Over the last few years, I've been reading lots of stuff about the Porsche Salzburg 1302 beetle that rallied during the 70s. Everyone said they were great cars and had amazing drivers, but the same thing keeps being said, "they were down on power compared to the rest of there class."

Why is this?

here is an article on the cars,

http://www.rallybugs.com/engtrans.htm 

which reports they were getting 126hp from a 1599cc motor. good in my books. What do people think?

What is a good power figure to get out a 1600?

The reason I ask is that, I have a 1600 in my garage. I was thinking of building up khanacross special, but a PRC rally car might be a lot more fun and street registerable too. To stay in the 1301-1600 class and be competitive, I was thinking of building a mental 1600 motor maybe with some EFI of some sort as I have the type 3 manifolds.

What would be the specs then?

which heads? valves? cam? compression ratio? exhaust?

Thats a lot of power from a 1600 beetle engine...

The Mitsubishi Lancers back in the 70s had 100 hp from their standard 1600 engines...
but what they got out of them from hotting them up I've never heard....

But it seems a lot more horsepower can be gotten from a water cooled engine, compared to a VW engine of the same size.....

I think its just the old design of the engine....

and I believe that a VW engine uses more fuel than a water cooled engine of the same horsepower....

Lee

yep, 126hp is plenty from a 1600 - there would be very few NA 1600's around nowdays that made that number, thats for sure.

I think its more that they were racing against cars like BDA escorts and the like - which were more like 200 - 220hp.

Its all in the heads I think......

You should chase down a copy of Reinhard Kleins 'Rally Cars' book (mine cost me I think about $80 a few years back) - the most comprehensive book on rally cars ever written. Has a couple of pages on the beetle.

good read.

well, these days we have much better heads available off the shelf don't we?

also, I just looked again at the site. It stated that the comp ratio was 9.1:1. Which they point out is quite tame. Surely between better heads and more compression you could do better?

Toyota was getting 125kw out of their 20valve motors. I know that's alot more, and they rev higher, but surely we could do better than 126hp.

BTW, I doubt lancers were making 100hp standard. I had a 1600 galant and it was ok, but it wasn't that good.

BDA escorts were 2litres weren't they?

The Cosworth BDA is a power plant that changed the face of rallying and racing after it was released in 1969 when it was fitted to the RS1600 Ford Escort.

It was originally developed as a 16-valve DOHC conversion to the Kent 1600 pushrod motor for Ford UK. The basic engine type has been built as a 1098cc unit taking it out to a 2137cc stroker. At its peak of development in 1986, it had evolved under Brian Hart’s expertise to be the BDT-E, a 2137cc fuel injected, turbocharged engine that could produce a whopping 650hp. In the early 1980s, other derivatives of these engines were used in the legendary Ford RS200 Group ‘B’ rally car, again turbocharged and injected in an 1803cc variant. For simplicity’s sake I will refer to this family of engines as the BDAs.

One of the challenges facing the use of the BDA for racing has been the choice of engine and specification for the required application. While capacity choice is fairly obvious, state of tune is not. If you are trying to shoehorn a methanol-injected 1600cc open wheeler engine into your Escort you may be disappointed. A full race 1600 engine built for race fuel and with cams that come on song at 6500 rpm but pull hard to 9750rpm, can have around 225hp.

So what's the verdict? It'd need better heads? It'd need to rev hard? how hard then?

I can't just put it down to boxer engines, ferrari made great boxers. And it can't be an aircooled thing. There are lots of aircooled bikes making mental power. It can't be a pushrod engine issue as there are lots of V8s making big power with only 2v/cyl and pushrods.

What's stopping the motor making the figures?

Added to that, how would you get good flow figures for a VW head of that size (1600cc)? Valve sizes? Porting style?

I wouldnt guarantee that better heads are available now. From memory the heads on the porsche salzburg were some fancy semi-hemi cut with big port work - no idea on the cam, but these also ran dry sumped. From memory they had a funny size twin weber setup - I seem to recall 46 IDA, but I'm sure they were never made - its probably a misprint from 36......

Think about it as specific power output Pete.

126hp, 1584cc = 79.5hp/L - 60yr old basic design (now), 2V/cyl, 3 main bearing crank, 9.1:1 compression etc etc

Ferrari 360 Modena - 400hp, 3586cc = 111hp/L - extremely modern design, 5V / cyl, fuel injection, much better ignition system, modern intake / exhaust and combustion chamber design, 11.2:1 compression.

If you could bet 111hp/L (for years the holy grail was 100hp/L for NA) from the 1584 that would give you 175hp. The only 1600cc NA engines that I can think of that make this sort of specific power are engines like the Toyota 4AGE 20valve, which makes about 165hp or thereabouts. And that has quad throttle body injection !!

