Classic Production Questions

[CTX-SLPR]

Howdy,

Blame HRM for getting me interested in LSR again. After reading the breakdown of the classes and noticing Classic Production Supercharged for supercharged cars up to 1981, it got me thinking about the early turbo Buicks.
Some questions about "modifications" and if they would still leave the car in the CPS body class.
1. The original turbo Buicks were draw through carberated. This sucks (literally) and I'd like to change it to a blow through. Is this legal?

2. Is electronic spark control legal despite the fact that EFI is not for any Classic Production car?

3. What are the restrictions on aftermarket parts for the stock engine type? I.e. can I run aftermarket aluminum heads or Indy race heads on a stock block or even an aftermarket race block?

4. Stroking/Destroking, can I stroke a 252cid V6 into the the 260cid+ class and likewise destroke a 231cid into the 181cid class?

5. Is there such a thing as an F engine for a domestic Classic Production (Supercharged)? Seems like the carbed Ford 2.3L SOHC turbo, Corvairs, and if destroking is allowed 3.0L Buick V6 would really open your engine options up for this class.

Thanks,

[DanStokes]

Basically, engine mods are wide open as long as it would be possible to bolt on the stock intake and exhaust manifolds. You don't have to run them but they have to fit. Porting, etc. is fine.

My rule book isn't sitting right here but I suspect that there IS an F engine class. Best bet is to contact the ECTA (<ecta-lsr.com>) or SCTA and buy the book (they parallel each other pretty closely). Allowed engine classes are called out. Only the specified classes are supported.

Yes, you can alter displacement as long as you declare your actual cubic inches. ECTA relies on your personal integrity but SCTA WILL check if you set a record.

Not sure on the electronic spark control. Remember, the idea is to run as/was "back in the day", hence no EFI. I ran a Pertronix distributor with a rev limiter and that was OK but it didn't control the spark. One of the officials needs to chime in on this one.

Hope that helps
Dan

[CTX-SLPR]

Thanks Dan, yes that is a big help.

I ask about the F engine is this: http://www.scta-bni.org/Rulebook/bcwe.html
Only shows E being the smallest engine while C is the largest. I can see a lot more factory cars fitting into F/CPS of both domestic and import manufacture than into C/CPS. Odd.

Anyway, the rule on being able to bolt on factory intake and exhaust definately excludes the Indy and other "Stage" race heads as the lobe order on the cams was changed to a symetric order vs. the "paired" order of the stockers meaning the intake and exhaust won't fit. There are however several different aftermarket aluminum units and ported stock iron heads that would still work.

I'm thinking 1981 Buick Regal with a 3.8 converted to blow through carb turbo. 3.8's are easier to find and slightly beefier than the larger bore 4.1's. Aftermarket supply is pretty good too.

[DanStokes]

I don't know what the reasoning was behind the decision to include or exclude certain engine sizes. You can always petition the committee for that class and request the addition. Classes are added and/or deleted from time to time and other changes are made so it's worth asking. For example, this year Comp Coupe (IIRC) was allowed a rear wing with no limitations - I suppose to try to keep them from flying. Pretty sure someone requested the change and they eventually supported it. No clue what that process looks like.

Dan

[Dynoroom]

Yes, as long as you run the same type of power adder you're good.

As long as you run the factory unit. You must supply supporting evidence to tech to show this is indeed a factory ignition.

The engine rules are fairly open but, the valve arrangement and port layout must remain stock. This means stage II heads are out.

The last issue was simply to keep the class (Production) what it was from the factory. So no smaller or larger engines were allowed. As Dan states you can go to the SCTA web site and apply for a rule change to allow smaller engines than "E". If you are looking to run ECTA only I don't think this is an issue but you need to check with them.

[CTX-SLPR]

Thanks for the further reply. It answer the question rather definatively about the changing of heads to some of the more modern designs.

On the ignition, 81 was the first year of the computer controlled "7-pin" HEI's and feedback quadrajets. Now I'm pitching the computer feedback quadrajet for sure but that HEI has me interested in hooking it up to a megasquirt and allowing it to run the ignition since the factory did use a computer to do that. Is this legal?

I'll do some digging around about parts but while I'd like to chase the 'F' engine record because there is none, an 'E' is more likely since that's the production displacement range of both the 3.8 and 4.1 Buick V6's.

More thoughts later as they have a chance to mature in my head.