ALFAGTV6.COM

[Greg Gordon]

Perhaps the weights are closer than I think, but having moved them around in the shop, it seems to me the Alfa V6 is quite a bit heavier than the Fiat 4cyl. I have not weighed them, so I could be wrong.

With all things equal, a supercharged Alfa 12 valve V6 will put out more power than a supercharged Alfa 4cyl. by a large margin. The problem for the V6 arises when you run into another limitation. For example if your transaxle can only handle 300hp and you can get that with either supercharged motor, the 4cyl may be the way to go for packaging, originality, and if it weighs less, performance. Of course you are right about the V6 not having to work as hard to make that amount of power. It's not a clear cut choice. If you want the V6, go with it. I am just saying I would stick with the original engine type, but that's me, and it's not my car.

It's easier to attach a picture than to try and explain this manifold thing. Although this picture is somewhat censored you can clearly see, we bolt the pipe carrying air from the supercharger, and through the intercooler to the stock manifold. This works very well.

Greg

[MR2 Zig]

Another way to think of the manifold thing is this....the supercharger (or turbo) is a compressor and compressed air is a little bit less sensitive to imperfections in the inlet manifold. The manifold for the carburator is actually a little big for the engine when you use a supercharger (or turbo).

While you may see some benifit to port work, cams, special valves, etc. the "bang for the buck" factor of other performance work is reduced when coupled with the supercharger. In a race, normally aspiated engine air is being sucked in by the piston, so everything along the way has to be perfect and without restriction to maximize the cylinder filling with air....with the blower the air is forced in making bumps and turns along the way to the cylinder less of a problem.

Look at this page http://www.mossmotors.com/Shop/ViewProd ... exID=37878

It is for the MGB but explains why to use a supercharger fairly well. (of course they are trying to sell you a supercharger though)

hth
zig

[Lancianut69]

Perhaps the weights are closer than I think, but having moved them around in the shop, it seems to me the Alfa V6 is quite a bit heavier than the Fiat 4cyl. I have not weighed them, so I could be wrong.

With all things equal, a supercharged Alfa 12 valve V6 will put out more power than a supercharged Alfa 4cyl. by a large margin. The problem for the V6 arises when you run into another limitation. For example if your transaxle can only handle 300hp and you can get that with either supercharged motor, the 4cyl may be the way to go for packaging, originality, and if it weighs less, performance. Of course you are right about the V6 not having to work as hard to make that amount of power. It's not a clear cut choice. If you want the V6, go with it. I am just saying I would stick with the original engine type, but that's me, and it's not my car.

It's easier to attach a picture than to try and explain this manifold thing. Although this picture is somewhat censored you can clearly see, we bolt the pipe carrying air from the supercharger, and through the intercooler to the stock manifold. This works very well.

Greg

Thanks for your patience mate! The weight issue is interestin and I will post info on the relative weights when I get that info.

Ok, I think I am pretty much sold on the idea now of a 12 valve install - which I know can be achieved with no structural changes that are 'permanent'. That way, I could go back to a standard 4 pot installation. Initially a normally aspirated install and look at supercharging at a later date, unless I happen across an M62 blower in the meantime! ;o)

The gearbox I understand is a very common part with internals that can be sourced from a multitude of cars depending on your own ratio requirements. I wouldn't expect to be over 300 bhp with a standard 12v on plenum with custom exhaust, megasquirt and blower?

Re the manifold - I take it the alfa has direct port injection and there is a throttle body somewhere in there? I could see then how you could install using the standard manifold with the injectors mounted on fabricated bosses? Intercooling may be an issue with the mid engined setup getting more air to the back, although I do have some ideas in this regard, it would require changing the rear buttresses for solid items and moving more to 037 scoops.

Cheers

Darren

[Lancianut69]

Another way to think of the manifold thing is this....the supercharger (or turbo) is a compressor and compressed air is a little bit less sensitive to imperfections in the inlet manifold. The manifold for the carburator is actually a little big for the engine when you use a supercharger (or turbo).

While you may see some benifit to port work, cams, special valves, etc. the "bang for the buck" factor of other performance work is reduced when coupled with the supercharger. In a race, normally aspiated engine air is being sucked in by the piston, so everything along the way has to be perfect and without restriction to maximize the cylinder filling with air....with the blower the air is forced in making bumps and turns along the way to the cylinder less of a problem.

Look at this page http://www.mossmotors.com/Shop/ViewProd ... exID=37878

It is for the MGB but explains why to use a supercharger fairly well. (of course they are trying to sell you a supercharger though)

hth
zig

Hi Zig,

Thanks for the info mate - it does make more sense. When I was originally looking at the Volumex install in my car, I was considering a change to Fuel Injection. The standard setup is to have the Rootes blower mounted inbewtween the head and the carb. However, this system is by no means perfect - aside from the issue of using a Rootes blower as mentioned by Greg earlier - and a number of valves and pipework was needed to aid with hot/warm starting.

