Well, my nostart problem turned out to be a broken valvespring on my #6 cylinder (i think? 3rd back on pass side) exhaust valve. The valve wont move up and down freely so I am looking at my options now...
1-compression test
2-pull the head...

any advice is helpful...
the springs were ex-component 612 springs good to .620 lift, the cam lifts to .595.... I guess we installed them wrong (or thats what i was told)... we did it moving the crank to TDC for each cylinder, then compressing the spring down far enough to put the locks on. Is this improper? he told me doing this would cause for the valve to not be seated in the proper place on the lock?

please help
many hours ahead...

 

I thought the 612s were good to .600" lift (I may be wrong). .595" would be too close for comfort, if so.

If your valve won't move freely up and down (notwithstanding the pressure by the seal), then it is probably bent, and the head will have to come off.

Not sure about all the details of your install, but it did not sound really abnormal.

 

Yeah that's what happened to mine. I broke 3 springs and bent a valve. But I thought i was smarter than comp cams and ordered my own springs.........I showed them!!!

You'll probably have to do a lot of what i did, get new valves and seals (went ahead and did them all), machined for new springs(mine were bigger in diameter from the stock seats), new locks, retainers (you might be able to just replace for the one), head gaskets. Believe me it's a lot of fun!!! I feel your pain!!

 

this is 96lt1tx on my friends computer...
Thanks for the quick replies guys, I have asked many times at www.cmotorsports.com in emails, and also over the phone, multiple times I have been told the same thing, that they are good to .620 which is why I wasnt afraid of it.

I am expecting a bent valve, and we are about to pull the head and see the dmg. Would I be better off with replacing all the valvesprings or using the same 612s? They told me at cmotorsports.com that they would send me a replacement after I told them what actually went wrong but that was the explanation that they told me as to why it broke.

Can you lock the spring on the valve at different places? I thought as long as the lock is on them correctly, then the valve will pull them all the way up, only thing you need to worry about was dropping the valve?

since I am pulling the heads, machinework is not out of the question, as neither are new pistons since I havent see nthe dmg yet.

I will keep you updated w/ what I find, thakns for the quick reply shoebox.

New valves=which are the best?
new springs?
I have also read that there are multiple size locks? Could I have gotten the wrong size lock?
How much does machinework for new valves run?

thanks again...

 

Ok, I called them again to get everything straight.

they are good to .600 lift ONLY with blue gm valve seals (some less bulky valve seal) which raises lift to .600" safely.
the lift w/ this cam is .592 so Im going to check and recheck install height of the springs after I install them again =/

Off come the heads, checking valves..
ill keep you posted.

 

I don't see how valve seals will affect any of the above listed.

You will have to pull the head, also check for a hole in the pistnn since it made contact with the valve hard enough to bent it.

I've broken 4 by following comp cams recomendations.

-Shannon

 

the max lift on a stock motor is somewhere in the .590's. you have hit a piston to a valve

 

Red94,
the motor is nowhere near stock... valvetrain fully upgraded. are you talkign about the stock shortblock having a limiting factor at .590' lift? If so I have yet to hear anyone say anything about something like that. The cam I bought (check sig) has .592"/.581" w/ 1.6 rrs on my cam.

The heads are on their way off... using the opposite of the tightening order to loosen them, then we will check the piston for valve-slap!J#*(@!&*$#^.

****ing valves.....

 

You wont hit a piston at .590 unless your running a cam with ~260* of duration.

 

He had to hit somthing to bend a valve

-Shannon

 

Not because of the .592 lift cam. Sounds like valve float to me. Those springs are at their limit with an 847. Anything over 5800rpm is asking for trouble

 

Just because the spring specs say the spring is good for 0.620" lift it still has to be installed properly. This is a lot easier to show on a head than to describe, but I'll give it a try.

The installed height - (coil bind + coil clearance) is going to be the maximum lift the spring itself can accomodate. But there can still be interference bewteen various parts that further limits the maximum lift. The most common prolem is that ths distance between the bottom of the reatiner and the top of the valve seal is too short. This will not break a spring though. If there is this kind of contact usually the pushrod will bend. Then other stuff can break as well. Similarly, coild bind will not usually break a pring. Again, the pushrod is oftent the first thing to go.

When you say the spring is "broken", what does it look like? I t may have just been a spring that wore out or was defective.

Rich Krause

 

Ok, today we got down to the passenger side head, and we are at the step to take it off. My problem is that it seems that the power steering pump and pulley is connected to the head via the alternator bracket. Is this really connected to the head? and do I have to take off the power steering pump/attachments of the alternator bracket? I really hope not, but I cannot go anywhere on the car until I get this head off... please help me!

 

by the way that was another post from 96lt1tx on my name

 

another 96LT1TX post :the spring is literally in 3 pieces, I have a picture if I can find a host to email it to... It literally was in 3 picees in the valvecovers when I took them off, seat and locks in there next to it... the retainer seems to have some contact marks on it as do the valve seats. there was also a small thread of bent metal shavings that looks to have come off either the retainer or the valve seat