Well, that didn't last long - ZR-1 Net Registry Forums

kenthompson · 03-15-2009

Car was back together (and running pretty good too!). Then I went to the track to see what had gotten better.

First run, stone cold tires, spins in first on launch, spins in second, and run a 13.49 @ 106. Hmm, surely there's another 1/2 second in there somewhere. Must launch harder....

Second run, RPM @ 3000, Launch, spin and keeps spinning. Wow, serious mid range torgue here. Ok, I'll put it in second and it'll settle down.... Hmm, second and it's still spinning the tires. Opps, it's all over the track at this point and headed for the wall. Guess I'll have to back out. 16.38 @ 106. Bummer.

Third run, Ok, we're gonna heat the tires a bit here, although it's against my better judgement, cause the GSD3's are just going to swallow water and drip it back on the surface before the launch. Well, first gear got them spining, now I need to put it in second. OPPSSS!!!! Took out the second gear syncro. Hate that when it happens. Ok, guess I needed to rebuild the trans anyway.

Ok, so now today, it's time to go to the local strip club for a car show.

Fresh wax job, clean the windows, polish the wheels, fresh tank of Chevron 91 octane good stuff....

And the freakin motor starts knocking!!!!!

WTF????

#8 spark plug, the electrodes are pushed together on top of the ground electrode. The knock is way more severe with the plugs in, especially when the car is running.

The sound seems to eminate from under the plenum (????), nothing moving under there....

I'm thinking camshaft follower. It's really a very tinny knock. Not deep like you would think a rod would be.

Oh heck, I'm pulling the motor out....

Guess it was fun while it lasted. Another six months won't hurt anything...

rhipsher · 03-16-2009

Don't you just love it! Ouch! Especially the part about #8 the eletrode pushed together. Your cars down. My cars down. We outta start a support group. Luckily I'm just waiting for a center force sprung hub clutch disc to arrive so I can put my Fidanza flywheel on. But your problem sounds like a real problem. I hope its not what we both suspect it is.

kenthompson · 03-16-2009

Quote:

Originally Posted by rhipsher

Don't you just love it! Ouch! Especially the part about #8 the eletrode pushed together. Your cars down. My cars down. We outta start a support group. Luckily I'm just waiting for a center force sprung hub clutch disc to arrive so I can put my Fidanza flywheel on. But your problem sounds like a real problem. I hope its not what we both suspect it is.

The part you missed is it was just down for four or five months for some upgrades....

jonszr1 · 03-16-2009

you may have a valve train issue . you might have floated or broke a spring doin a 1st gear burn out. its easy to do in first gear.anyone, if you are going to the strip ,start you burnout in second gear .for 2 reasons greater wheel speed will heat the tires better 2you can control the rpms alot easier . i found this out the hard way 25 years ago. also i have fiound short shifting 1 to second @5500-6000 worth a tenth and a half due to less traction loss compared to shifting at 6900 as i do in the other gears .sorry that your car is down. i know rick is just about had it with parts taking forever to get to him . arent you close to pete maybe he can help .good luck and may it not be too bad .

kenthompson · 03-16-2009

Quote:

Originally Posted by jonszr1

you may have a valve train issue . you might have floated or broke a spring doin a 1st gear burn out. its easy to do in first gear.anyone, if you are going to the strip ,start you burnout in second gear .for 2 reasons greater wheel speed will heat the tires better 2you can control the rpms alot easier . i found this out the hard way 25 years ago. also i have fiound short shifting 1 to second @5500-6000 worth a tenth and a half due to less traction loss compared to shifting at 6900 as i do in the other gears .sorry that your car is down. i know rick is just about had it with parts taking forever to get to him . arent you close to pete maybe he can help .good luck and may it not be too bad .

The car was fine until this morning. The burnout was last week. I really think it's a cam follower. But I won't know until it's taken apart. Probably later this week. The trans was hurt in the burnout due to stupidity.

rhipsher · 03-16-2009

Mine has been down 7 weeks so far. I just ran out of money to do anything about it. Having cars as a hobby is not cheap.

Zr1 Destroyer · 03-16-2009

Pop your chain tensioners out real quick and see if one is not pumping up for some strange reason.

kenthompson · 03-16-2009

Quote:

Originally Posted by Zr1 Destroyer

Pop your chain tensioners out real quick and see if one is not pumping up for some strange reason.

