mvvette97

iTrader: (18)

Just done the cam swap about 150 miles ago. I was putting headers on tonight and while I had the valve covers off I thought the springs looked strange. Almost all of the springs on the very top coil that sits against the retainer is broken. Why would it of done that? The cam is the Comp 228/230 571/573 112lsa. The springs are comp 918. I also have the 7.425 pushrods. Is there a right and wrong way to set the spring down on the seat? I don't know what to do.

Mikey 97Z M6

iTrader: (37)

Pics would sure help. Who installed the springs?

Mike

Nate_Taufer

iTrader: (1)

Were you beating on your car when cold? Brittle metal tends to snap pretty easily.

Nate

mvvette97

iTrader: (18)

I done the install. I wopn't be able to get pics till the morning. The car is in town at the shop

mvvette97

iTrader: (18)

nope. i didn't even get on it till after about 100 miles. I always let it run for about 5 min before I even drive it

N4cer

iTrader: (11)

Wow that sucks. I remember you posted that you bought that cam with the lame XE lobes because they're easier on the valvesprings. I'm sorry to hear this news man. That's just awful when that's what you were trying to avoid by going weaker in the first place.

Oh well. Time to get bigger springs and go with a bigger cam.

Nate_Taufer

iTrader: (1)

Something has to be wrong. I can't see damn near all 918s breaking after 150 miles especially with those cam specs. Did you use the stock retainers?

Nate

mvvette97

iTrader: (18)

nope, i used the retainers that comp told me to use. I can't remember the part number off hand

Ferocity02

iTrader: (60)

Maybe your pushrods are too long.

mvvette97

iTrader: (18)

do ya think that would do it?

mvvette97

iTrader: (18)

Jimmy P

iTrader: (177)

I used pushrods that were too long and it broke 4 valve springs.

mvvette97

iTrader: (18)

do ya think a cam with 571/573 lift with the 7.425 pushrods would exceed the limits of the 918?

transAm-98

iTrader: (1)

918's should be pretty durable with anything under .600 lift. Unles they were cold. I try not to take my motor past 2k RPM's until the oil is at opperating temp.

vettenuts

iTrader: (4)

I don't think its the pushrods. There are hundreds of people running 0.025" longer pushrods on aftermarket cams, you can't maintain lifter preload without them because the cam base circle is smaller. Running the 7.400" pushrods will only lessen your preload. There is something else going on here and you are going to have to play detective and figure it out unfortunately. Just don't throw in some new parts and call it a day as you caught a break this time and there appears to be no major damage. You really need to diagnose this problem and figure it out.

What retainers are you running, what is the rest of the setup.

What is the installed height of the springs?

How far are you from coil bind?

What retainers are you running?

What locks are you running?

What is the retainer to seal clearance?

Are the seals OK?

Did you degree the cam, or at a minimum do you know you are dot to dot?

What rockers are you running?

Did you check the wipe pattern of the rocker on the valve stem?

Have you examined the underside of the retainer for damage?

What is your measured lifter preload?

If a retainer is a "tight" fit, it can break the upper coil. They are supposed to be a "line" fit in the spring, i.e., they slide in with no side to side motion once in place. Where exactly did the spring break? On a beehive spring, the upper springs don't compress unless you are are approaching coil bind, they are the last coils to compress. The lower coils compress first by design. There is more going on here than pushrod length.

Piston to Valve clearance is determined by duration, not by lift. I doubt that cam requires flycutting but if you didn't check the PV during assembly I would see who else is running that cam and see if they had to flycut.

AdamSS

iTrader: (3)

Longer pushrods may, or may not make a difference. I'm sadly suprised that most people simply slap everything together thinking that it's perfect, because Mr X did the same on the forum and it works for him, so it'll work for me.

Did you check the preload ?
Did you check the valvetrain geometry ?
Did you check the installed spring height ?

Also, regradless of what your dummy temp gauge says, car doesn't achieve nominal temperature until 13 minutes. Hook up Hptuners, or Efilive and you'll see. I always wait at LEAST 10 minutes...

I seriosuly doubt it's the springs' quality that caused it. Longer pushrods definitely alter the geometry. Re-check it ! Oh wait, I forgot - most people (including you) don't even have the Spring height checker..... Keep playing like blind kittens....!!!

EDIT: Sorry for the rant....reality check. Truth hurts !

V6 Bird

iTrader: (15)

Did you leave the spring locator on the head when you pulled the stock stuff off? If not, im going there with the issue.

mvvette97

iTrader: (18)

going to call comp and see what they say.

Billdog350

iTrader: (3)

Warm your car up for 10 minutes every time you drive it? Dude, you must be getting 10mpg! It only takes 20 minutes for me to get to work. If I let my car "warm up" it will take more than 10 minutes just sitting there idling. However if I let it idle 30-60 seconds, and then drive normally and don't rev the car past 2000rpm, the car is warm in less than 3 minutes. Engine oil temps don't get up above 150 until I'm almost AT work.

I just can't see warming up a car for 10 minutes every time you drive it, that's just plain nuts. No way OEM's or even performance products are designed for >10 minute warm up per trip.

DONAIMIAN

iTrader: (18)

How will a 7.400 pushrod lessen your preload when the stockers are 7.380?