Patriot Dual Spring Failure
 

I had my car tuned a while back (>1000 miles) and drove great since then. Then after a drive I was having major stumbling issues trying to get into boost and overly rich conditions all of a sudden (more or less) but it drove just fine in vacuum. Started troubleshooting and I ended up checking FPR, Injectors (cleaned), new fuel filter, spark plugs, checked coils/wires. Still nothing but i could hear a slight tick more than normal valvetrain noise and predominately from the driver bank. so i decided to dig deeper and pull the valve covers.

Cylinder 7 Intake outer valve spring snapped and spun inside of its self (to where it can spin by hand). Inner spring looks ok though. That pushrod (Thunder Hardened) is just ever so slightly bent too, just barely enough to see a sliver of light (probably around 4-6 Thou). I pulled that plug and it looked fine. Looked inside of the spark plug hole and looks fine just a bit black/rich but obviously can only see so much.

The rest of the springs look ok too.

Well any ideas what could cause this or damage it could have done?
Can i just throw another replacement spring into it?


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How many miles on the springs and what camshaft?

Not sure on mileage since I bought the heads used (supposedly low mileage) but i've only put less than 1600 miles on them.
cam is Custom CamMotion 223/219 .577/.566 116lsa

Could this be from oil not being hot and beating on it?
Just was thinking about the fact that since i have the oil cooler now (and its cold out) it takes twice as long for my oil temps to get to 180*.
but i always let it get some heat into it first.

IMO, I would have a hard time replacing just the failed one(s), I would just put a new set in.

I agree, I'd put a whole new set it. This is a good example of how dual springs can save an engine from serious damage. Bob

Yes replace the whole set!

Every so often you hear about springs failing or spring related failures, it has changed my thinking. If I ever buy a set of used heads I'll throw a set of springs on no matter the mileage, cheap insurance.

Thanks guys!

After thinking about it some, i believe the spring cracking was the initial failure. after it cracked and spun up into its self that caused it to coil bind which bent the pushrod.
I'm going to scope it next week to check the piston and head out.

Dual Springs save your ass..there is proof right there..:nod:

Eeesh man, I'm glad you had dual springs! I had that happen with a set of doug herbert springs when I was running a solid roller in my pontiac 455. Broke 4 of them and the thing still ran!

anyone come up with a possible cause?

Did you beat on it when it was cold? I think that's why mine grenaded.

Give Gunnar at Patriot a call. He can set you up with a new set of just springs (since you already have locks and retainers)

Talked to Gunnar and he said its really rare that an outer spring breaks. Must have been too cold when i dropped the hammer.

Like I said, that's what happened to 4 of my solid-roller springs. Glad you caught it though, just be thankful you had double springs!

Thanks for all the help guys,
what spring compressor do you guys normally use?