Questions re 131 Volumetrico Supercharger

[WestoE]

Gentlemen

I am in the process of accessing whether I can use a Volumetrico Supercharger with my Beta 2000 Fuel injected Volumex project and I need some information from owners or users of these Superchargers.
Firstly on the original Fiat 131 pulley driving the Supercharger how many teeth are there?

My Volumex Crank Pulley has 29 Teeth and the Volumetrico unit has 32 Teeth on the original pulley. If I ran this with an appropriate 1 inch belt the drive ratio would be 0.906:1 is this similar to the ratio used on the 131 or the 037 which uses a very similar 15PSI Supercharger?

Be contrast the VX Supercharger rated at 6PSI has a 22 tooth pulley giving a ratio of 1.318:1. I want to ensure the supercharger is running fast enough to deliver the boost without spinning so fast that it breaks or creates surge.

I would also be grateful for any photos that show how the engine oil feed and return are connected in the original installation and of course if you have installed one of these units on an 8 valve 2000 Lancia or Fiat engine.

If you have installed a Volumetrico with a Beta Volumex crank pulley what size pulley did you use on the supercharger? Did this work effectively? Where did you get the pulley from?

Thank you in advance for any help you can provide.

Eric

[Guy Croft]

SURELY THERE IS A READER WITH ONE OF THESE WHO CAN ANSWER SOME OF ERIC'S QUESTIONS???

GC

[tmvolumex]

I have been eagerly waiting for someone who owns a Volumetrico or 037 Stradle to answer this post, but it has not happened so I will l chime in.

I do not have a Fiat 131 Volumetrico or Lancia 037, but I do own a couple Volumex conversions that I have built. As far as the Volumex supercharger go here are some facts. The Volumex supercharger on the Fiat 124 spider it has 1 less tooth on the supercharger drive pulley compared with the Volumex supercharger on a Lancia Beta VX. The smaller diameter pulley spins the supercharger faster resulting in a little more boost. The Lancia Beta Volumex came from the factory developing 6-7 PSI of boost, so the Fiat spider Volumex should develop slightly more boost. The supercharger that came on the Fiat 131Volumerico is much larger than the Volumex supercharger but it spins much slower due to the larger diameter pulley on the supercharger. The Volumetrico supercharger, the Lancia 037 Stradle supercharger and the Lancia Rally EVO I supercharger all have the same displacement. The Lancia 037 Stradle came from Abarth delivering only 7 PSI of boost, yet developed 205 HP. From pictures I have seen of Stradle engines, the supercharger pulley and the crank pulley are similar in diameter so the drive ratio must be around 1 to 1. Guy has possibly worked on one of these engines so he could tell you for sure. Guy may also be able to tell you the drive ratio on the rally car engines. The rally cars developed more boost by spinning the superchargers faster and then later (EVOII) by an even larger 3 port supercharger. Take a look at the information below, some of which I got from Voltas web site, Lanciarally037.com.

Lancia 037 rally car, not the Lancia 037 Stradle

EVO I ENGINE:
Centre-rear longitudinally mounted, four cylinders in line, bore 84 mm, stroke 90 mm, 1995 cc, compression ratio 7,5:1. Max. torque at 30.5 mKg at 5000 rpm. Max. power from 255 to 280 bhp at 8000 rpm. 255 hp on carb, 280 hp on mechanical fuel injection.

EVO II ENGINE:
Centre-rear longitudinally mounted, four cylinders in line, bore 85 mm, stroke 93 mm, 2111 cc, compression ratio 9:1. Max. torque at 34 mKg at 5500 rpm. Max. power from 310 to 325 bhp at 8000 rpm.

SUPERCHARGING :
Roots Volumex compressor type ABARTH with variable pressure from 0.60 to 0.90 bar, increased and powered to 1 bar for EVO II version

On your oiling question. The Volumetrico and 037 superchargers have their own oil pump at the rear of the supercharger. I do not know for sure if it is used for evacuation or pressurization. Hopefully a Fiat 131 Volumetrico owner and or Lancia 037 owner can help fill in the blanks.
tmvolumex

[cstorry]

I too was hoping for authoritative answers here from owners of Volumetrico-engined cars.

As Eric also asked the question on another forum I will summarize the replies I provided there for the sake of completeness of this thread.
Disclaimer: I do not own a 131 volumetrico or an 037 but have been an enthusiast of these cars for some time

Like so many Fiat-base cars and parts it is often very difficult to determine exactly what was factory standard vs what a subsequent owner has modified - not the least of which performance parts like a supercharger.

Here's what I believe to have been the factory standard configurations:

Beta Volumex has 29 teeth on the crank pulley and 22 teeth on the blower (1.32:1 overdriven)
Fiat 124 volumex has 29 teeth on the crank pulley and 21 teeth on the blower (1.38:1 overdriven)
BTW the car is properly called Pininfarina Spidereuropa Volumex Azzurra - you can see why that name's not often used
131 Volumetrico had 29 teeth on the crank pulley and 32 teeth on the supercharger (.9:1 underdriven)
037 Stradale had 29 teeth on the crank pulley and 29 teeth on the supercharger (1:1 drive)

(I am not 100% certain about the Fiat Argenta volumex but I believe that it was the same as the Beta rather than the 124.)

I have seen 037's with different supercharger pulleys from 27 to 32 teeth (I am 99% certain that 29 teeth was stock for the Stradale) but can not confirm ever seeing a crank pulley with any other tooth count from 29 teeth.

Note that the 131 and 037 variants of the volumetrico compressor differ, I think, because of the differences in oiling systems between the cars; the 131 is a wet sump car and all 037 variants are dry sump. The 131 volumetrico compressor indeed integrates a scavenge pump. Pressurized engine oil is fed to the front of the conmpressor and is sucked out the rear by the integrated pump. Note that the volumex does not use engine oil for lubrication nor are the front and rear casings connected. Only the front is lubricated with a closed loop reservoir. On the 037's the volumetrico compressor uses a different rear casing and does not integrate a pump however the compressors appear identical in all other aspects.

Chuck

[tmvolumex]

Chuck,
I am glad you responded with additional information.
I can answer the Argenta issue. The supercharger and crank on the Argenta had the same supercharger pulley drive setup as the Beta Volumex cars. I bought a factory crate engine years ago, that was supposed to be a Volumetrico, but turned out to be a NOS Argenta engine. There were 10 crate engines that showed up in Germany, still in the crates, covered in a Cosmoline like rust preventative. Wish I had bought more than one engine.
You forget to mention my oddball, Lancia 037 (EVO I, according to Volta) supercharger that I have, with no rear scavenging pump and a 27 tooth supercharger pulley. Thanks for getting that EVOI, information for me when you went to Italy a few years ago.
Tom