Back to SCCA 1972 rules?

[RHough]

I'd like some help. I'm building a 1972 KG for vintage racing and rallies. There are so many rules and organizations around it is hard to find a set of rules to use as a guideline.

If you were building the car in the 1970's what would it look like?

Tire/Wheels sizes?
Engine Displacement?

I think a header that keeps the heater boxes and 40mm Webers are period correct ... what else?

If someone has a SCCA book that covers what class a 72 Ghia would run in it would be wonderful! Most club racers that are based on production cars are just fine as street toys so that is where I want to end up.

Thanks in advance!

Randy

[Marc]

SCCA rules have no natural niche where an ACVW can be competitive. No way that it's an accident, either - sports-car guys hate being embarrassed by economy cars.
Show up with whatever you want, pass safety tech, and run as a "Novice". If you're any good as a wheelman, it won't be long before they'll tell you not to come back.

[Ol'fogasaurus]

Marc is probably true. I have never known the SCCA to be about anything but money!

[RHough]

Thanks. I've been around long enough to know that politics rule. For the same displacement/weight ratios it is a challenge to make an AC engine competitive. That's not the question. In vintage the idea is to either restore a period race car or to build one as it would have been. Would they have put a 1600cc Type 1 or Ghia in the same class as a Datsun 510? (also 1600cc). I have no illusions about winning anything, I'm 61 years old and just want to have fun.

The time and money invested in my street/track toy is about the same if I follow a rule as a guideline or if I don't.

I crew chief for a Spec Miata, I know those are about #2200 and 120HP at the rear wheels with a 1600. That would require 107HP at the rear wheels to make a Ghia competitive (on paper).

What would it take to get 105-110 HP on the ground? 1776? 1915? bigger? Could a 1600 do it?

I have been searching and reading the forums for awhile looking for answers before I started the thread.

http://www.shoptalkforums.com/viewtopic ... 1&t=127619 is what made me decide to go with the Ghia.

Cheers,

Randy

[RHough]

I think I found it.

A Ghia would run B Sedan
Stock stroke and a max 1.2mm overbore ... 1584 with 85.5mm or 1603 with 86.0mm pistons

The rule allows the car to run at 1.0 lb/cc (what a weird mix of imperial and metric units).

To have the same power to weight ratio as a 1600 Spec Miata at 2285 lbs and 120 HP ~ 19.0 lbs/HP I need 85 HP at the rear wheels out of a 1584.

69mm stroke
88.5mm bore
L3 Heads
Weber 40 IDF's
1 3/8" exhaust

FJC seems to like the W110 for cam with the Kadrons

What cam in a 1600 will give 90+ HP at the wheels?

Cheers,

Randy

[Marc]

Wishful thinking I'm afraid. Many before you have tried. Again, there is no SCCA class where a (legal) ACVW can be competitive (unless all of the competition are boobs). They may let you play in their sandbox so long as you're just a novelty, but as soon as you start making them look bad the rule book will come out and you'll be sent home. Carburetion was always the big bottleneck, ACVWs being more severely stifled than any contemporary cars...and when you step up to a class that allows the VW to breathe, their rules offer other marques the advantage in other areas...it's no accident, they were written specifically to exclude us.
Another place where VWs come up short is in rim width. There were some limited-production Beetles in the mid`70s with 5½", but 99% (and 100% of `Ghias) came with 4½". That limits us to 5½" while most other cars can run 6½-7" legally.

Forget about oddball bores, it's been decades since +.5 or +1mm pistons and rings were readily available. SCCA cuts it off at +1.2 to spite VW guys - another .3mm and we'd have an off-the-shelf solution, 87s are easy to come by. So you're stuck at 85.5; if you want to get cagey (and there are no teardown inspections, just pumping for displacement) you can tell them it's 86.5x69 and have the crank welded up & reground for 85.5x70.5 instead...but besides being illegal, that's still not going to be enough.

