2.0 8V Volumex Race Engine Build - Help?

Competition engines and ancillaries - general discussion
wmausbach
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by wmausbach »

Bill,
I have a Volumex project too but with street use in mind. I have the Volumex and a Weber 45 with a Volumex Head with the sodium filled valves. I also have an alumnium casting of the original Abarth unit that several of us bought a few years back. I would like to see a picture of your airbox setup since I'll have to fab a similar one. Are you running the original ratio or is the Volumex running faster than stock relative to crank rpm? Thanks for the update.
I'm lucky living in Houston with Jason Miller a local guy to help fab up the manifold etc.
Wayne in Houston
MACAuto
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by MACAuto »

037_beta,
Thanks. The NOS kit I bought was for the Spidereuropa VX (sp?), and was a complete kit with all parts including the intake manifold. Left over from the mid 80's, and offered by Fiat Ricambi at the time to certain customers. It was one of three kits purchased at that time by the vendor I purchased it from. He kept it for more than 25 years before selling it to me!

The manifold was a very rough casting, in my opinion, and I port-matched the runners into the head "ski-jump style". That type porting was necessary as there was very little material on the under side to remove. I have noticed no discernable difference in plug color from cylinder #1 to #4, but I have not monitored temperatures. It was a concern of mine, as the blower is mounted directly across from #1 and #2, with #3 and #4 offset to the rear. Initially, I worried when #4 exhaust valve was found to be burned, until my head builder informed me that all 4 exhaust valves were bent, I believe from an earlier pre-VX racing event. I am hoping the rich, cooling, fuel characteristics of E85 will protect from any possible combustion temperature problems. I run a rich mixture of 12:1 from 4000 to 7000, which is flat across that range, at that mixture. Perhaps I need more hours on this engine to better answer your question.

Wayne,
you will have to wait for pictures of the airbox, but I am posting pictures showing the tight fit in the engine compartment. I am running 1.57 ratio (21 teeth blower, 33 teeth crank). From a purely practical standpoint, I limit racing revs to 6500 - just over 10,000 blower speed. Changing up gears at that engine speed doesn't seem to be a problem, with the gear ratios I have. No need to wring this engine out any higher than that. Jason Miller produced my new crank pulley, utilizing the crank cog from the kit.

MACAuto (Bill)
Attachments
VXdoghouse.jpg
VXdoghouse.jpg (50.97 KiB) Viewed 11199 times
MACAuto
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by MACAuto »

Some pictures:
Attachments
The engine bay of the Spider:
The engine bay of the Spider:
Racer engine.jpg (42.74 KiB) Viewed 11199 times
The pipes:
The pipes:
VXpipes.jpg (45.35 KiB) Viewed 11199 times
Pipes showing 2.5 round, and 3" oval exhaust pipes:
Pipes showing 2.5 round, and 3" oval exhaust pipes:
VX headerpipes.jpg (39.72 KiB) Viewed 11199 times
VX Engine before install:
VX Engine before install:
VX engine1.jpg (42.43 KiB) Viewed 11199 times
037_beta
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by 037_beta »

Thanks for the note Bill on the intake manifold and plug colors. That said, I am not across the differences between the Spidereuropa VX manifold and say the 131 or Lancia Beta VX manifold. It would be great if you had a photo of said manifold.

The exhaust headers look wonderful and are quite an inspiration. I am currently building a set (thanks to Guy for the advice on the system) to suit a Beta Coupe. I will be posting a full report on my build once complete, but this will not happen until next year.
Book #188
volumetrico
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by volumetrico »

WOW - great acheivement - you must be very happy with the results and quality of work !
Thanks for sharing on here.

I am curious how you rate the service life of this engine or what you plan to do to maintain the setup.

Melo
GC #162
Guy Croft
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by Guy Croft »

Bill,

thanks for the nice photos.

Could you possibly let me know final choke size (it's a 45 DCOE?) confirm valve size and cam spec - cam timing (full lift only) too if poss? No worries if you don't want to tell me but send by pm if you don't want to publish.

I would like to know this as my own dyno archive is rather 'thin' on VX units, Tom has helped and a few others over the years. However in extreme states of tune like this I have very little to guide me and as you will appreciate I do get asked...

Why the ethanol fuel? To reduce detonation risk?

