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Took old crispy for a spin today and didnt make it far before I heard the dreaded cam/lifter chirp at a stop light.
Tore it down and found cylinder 1 dogbone was above the spider and both lifters had spun in the bore.
Now my question: what came first? The chicken or the egg?
I over-revved the car substantially a few weeks ago - hard enough to spit a lash cap. After re-assembly the car seemed fine. I've been running it hard since then.
The dogbone is torn up pretty bad like this had been going on for a while - but the motor was quiet...
So, what happened? Just coincidence? Wheel locked and got ground down to the point where the lifter picked up the dogbone? Dogbone caught a burr and the lifter tossed it up past the spider?
Edit:
Original lifters from my dads 1987 vert.
Old comp/tpis 288/288 .570/.570 cam
Regularly shifting at 6400rpm
Last edited by TravisSchoech; 07-06-2019 at 07:30 PM.
It reads like you just adjusted the valves/lifters just days before this happened. Well you didn't do it correctly as the lifters hammered themselves into the cam lobes. Now the cam will be trash also and metal partilces will circulate in the oil unless the oil filter catches all of it.
I maybe a bit unsympathetic here but that's an a typical example of overconfidence. I'm out as I think you need some training before trying this again.
It reads like you just adjusted the valves/lifters just days before this happened. Well you didn't do it correctly as the lifters hammered themselves into the cam lobes. Now the cam will be trash also and metal partilces will circulate in the oil unless the oil filter catches all of it.
I maybe a bit unsympathetic here but that's an a typical example of overconfidence. I'm out as I think you need some training before trying this again.
Thanks for the diagnosis there, doc.
Fyi, a hydraulic roller adjusted too tight will just hang valves open.
I've seen the stock type lifters kick a dog bone out and bend the spider before just like yours.... same scenario. Overreved and ran fine for a while then ate itself. LS engines will do the same thing except they bust the plastic lifter guides.
Hopefully the oil filter caught most of that metal but I highly doubt it.
Fyi, a hydraulic roller adjusted too tight will just hang valves open.
I imagine that the preload was to little and the lifter was allowed to bounce. But blaming over reving the motor and bad parts is not helping you Travis. You are having one valve train problem right after the other. Denial happens with all of us and I can say I've wiped at least one cam and didn't/couldn't admit it until I pulled the lifter to see it.
Someone has to make an aftermarket spider that isn't the thickness of a ****** tin can. If I was you and frequented high rpms (sounds like your new cam is gonna like rpm) I'd invest some dollars in more bulletproof ****
Then set the rev limiter for 7200 and let er ****** eat I wanna see more YouTube videos of Mexico!
Last edited by Pwnage1337; 07-07-2019 at 05:13 PM.
Someone has to make an aftermarket spider that isn't the thickness of a ****** tin can. If I was you and frequented high rpms (sounds like your new cam is gonna like rpm) I'd invest some dollars in more bulletproof ****
Then set the rev limiter for 7200 and let er ****** eat I wanna see more YouTube videos of Mexico!
It's really pretty easy to solve this with stock parts and just throw away the spider.
Just drill a hole in the middle of each of the dog bones and then use the dog bones with a pair of lifters as a guide to drill and tap the block on top between each pair of lifter bores.... bolt the dog bone to the block with a stud and nut.
This is how we do our Stock Eliminator LTXs, L98s and LB9s.
Will
I'm thinking that one of the lifters launched off the cam lobe resulting in excessive lift that the valve spring couldn't control. The dogbone and other lifter came along for the ride. Remember those "launcher" cams they used to sell to get around static lift limits of 0.400" in some racing classes. Same idea, but doesn't work so well with roller lifters if they can become mis-aligned.
Might be interesting to know the lift at coil bind compared to the expected valve lift to get an idea of how far the valve could have really been lifted. Enough to cause the damage, I guess.
It's really pretty easy to solve this with stock parts and just throw away the spider.
Just drill a hole in the middle of each of the dog bones and then use the dog bones with a pair of lifters as a guide to drill and tap the block on top between each pair of lifter bores.... bolt the dog bone to the block with a stud and nut.
This is how we do our Stock Eliminator LTXs, L98s and LB9s.
Will
Do you have a photo of this mod? What kind of cam lift did you have?
It's really pretty easy to solve this with stock parts and just throw away the spider.
Just drill a hole in the middle of each of the dog bones and then use the dog bones with a pair of lifters as a guide to drill and tap the block on top between each pair of lifter bores.... bolt the dog bone to the block with a stud and nut.
This is how we do our Stock Eliminator LTXs, L98s and LB9s.
Will
I swapped the cam out today and everything looked pristine aside from the cylinder 1 mishap.
New cam seems fat and happy. About 20° more exhaust duration and 10° more intake duration at .050" 113LSA advanced 2°
All of the other lifters rolled smooth and looked perfect, so I'll chalk this up to a failing lifter that didnt like years of abuse and one huge over-rev.
I imagine that the preload was to little and the lifter was allowed to bounce. But blaming over reving the motor and bad parts is not helping you Travis. You are having one valve train problem right after the other. Denial happens with all of us and I can say I've wiped at least one cam and didn't/couldn't admit it until I pulled the lifter to see it.
Okay enough.
Not denying the abuse I have put this car through, but the preload was untouched on all cylinders except cylinder 2 which spit a lash cap on the over-rev. Unless I boned the adjustment a year and a half ago, your theory of too little preload is no good here.
I appreciate your input, but tone it down a bit. No need to come out guns blazing about how I can't set preload on a hydraulic roller lifter. That's a task even hellen keller could have accomplished with great success.
Do you have a photo of this mod? What kind of cam lift did you have?
No. I won't ever take pics inside of a Class Racing engine. We spend way too much time developing these things.
Stock Eliminator engines are limited to the same camshaft lobe lift as factory. The duration and valve events can be moved but lift remains same stock.
If you just want a visual representation of what we do, google "Jesel Dog Bone Lifters". That's identical to what we do by modifying and reusing the stock lifter guides instead of using billet.
Will
A new video will be required or come out on a Thursday or Friday night for the rolls over in Dallas. Your car will eat up a lot of rides out there for sure.
A new video will be required or come out on a Thursday or Friday night for the rolls over in Dallas. Your car will eat up a lot of rides out there for sure.
If your car is shifting before 7000 rpm your cam is too small!
07-06-2019, 07:25 PM
Cam guru's, come on in