100+ HP through a street header and stock heaterboxes? Not likely, and not wise if you plan to drive this other than on weekends.
We knew enough even then to remove that cork - go ahead and use a decent merged-collector exhaust system.

The Engle W-110 is a fine cam for a mild street motor but nowhere near enough for what you're after. If you want to be able to pop off a valvecover and show stock rockerarms, WebCam makes some hi-lift grinds. Their 121, ground on a 105° lobecenter, would be more like it. Bugpack's 4063 is also a good grind, a shade less top end but a wider torque curve that'd be better for gymkhana. Otherwise, get a real cam and some 1.4 or 1.5 rockerarms...something in the FK-8 range.

Some Solex 40 P11s would be "period correct" but even then they weren't easy to come by in good shape (VW guys tended to settle for the "almost-right" hand-me-downs from Porsche owners who'd given up and converted to Webers). IDF Webers would look close enough I suppose, although the serious guys ran IDAs back then. DCNFs look right but have float-level control problems when cornered hard mounted "sideways" on a VW.

100+ HP from a 1600 is possible but if you want a usable power band more CCs would be smarter. I'd go right in-between with an 1835...the displacement will be nostalgic ....even bigger, with a stroker crank, would make it a lot easier to get that much power reliably if nobody's going to be checking the displacement.
You don't need to run tin-cans-with-fins for the 92mm bore these days, there are thickwall jugs on the market.

There are lots of choices in aftermarket heads today that as-cast will put welded-up/massaged stockers from the `70s to shame.

If the 1lb/cc limit is the dominant factor, get busy gutting the interior, doors, etc...replace glass with Lexan...the winning end of that weight break is at the lightest possible, I'd take a 1585lb car with a 1584cc engine over a 1900lb car with a 2-liter any day. That's not just theory; the #25 is mine (read the hood):

[RHough]

100+ HP through a street header and stock heaterboxes? Not likely, and not wise if you plan to drive this other than on weekends.
We knew enough even then to remove that cork - go ahead and use a decent merged-collector exhaust system.

The Engle W-110 is a fine cam for a mild street motor but nowhere near enough for what you're after. If you want to be able to pop off a valvecover and show stock rockerarms, WebCam makes some hi-lift grinds. Their 121, ground on a 105° lobecenter, would be more like it. Otherwise, get a real cam and some 1.4 or 1.5 rockerarms...something in the FK-8 range.

Some Solex 40 P11s would be "period correct" but even then they weren't easy to come by in good shape (VW guys tended to settle for the "almost-right" hand-me-downs from Porsche owners who'd given up and converted to Webers). IDF Webers would look close enough I suppose, although the serious guys ran IDAs back then. DCNFs look right but have float-level control problems when cornered hard mounted "sideways" on a VW.

100+ HP from a 1600 is possible but if you want a usable power band more CCs would be smarter. I'd go right in-between with an 1835...the displacement will be nostalgic ....even bigger, with a stroker crank, would make it a lot easier to get that much power reliably if nobody's going to be checking the displacement.
You don't need to run tin-cans-with-fins for the 92mm bore these days, there are thickwall jugs on the market.

There are lots of choices in aftermarket heads today that as-cast will put welded-up/massaged stockers from the `70s to shame.

The car will live in Canada, I'm kinda partial to having heat about 10 months a year. At 1600cc at what point does the exhaust/heater box become the bottleneck? I have the impression that the less restrictive heater box replacements don't put out great heat.

I agree that the "production" classes that require stock intake manifolds are not attractive. If I can get 85-90 HP at the wheels the car should be able to turn decent times. Forget competitive, I'm looking for "not embarrassing" and about the same performance as the Spec Miata that I work on now. 85-90 at the wheels should get me right there.

I'm trying to get the spec sheet right to order a long engine from John at Aircooled.

If I get a 74x92 1968 with L3 Heads, 1.4 rockers and an FK-8 cam I can always change the exhaust size later if I have to.

Sure would like to have a 90HP 1600 though ...