Proceedure on the web somewhere?

Zr1 Destroyer · 03-16-2009

Quote:

Originally Posted by kenthompson

Proceedure on the web somewhere?

Not sure!?!?

The passenger side tensioner is easy to get to, but the plenum has to come off for the other side. If I remember right it's an 8mm wrench.....I had to do mine right after I did my stroker and it was loud......replaced with a new one from GM and she pumped right up and the noise went away.

Hopefully this is what yours did since my tensioner took a chit after bumping the hell out of my rev limiter on rock hard michelins.

kenthompson · 03-16-2009

Pics?

The plenums off now, along with the radiator and hood.

03-15-2009	#1
kenthompson Join Date: Jul 2007 Location: Las Vegas Posts: 298	Well, that didn't last long Car was back together (and running pretty good too!). Then I went to the track to see what had gotten better. First run, stone cold tires, spins in first on launch, spins in second, and run a 13.49 @ 106. Hmm, surely there's another 1/2 second in there somewhere. Must launch harder.... Second run, RPM @ 3000, Launch, spin and keeps spinning. Wow, serious mid range torgue here. Ok, I'll put it in second and it'll settle down.... Hmm, second and it's still spinning the tires. Opps, it's all over the track at this point and headed for the wall. Guess I'll have to back out. 16.38 @ 106. Bummer. Third run, Ok, we're gonna heat the tires a bit here, although it's against my better judgement, cause the GSD3's are just going to swallow water and drip it back on the surface before the launch. Well, first gear got them spining, now I need to put it in second. OPPSSS!!!! Took out the second gear syncro. Hate that when it happens. Ok, guess I needed to rebuild the trans anyway. Ok, so now today, it's time to go to the local strip club for a car show. Fresh wax job, clean the windows, polish the wheels, fresh tank of Chevron 91 octane good stuff.... And the freakin motor starts knocking!!!!! WTF???? #8 spark plug, the electrodes are pushed together on top of the ground electrode. The knock is way more severe with the plugs in, especially when the car is running. The sound seems to eminate from under the plenum (????), nothing moving under there.... I'm thinking camshaft follower. It's really a very tinny knock. Not deep like you would think a rod would be. Oh heck, I'm pulling the motor out.... Guess it was fun while it lasted. Another six months won't hurt anything... __________________ 1990 Grey/Black Too many for the sig.

03-16-2009	#2
rhipsher Join Date: Aug 2008 Location: Houston 90 Red ZR-1 Posts: 2,320	Re: Well, that didn't last long Don't you just love it! Ouch! Especially the part about #8 the eletrode pushed together. Your cars down. My cars down. We outta start a support group. Luckily I'm just waiting for a center force sprung hub clutch disc to arrive so I can put my Fidanza flywheel on. But your problem sounds like a real problem. I hope its not what we both suspect it is.

03-16-2009	#4
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,407	Re: Well, that didn't last long you may have a valve train issue . you might have floated or broke a spring doin a 1st gear burn out. its easy to do in first gear.anyone, if you are going to the strip ,start you burnout in second gear .for 2 reasons greater wheel speed will heat the tires better 2you can control the rpms alot easier . i found this out the hard way 25 years ago. also i have fiound short shifting 1 to second @5500-6000 worth a tenth and a half due to less traction loss compared to shifting at 6900 as i do in the other gears .sorry that your car is down. i know rick is just about had it with parts taking forever to get to him . arent you close to pete maybe he can help .good luck and may it not be too bad .

03-16-2009	#6
rhipsher Join Date: Aug 2008 Location: Houston 90 Red ZR-1 Posts: 2,320	Re: Well, that didn't last long Mine has been down 7 weeks so far. I just ran out of money to do anything about it. Having cars as a hobby is not cheap.

03-16-2009	#7
Zr1 Destroyer Join Date: Oct 2005 Location: Candy Apple...yUmMy Posts: 1,137	Re: Well, that didn't last long Pop your chain tensioners out real quick and see if one is not pumping up for some strange reason.

03-16-2009	#10
kenthompson Join Date: Jul 2007 Location: Las Vegas Posts: 298	Re: Well, that didn't last long Pics? The plenums off now, along with the radiator and hood. __________________ 1990 Grey/Black Too many for the sig.