Thanks,

G
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by MACAuto »

037_beta,
I am not certain, but I think that the kits for this size blower unit to be fitted to the 132 series Fiat TC engines were all the same, and had the same manifold. I can take a closer photo of the manifold (installed), and post. A manual on this set-up was kindly sent to me by Tom McG, and references Lancia more directly, than Fiat. The illustrations in the manual show the exact bits that I have on the race engine. One difference that might exist from kit to kit is the oil filter housing, which incorporates the lower mount for the blower. Some 132 TC blocks have 4 fasteners to secure that bit to the block, and some have 6 fasteners. Mine has 4. Modification was required to make that particular bit fit the engine. Nothing huge or time consuming - just solidly in line with the 3 rules of racing:
1- There is not enough time.
2- There is not enough money.
3- Nothing fits.

The Header really did turn out well. The design was for internally stepped primaries. They are schedule 10 304 stainless 6 inches out from the flange, and 16 guage from the step point to the collector. The primaries are big. It is v-band flange-connected to the exhaust pipe. We built and tested 2 exhaust pipes - one a 2.5" round pipe, and the other was 3" oval piping, for clearance to the road. My bet was that the 2.5 would make more power, but was surprised the the 3" oval won out. My N/A engine version had a 2.25" exhaust pipe. I guess this engine like big pipes. After arguing with my shop fabricator for more than 6 months about this header, with nothing finished, I let him go. My new man and I discussed the design I had in mind for about 15 minutes, and he had the completed system done in about 3 weeks, working it in with his other duties - voila! If there are members wanting more information about this exhaust - let me know. I have been told to NOT reveal my secrets, or development about this engine, but I don't see their point, so let me know.

Volumetrico,
This project is really just a good way to recycle an old Fiat racecar into something useful for the present racing scene. The chassis sat for better than 3 years, engineless, in my shop, until I discovered that NASA (National Auto Sport Association) in the USA had a class structure where I could rebuild the old Spider into a competitive racer again. It was finished in SCCA, and uncompetitive within their rule structure (too rigidly structured!).

As far as service life is concerned, I really don't know, as I have limited track time so far on this engine. I have a full race weekend this Saturday and Sunday, where I will get about 2 hours track time, so time will tell. With the blower positioned over the oil dipstick hole, it takes about 30-40 minutes to check the oil level! I have a 3-quart Accu-sump, which supplies oil to the main oil galley, if needed, and I use Schaeffer's Racing oil which is excellent, but not well known. Timing is very conservative, with 10 degrees initial advance (doesn't idle well), with total maximum advance of 32 degrees (the ElectroMotive crankfire Ignition has 3 adjustment pots for timing control). The E85 fuel cools the charge, and cools the blower as well.

MACAuto (Bill)
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by MACAuto »

Guy,
I sized one picture down from 3 MB! My Admin took it with an iPad...

It is a 45DCOE, with the stock velocity stacks removed, yielding an inlet dimension of 48mm. I am using 35mm tall 48mm TWM/Borla full-form velocity stacks, which allows the use of a Pipercross all-foam filter which stretches over the stacks and is held on by them - slick and effective. I swapped in my available 32mm, 33mm, and 36mm venturis, and the 33mm worked best. The 36mm fell flat. I worked with Pierce manifolds in California to get the jets, and on getting the fuel to actually draw into the carbie. It was showing lean on the wideband, and bigger main jets were not making a sufficient difference. They suggested a change from 4.5 secondary venturi to 5.0s. Response to jet changes became much more pronounced. They also suggested very small air corrector jets. Current set-up is 275 mains, and 130 Air correctors - really weird, but it works..

Cams were a puzzle. I had your 3A, 3D, and 2 different Bayless regrinds that approximate the same actual lift as your 3A and 2B. Lift interval is not anyway near your cams, as they are regrinds. Your cams, at least the 2 I had access to, were just too much, and suffered in the midrange. The cheap regrinds actually worked the best. It might be the altitude here (6000 ft.), or just that better results are achievable with less cam - don't know for sure. I do know that I have a street driven 1800 TC 124 Spider with the 40IDFs that will get the 3A on the inlet. Cam specs are available at Midwest-Bayless. Both inlet and exhaust are the A-16 grind. I have always used your cams for my race engines, but with the boost as a factor, I just didn't have the right combination. If you have a suggestion after reading the specification on the A-16 grind, I would like to know, as these regrinds might regrind themselves into my engine!

The E85 is used to reduce detonation, and provides good power for 1/3 the price of 110 octane leaded racing fuel (more power than 110 race fuel). It also allowed the CR on the pistons to be 10.4:1on this build. The fuel delivery volume required is about 20-30 more than gasoline, so that extra fuel has a tremendous cooling effect on the combustion temps, and I believe also on the blower unit.

