May Fastrack posted

Improved Touring
1. Clarify section 17.1.4.D.1.j. by changing to read as follows: Engines may be bored to a maximum of .040 inch over the standard bore size.
Factory oversize replacement pistons or their exact equivalent with the exception of diameter shall be used. Cast or forged equivalent pistons
shall provide the same dome/dish/valve relief configuration, ring grove width thickness and spacing, pin height relationship, weight no less than
the factory standard bore pistons, and compression ratio as factory replacement oversize pistons. Piston rings are unrestricted.


good move...
 
Really? It doesn't resolve the single biggest mystery of whether or not oversize pistons are legal if "factory oversize replacement pistons" aren't - or were never - available, up to 40-over.

K
 
"Factory oversize replacement pistons or their exact equivalent with the exception of diameter shall be used."

Kirk-

Seems clear to me... I am sure this could be tourtured, but I know your a changed man!!!

Raymond

PS: your car looks great ;)
 
Improved Touring
1. Clarify section 17.1.4.D.1.j. by changing to read as follows: Engines may be bored to a maximum of .040 inch over the standard bore size.
Factory oversize replacement pistons or their exact equivalent with the exception of diameter shall be used. Cast or forged equivalent pistons
shall provide the same dome/dish/valve relief configuration, ring grove width thickness and spacing, pin height relationship, weight no less than
the factory standard bore pistons, and compression ratio as factory replacement oversize pistons. Piston rings are unrestricted.
good move...
[/b]
Click to expand...

Jim, next time please post accurately...

The clarification should read as folows:

1. Clarify section 17.1.4.D.1.j. by changing to read as follows: Engines may be bored to a maximum of .040 inch over the standard bore size.
Factory oversize replacement pistons or their exact equivalent with the exception of diameter shall be used. Cast or forged equivalent pistons
shall provide the same dome/dish/valve relief configuration, ring grove width <strike>thickness</strike> and spacing, pin height relationship, weight <strike>no less than
the factory standard bore pistons, and compression ratio as factory replacement oversize pistons.</strike> Piston rings are unrestricted.

Raymond "Thank you for the clarification" Blethen
 
Improved Touring
1. Clarify section 17.1.4.D.1.j. by changing to read as follows: Engines may be bored to a maximum of .040 inch over the standard bore size.
Factory oversize replacement pistons or their exact equivalent with the exception of diameter shall be used. Cast or forged equivalent pistons
shall provide the same dome/dish/valve relief configuration, ring grove width thickness and spacing, pin height relationship, weight no less than
the factory standard bore pistons, and compression ratio as factory replacement oversize pistons. Piston rings are unrestricted.
good move...
[/b]
Click to expand...


"Factory oversize replacement pistons or their exact equivalent with the exception of diameter shall be used."

Kirk-

Seems clear to me... I am sure this could be tourtured, but I know your a changed man!!!

Raymond

PS: your car looks great ;)
[/b]
Click to expand...

Funny, I read it the other way :P

Read the first sentance first and alone, it's the only place where maximum size is stated. Even the second sentance you quoted indicates that exact equivalent doesn't extend to piston diameter. Even If you ment it tounge in cheeck, there's enough mis-information on the internet, and I regret any I may have posted.

James
 
Really? It doesn't resolve the single biggest mystery of whether or not oversize pistons are legal if "factory oversize replacement pistons" aren't - or were never - available, up to 40-over.

K
[/b]
Click to expand...


They could have written that a lot better.
 
Jim, next time please post accurately...


Raymond "Thank you for the clarification" Blethen
[/b]
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Yeah, I guess the copy/paste thing didn't pick up the formatting from the PDF file. I'll have to hire a new proof-reader for my posts...good help is hard to find :P

Jim "should have read the post after posting" Cohen
ITS66
 
Guys... It looks to me like the printing of this rule clarification is all wrong... There are parts struck out that shouldn't be... etc... This isn't how we had it in our notes...

I'll see if I can get it clarified...

Basically, .040 over is suppose to be CLEARLY allowed for all IT cars, but must be no lighter than the STANDARD BORE stock piston... all other dimension requirements remaining the same... The allowance being based on the availability of "factory replacement oversized pistons" is suppose to be eliminated...

When I get home tonight, I'll look over the notes and get a letter in the the tech department to get this printing corrected, or otherwise straighten this up...

I think this is how it is SUPPOSE to read:

Improved Touring
1. Clarify section 17.1.4.D.1.j. by changing to read as follows: Engines may be bored to a maximum of .040 inch over the standard bore size.