R

[RHough]

100+ HP through a street header and stock heaterboxes? Not likely, and not wise if you plan to drive this other than on weekends.
We knew enough even then to remove that cork - go ahead and use a decent merged-collector exhaust system.

The Engle W-110 is a fine cam for a mild street motor but nowhere near enough for what you're after. If you want to be able to pop off a valvecover and show stock rockerarms, WebCam makes some hi-lift grinds. Their 121, ground on a 105° lobecenter, would be more like it. Otherwise, get a real cam and some 1.4 or 1.5 rockerarms...something in the FK-8 range.

Some Solex 40 P11s would be "period correct" but even then they weren't easy to come by in good shape (VW guys tended to settle for the "almost-right" hand-me-downs from Porsche owners who'd given up and converted to Webers). IDF Webers would look close enough I suppose, although the serious guys ran IDAs back then. DCNFs look right but have float-level control problems when cornered hard mounted "sideways" on a VW.

100+ HP from a 1600 is possible but if you want a usable power band more CCs would be smarter. I'd go right in-between with an 1835...the displacement will be nostalgic ....even bigger, with a stroker crank, would make it a lot easier to get that much power reliably if nobody's going to be checking the displacement.
You don't need to run tin-cans-with-fins for the 92mm bore these days, there are thickwall jugs on the market.

There are lots of choices in aftermarket heads today that as-cast will put welded-up/massaged stockers from the `70s to shame.

The car will live in Canada, I'm kinda partial to having heat about 10 months a year. At 1600cc at what point does the exhaust/heater box become the bottleneck? I have the impression that the less restrictive heater box replacements don't put out great heat.

I agree that the "production" classes that require stock intake manifolds are not attractive. If I can get 85-90 HP at the wheels the car should be able to turn decent times. Forget competitive, I'm looking for "not embarrassing" and about the same performance as the Spec Miata that I work on now. 85-90 at the wheels should get me right there.

I'm trying to get the spec sheet right to order a long engine from John at Aircooled.

If I get a 74x92 1968 with L3 Heads, 1.4 rockers and an FK-8 cam I can always change the exhaust size later if I have to.

Sure would like to have a 90HP 1600 though ...

R

[Marc]

The Dansk replacement "hi-flow" heater boxes have tubes inside rather than the cast aluminum guts of a stock box, so although you do get some warmth from them it's mostly only good for demisting the windshield, you'd be leaving your coat on for certain up there. You do get more heat out of the port with a larger displacement and higher-duration camshaft, but the tubing-style heat exchangers obviously aren't as efficient transferring it into the cab. I've got heated seats in my car, they make a world of difference in wintertime comfort.
The point at which the stock boxes are too restrictive depends upon the displacement, RPM range and head work - but at the risk of oversimplifying, suppose they're just adequate for a 1584 that turns 5500 RPM - that's about the same CFM as a 1775 has to pass at 4910, or a 1968 at 4425 RPM...in other words they're borderline for an average street 1835 but aren't going to cut it on any performance engine, even one with stock-valve heads.
The L3s are nice but I'd want something bigger for a 1968...or even an 1835, for that matter.
It seems that we're now talking about a "cheater" engine with no regard for the bore and stroke rules; were you at least going to try to honor the 1lb/cc limit? Your car's curb weight should be around 1960 lbs and it shouldn't be too challenging to get it down to ~1800 without making it uninhabitable for the street. When it comes to HP per ton, reducing the latter is nearly always cheaper than increasing the former - and a lighter car handles and brakes better, too.

