19scamp71
Well-Known Member
Anyone have an idea on what happened. I was running on the freeway at 2800 rpms and it started to miss.
Valve spring failure??
- Thread starter 19scamp71
- Start date
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It broke a valve spring.
19scamp71
Well-Known Member
Any idea why, and what kind of damage may I have to piston?
440outlawdart
Well-Known Member
how old is the spring,what make,is it a double or single stock spring,will the valve move up or down depends if you bent the valve,can put a spring on it on the car,or take the head off
cudavert
DARTAHOLIC
I'd just change out the spring, with the special tool to pressurize the cylinder (so the valve won't fall down inside the cylinder) then use the little hand spring compressor, re-install a new one and see how it runs after that. My Brand X hot rod did the same thing and I was fine.
19scamp71
Well-Known Member
the heads are fresh stock "302" heads with stock springs. Probably around a 1000 miles on them. I'm running a 454 lift cam.
Sometimes they simply fail. Metal fatigue. I wouldn't worry about valve or piston damage. Replace the spring. I bet it's fine.
19scamp71
Well-Known Member
I found a spring and borrowed a spring tool, going to change it out tonight. Thanks for the info
19scamp71
Well-Known Member
changed the spring, everything back to normal.
cudavert
DARTAHOLIC
But does that mean fresh 302 heads with stock, 25-year-old shimmed-up-by-the-machine-shop valve springs?.......they weren't all replaced when the heads were freshened up?
I'm asking because another old valve spring could fail. That .454 lift cam is a bit more than came stock.
Even if they are brand new springs, they are not enough for that cam. You need matching springs badly.
Spring fatique plain and simple. You can replace that one and keep on trucking or replace them all with new springs. Consider yourself lucky the keepers didn't pop out and suck a valve. Or you would be doing a lot more that this.
zhandfull
Well-Known Member
Don't know why they break. I had one break recently on a Mopar Performance crate engine. It probably had about a 1,000 miles or less on it to.
moper
Well-Known Member
x2.
Looking at them they are stock non-performance 318 springs. Get a set of Comp 901-16s and stick them in there - the factory spec ones won't live long.
19scamp71
Well-Known Member
I think I will change them all out.
That's a good idea. Run the ones moper suggested. I run the same lift with those springs.,
TrailBeast
AKA Mopars4us on Youtube
That's the kind of stuff that makes me leary of messin with my engine.
I have a cam, lifters, roller chain, and valve covers and I need springs.
Makes me nervous to think some dumb thing could happen and trash my only motor.
I have a cam, lifters, roller chain, and valve covers and I need springs.
Makes me nervous to think some dumb thing could happen and trash my only motor.
The 901-16 Comp spring would work well.
19scamp71
Well-Known Member
Those are the ones I just ordered form Jegs
Gator
Mopar or No Car
I broke a valve spring also last spring so I purchased 901-16 also and changed all 16 springs so that would not happen again and I also replace all my rocker arms while I was there since I had a push rod go thru the rocker arm. Running a .509 purple cam I thought that was the best thing to do....
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