Exhaust heat riser sticking open

[Tom B.]

It hasn't mattered too much since we're into warmer weather, but I recently found my heat riser valve to be sticking open. It won't "free-wheel" on it's own, but it will move, and I have tried WD40. If I close it by hand, it will open when it gets to temp.

Is there anything I can use that won't "burn off", do I need to remove and clean it, or is it on it's way out? The only time I've really seen a "bad" one was when they were rusted solid shut, and the one time I've had this one off it appeared fine. Just thought I'd check before I start unbolting stuff. TBarr #24014

[Jeph]

Re: Exhaust heat riser sticking open

Tom, Does the WD-40 seem to help it when it is cold? Mine just happens to be laying here on the table, and I agree, I don't see any way for it to stick open without horribly deforming the springs. If the WD-40 helps, try Kroil (Kano Labs) or some other penetrating fluid. They should all be pretty much the same. It will burn off, but if you have rust impeding your movement, it should help if you let it soak some. Of course the internal rust that falls off will go into your exhaust system. If it is rust on the spring interfering with the movement, all that is external so you can just soak that and not worry about it. I use Kroil to break all of my rusted bolts (usually only takes minutes). If I have a day or two before I need them again, I let them soak and some look new afterwards without brushing. Good Luck, Jeph.

[Dave - NCRS#24235]

Re: Exhaust heat riser sticking open

GM sells a heat riser lubricant that works. I prefer to have mine open, so I took it off and removed the butterfly - at the same time I blocked the passages in the intake manifold. It takes five more minutes to get the intake to atomize fuel properly, but performance is better and I never worry about having one exhaust and a hot carburetor. As a side benefit, the smell of gasoline in my garage (after shutdown) is half of what it used to be. - Dave

[Iron Duke NCRS #22045]

Re: Exhaust heat riser sticking open

Tom - You might want to just leave it stuck open unless you are going to have the car judged or PVed. They usually stick closed which looses a lot of horsepower, overheats the manifold, and causes the RH muffler to rust out very quicky.

Duke

[Iron Bar]

Re: Exhaust heat riser sticking open

Duke,

Thanks. I was sort of hoping I wouldn't get into the reverse situation of it sticking closed, which hopefully it won't. What is it that I've missed out on now that you are the "Iron Duke"? Anything like the "Iron Eagle?" I noticed there's a few other "Iron's" showing up too. We may be getting too many "irons" in the fire. TBarr #24014

[Ironing Clothes]

Re: Exhaust heat riser sticking open

I often have the stuck clothes problem, usually too much starch.

Thee Ya

[Iron Triangle]

Re: Exhaust heat riser sticking open

Some guys even go so far as to remove the internal "wings" from the rotating shaft on the riser valve, so it looks correct externally, but has no block-off inside. Then it does not matter if or what position it sticks in. You pass judging, but have unrestricted flow. Disclaimer; one more time, the famous quote from that un-named member: "No NCRS member has ever knowingly tried to deceive a Judge" !!!! Lighten up guys, this is all in fun.

[Iron Butterfly]

Re: Exhaust heat riser sticking open

I guess it beats TBarr the Terrorist, or Bomb Thrower or whatever that was. Inna godda divita, baby. IB

[Plutonium 239 Duke NCRS #22045]

It's Friday - Here we go again

Uh-oh! Is this going to be another one of those runaway chain reaction "weekend threads". Technically, removing the butterfly might cause you a problem on a PV as the judge is supposed to check exhaust flow. With the valve closed on cold startup there is noticeably more flow out the LH exhaust. I got so fed up with the damned thing I replaced it with the FI spacer that is essentially the valve body with no valve, but I kept the original, and I think it still works - sort of.

Duke

[He Ain't Heavy, He's my Duke.]

Re: Weekend Trivia: Heavy Metal (the movie)

Fe Duke,

Hopefully I could get the valve back to original operating condition, but if not I'm glad to know my options.

This week's trivia: How did the opening scene of the animated movie "Heavy Metal" begin? Extra credit for the year model and color. TBarr #24014

[Unobtanium Everett]

Re: It's Friday - Here we go again

Yep, there is something in the air - we are out of control (again). But have you guys noticed how quiet it is around here without VARROOOOMM? Good point about exhaust flow on the PV. For all other situations though, the modifed risers or spacers are nice. Iron Butterfly, if your heat riser had been made of Unobtanium, it would not be giving you problems. The engineering material of choice!

[Ol Geezer]

Re: Exhaust heat riser sticking open

Graphite oil works just fine. Even after the oil burns off, the graphite lubes the shaft quite well.

[Ken Karsen]

Re:Where Is Varooooooooooooo ?

I just sent a message to the Rev, he must either in the floor again or, heaven forbid!, In the road. Hey!, you Moron! Get out of the street!!! Karsen

"Pot Metal", Yep, It's Friday! "Gentlemen, start your games!"

[Jerry Clark]

Re:Where Is Varooooooooooooo ?

Looking up rare metals in an old metallurgy book, no doubt.

jer

[Distorted Les Paul #33101]

Heavy Metallica

Opening Scence - the credits

Extra credit:

year - heh it's 2000 model - have done trains, planes, and cars color - yes

clanging exhaust butterfly Don (too much S/D/R&R)