[quote=mdacton;4455174]you still need to check that valve....the damper isn't goin to be enough to hold the valve up at any rpm...chances are it probly kissed the piston. I never thought k-motions were really for street use or mileage, thats what I have been told....how old are the springs? k-motion switched the material a few years ago b/c the older ones were too brittle. I think those were the h-11 tool steel ones.

I run that same spring. Are yours shimmed at all?[/quote

What he said. You might want to pull that head cause the valve might have been just bouncing off the piston. Also, what are the lift specs on your cam? You said the springs are good to .600 lift but if your cam is already pushing that and those specs are with a 1.5 rocker, putting a 1.6 rocker may push you over the limit to where you start getting into coil bind. Drive that way long enough and springs eventually start breaking. Ask me how i learned about +/- valve locks.....

Ken R.

 

Just a heads up so you can save $60, the Trickflow chromeoly pushrods are the exact same ones as the comp hi-techs made by the same place, just $60 cheaper.

 

Yeah Im running the 1.6 crane gold nsa rr's with gm guideplates.
yeah I paid 43.00 counting the overnight shipping. I just need this running, this is my daily driver for now.

I will check with a pushrod length checker. and also I am going to do a compression test on the cylinder. and the air test. to see if the valve was smacking the piston.
and I will get the trickflow chromoly pushrods. and save some money....thanks..Lonnie

 

It's very possible a valve made contact with this piston in this situation causing the pushrod to bend. I think it'd be wise to take the head off to make sure no further damage has happened to your piston/valve. If there is damage to either component and is ignored it can only lead to worse problems.
That doesn't really explain how the spring broke. Don't all up and assume the pushrod is at fault here.

 

[QUOTE=SS RRR;4455620]It's very possible a valve made contact with this piston in this situation causing the pushrod to bend. I think it'd be wise to take the head off to make sure no further damage has happened to your piston/valve. If there is damage to either component and is ignored it can only lead to worse problems.

[QUOTE]

100% agree.....I would almost bet you have more on your hands than what you think.....at the least I would do a leakdown test on that cyl.

I hate to bring bad news but don't get your hopes up, it is very likely you have a bent valve

 

Yeah that's what Im afraid of. I'll do a leakdown test tomorrow. and let you know how it turns out.

 

Leakdown test or not I'd still pull the head.

 

Same here, yeah it sucks, but you really should pull the head.

 

Compressed air is lot harder IMHO, with the limited space in the f-body. The TDC method works fine and most people change all their springs with this method. I did. There is no problem getting the retainers out if you free them up before compressing the spring. You normally do this anyway, no matter which method you use.

 

This question really needs to be answered if you want help determining why the spring broke. Do you know which cam the builder installed?

BTW: 7.20" is the stock length for an LT-1 pushrod. This may be why the builder recommended them.

Thomas.

 

the cam in my sig. a cc306, I believe a 230/245 duration. I forgot the lift. but it isn't over .600 on 1.6 rr's.