The MG site you linked to shows the blower at the start of the induction loop as it were and maintains the SU type (I forget the actual name as its been a LONG time since I worked on minis! - The SU has the bowl to the side the IDF (?) has the bowl underneath. Therefore I'm guessing from Gregs picture and a certain amount of logic that it would be possible to mount a blower on the original engine where it won't cause clearance problems and replumb as follows - filter - throttle body (off what I'm not sure) - blower - manifold with injectors and fuel rail?

Cheers

Darren

[Bruce]

I was going to suggest a Thema 16v turbo engine which will give you easily 300hp but those are getting quite rare now!

[Greg Gordon]

In the picture I posted the throttle body is located before the supercharger. This particular setup goes air filter, throttle body, supercharger, intercooler, intake plenum. More often I leave the throttle where it is and go air filter, supercharger, intercooler, throttle body, plenum. There are advantages and disadvantages to each configuration.

Greg

[Lancianut69]

I was going to suggest a Thema 16v turbo engine which will give you easily 300hp but those are getting quite rare now!

Hi Bruce,

You're not kidding! And it's not a straightforward install. Has been done though. This is Ken Haven's car from the States.

Cheers

Darren

[Lancianut69]

In the picture I posted the throttle body is located before the supercharger. This particular setup goes air filter, throttle body, supercharger, intercooler, intake plenum. More often I leave the throttle where it is and go air filter, supercharger, intercooler, throttle body, plenum. There are advantages and disadvantages to each configuration.

Greg

I guess that as the inlet is charged or 'forced' you can get away with more a more convoluted inlet tract? Can you give me a brief synopsis of the pros and cons to each?

Thanks!

Darren

[Greg Gordon]

Think of it this way; the intake tract I showed in that picture is no more complex than it would be with either a turbo or centrifugal supercharger using an air to air intercooler. It's just not a problem.

I just don't have time to go over all the pros and cons of the various throttle positions right now. It's a complex subject that gets into all sort of other areas for example, bypass valves and fuel injection tuning issues. I will try and get to it when I have time.

Greg

[MR2 Zig]

Something to note with Greg's blower installations is that he has room (not much!) to put the blower on one side of the engine. He then uses piping to get the air where he wants it. (this gives lots of options about how you want things to work)

That MGB link I pointed you to takes a different aproach because of the layout of the engine compartment on that car. It has a SU carb (a bunch bigger one than stock) attached to the blower which is then bolted to a cast manifold that is bolted to the engine. It is sucking both fuel and air thru the blower and has no provision for adding an intercooler.

The text was what I thought you might find interesting.

zig

[Lancianut69]

Think of it this way; the intake tract I showed in that picture is no more complex than it would be with either a turbo or centrifugal supercharger using an air to air intercooler. It's just not a problem.

I just don't have time to go over all the pros and cons of the various throttle positions right now. It's a complex subject that gets into all sort of other areas for example, bypass valves and fuel injection tuning issues. I will try and get to it when I have time.

Greg

Hi Greg,

No probs mate, perfectly understand that you no doubt have a huge number of other folks to speak to - thanks for all your pointers to date. Is there any reading you recommend for me. I do notice that you have a publication, and 35 bucks is a good price, but when you add the cost of VAT to proposition and customs clearance, it does become a very expensive book for a Brit on this side of the pond. I don't suppose there are any UK stockists? ;o) Are the other issues of throttle positions mentioned as well?

Cheers

Darren

[Lancianut69]

Something to note with Greg's blower installations is that he has room (not much!) to put the blower on one side of the engine. He then uses piping to get the air where he wants it. (this gives lots of options about how you want things to work)

That MGB link I pointed you to takes a different aproach because of the layout of the engine compartment on that car. It has a SU carb (a bunch bigger one than stock) attached to the blower which is then bolted to a cast manifold that is bolted to the engine. It is sucking both fuel and air thru the blower and has no provision for adding an intercooler.

The text was what I thought you might find interesting.

zig

Have gone back and ready the text, as well as the article - thanks again Zig. That setup is very much akin to the Vx setup using the original Rootes blower. If I were to stick with the original engine, then I would need to do fabrication to avoid having to cut the firewall. The installation of that would require more thought and research as to the best way to proceed reference fuel injection and throttle bodies, plenums etc etc. I don't know if the addition of an intercooler is possible with the monte install. There would potentially be room for it over the exhaust cover at the back of the engine bay (rear of the car) but ducting fresh air through it would be another matter entirely! ;o)

As I said to Greg, I don't have enough knowledge right now so need to do some research.reading and any recommendations for material would be greatfully received.

Cheers

Darren

[MD]

Lancianut69

right now so need to do some research.reading and any recommendations for material would be greatfully received.

..mate, just to help you along..

I been thinking you are getting stressed out with all this high tech thinking and if you keep this up you could just blow a fuse or something.

So i suggest some R & R and kick back with some light relief before you roll the sleeves up..

After all, t's JK's main reference material. How could you go wrong?

[Greg Gordon]

I am stuck in my annual recurrent training at work. It's five intense days that don't allow me much time for forums or anything else. I am attaching the bibliography from my book. The first 18 items are NACA reports. Numbers 22,23, and 24 can be found in most book stores, I suggest starting with Pat Ganahl's book. Well, actually I suggest starting with my book, but I understand the shipping cost issue, I just don't have a good way around it.