Tom was most valuable with his consultation on this build. He has been surprised by the results, but also elemental in achieving them.

MACAuto (Bill)
Guy Croft
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by Guy Croft »

thanks Bill

I am conscious that you are sharing private expertise here.

yes Tom is very good!

Interesting about the cams, though I will admit use of comp cams of any sort is kinda 'uncharted territory' for me and most folk. The idea of 'blowing down' by overlapping to purge and cool the chamber has been around for a long time but it may in this case given the alcohol fuel that less is needed. Interesting that the lower lift integral works better.

The relatively large 33m choke is interesting - on the GC 3A even with stock VX ex cam would definitely need a 28mm or it would barely run at all, I think (emphasis on think) & from exp the more radical the cams the smaller the choke has to be. The regrinds might have less LATDC which would be relevant than my cams but they would certainly flow less during the inlet and ex events. To an extent the use of alcohol fuel limits my ability to draw meaningful conclusions.

If you can share valve size and cam FL timing I'd be pleased to hear it.

Some things for me to think about there. Not that it's any of my business but this one does interest me greatly, esp the question of the cams.

If you have not exp with a significant ram-tube outboard of the carb rather than just rampipes you certainly should. In my opinion (and it is a 'theory' to an extent) this will overcome some of the reverse pulsing that can upset the fuel signal in the carb and lead to enhanced torque. A PhD at Cork Inst was supposed to explore this for me some years ago but unfortunately intereference on his sensors messed all the testing and it was discovered too late to do again....

Please do not read my enquiries as my being intrusive or probing, it is just that is has been so long since we heard from you and there is no doubting what you have achieved, it's very remarkable really and certainly way out at the frontier of what has ever been done with one of these..


G
Guy Croft, owner
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by MACAuto »

Guy,
I didn’t try any other chokes other than the 32, 33, and 36mm ones. It did not occur to me to introduce a smaller choke for the GC3A. I am certainly open for any suggestions to increase torque, as that power parameter is NOT limited in my race class - just Wheel Horsepower-to-weight.

Valves are 46mm inlet, and 40mm exhaust. Intake Cam timing at full lift is 106 degrees ATDC, and Exhaust cam timing is 106 degrees BTDC.

I barely have headspace for the 35mm tall velocity stacks on the 45DCOE. The blower set-up makes this engine very Wide. Enough to contact the tire on severe right hand turns. The multiple redesigns on the Airbox in the wheel well, was necessary for tire clearance. I needed to add a thicker wheel spacer for some clearance gain.

There is no percieved intrusion, as this forum is a means to share with you and others interested in the same thing. I’m surprised no one has asked for details on the header, and pipes... I may be on the frontier (actually the High Plains of Colorado...), but it remains to be seen if this package is now truly competitive, and has sufficient longevity. I wil let you know about that.

MACAuto (Bill)
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by Guy Croft »

Thanks Bill,

I was one of the first to bolt a DCOE to a VX and choice of 45 carb really just followed from using 45s on 2 liter atmo engines. Tom, eg, pitched for 40 carb and has more exp of the 40 carb than I. With the 45 I imagine you found that the engine would not pick up (even off load) with a 3A inlet (irrespective of ex cam) with 34/32 choke. It would just bog down. You would have to go way smaller - my call is 28 but I have not tried 29mm and FWIW it does not appear to be an impediment to power. This is characteristic of suck thru on a blower and I am sure - something to do with wave action upsetting the fuel signal in the venturi. It will certainly be the case that your inlet cam will be far less radical than the 3A and thus the wave effects would be less agressive. If you get the chance try the GC cam again and choke-down and see what happens.

As for cam timing my exp is blown engines don't like late inlet event and I would ordinarily run 103 or even closer to 100 FL. On the ex side one can either extend the power stroke for torque by having the ex opening very late in the power stroke (near BDC) or maximise top end power by opening early in the power stroke when the cylinder is at high pressure; that of course gives a more powerful primary wave in the header. I stress that I do not have exp of ethanol and how valve events are affected. Perhaps there is no difference compared with gasoline, dunno.

The selection of cam profiles for applications like this (as it is for turbos) can - in the extreme - be rather involved. That said with a blown engine with full primary separation at least you don't have to worry about pipe-pipe interference which you most definitely have to on a turbo unit. You've done very, very well with off-the-shelf cams. It's all very well to choose your FL timing but LATDC and valve open - shut timing is hugely significant. This can inevitably means designing from scratch. The golden rule for all engine types is inlet lift should be that required to achieve minimum valve-in loss (even a 45mm inlet ideally needs to go way over 12mm, see graph) and the bigger the valve the higher you have to lift it, but as far as the ex is concerned on the TC radical peak lift simply is not needed and one would generally go for something around 10.5 valve lift or conceivably as little as 9mm. The trouble with off-the-shelf cams is you cannot tailor LATDC to your particular requirements simply by swinging the cam without shifting the FL location too - the latter being every bit as much a fundamental tuning criterion.

