legal to remove casting marks?

C

Chris Sawatsky

New member
is it legal to remove the casting marks on the inside of intake manny/head?

it seems to me that it would be, since the casting marks were not designed to be there in the first place
 
LOL... good justification.

I would say, that if all the casting marks were within 1" from the port opening, then yes, otherwise a big fat no

------------------
Scott
It's not what you build...
it's how you build it
 
The other side of the coin is that I've used a lack of casting marks as evidence that something illegal had been done, in this case to a Rabbit intake manifold.

Carbs were removed at tech and it was obvious looking down the hole that the plenum on one car had been cleaned up and then perhaps sandblasted to mimic the as-cast finish of the OE part - evidence being the lack of the mark that they all have.

K
 
At the risk of infuriating the rules nurds, blue printing is legal. If the casting marks were not intended by the factory, they should be removed during blue printing by any good engine builder. The fact that one car does not have them is not prima facia evidence of cheating. Chuck
 
The rules state "balancing & blueprinting permitted, but lightening parts beyond the minimum material removeal necessary to balance is prohibited."

I would think that casting marks or seams would be the preferred area to remove material for balancing without weakening the part, in the case of con rods or cranks, for example. But you can't go nuts with it.

BTW, I liked the old Pro S2000/Pro Olds rules. One con rod had to remain absolute boe stock with absolutely nothing done to it. You could do what ever you wanted to the other 3 rods to match the stock one.

Yes it means going thru dozens or hundreds of stock rods to find the lightest one for the baseline, but it does provide a means of defining 'required to achieve balance' since you wouldn't gain lightening to extreme limits.

[This message has been edited by Greg Gauper (edited March 06, 2004).]
 
Yeah, but don't stop at D.1.k - the next clause specifies that...

"Manifold and cylinder head port matching is permitted. No material may be removed further than one (1) inch from the manifold to cylinder head mounting face(s)..." (italics mine).

Not that I wouldn't be entertained by someone trying to demonstrate how they established blueprint tolerances to "balance" the intake manifold, you are explicitly prohibited from removing any material from the intake more than 1" from the gasket surface.

Within that dimension, balance away!

K

EDIT - Read the definition of "Blueprinting" as well. There are several aspects that make what is described here outside of the rules.

[This message has been edited by Knestis (edited March 06, 2004).]
 
I didn't mean the intake manifold. My response was meant as a more general statement as far as blueprinting.

I agree that it wouldn't be legal for an intake except for the 1" rule.

My response was where I felt the only legitimate area to remove casting marks.

Although....it just says 'balancing' not 'balancing of rotating or reciprocating parts'. Hmmmmm....when I pick up my intake, one end is much heavier then the other
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Hmmmm....Loophole? I promise I'll only take off enough to make it balance.
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I disagree here..

The rule states that blueprinting is permitted. The 1" rule is stated in a later paragraph about port matching. My interpretation is that any action commonly associated with blueprinting is fine. IF that means casting mark removal, so be it.

Again, the 1" rule is only associated with port matching, by fact that is is referred to in that paragraph.

Rules creep can work both ways.
 
eh_tony, I agree to disagree with you on blueprinting per YOUR description.
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Please re-read GCR glossary Blueprinting including point B).

I agree with Chris that the casting marks/gates/flash whatever were not designed to be there. But they are there by manufacturing process & per GCR glossary blueprinting definition you may CLEAN but you may not REMOVE or MODIFY the base material of the original part. A cast surface is not a machined surface.

eh_tony, what do you beleive after re-reading ?

Have Fun
wink.gif

David

ps: I know picky, picky, but that's the way I read/understand the rule.

As an edit thought: IIRC Tom Feller H Production Limited prep got busted in tech at the 2003 Runoffs for some such material removal in the intake manifold.

[This message has been edited by ddewhurst (edited March 06, 2004).]
 
