke, I popped the hood, opened it up and it just bellowed smoke. Ive never been so scared. My heart sank. Then it faded away. Took me a while to gather myself and figure out what happened. Pretty scary...

[Electric Space]

My header bolts stayed tight twice. How does oil come through the header and catch fire???? Course I'm not turbo, but none of that makes sense.

[Mike323i]

The holes for the upper mounting bolts for the header/exhaust manifold actually go clean through into the head (into the oil galley area under the valve cover near the valve train). That's just the way they are on these. Means you have to be extra careful when installing manifolds to make sure the threads/holes are completely dry and oil free before installing or they won't stay put.

[erok320i]

The holes for the upper mounting bolts for the header/exhaust manifold actually go clean through into the head (into the oil galley area under the valve cover near the valve train). That's just the way they are on these. Means you have to be extra careful when installing manifolds to make sure the threads/holes are completely dry and oil free before installing or they won't stay put.

+1

[epicfail]

Pics or it never happened..!
JK. glad you and the car didn't burn to the ground.

[Layne]

Interesting bit of trivia, they fixed this problem on later factory replacement heads. I have a 2002tii head that was made in 1986 and these holes are fully sealed. I'm not sure exactly when that happened.

[vtgti]

That's the odd thing. The other e21 M10 head I have, all the holes are capped by the casting, and on the head currently on the car, two are capped an two are through. Almost like the casting varied a wee bit and if it was the slightest bit thin it poked through.

[erok320i]

I only know because my old '79 e21, which had a 2002 motor from '76, weeped oil from one or more of my header studs if I didn't keep them tightened.

[Layne]

That's the odd thing. The other e21 M10 head I have, all the holes are capped by the casting, and on the head currently on the car, two are capped an two are through. Almost like the casting varied a wee bit and if it was the slightest bit thin it poked through.

I don't think it's that. On the fixed heads, there is clearly a protrusion in the casting to enclose the studs that the earlier ones don't have.

[TheNeek]

There are two types of products for threads. Sealants and lockers. In my opinion you want a locker, not a sealant. In the world of thread lockers Loctite 272 is pretty standard and is referred to as "red", but only is rated to 200°C. The good news is that your head doesn't get nearly as hot as that header so this might work really well. If you're gonna go the non-reworkable route (which any red loctite is a permenant adhesive), I'd suggest 2620 or 2420. 2620 being the most robust of the two. This stuff means business and must be heated to 650°F to even be removed (premenant never means permenant). 2620 is actually a locker and a sealant so it's tailored for what your'e trying to do. Not sure if you can only get it through distribution though.

[JeffCiesielski]

There are two types of products for threads. Sealants and lockers. In my opinion you want a locker, not a sealant. In the world of thread lockers Loctite 272 is pretty standard and is referred to as "red", but only is rated to 200°C. The good news is that your head doesn't get nearly as hot as that header so this might work really well. If you're gonna go the non-reworkable route (which any red loctite is a permenant adhesive), I'd suggest 2620 or 2420. 2620 being the most robust of the two. This stuff means business and must be heated to 650°F to even be removed (premenant never means permenant). 2620 is actually a locker and a sealant so it's tailored for what your'e trying to do. Not sure if you can only get it through distribution though.

If you want to be hardcore about the whole thing, look into Resbond 940HT. Cures in 5 minutes at 175*f. Good for continuous use at 2500*f. THIS SHIT WILL NOT COME OFF. Miataturbo guys who use a BEGi or FM manifold end up having issues with turbo to manifold studs backing out due to a couple of them protruding into the collector. Some have used this with success (although, due to the uneven heat cycling because they are exposed to the exhaust stream, some of the studs just flat out break...but thats a different matter).

This shit is about as close to *permanent* as you can get. Its pricey though...

[eseeling]

I was considering putting JB metalweld on the inside to cap the exposed threads. After it's been hot dipped of course because I don't want it coming loose and blocking an oil galley.
Has anyone ever done that? It's properties are good for the temp and oil exposure. I wouldn't put too much, because I want the stud fully seated against the shoulder.
One thing I noticed on my old Calloway cast log-style manifold is that it would contact the block on cylinders 2,3, and 4. There is no block interference on cylinder 1 so the manifold was in a stressed position, and cylinder 1 studs would shear or come loose. I ground down the block enough so the manifold would sit flush to the head. Not sure if that is the case with your manifold but something to check.

[davidgoerndt]

I was searching the threads for a fix for this problem. I thought it was in the FAQ section, but couldn't find it, anyone know where i can find a description of the fix. I have this problem on the top stud at the front of the engine and was wondering if you have to remove the valve cover to properly clean the hole.

[vtgti]

I don't think it's that. On the fixed heads, there is clearly a protrusion in the casting to enclose the studs that the earlier ones don't have.

I'll have to take a pic to show this. Mine have the protrusions. Perhaps the machine shop broke through the protrusion when they rehab'd the head.

[Eurotrash323]

My 79 leaked oil out of the back (rear of car) upper header stud, had to constantly keep it tightened.

Glad you got the fire out safely......scary stuff dude.

[Layne]

I wouldn't use JB weld. (it's kind of like WD-40...useless) I have seen some grey silicone that is incredibly difficult to remove that would work good. I don't know what it is though. The standard blue silicone is nowhere near good enough to stay in there.

[JeffCiesielski]

I wouldn't use JB weld. (it's kind of like WD-40...useless) I have seen some grey silicone that is incredibly difficult to remove that would work good. I don't know what it is though. The standard blue silicone is nowhere near good enough to stay in there.

JB weld is far from useless, most people just suck at applying it (500+hp RX7 engines use it INSIDE the rotor housings) or try to use it outside its safe operating conditions.

Seriously - Look into resbond.

[vtgti]

Due to time restraints and as both my local engine machine shops said to do so, I'm going to use red Loctite.

For more protection, I'm also going to safety wire it all.

[jjgbmw323]

Due to time restraints and as both my local engine machine shops said to do so, I'm going to use red Loctite.

For more protection, I'm also going to safety wire it all.

See you at the show...

[epmedia]

...For more protection, I'm also going to safety wire it all.

Now your talking! Common practice for "very critical" machinery hardware.
You see alot of that onboard ship, which also doubles as a "tamper seal".