Of course - getting to radically high inlet lift quickly (there is no benefit at all to opening the inlet valve slowly, the reverse is true..) calls for a spring pack that can take the strain (so to speak). Extending the cam duration to compensate for a spring pack that cannot cope with a high rate cam flank completely defeats the object of having the high lift in the first place. The ultimate designs will give you VO, FL and VC exactly where you want them with commensurate attention to the LATDC and peak lift too but the profiles definitely have to be entered into advanced spring software to make sure the radical cam doesn't send the valve into orbit or the contact pressure wipe out the cam lobe.


Some thoughts anyhow..

G
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Guy Croft, owner
Guy Croft
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by Guy Croft »

BTW - naturally your E fuel needs bigger jets because of the A/F ratio but one thing I have seen many times is weird main jet and a/c sizes when the chokes are too big. That is not by way of saying this is the case with your setup but many folk running gasoline will read this and so it's worth mentioning.


G
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2.0 8V Volumex Race Engine intake manifold

Post by tmvolumex »

The intake manifold (the one between the supercharger and cylinder head) on the Lancia Beta Volumex (Coupe and HPE), Fiat 124 Europa Volumex, Fiat 131 Volumetrico and the Fiat Argenta Volumex are all the same. These are all 8 valve cars. Bills car uses the same manifold as the above cars. The manifold has 2 small casting features (on some manifolds these are not drilled and tapped) for locating a manifold pressure line (boost gauge etc). There are also 2 cast boss features for the pop off valve, one vertical and one horizontal. I have never seen a manifold that has the horizontal cast boss drilled and tapped, I have only seen the vertical cast boss drilled and tapped for the pop off valve. A pop off valve is NOT a blow off valve, as used on a turbo. A pop off valve allows the release of explosive manifold pressure (explosion inside the manifold) if a backfire occurs. Without the pop off valve the backfire would blow the intake manifold and supercharger off the engine. Nitro drag cars use “burst plate” which operates by tearing open in the event of a backfire. Sometimes saving the engine, sometimes not.
Tom McG
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by MACAuto »

Guy,
Much to ponder. I don’t think I will make any additional changes for this season, as there is only one more race event weekend, which is October 20-21 on the fresh pavement of Pueblo. I will have the off-season to do some experimentation on the power curve. I am topped out on WHP/Weight, but any good increases I can achieve to Torque will be welcome. I also have some suspension changes relating to roll center on the front that I will address. Everything else seems to be holding up quite nicely.

This last weekend was a lot of fun. Pikes Peak International is a 1 mile D shaped oval with an infield paved road coarse section, which is very fast, and a track I really enjoy. The car is very fast. Faster than the tires, which have gone off, and faster than the driver, who has some rust from lack of track time. More the tires than the driver, though.... Acceleration out of the turns, I was the 2nd fastest car on track, other than the Porsche GT3, which was really amazing everywhere on the track. The tires really let me down, but in the remaining race I will move through my existing inventory of tires, and purchase new next season.

I was running in the fastest race grouping, which was GTS3,4,5, American Iron, Super Unlimited (my car and 4 others), and Camaro-Mustang Challenge. So, a variety of cars from a very fast Porsche GT3 Cup car, to BMWs, Camaros, Mustangs, and Road Racing Stockcars (in my SU class). My little Spider out there with the big, heavy cars. I watch out for them, and for the most part, they watch out for me. Most of them, from a mass standpoint, could squash me like a bug.

I had one incident on Sunday where a Camaro that didn’t see me passing it out of a turn, pinched me off, which launched the car into a long 90 to 90 spin for about 300 yards. I didn’t hit any walls or other cars, and continued. Flat-spotted the tires, though, and I got a headache from the vibration on the banking. The tires leveled out somewhat, but are goners at his point.

Bill
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Re: 2.0 8V Volumex Race Engine Build - Help?

Post by tmvolumex »

Bill,
Glad that all went well and everything and everyone held together.
Very impressive showing, considering over 2 hours of track time in anger, in a car that has had major modifications since it was last on the track, over a year ago.
Congratulations to you and your team.
Tom McG.
GC_31
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