I think the porsche salzburg guys did pretty well.... I'd guess they kept compression down to 9.1:1 to keep things relatively cool and for engine longevity....

its also an efficiency issue as you wouldn't want to rev it past 8k. the heads need to be cut for mental compression. mental for aircooled machinery standard for watercooled engines.

mmm, interesting. I spose 126hp from a humble 1599cc motor is not bad considering it seems they were running stock crank and rods.

found this site.
http://users.erols.com/srweiss/index.html 

has heaps of interesting figures on it. like these head flow figures...
http://users.erols.com/srweiss/tablehdc.htm#VW 

can anyone interpret them?

Lets just put this into perspective.
If this is the same "HP" as the one they invented years ago, then that is outstanding.
And not the Shetland pony kind of horsepower.
If your volksy had 126hp, and weighed 850kgs, it would run 96 to 97mph at the drags in about mid 13s.
So if that is poor HP, then all those 1915s and bigger that cant get faster than 16s better get them updated to '70s technology.
I don't know what pressure drop those flow figures are quoted at, but they are irrelevant unless the manifold and carb are
included (type 3 manifolds will kill flow), and my experience has shown that you will need to optimise the engine to achieve anything close
to the theoretical HP potential.
The general rule is the flow at 25" pressure drop is the potential power available in an optimised engine.
On a volksy with low comp and poor optimisation of intake and exhaust lengths, you may only see 100hp from the same head....but that is still in the 15s at close to 90mph.

I was hoping you'd wade into the debate Dave.

What sort of manifolds would do the trick then? How much compression could you safely run? 10:1? What would the heads and valves look like in terms of size and porting?

Can you explain a bit more about how the flow figures work. What does 25"of pressure drop mean?

I think also it comes down to VW engine are restricted to 2 valves per cylinder, while most of the other 1600's where 4 in race spec.

Hi

Regarding the 46 IDAs, they were from a 904 Porsche, I used to run them on my 1302 before I went EFI.

I think its mostly in the heads.

I helped a friend with an old Volvo Penta, 2 litre Volvo car motor, pushrod, twin carbs, just like a 2 litre kombi. It looked like an Cortina motor. It was rated at 120 hp. A 2 litre Kombi motor is rated at around 70 hp. The volvo heads were far better design than the VW kombi heads.

The thing that helped VWs in rallying was thier traction and durabilty on rough roads.

Steve

Similar? What's similar to a VW?!:P

Keep in mind these were big dollar engines and as impressive as 120-ish hp from a 1600 is, attempting to replicate one might drive you nuts and make you broke!

Steve is right, the Beetles' strength were that they were simple and durable (Larry Perkins built one for a Wynns safari years ago and nearly won against factory Ralliart Pajeros et al!!) but as far as I know, never really set the world on fire

if you are reseraching a hottie engine for fun, maybe grab a 'bolt-in-and-go' package from an engine builder



[ Edited on 17-5-2006 by VWCOOL ]

maybe I'll go back to the mid engined turbo khanacross special idea. I'm not really interested in a grenade.

Pete,
The pressure drop is the term used to describe the size of the suck used to test the heads.
!0" pressure drop would be small and give a smaller number and 28" is a big suck and would give a higher CFM.
The engine does not have to be a grenade.
Building a smaller engine should cost nearly the same as a larger one as far as care and quality parts,
But a bigger engine will make the power easyer because of bore shrouding and reaching the
efficiency rpm point earlyer.
I can share some thoughts on a small engine combo (88x69) if you want, but a 94 bore engine
will open up alot more power because the off the shelf heads that are available suit these and the
end cost for more power will be nearly only the cost of the bore kit and machining (under a grand extra)
Will add more to this discussion when I can make the time.

HI all! hate to be a busy bee but I think you'll find the hp figures quote were flywheel and not brake hp.There are lots of homologation paper pics and articles and pics on rallybugs. Compatitive vehicles of the time were?????? Rally cars of the EARLY seventies were quite simple with modest hp figures(really good for VW)When ford introduced the Group 4 multi valve engine everyone now knows as the BDA the poor bug couldn't ever hope to compete even with its excellent traction and lightness.The Austrian bugs were driven the way they were because even THEN they struggled to keep up! You've got to make up time in the stage somehow,if the car won't keep up with you,you overdrive it!!!!:bounceand work upon its strengths.Drag blokes find this part of our sport to understand. Most average bugs go out the traps at 70-80 mph?I'm still trowing mine sideways at 60mph... well ....In my rally beetle 80 is about as fast as you would dare to go with it in the forrest.beetles do not hit trees very well.Hp isn't the ONLY thing in a rally car. Reliability,ease of service,enjoying driving your vehicle for longer than 13seconds....but i will admit under the present production rally car rules even with the freedoms allowed for pre 1985 cars,it's hard to make one air cooler stay together for over the first 100kms of FLAT out driving. Still, go and have some fun.