Challenger Drag Pak Owners

[Chris "drooze" Wertman]

Stockers often run some very close P-V clearances and it sounds like you need to be checking this.

Already done, lots and lots, clay didnt even touch at over .100 same cam, no advance.

I added a 4 degree advance on this install...so if anything, I would be getting closer on the intake side.

This motor (same setup not same motor) has gone to over 8k without P/V issues..... And this motors deck heights are a hair lower than the last.

I am not familair with any of these engines or the valvetrain layout.

The way the exhaust rocker is, if the clearance (and we Did NOT use stantons keepers as they were heavy for me) but I will, that could have been out issue, on the last motor the valve train was picture perfect albeit saw other failures, we simply replicated it....

BUT on this motor with the Valve job and seat work, well it looks like the valves may have moved up .010 or so, closing up the rocker clerance, because of the odd short throw they could possibly and I say possibly end in a jam up or lockup condition. It would appear.....

Warped valve stems is a new term to me....
Of course with the questionable quality of the parts out there today anything is possible I suppose.......

The valves are made in Argentina....true....nuff said.

Your valvetrain is your most critical area in most any race engine and that has always been my view......You break something on top and it often leads to catastrophic failure.....

Couldnt agree more, well be "ironed" out before were running, and right.

[johnny shot]

"Only left scuffing a light tip on the valve pocket of the piston"

Seems to me on more than one occasion guys in tear down have been bounced for piston to valve contact leaving a mark on the piston....... Granted they were flat top or dish pistons but I think a mark on a piston is a mark on a piston. I'd be double checking my double check.

[Chris "drooze" Wertman]

Explain how to me you could get bounced for that ?

That seems like getting boucned because you have scores on your cylinder walls, or signs of predet on your pistons. Or any one of a 1000 other , wear items....

The rules specifically says, "

Piston may not be remachined for special rings, deck
height adjustment, valve relief size, depth, location, or to modify

dome or dish."

A piston tap in NO way shape of form qualifies under that, as well it would actully be ILLEGAL to Correct the damage, in our case Im lucky I dont have to , it is as I said a scuff....

NOW if there were legality issues that caused this I could see that, IE, over lift, or improper deck height.

Our deck heights have been checked by stanton and by us...kosher. Pistons are Kosher, Cam is Kosher....so

Explain to me how they could "bounce you" for a LEGAL setup ?

Originally Posted by johnny shot

"Only left scuffing a light tip on the valve pocket of the piston"

Seems to me on more than one occasion guys in tear down have been bounced for piston to valve contact leaving a mark on the piston....... Granted they were flat top or dish pistons but I think a mark on a piston is a mark on a piston. I'd be double checking my double check.

[johnny shot]

I guess you have yet to be welcomed to a tear down party. It's hard to figure who gained piston to valve clearance on accident from unintended contact, and who gained it by a whack of the hammer on the end of a valve stem with the piston at TDC. Not that anyone would do that......

[Chris "drooze" Wertman]

I could see that on all 8

On 1 I couldnt, and there is an appeals process.....Nor could any reasonable tech.

Especially when that 1 isnt even the "highest" of the 8.....

Diamond pistons.....nuff said....

Originally Posted by johnny shot

I guess you have yet to be welcomed to a tear down party. It's hard to figure who gained piston to valve clearance on accident from unintended contact, and who gained it by a whack of the hammer on the end of a valve stem with the piston at TDC. Not that anyone would do that......

[johnny shot]

Hey, I'm on your side, just passing on real information on what has happened in the past. But to address a few of your questions, all your stuff could be "kosher", and still have contact. And I know you know this, but with duration not being speced, that could be the cause of contact, not just lift on a "legal" setup. And as you quoted from the rulebook, it does not say 1 of 8 is ok, or 2 of 8 is ok, its says it can not be modified. It does not say modified on purpose, or modified by accident. If you have two identical engines in tear down and one has "scuffs" on the piston or pistons and one does not, there may be a problem. A piston with a mark in it from contact with the valve is modified. From first hand experience you don't want to have a judgement call made at your expense. Carry on.

[Chris "drooze" Wertman]

Understood and appreciated....

In our case I know its not the duration or float, the clay test prior showed we were wayyyyy good.

On top of it the prior engine with slightly higher deck measurments was fine at 8k

Thats what leads me to believe something had to "stick" to cause this contact no other reasons exist...the cause of the stick ? But Ill be dammed if Im buying a $1500 set of pistons becuase a scuff on 1 of em..... Ill just richen it up a few passes carbon will hide it

The rules says Machined, in terms to the valve pockets, On these pistons the valve pockets correspond to the valve angle so when it hits it hits flat, which in this case was nice because it didnt "ding" the piston, rather left a scuff I could proabably clean off with scotchbrite.....

Originally Posted by johnny shot

Hey, I'm on your side, just passing on real information on what has happened in the past. But to address a few of your questions, all your stuff could be "kosher", and still have contact. And I know you know this, but with duration not being speced, that could be the cause of contact, not just lift on a "legal" setup. And as you quoted from the rulebook, it does not say 1 of 8 is ok, or 2 of 8 is ok, its says it can not be modified. It does not say modified on purpose, or modified by accident. If you have two identical engines in tear down and one has "scuffs" on the piston or pistons and one does not, there may be a problem. A piston with a mark in it from contact with the valve is modified. From first hand experience you don't want to have a judgement call made at your expense. Carry on.

[hemidup]

PTV contact? Ask Jason Line about it. He won his very first National event at BIR with his Buick GN. Upon tear down, it was noticed that there was PTV contact and his win was taken away.

Wasn't your new cam ground with a 4* advance already?

[Chris "drooze" Wertman]

Nope I had it ground straight 0

Originally Posted by hemidup

Wasn't your new cam ground with a 4* advance already?

[Chris "drooze" Wertman]

A note confirmed by Bruce B.

PTV Contact is NOT a DQ, it USED to be , it is NO LONGER. That when DURATION was in the mix.

#24 Is BACK Together and Ready for Testing.

Valve issue, combination of issues either my fault, clearances on Rocker setup and retainer choice, valve job was more aggresive and cutting of valves on this head setup, clearance I didnt like, looks like I had reason not to caused Lock condition on exhaust rocker. Confirmed by Pro Stock head guy that did our heads (independently), solved, reassembled.

See some track Saturday......

Adding second fuel filter and different alternator pulley

Zip Zap relax..........

Originally Posted by hemidup

PTV contact? Ask Jason Line about it. He won his very first National event at BIR with his Buick GN. Upon tear down, it was noticed that there was PTV contact and his win was taken away.

Wasn't your new cam ground with a 4* advance already?