1.6 head modifications

[Grumpa]

How far can I take a 1.6 head and still be legal? cc the chambers? Radius the valves? Take it to .025 below service limit? Whatever I can get away with? Get a BSI rebuild and fuggedaboudit? Your thoughts, Mr. Linerud, and all others who stumble across this post.

[racer_tim]

You can do a triple cut on the valves, and port match the head 1" into it, but that's about it.

Get BSI (www.bsiracing.com), Shine (http://www.srsvw.com) or Jose Rotger (http://joserotger.hypermart.net/Porting%20services%202.htm) to prep it, and be done with it.

Nope, you can't cc the chambers, or go with the 7mm valve stems.

Don't open yourself up for protests / problems with competitors for blatent infractions. It's not worth it. Once your label'd as a cheater, it's hard to loose the label.



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Tim Linerud
San Francisco Region SCCA
#95 LP GP Wabbit
http://linerud.myvnc.com/racing/index.html

[Grumpa]

Thanks, Tim, I appreciate the input. Curious about something, if you were racing a Scirroco before, why build a Bunny? Isn't the Scirroco a slicker car dragwise? The Bunny looks like a brick next to a Scirroco. Gotta go, Mid-Ohio beckons this weekend.

[racer_tim]

I purchased the bunny in 1981 as my street car. I'm the only owner of that car. Then I decided to get into racing, I purchased an A1 Scirocco since I knew how to drive it, as well as maintain it.

I wrote off 2 cars in 2 years, and it took me 8 years to pay everything off. I used lots of the parts from the Scirocco to maintain my bunny, and I actually autox'd it a couple of years, before I parked it with a broken spring in the clutch disk, which fused it solid. Needless to say, with a leaking heater core, and a frozen clutch, I parked it, and then converted it to an ITB car in 2001, ran a couple of races that year, then converted it to Limited Prep GP last year, and am still developing / improving it this year. The car has the original paint still on it, and I'm the original owner. Still have the DMV records, though it's listed is "Non Operational" in California.

Yea, your right, the bunny is a brick compared to the rocco, but it's lighter because of it too.

Good luck @ M-O. I'm towing next Friday to Portland for the Rose Cup National the 13-14. First out of region race and first national. Wish me luck.



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Tim Linerud
San Francisco Region SCCA
#95 LP GP Wabbit
http://linerud.myvnc.com/racing/index.html

[Bildon]

>> Nope, you can't cc the chambers

CC'ing the chambers is part of the "blueprinting" process and is explicitly allowed.



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Bill Sulouff - Bildon Motorsport (http://www.bildon.com)
Volkswagen Racing Equipment
## 2002 ITB NYSRRC Champs ##

[Bill Miller]

[rules nerd mode]Bill, where is the spec for the chamber CC's listed? I've never seen it for any VW.[/rules nerd mode]

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MARRS #25 ITB Rabbit GTI
SCCA 279608

[Bildon]

Where is the weight for the big end of the connecting rod listed?



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Bill Sulouff - Bildon Motorsport (http://www.bildon.com)
Volkswagen Racing Equipment
## 2002 ITB NYSRRC Champs ##

[Bill Miller]

So, I guess you're saying that you can CC the chambers to match the smallest/largest one?

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MARRS #25 ITB Rabbit GTI
SCCA 279608

[evanwebb]

CCing is a head modification and is explicitly NOT allowed as I understand it. You are modifying the combustion chamber by grinding, right? Or are you just sinking the valves more or less to achieve the same volume? And where is the list of allowable things to be done in the "blueprinting" process kept? Or is it an imaginary list that is different for each person that reads that word in the GCR?

[metalworker]

You are confusing this. CC'ing is just a matter of checking the volume of the cylinder head. It's something that you really should do to make sure that your compression is OK. How deep you set your valves in the head, how much you shave off the surface and what kind of spark plugs you use, all contribute to the volume of the head. It's a number any good engine builder should know and provde. It's a result of modifications, not a modification itself.

[Grumpa]

Interesting, ask a simple question... Is the SCCA Competition comittee remotely aware of the ambiguity in the rules? It seems that the replys have a different take on what is/isn't permissible. Are the Tech people on the same page? I have read a number of posts on different subjects and get the feeling that what is legal in one region may not be legal in another. My confusion?