This isn't supposed to look like this, right?

[bruce]

Damn heavy right foot...

[471Magnum]

That's not good.

How does the piston look? Everything else stay together? Did the push rod and lifter stay in place?

[bruce]

Surprisingly the piston looks pretty good--a couple light marks and a ding... the cam and lifters amazingly still look like brand new. I may have lucked out about as well as I could have. Only about 2,000 miles on this engine.

[471Magnum]

So what triggered it? Over revved, part failure or questionable guide clearance?

[bruce]

So what triggered it? Over revved, part failure or questionable guide clearance?

At the risk of sounding like a smart ass, my right foot.

[71bird]

Now that looks like one of those around the corner hi flow valves.

[dangina]

Now that looks like one of those around the corner hi flow valves.

I heard you get about 10 more hp!

[moparite]

Time for stiffer springs!

[71bird]

Now that looks like one of those around the corner hi flow valves.

I heard you get about 10 more hp!

Yes but you have to re machine the ports and seats to match, then you get the hemi effect. Very tricky, but stealthy, a twisted Hemi with wedge valve covers.

[Doright]

Damn heavy right foot...

Not cool
2000 miles on a rebuild? I would be talking to my engine builder
Don't care how bad your foot was in it that's a dropped valve. NOW IF ALL 16 floated and kissed the pistons Then I would say Ya your fault as you floated them, But They are all bad not just one or two!!!
All will have kissed the pistons not just one or two if you floated the valves, some lighter than others some harder than others due to spring set up.
I have been guilty of this myself once or twice

That said I would be inspecting Keepers retainers springs. Personally I would throw all away buy all new.
I always use New hi quality springs retainers and valves in any engine I build. these parts while reusable in many cases do have a cycle life.

Also if you suspect you did indeed floated the valves and you used Cheap Cast pistons during your build I would inspect ALL of them VERY carefully for cracks. I personally would discard any Cast OR Hyperconetict Piston that kissed a Valve.

[bruce]

It's really a long story and not entirely the engine builder's fault... It wasn't the result of one catastrophic event but rather happened after a related series of events... My lack of mechanical ability as well as my heavy foot played a factor. Have some really good guys working on the car and they've been thorough in checking it all out. So thankfully everything is cool and the engine is going to be okay.

[Doright]

I am a Pro mechanic and a licensed certified engine builder, I was just offering my opinion.

I will try to explain Valve float a little better, Perhaps you now know what it means but perhaps others reading this do not understand it so clearly so I would like to try and explain it a bit better.

There is a Tad bit of info on any Good Cam mfg Cam card you should know its called "Valve float"
On the Cam card you will find the words "Valve float" and an RPM # This is the RPM at witch the valves will float with the recommended Valve springs assuming that the Valves and springs are set up properly per the Cam mfg recommendations This is a DO NOT EXCEED RPM!!!! Your RED LINE!

A little description of what Valve float is:
Valve float is an RPM at witch the Valve springs can no longer Keep the Lifters in solid contact with the Cam shaft lower part of the lobe what happens is the cam is spinning so fast basically just the top of the Lobe tip is skipping hitting the bottom of the lifter and the Valves never get to follow the cam lobe profile so it can fully close in proper timing in relation to the Cam profile & timing with the piston.

The Lifters actually bounce off the Top of the cam lobe and the valve floats open never closing pounding on the Cam lobe and lifter, The Cam lobe is skipping on the bottom of the lifter and the Valve is actually floating open when it should be closed and the piston hits the valves.

ITS not just one Valve when it happens it's ALL of them, The cam and lifters are destroyed in most cases.


Its a no brainier that all of the Valves need to be checked for straightness after this occurs but ALSO there is a need to check the Valves for stretch as well and microscopic cracks in the valves themselves. A good builder will be able to check Valves for straightness AND for stretch if you corner him into it, this requires a Tulip template of the Valve available from the Valve mfg. If you know who made the valves?
Checking for Micro cracks requires expensive equipment that not many builders have That's why Most engine builders would prefer to just trash all of the Valve train and start over.

The Valve springs should also be rechecked for proper spring pressures opened and closed and correct installed height etc. etc..

I have seen the extreme Harmonics induced into the valve train at Hi engine rpms with Hi-speed cameras at normal operating ranges for a cam and then again at full valve float, trust me your better off trashing the whole set up and starting over, especially in a Hi RPM engine that see's Hi rpm on a regular basses. Its just not worth the wasted effort and reliability still being questionable with the used parts.

Now If this is just ONE valve and one valve Only.

The spring retainer OR Valve keepers/locks Or the Valve itself Have failed OR the Valve Guid to Valve stem clearance was or is incorrect. All of these come under the engine builders responsibility as He should have inspected these parts thoroughly or used New certified parts, Holding your engine builder responsible for a Failed valve is pushing it a Bit but were they inspected properly before use? especially if and when reusing old used parts or valves?????
This would include Valve straightness Valve stretch and checking for microscopic cracks in the Valve stem Base and Tip with close inspection of the area of Valve lock keeper groves. Probably not as this would require a Eddy current magnetic particle inspection under ultraviolet light or Xray.
Most shops don't have these kind of machines and so they cant fully inspect these parts and that's why most sane builders will not warranty these parts and why Most builders suggest or demand new parts.

Eddy current Machines have the advantage of showing Microscopic cracks under the surface of a machined parts surface before they fully mature and fail in use, in what looks like a good part too the naked eye
Cracks appear as faint lines under the Ultraviolet light across the surface.

Don't confuse this description with ordinary Magnetic particle inspection where a Powerful electro magnet is used to magnetize the part surface and a dry powder is gently dusted over the parts to show cracks.

Eddy currant machines Use a Large Coil in which the whole Part is passed threw Magnetizing the whole Part allowing you to see deep inside the grain structure of the metal after the inspection the Part must then be Degaussed by passing the Part back through the coil again.
These machines are Very expensive and Very dangerous to use, You can be killed by them easily as very strong electrical currents are used. Generally these machines are only found in aircraft engine builders shops OR Propeller shops To inspect various engine & aircraft parts.
If your lucky enough to have a Good aircraft engine builder in your area they will inspect any part for you in this fashion for a few bucks especially if they aren't sighing a Yellow tag or 337 form for the Part certifying it for use in an aircraft that's where the big bucks come in at.

I'm kinda Lucky My Machinist has one of these machines and I can get him to inspect anything for me.
He also Builds and Leases Racing engines, his engines go entire seasons without failure.

There is a lot more to building a Reliable engine than just boring the block turning a crank and doing a cheap valve job witch in most cases is fine for a grocery getter or your Saturday night special in most cases.
But if you wanna turn some RPM every now and again find a good engine builder and let him do his job this means Tell him exactly what you want the engine to do and what you expect from it when he is done and what you expect for a warranty after the job is completed and DON'T argue with what he does or wants as far as parts go or the price of all of it when hes done just smile and sign the check.
AND most important of all Don't change your mind of what you want part way threw the process! This is the number one complaint of engine builders the 2nd is the owner wanting to reuse old parts or parts that are miss matched for the combo.

I Build very Reliable very powerful engines that don't fail.

[bruce]

She's back! Click on it...

[quapman]

Awesome. Now if you could just get the electrician over there....

[bruce]

Yeah, I've come to the conclusion that I will NEVER be done messing with this car... there's always gonna be SOMETHING to diagnose, chase down, hassle with, etc. It is what it is, a 42-year-old POS, but at least it's MY POS.