Originally posted by eh_tony!!!:
The rule states that blueprinting is permitted. The 1" rule is stated in a later paragraph about port matching. My interpretation is that any action commonly associated with blueprinting is fine. IF that means casting mark removal, so be it.
Click to expand...

Egads. Now that's torture.

I wish the word "blueprinting" was not in the ITCS. That is a term that has as many definitions as there are people to utter it.

I'd suggest that in the case of a race engine, blueprinting is simply building to the limit of what the rules specifically allow. Which BTW does not include removing material more than 1" past the mounting face.


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
at this point I'm just playing devil's advocate, I'm not really all that hung up on removing casting marks...


My understanding of the term "blueprinting" in this context, is that you build the engine EXACTLY to the design specifications, with tolerances of zero.
As a rather arbitrary and completely unrealistic example, if a cylinder bore was, by design, 10", but the acceptable manufacturing tolerance was 0.5", you stand a good chance of getting a brand new car with a cylinder that is not exactly 10". The blueprinting process would see the cylinder bored/sleeved/whatever to exactly 10"
By this definition, blueprinting the engine would allow you to remove casting marks.
Now, one's definition of "engine" is called into play, as you question whether "engine" includes the intake manifold, or refers specifically to the block, or block + head, or whatever.

Wow I'm glad I race in an area where rules are "loose"
not to say I don't try to follow them as closely as possible.
 
Originally posted by chuck baader:
At the risk of infuriating the rules nurds, blue printing is legal. If the casting marks were not intended by the factory, they should be removed during blue printing by any good engine builder. The fact that one car does not have them is not prima facia evidence of cheating. Chuck
Click to expand...


Chuck you think like I do, LOL
 
Originally posted by chuck baader:
...If the casting marks were not intended by the factory, they should be removed during blue printing by any good engine builder...
Click to expand...

The roughness wasn't designed to be there either so forget the 1" rule and polish everything too.

Grafton
 
Actually, when manufacturing there is always a surface finish specificied..at least there was when I worked for Ford. It was usually a maximum level of roughness acceptable, therefore, polishing would be illegal. chuck
 
Originally posted by chuck baader:
Actually, when manufacturing there is always a surface finish specificied..at least there was when I worked for Ford. It was usually a maximum level of roughness acceptable, therefore, polishing would be illegal. chuck
Click to expand...

Like you said, maximum roughness allowable... so an Ra value of 0.000005 micron is almost surely permitted per the OEM prints.

You might just win on appeal if you can come up with some certified copies of the prints. Or better plate the inside, polish that and call it a lubricant... unless you follow to COA reports you've seen that one before.

[This message has been edited by GKR_17 (edited March 09, 2004).]
 
Originally posted by eh_tony!!!:
The rule states that blueprinting is permitted. The 1" rule is stated in a later paragraph about port matching.

<snip>

Again, the 1" rule is only associated with port matching, by fact that is is referred to in that paragraph.
Click to expand...

Actually, the rule is about as explicit as tehy come. I don't know how you could interpret it any other way.....

"No material may be removed further than one (1) inch in from the manifold to cylinder head mounting face(s)."

I don't see any room for interpretation there.


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
...and - even though I'm traveling and don't have my GCR with me right now - the definition of "blueprinting" allows the optimization of machined surfaces: An as-cast portion of a manifold is NOT a machined surface.

I'm with Geo on this. It takes some pretty tortured word games to rationalize doing something that the rules do not specifically allow.

K
 
FWIW I ran this past a Steward who has been in this game for a while.

He is of the opinion that as the manifold is listed as a seperate item, the intention of the Comp Board when they wrote the rule is very clear; you can not touch the inside of the manifold past the 1" point.

To call polishing "blueprinting" is going to be a very hard sell. The first thing the Stewards will ask for are the factory blueprints showing the designed interior configuration of the part. Got 'em?
 
It doesn't change the final answer but I was surprised at the GCR definition of engine, in the sense that it included all of the stuff that it does...

K
 
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