Greg


1. The Way To Increase Airplane Engine Power.
2. Italian High Speed Airplane Engines.
3. Correlation Of Knocking Characteristics Of Fuels In An Engine Having A Hemispherical Combustion Chamber.
4. The Comparative Performance Of Roots Type Aircraft Engine Superchargers As Effected By Change In Impeller Speed And Displacement.
5. Engine Knock And Combustion Chamber Form.
6. The Comparative Performance Of Superchargers.
7. The Problem Of The Turbo-Compressor.
8. Preliminary Flight Tests Of The N.A.C.A. Roots Type Aircraft Engine Supercharger.
9. An Investigation Of The Use of Discharge Valves And An Intake Control For Improving The Performance Of N.A.C.A. Roots Type Supercharger.
10. Mathematical Analysis Of Aircraft Intercooler Design.
11. Effect Of Water Injection On Knock-Limited Performance Of A V-Type 12-Cylinder Liquid-Cooled Engine
12. End-Zone Water Injection As A Means of Suppressing Knock In A Spark-Ignition Engine.
13. Some Effects Of Internal Coolants On Knock-Limited And Temperature-Limited Power As Determined In A Single-Cylinder Aircraft Test Engine.
14. Knock-Limited Power Outputs From A CFR Engine Using Internal Coolants II – Six Aliphatic Amines.
15. Continuous Use Of Internal Cooling To Suppress Knock In Aircraft Engines Cruising At High Power.
16. Effect Of Water-Alcohol Injection And Maximum-Economy Spark Advance On Knock-Limited Performance And Fuel Economy Of A Large Air-Cooled Cylinder.
17. The Induction Of Water To The Inlet Air As A Means Of Internal Cooling In Aircraft-Engine Cylinders.
18. Knock-Limited Performance Of Several Internal Coolants.

The Following publications were also used.

19. Allison V-1710 Engine by Allison
20. The Turbosupercharger And The Airplane Powerplant by General Electric.
21. Sports and Classic Cars by Griffith Borgeson & Eugene Jaderquist.
22. Supercharging, Turbocharging, & Nitrous Oxide by Earl and Diane Davis.
23. How to Build Horsepower Volume 1 by David Vizard.
24. Street Supercharging by Pat Ganahl.

[fedezyl]

I am stuck in my annual recurrent training at work. It's five intense days that don't allow me much time for forums or anything else. I am attaching the bibliography from my book. The first 18 items are NACA reports. Numbers 22,23, and 24 can be found in most book stores, I suggest starting with Pat Ganahl's book. Well, actually I suggest starting with my book, but I understand the shipping cost issue, I just don't have a good way around it.

Greg


1. The Way To Increase Airplane Engine Power.
2. Italian High Speed Airplane Engines.
3. Correlation Of Knocking Characteristics Of Fuels In An Engine Having A Hemispherical Combustion Chamber.
4. The Comparative Performance Of Roots Type Aircraft Engine Superchargers As Effected By Change In Impeller Speed And Displacement.
5. Engine Knock And Combustion Chamber Form.
6. The Comparative Performance Of Superchargers.
7. The Problem Of The Turbo-Compressor.
8. Preliminary Flight Tests Of The N.A.C.A. Roots Type Aircraft Engine Supercharger.
9. An Investigation Of The Use of Discharge Valves And An Intake Control For Improving The Performance Of N.A.C.A. Roots Type Supercharger.
10. Mathematical Analysis Of Aircraft Intercooler Design.
11. Effect Of Water Injection On Knock-Limited Performance Of A V-Type 12-Cylinder Liquid-Cooled Engine
12. End-Zone Water Injection As A Means of Suppressing Knock In A Spark-Ignition Engine.
13. Some Effects Of Internal Coolants On Knock-Limited And Temperature-Limited Power As Determined In A Single-Cylinder Aircraft Test Engine.
14. Knock-Limited Power Outputs From A CFR Engine Using Internal Coolants II – Six Aliphatic Amines.
15. Continuous Use Of Internal Cooling To Suppress Knock In Aircraft Engines Cruising At High Power.
16. Effect Of Water-Alcohol Injection And Maximum-Economy Spark Advance On Knock-Limited Performance And Fuel Economy Of A Large Air-Cooled Cylinder.
17. The Induction Of Water To The Inlet Air As A Means Of Internal Cooling In Aircraft-Engine Cylinders.
18. Knock-Limited Performance Of Several Internal Coolants.

The Following publications were also used.

19. Allison V-1710 Engine by Allison
20. The Turbosupercharger And The Airplane Powerplant by General Electric.
21. Sports and Classic Cars by Griffith Borgeson & Eugene Jaderquist.
22. Supercharging, Turbocharging, & Nitrous Oxide by Earl and Diane Davis.
23. How to Build Horsepower Volume 1 by David Vizard.
24. Street Supercharging by Pat Ganahl.

That must be enough to be entertained for a while!!
Hey Greg, you're still on the 727? i'm up for my recurrent in Madrid next month....it's that time of year to get back to booksss