[RHough]

The Dansk replacement "hi-flow" heater boxes have tubes inside rather than the cast aluminum guts of a stock box, so although you do get some warmth from them it's mostly only good for demisting the windshield, you'd be leaving your coat on for certain up there. You do get more heat out of the port with a larger displacement and higher-duration camshaft, but the tubing-style heat exchangers obviously aren't as efficient transferring it into the cab. I've got heated seats in my car, they make a world of difference in wintertime comfort.
The point at which the stock boxes are too restrictive depends upon the displacement, RPM range and head work - but at the risk of oversimplifying, suppose they're just adequate for a 1584 that turns 5500 RPM - that's about the same CFM as a 1775 has to pass at 4910, or a 1968 at 4425 RPM...in other words they're borderline for an average street 1835 but aren't going to cut it on any performance engine, even one with stock-valve heads.
The L3s are nice but I'd want something bigger for a 1968...or even an 1835, for that matter.
It seems that we're now talking about a "cheater" engine with no regard for the bore and stroke rules; were you at least going to try to honor the 1lb/cc limit? Your car's curb weight should be around 1960 lbs and it shouldn't be too challenging to get it down to ~1800 without making it uninhabitable for the street. When it comes to HP per ton, reducing the latter is nearly always cheaper than increasing the former - and a lighter car handles and brakes better, too.

It is always hard to have everything we want in only one wife ... er car.

Fun to drive is the first priority.
19 lbs per HP is the sort of number that puts the car into the same range as a Miata.
You are quite right that reducing weight to get to 19HP/Lb is more effective than adding HP.

If a 1584 lb car with 84 RWHP using a 1584cc (53 HP/L) period legal engine is not possible I need to look at a combo that is.
1835 lb car with 97 RWHP using 1835 cc? (52.8 HP/L)
1968 lb car with 104 RWHP using 1968 cc? (52.8 HP/L)

The output I need to get the HP/Ton I would like is about 53 HP/Liter ... A basic 265 HP 302 V-8 state of tune ... smooth idle and an automatic?

I don't understand why a 1835 would be likely to produce more power per liter than a 1584.

The port/valve area ratio is best with the smaller engine so my experience says that the target of 85 HP at 1584cc might be easier than 97 at 1835?

Dub Dyno (for whatever it is worth) suggests these numbers:
85.5 x 69 (1584)
L3 Heads (35/32)
Engle FK-8
1.4 Rockers
40mm IDF's
1 3/8" exhaust

106.4 HP @6500
99.7 ft/lb @ 5000
8000 RPM Redline

I'm looking for 84-85 at the wheels if I can get the car down to 1584 lbs in race trim.

At this point the only thing more HP means is higher top end, but that is not much of an issue on the track I'll run on (Spec Miata never hits 5th and only uses 4th for short periods).

So not looking to build a cheater motor, just trying to understand why the advice is to go with bigger displacement when the state of tune I'm looking for is the same HP/L.

Sorry to be so confused.

R

[gearheadgreg]

Interesting discussion - but I am a little confused. You menton vintage racing, not SCCA racing today. When I was building a vintage race '67 Beetle, I had to look up some rules from the period for VW's. So, my real question is, what sanctioning body are you going to race in, and what do you need to find? Any rules for a 72 VW? Treuhaft raced the Trans Am series in the early 70s with a '71 Super Beetle. It was a 1600cc, but with lots of headwork and a dry sump system, 48 IDAs, etc. and was still really down on power compared to the Alfas, Datsuns, etc. and had reliability issues.

I think what Marc is saying is not that an 1835 (or any other size) will inherently make more hp/liter, but it will allow you to meet your goal of 90hp at the wheels with a more flexible and reliable engine. In my situation, we came up to the same decision, because the vintage race association restricted our carburetion compared to the Porsches - because they didn't want us passing those guys!

[RHough]

Interesting discussion - but I am a little confused. You menton vintage racing, not SCCA racing today. When I was building a vintage race '67 Beetle, I had to look up some rules from the period for VW's. So, my real question is, what sanctioning body are you going to race in, and what do you need to find? Any rules for a 72 VW? Treuhaft raced the Trans Am series in the early 70s with a '71 Super Beetle. It was a 1600cc, but with lots of headwork and a dry sump system, 48 IDAs, etc. and was still really down on power compared to the Alfas, Datsuns, etc. and had reliability issues.

