I'm looking at modifying my car for historic racing, namely class Nb.

I wanted to run the engine by you all that I was thinking of putting in, and tell me hwo much power at the wheels you reckon it's worth. The rules state that bore can be increased by 1.5mm and stroke to remain the same.

Heads need to be of the same design and type (not sure whether that means SP or DP...)

So on this basis my 1285cc, bored out 1.5mm to 1336cc.

With the following mods.

Lightened Flywheel
Counterweight crank
engle 100 or 110 something mild for the SP (or custom grind but thats not "known")
Larger ports in the SP heads, probs 35in 31 or 32out
Twin Kadrons
and Stock dizzy with vacuum hooked to the carbs.
and obviously balanced and blueprinted
and an extractor (i think 1 3/8 its a VVDS mild steel US jobbie).

At the moment the motor should be 50hp at the flywheel, which I guess would be 35 or so at the wheels, so with the above combo I would hope for 55 - 60hp at the wheels?

I'ved moved away from a 1916 SP (the voice of reason came home after holidays) but I wanted to keep as much intregrity in the car as possible so that no one would ever say thats not a VW anymore or the like. (and after driving a friends 944 racer something like that looks to be a better option for a proper competition car).

Cheers

Shaun

What Comp Ratio you thinkin Shaun ???

I'd really only be guessing about power output, but plenty of twin port 1916's with around 9:1 and twin Webers pull around 80 to 90 at the wheels with bigger cams than what you're talking.... so yeah, I don't know you'd get as high as 55 or 60

At least not without some pretty nifty tricks like what the F Vee guys get up to (and even then I think they get like 55hp flywheel from a 1200, with a big part of that being from running the fan belt very damn loose)

With heads the thing of "same design or type" would mean Single Port for your year. Also check into the carbs situation, cos twin Kadron's basically didn't exist back then... you'd most likely have to go twin SU's or something like that methinks (eg Monaro Motor's kit).

Why historic's tho and not just Improved Production ???

Thought historics becasue its something different, and I thought they wouldn't reallly take to a VW racing in it, so stirring up the chooks sounds fun it its self!

The other thing is too, there will be mini's running around in this class and it's always fun to dice with a mini... especially if you win (greg mackie did this in his supersports sedan).

So although a bit silly, and not really the best performance set-up for a VW I thought it would be fun for a laugh.

But I've looked up a 1275cc Cooper S, and it came with 76hp at the flywheel, so if I can get this much (doubtful) I'll be fairly chuffed.

Compression Ratio, yeah was thinking of around the 9 to 10 range, and the Kadrons are from the early 70's which hopefully will be ok to race with, as technically they are period... read into it a little and thought they might be allowed.

Cheers

Shaun

http://www.camsmanual.com.au/pdf/08_historic/HI06_3.4_Historic_Touring_Cars_Q...

The best FVees are around 72 rwhp from a 1600 tp with stock manifolds and a 28mm restrictor on a 34 PICT Solex, plenty of r&d to get there though.

I think you'd be pushing to get 45 from what you have described.

Using the original Appendix J rules - in 1961 - Jack Bono made the following mods to my 40HP motor:-

Lightened flywheel, std. crank(with modified oil-ways) & rods, all balanced.
Camshaft ground (Porsche 356 Super) - similar to Engle 100.
Cylinders bored to 80mm, giving 1286cc, with modified Ford pistons.
Inlet valves 1.25", exhaust std. size. All valves S.Steel.
Inlet ports (single) opened out to 1.5" at manifold, and blended to valve seats.
Comp. ratio 9:1.

I made the inlet stubs to suit a pair of 1.75" SU carbs., and the exhaust - 4 into 1 - using 1.25" tube.

On Frank Kleinig's dyno a figure of 69HP @ 7000rpm was achieved. Please note that dynos are like snowflakes - no two are the same.

Cheers, Greg

Cheers for that Greg.. we might talk about it more on the weekend

The power in that Vee engine wouldn't be real nice in a street beetle, race only, as I'm sure longevety of the valve train would be an issue, although, if your not governed by the same engine regs, you may be able to get a cam compatable with 1.4:1 rockers and really liven things up if you do some port work to match. Remember, rpm = hp with a give engine size, so get a cam and valve train to make it rev. I built Guy's Targa car that won class in '98 Targa Tasmania with a 1300 tp. Was great to drive when reved to 8000 .

Cheers Matt, I really love that targa car! the rally specs on historics are alot looser than the circuit side of historics. I reckon i'll get a custom grind cam and have the 1.4:1 rockers, but I'll talk to my mate Stan and see what he thinks.

Stan is a "stock rockers" man.

What is your capacity limit?
Stock 1500 single port heads come with 35.5 intakes and 32 exhausts.

Nobody will care what you do inside the engine....... UNTIL you start beating cars that 'they' think you shouldn't beat.

Most of the Group N players cheat like buggery, so be careful not to get caught up in very expensive chase for HP. We can talk more on Sunday.

Cheers, Greg

capacity limit is 1300cc but if you bore out 1.5mm and you go over ie 1336cc, then you still race in 1300 class.