Factory oversize replacement pistons or their exact equivalent, with the exception of diameter, shall be used.

Cast or forged equivalent pistons shall provide the same dome/dish/valve relief configuration, ring groove width and spacing, pin height relationship, and compression ratio as factory replacement oversize pistons, and weight no less than the factory standard bore pistons. Piston rings are unrestricted.

[/b]
Click to expand...
 
"They could have written that a lot better."

Isn't that usually the case? :bash_1_: Who is the "they?" I have been complaining about rules drafting for quite awhile now but nothing seems to change. BTW I don't run a piston engine so maybe I just don't know, but what is a ring GROVE?
 
Ring grooves on the piston holt the compression and oil rings into place. So the rule as I read it wouldnt allow you to use a thicker ring then what comes in stock form.
 
BTW I don't run a piston engine so maybe I just don't know, but what is a ring GROVE? [/b]
Click to expand...

Isn't that where you plant a bunch of rings in long rows, then wait for them to ripen so you can pick them? :D
 
Isn't that where you plant a bunch of rings in long rows, then wait for them to ripen so you can pick them? :D
[/b]
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Well, in ther interests of absolute accuracy, no.

That would be a ring roe...

A ring grove has the rings planted in a more randome, but grouped pattern..

And yea, not sure what happened along the way, but the rule is indeed not as we intended, nor drafted.

Basically, the goal was to eliminate the loophole that allowed you to make any piston you wanted if your manufacturer didn't supply a 40 over. The new rule will allow you to use any 40 over in any engine, but the piston must match a stock piston, (with dimensional exceptions as noted) and must not be lighter than a stock piston. Before, if you were building a car with no factory 40 over, you could legally make a piston that weighed mere ounces and was way out of the desired scope of the rule.
 
Engines may be bored to a maximum of .040 inch over the standard bore size.

Factory oversize replacement pistons or their exact equivalent, with the exception of diameter, shall be used.

Cast or forged equivalent pistons shall provide the same dome/dish/valve relief configuration, ring groove width and spacing, pin height relationship, and compression ratio as factory replacement oversize pistons, and weight no less than the factory standard bore pistons. Piston rings are unrestricted.[/b]
Click to expand...

I think it is definitely clear in the language that any IT pistoned car can overboar .040 inch. The piston language has gaps I believe.

If a factory oversize is available - I assume by the language an exact equivalent can still be used.

We have discussed in other places before that exact equivalent also means material and I assume method of forming said material? However, the last section would seem to have gone to quite some length to lay out all metrics which determine exact equivalent and I don't see forming method.

So could one walk away from reading that rule with the following:

A motor that has .040 over cast pistons available, can use exact equivalent as defined forged pistons instead? I think so based on the language, but do not know if it was the intent.

If it wasn't the intent, then if standard are cast and an over bore size is not available and someone is going to use e.e. pistons, then e.e. should also be defined to include forming method and the e.e. in this case should be cast as well.

But I don't think the language says that.
 
I might not have said this before but I think "they" should have kept it simple and said that factory replacement or their exact eqivelent must be used. It would have made the cars a lot cheeper to build, and more stock. Now if I want the best motor I need to find someone to build an Audi piston that is .040 over rather than use a factory replacement .020 piston... stupid and expensive, but hey I just enforce the rules... :rolleyes:

blah, I think its stupid, but I admit I did nothing to encourage the rules to be written either way, I just simply wanted to see it clarified and spoke to a few people.

Raymond

PS: as for typo's miss spelling is ok by me, so long as I can read it still!!! lol we should have spell check and gramar check like "Word" on this forum!!!
 
OK, Raymond, but how much will the 40 over get you? How much more that is, than the 20 or 30 over that you can get inexpensively?

I bet it's miniscule. That's a bit of diminishing returns....if someone wants to spend it, let them. It actually makes your job a lot easier...you won't have to figure out if the car could or could not have 40 overs...all that needs be done in a protest is procuring a new piston...of any factory size, and measuring the required items, and checking weight. I think it actually is simpler than you think.
 
Before, if you were building a car with no factory 40 over, you could legally make a piston that weighed mere ounces and was way out of the desired scope of the rule. [/b]
Click to expand...

I disagree that it was legal by ANY stretch, but admit that some have built like this who will claim "There was no spec so I can do what I want..."

:bash_1_:

AB
 
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