I think what Marc is saying is not that an 1835 (or any other size) will inherently make more hp/liter, but it will allow you to meet your goal of 90hp at the wheels with a more flexible and reliable engine. In my situation, we came up to the same decision, because the vintage race association restricted our carburetion compared to the Porsches - because they didn't want us passing those guys!

Vintage Racing locally is a mixed bag. There are all sorts of rules in use. The common thread is that the car is a fit for the period GCR of the day when it would have raced. I have not found a VW listed in the 1970's era GCR's as production class cars. I'm assuming the reason is Production Class requires using the stock intake manifold. The Sedan classes allow more freedom so that is where I started.

The B Sedan rule sounds about right for the car. Although there is a technical requirement that the car was homologated as FIA Group 1 or 2 building the car to fit this rule should get me a warm welcome at club level vintage races. If I can hit the spec miata target HP/Ton number, I can probably talk my way into a class where other 1600's run (Honda Civics) in the regular schedule ... there is a 66 year old lady that I can race against ...

I'm not going to win (thats not the goal) ... the pack needs the slower 50% too. I'm certain that I can build a car that won't always be last.

I also like the challenge and putzing about in the shop.

53 HP/Liter just sounds like an easy target. The stock Spec Miata engine at 120 HP at the wheels is at 75 HP/Liter using stock intake, exhaust manifold, cam, valves and springs ...

I admit I don't know VW's, but that 53 HP/Liter seems well within reach. When the VW guys with experience tell me something I keep asking questions until I understand. I don't doubt the experience, it just does not make sense to me yet.

I'm slow and hard headed ...

R

[gearheadgreg]

53 HP/Liter just sounds like an easy target. The stock Spec Miata engine at 120 HP at the wheels is at 75 HP/Liter using stock intake, exhaust manifold, cam, valves and springs ...

I admit I don't know VW's, but that 53 HP/Liter seems well within reach. When the VW guys with experience tell me something I keep asking questions until I understand. I don't doubt the experience, it just does not make sense to me yet.

Yes, seems reasonable, but - that Miata is a much more modern design, compared to the Type 1 VW, which is basically the same as the engine developed in the 1930s! Compare valve curtain area and RPM range - it starts to show itself how the VW will need a lot more work to even come close to the Miata level with mostly stock parts. Not that it can't be done, of course, but will take a lot more work than lots of other engines.

Marc has a photo of his Mini-Stock car - there were a lot more of these in the 70s and 80s, and articles in Hot VWs about them.

[helowrench]

You might be able to weasel into production class with the pdsits since some types of the type 1 engines came in brasil with those and the type 3 same size engine came with the 32 pdsits. A lityle finagleing could get a hybrid setup with bus 32-34 pdsit throttle plates and type 4 euro larger venturies. But didnt the brazilian variants come with what we know as Kadrons?

Thinking outside the box here. Could easily be considered crazy ramblings of a demented mind.

[Marc]

We had a circletrack class back in the `70s which allowed all ACVWs to run any carburetion which would bolt to stock manifolds (and permitted the interchange of manifolds between models, so `67 III manifolds were legal on a Bug)...32PDSITs were the most readily available carb back then and could be made to work, but they didn't offer much in the way of performance - nor did the 32/34s. Everyone sought out the Opel 35PDSI carbs and ran them as soon as they could find a pair. Engines were limited to <1300cc original displacement +.040" overbore, with a stock crank and even those little engines at 5500 RPM needed more breathing than the PDSITs offer.

The thing about these "nostalgia" classes is that they let anything reminiscent of pre`73 SCCA cars run, and rules enforcement is arbitrary and capricious - it's all about who your friends are and whether you're beating the wrong people on the track. The rules are quite clear that you must retain the stock stroke and can't overbore beyond a specified limit, yet here we are discussing cheating on displacement because it's going to be mandatory if you want to be anything but a back-marker. You'll be allowed to run as long as you're needed for car count and don't piss off the wrong competitor, but they can shut you down anytime they like. Make lots of friends.