I would change the plug in that number 5 cylinder again, because if the plug is defective it may be getting so hot its causing that issue. A few years back in my dads v4 johson out board, a champion plug we got was defective and got so hot, it melted one of the forged pistsons, domes right off, and locked the motor up in an instant. Even if the motor is running very lean, it still wouldn't create enough heat to make that header turn red, or glow, unless the header primary cracked, which may be possible, I would change that plug lickedy split, before any damge occurs, I would also wonder if your oil ring, is messed up, and not enough oil is getting to that cylinder to lube the walls, and could help contribute to that cylinder running too hot.

 

I suppose if the header was glowing it might affect the plug. OTOH, I had a Turbo Couple (XR4Ti) that had all header tubes glowing after a good hard run.

 

"Even if the motor is running very lean, it still wouldn't create enough heat to make that header turn red, or glow, unless the header primary cracked"

untrue.

if its lean...... they are gonna glow orange, just like a torch has been on them.

 

NO more hi pro glow on any header since I fixed teh broken screw in stud/bent push rod! P u r r s like a kitten!

 

If they turn orange or glow, either the metal the headers are made out of is low quality, not thick enough, or has been worn away. A n/a motor that is running correctly shouldn't have any headers glowing unless your at sustained HIGH rpm levels, even then the motors not running the best for power and long life. Now on nitrous motors and force fed motors a set of headers that are glowing is normal right after a run, as they both create alot of heat, which is also why your supposed to run a cam shaft with increased exhaust lift and duration.

 

Dude,

ARE YOU SMOKING CRACK?? Or have you not read the entire thread? I"m gussing the later.

 

Of course I read the thread, no smoking crack though. I was still going to say that anyway, its good it wasn't anything worse than what it was, and you should be glad nothing got ruined.

 

I'm thankful to the automotive god's above! If any engine dammage would have happened, I would have called AFR on it! The rocker arm studs they provide with their heads suck! I've read a lot of therads talking of the poor quality of the screw in studs they provide! I read many threads on this subject on the lightning board and the thirdgen board! I replaced all screw in studs with 7/16, took pictures and emailed AND snail mailed pictures to AFR and their HR dept! YOU spend top $$$$ for the best heads on the market and get crap for the little things??? Just does not make sence!

 

yes, its horrible, inexpensive 3/8 studs(pioneer an example) are as little as 19.95 a set...... its sad.

good you got it going!

 

OK, NOW i'm ready to take this ****ing car to the junk yard! It seems to run fine, Idle's perfect, BUT BUT>>>>>>>>>>>>> took it out for a run, come home and the no.5 header tube is red! I'm so pissed that I think I should crap on the hood and write for sale on the windshield!!!!,

ONce again,

Checked fuel pressure 48psi
Changed injectors
compression check 175 around on all 8 cylinders
lashed valves, changed broken rocker arm studs on OPPOSITE SIDE

I am going on vacation tomorrow and will not be back for 10 days, IF YOU HAVE ANY THOUGHS OR COMMENTS that may help me find out what's up, PLEASE DO!!!!

As for now, I"m gonna wait for it to cool down, take it for a spin with out the no.5 spark plug wire on and then look at the header tube! I hate this car!

 

OK, I unpluged the no.5 spark plug wire and ran it on the freeway, got on it a bit on the way home to put a load on the engine. With the plug wire no.5 unpluged.....the no.5 header tube did not glow??? Did a compression check and all cylinders are 175psi. So a burned valve is not so possible. changed the fuel injectors, so that aint the probleml Lashed the valves while cold and put them 1/2 turn past zero lash. then I warmed the engine up, then hot lashed them. the cold lash was almost perfect becasue after 1/2 turn, they started clacking while the engine was running and warm. Then, I went to zero lash and did the same.

I have no idea????

 

when you did the compression check, was the throttle body closed or at WOT? you can do it either way, and since yours were all at 175, that shouldnt be a problem.

i cant think of anything at the moment, except a blockage in the exhaust portion of the head, or in the primary of the header. i know its a pita to take the header out, but at least unbolt it and stick a pipe cleaner or something in it.... may be something blocking?????

good luck!

 

That was my initial idea too but what could block such a large tube?

We know that he has even compression. More than enough and even so that is good whether he cracked the TB open or not. That tells me that the valves are opening and closing as they should. It is a PITA but could the valves be bent or shorter than the others? Grasping at straws here but I can't think of anything else.

 

i suppose the valve heights may very depending on how the heads were setup, but minimal.

are the AFR heads new? maybe a flaw in the cooling passage around the #5 bank?

cant be the piston, cause you got good compression.
just ranting anything i can think of, hope it helps...

 

THANK YOU! Keep it comming. The wife and I are leaving tomorrow for a curise But the more ideas the better! I may end up taking it to a shop and Paying through the nose! gawd I hope not!

keep the ideas comming, they are greatly appriciated!

Oz