CYA-Vett

Help!
Did I goof up the timing chain?
Whats the deal, I added a cam (springs double roller chain), the car started right up, idled fine but after about 5 minutes the headers were glowing! Pretty much all of them.
My car has headers, exhaust, intake and now a mid sized cam (230 227)cam, this is all with a stock tune. (Dealer reflashed my pcm a couple weeks ago) I didnt check out teh heaaders before the cam install but I don't think they were glowing.

'06 Quicksilver Z06

Glowing headers. I have heard of this happening before and in the case I recall it was a problem with A/F ratios. Can't remember whether it was too lean or too rich but I am guessing too lean. That might be a place to start.

Do a general search under "glowing headers" and you will find quite a bit of information on this. Good luck.

Old Timer

To rich. Fuel is still burning after leaving the cylinder and entering the headers. Been there, done that.

'06 Quicksilver Z06

Thanks for the clarification, Old Timer

sxeC7

Sounds like late ignition timing IMHO. Too rich a mixture would have a cooling effect. Late timing would have the fuel still burning while being exhausted.

Dave_Busch

I agree

CYA-Vett

Too rich? What would cause that? I figured I'd be lean with all those mods and no tune? Is it the reverse split cam? Also would that cause the "reduced power" mode to kick in? Or maybe I forgot to plug in a wire somewhere since that message appeared before I even started it?
I'm not sure I can even drive it to get tuned.

How can I be sure the lower timing sprocket was put on right. I lined up the notch and dot with the old one, but now after reading the directions again I think it may be 2 degrees off....AARRRGHH!

Thanks
Dave

CYA-Vett

S.O.S
Need help...

Ikester

For starters, have the car sent to a tuner and have it tuned. That can eliminate the rich/lean factor as a probable cause.

Rob'sC5

If you dont think you get drive it. Call the tuner and haev them pick it up on a flat bed. It sounds like

CYA-Vett

Thanks guys, I just found out that I'm a dope...While I still think we may have advanced or retarded the timing 2 degrees I did find that the throttle body was not plugged in, it could not open thus no air could get in.
I let it idle for about 1/2 hour and the headers were measuring from 350-400 degrees, I think that would be about normal. Certaintly did not begin to glow after 5 minutes.

Now, if the timing gear is on wrong can a tune compensate for the 2 degrees it may be off?? Will it hurt the engine? Is there any way to tell without taking it apart? Should I take it apart just to be sure, yuk!

The saga continues...

msuc5vette

I woud wait to talk to the tuner who speced the cam, but if you don't think you lined them up right IMHO double check it!

On my cam I would be afraid that the pistons would smack the valves, especially at higher RPM if the cam was off even two degree.

I realize the steering is a pain to get off, and the crank bolt and all, but a few hours of extra work would be worth the piece of mind to me.

When I did my cam swap, my crank pulley wasn't torqued enough even though I followed the specs, so I had do do the same thing and take the front of the engine apart again.

just my $.02, I hope it works out well.

Geneus

Dave,

I could have told you that. I still have the aspirin...just say when.

Don

Special K

What price can you put on 'piece of mind'? Get out the Advil and go to it.

Bob

Bink

Ignition/Spark timing can be changed with "Tuning" - simply by changing spark timing tables.


Valve Timing is a mechanical relationship and can only be changed via mechanical means i.e. Timing Set (cam gear/crank gear/chain). You are talking about valve timing - Sorry.

CYA-Vett

Then I guess it will have to come apart just to be sure...
I am assuming there is no way to tell if we have it right or not without visually checking???
I guess I'm lucky nothing broke when it was idling.

Can anyone list the parts I need to remove to get to the chain? I think I can leave the radiator in, or will there not be enough room?
Will I need to unbolt the rockers to turn the cam to line up the dots?

Needs to come off:
Throttle body, rack, water pump, balancer, sway bar, power steering pump...

vettenuts

Which way are you off do you know? I would contact the people you bought it from prior to pulling it apart again. Some people do install them advanced or retarded. It will shift the power curve. Not sure if one tooth is only two degrees though.

CYA-Vett

The dots on the teeth were dead on, we mounted the bottom sprocket dot to match the dot on the stock sprocket, instead of placing the key where the dot was on the rim of the sprocket. The directions that come with the chain suck. Basically we matched the dots on the new and the old sprocket, we used common sense...so we thought.....

TopCat

If you do take it apart, I'd recommend indexing the cam rather than trusting the dots. Do you have an adjustable sprocket? That's the only true way to know you've got it dialed in right. Otherwise, you could still be off 2 degrees (you'd just not know it).