Overrev ?

[LM5000]

Guys, I have just installed a rebuilt engine about a month and a half ago. The engine consisted of 308 cu.in. with ported stock head, and E-cam with forge piston, etc. After the car broke in at 500 miles, I decided to test the car (before that I was babying it) and took the car for a spin. First gear, rev the engine to about 5500 RPM and shift!! WAHHHH !!! gas pedal stuck on me, I shut off the engine right away and let the car roll down to stop. Pull the cable back to its position, started the car and found nothing wrong and drove the car home.
3 weeks later, normal driving to pick up my son but when I parked the car, I heard a loud ticking noise coming from the driver side valve cover. Drove for a couple blocks, the sound was getting louder so I stop the car and called shop owner who built and instlled the engine for me and he sent a tow truck to pick my car up.
The next day, he told me that I overrev the engine which broke lifter keeper damaged the lifter and destroyed the cam. My engine has 12000 miles or 12 months warranty from him unless the engine suffered from overheat or overrev. Another word he was trying to say that it was my falut. My question to you guys are " If I really overrev the engine, why my car still running good for another 3 weeks ?" If I floated the valve like he said, wouldn't the damaged be exposed right away? Are there any other reason for keeper to break like that ?
Any help, I would greatly appreciated because I am very upset right now.

[T5superduty]

It must had gone way past 5500 for it to go out like that. The E cam is meant to be taken to 6500 no problem. The guy who built it sounds like he is gunna stick ya on this one. Sorry to hear about that man. Mabye the timing was off or it really went to like 7500 8 grand ?

[420nitro]

Generally when you over rev an engine, you have a failure of some sort right away. I honestly believe you have a defect in your valve train and he is trying to get you to pay for it.
When you over rev an engine and the valve train starts to float, the first thing that usually happens is the valve hits the piston. I have over rev my engine by mistake (with the rpm pill out) and never broke a keeper or retainer. (the motor went 7,000rpms) Now granted I had decent parts but never the less your valve train needs to match the cam. I would fight him on that, at least have him pay for half, and get better parts. As goes for the E-cam it suppose to make peak power at 6,000 rpms unless you have had the cam installed 2-4 retarded for a higher shift point. But don't forget that you are still running a hyd. roller cam and the stock type lifters will float at approx. 6500 rpms. To exceed this point will require trick and expensive titinum valve train parts.
Good luck

[Dark_5.0]

If your car still has the stock rev limiter you didnt overrev it.

[420nitro]

That's right Dark50! I totally forgot that! Yea, if he has the stock computer he did not go over 6,250, and if that is true then it really is a part defect or the tech f-up on the work.
Yea, I would definitaly go in there swinging now!!

[Jeff Chambers]

A broken dog-bone will result in the lifter spinning and cam damage within mere seconds of the dog-bone failing. Seen it happen several times. The dog-bone failure had nothing to do with your stuck throttle cable. Failure of the dog-bone is actually more common than you might think. IMHO, you are well within your rights on the warranty.

[andy669]

I agree with Jeff 100 percent.

Did you ever figure out what made the throttle cable stick wide open? Maybe they bent a bracket or kinked the cable when installing the engine. That could be their fault as well.

420Nitro Be careful. You might find somebody on here that revs their motor to 8000 with stock unmodified lifters and lightweight nothing.

Andy

[Jeff Chambers]

That's right Andy.....8000+ on stock lifters, stock dog-bone and heavy stainless valves. Don't let anyone tell ya it can't be done.

[Tony Frank]

ive had my throttle stick once on my 85, turns out it was just my stupid floormat that slid up towards the pedals. when i did it it was at the track spinnin my tires to clean them off a bit before i came to the lights. i went up to approx 7500 rpm and shut it off. nothing happened to my motor and no noises. i have stock heads and motorsport double wound springs. id say argue for him to cover it under warranty.

[LM5000]

Thank you guys for the responded. Well, when I tried to shift to second gear that's when it stuck. At that moment the car was not under load, another word it was in between gears. The shop owner gave me some lecture about overrev theory and he said he is going to eat all the cost but my warranty is now void. I said to myself what the hell because I am totally broke and can not get over the idea of spending another $800-900. Besides, I'm going to spend all day arguing him about my theory. The guy fixed it in one day and he showed me the keepers, lifters and the cam which by now is nothing but a whole bunch of scrapped metal.
Now, if I installed the rev limiter and let say it happens again (when the engine is not underload) will it protect the engine or it's working only when it underload just like stock limiter? What setting should I set the limiter to, anyway ?
I have changed the cable now, checked throttle body and everything else that has to do with the acceretion and hopefully nothing like that would ever happened again.

[Jeff Chambers]

Fixed it in one day? Where do you figure all those little chunks of metal went to? IMHO you're only headed for more problems on down the road.

[420nitro]

Originally posted by andy669
.
420Nitro Be careful. You might find somebody on here that revs their motor to 8000 with stock unmodified lifters and lightweight nothing.
Andy

OK, you got me intrested!!!
How do you do that, or is it one of those secrets that I will have to do some digging for?
Come on.....Come on...spill the beans .
Thanks, you can even PM if you want???

[Jeff Chambers]

How do you do that, or is it one of those secrets that I will have to do some digging for?

There's alot that goes into being able to do this, the first of which is competent engine building with exacting attention to detail. You won't get there with any production line engine building IMHO.

Cam design plays a critical role as well. Not just the usual duration, CL and lift issues, but ramp rates and lobe profiles are more important. I've got similar duration cams with significantly different profiles where one cam launches the lifters at 6000rpm but yet I can spin the other to 8500 without floating anything.

Spring packages. I'll often try four or five different spring packages before finding the spring package that works best. Again, seat and open pressures are not the only factors. Different spring materials, windings and springs in general react differently. Some springs work great with hyd rollers while others are meant specifically for flat mechanicals. I'll also swap springs out on the average of about every 30 passes and lifters about every 60 passes. There's nothing wrong with either at this point, but its cheaper to maintain the valve train than it is to reconstruct a failed motor. This is why you'll see several sets of lifters and springs for sale on my website all the time.

Valves & heads. Reaming and honing valve guides, and replacing the valve guides at the first sign of wear is crucial. Got to keep those valves running true. The valve job also has an effect on whether the valve will land softly or bounce off the seat.

Valve train. Attention to detail is key here. Perfect alignment and geometry is a must. Slight changes in geometry can have a huge effect in performance.

[420nitro]

Thanks for the info!!