14 replies to this topic

[Brummy]

I am currently a student studying Avionic Systems. For part of our degree we have to perform a technical presentation. As I have a real interest in Formula 1 I hoped to do this on perhaps some engine managment system used, or some other electronic system. I have spent the last 2 hours searching the internet and have not found any worthwhile sites. Is there anybody out there who can give some good sites where I can find the technical information I require?

I would appreciate any suggestions.

Catch you later

Brummy

[Billy Gunn]

Brummy,

First off are you a Blue Nose or a V*llian?
Secondly I believe if your from Brum there is a company close to you that may be able to help. Zytek Systems at (I think) Bassetts Pole, Sutton Coldfield.

These people were involved originally with Lucas of Great King Street and were the first to supply a F1 team with Digital mapped PI system (1982 Toleman at Monaco - A Senna 2nd place first time out if I remember correctly) They supplied Yamaha as well - but don't think they currently supply anyone at the moment.

They are involved in F3000 and they have a web site - do a search on "Zytek"

Try also: www.tagelectronics.co.uk
and: www.magnettimarelli.co.it

Billy G

[This message has been edited by Billy Gunn (edited 03-17-2000).]

[PDA]

You could also contact Visteon.

I don;t think you will get your data directly from the net. You will have to contact the companies concerned, explain your position, and maybe they will help.

[Ray Bell]

A good topic or subject would be detonation control, the principal problem that led to the sophistication of today's engine electonics.

[desmo]

Detonation control did indeed spur the development of today's sophisticated engine managment systems, but detonation isn't an issue in current F1. John Judd:

"One problem you never have to worry about is detonation. You just don't get the compression ratio into the area where that is a problem!"

You cannot make the c.c. small enough with the nearly 20mm valve lifts required to aspirate these engines.

[tak]

Have you tried Sociatey of Automotive Engineers? I believe it's www.sae.org (but am not certain!).

[Ray Bell]

20mm of valve lift?
I was howled down before when I questioned the engine weights - can I ask if this is right? Man, those cams would have some ramps!

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Life and love are mixed with pain...

[This message has been edited by Ray Bell (edited 03-21-2000).]

[desmo]

Nearly, Ray. I would bet the Macs run at least 18. 17mm lifts were admitted to a couple of years ago, and rpms have only climbed since then.

[PDA]

ray - the big block motors used in drag racing have valve lift of 1.5 inches and more, so it is more than possible that F1 engines would have 20mm and more

[Ray Bell]

Drag engines, however, have rockers between the cam and the valve, allowing for a working ratio that will increase lift at the valve compared with the cam. Still, 1.5", that's hard to conceive...

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Life and love are mixed with pain...

[desmo]

I'd bet most teams are using finger followers now. Judd again (Thank goodness for him. No one else with any real insight into F1 engine tech will spill the beans!

"However, I think you need finger followers in Formula One now. The use of air springs means that the spring itself is no longer a problem. With wire springs you got pushed into a corner between spring design and valve lift. You had to compromise badly whereas with air springs there is no real compromise - you just have to make sure that you don't overload the cam/tappet interface.

"As much as 17mm of valve lift is not out of court these days [1998]. To get the valve open to that amount of lift in the time available you need a very high acceleration and for that you need a large-diameter tappet. The steeper the rate of lift the bigger the tappet needs to be and there comes the point at which it is better done with a finger-type follower where you have some rocker ratio.

"Essentially you don't put the cam directly over the valve, you get some rocker ratio on it and you can get the lift you need with lower valve gear recipricating mass. If we were to build another Formula One engine I think we would have to look very seriously at finger cam followers."

[PDA]

Ray - you are quite right to find 1.5 inches inconceivable. I have checked my authorities and see that my recollections were incorrect. The figures given in Race Car Engineering earlier this year for ProStock engines were .560 for cam lift, and .95 or thereabouts for valve lift.

ANother article by Vizard in March 98 is most illuminating. Parallel vertical valve engines (such as dragster stock block V8s) can get maximum flow at valve lifts of 0.4 to 0.42 times the valve diameter. for a large cylinder (1 litre per cylinder) V8 such as a ProStock, this would amount to 1.05 inch for a 2.5 inch diameter intake valve.(So .95 actual seems reasonable). For the much smaller, inclined valves of a 4vpc F1 engine cylinder (300 cc) the lift required for the 1.5 inch (or thereabouts) inlet valves, to give .32 to .35 x Diameter would be closer to .42 inches (or 10.7 mm) of lift. (for inclined valves, max flow occurs at lower comparative lift)

The conclusion to be drawn is that valve lift on F1 engines is unlikely to be more than 10 - 11 mm, as flow is maximised at that point. (Unless the inlet valves are much bigger than 1.5 inches (38 mm)

[desmo]

I consider Mr. Judd's authority on the subject beyond question. He has the first hand knowledge and no motive to lie. 10-11mm valve lifts were abandoned in F1 many years ago. Lift of that order will simply not get the job done at 17+Krpm.

[PDA]

Difficult to argue with Judd. However, the Vizaed article is basewd of flow measurements made on teat rigs, and they show that flow is maximised when lift is about .35x valve diameter. He argues that additional lift would be useless. It would only make sense if the valves were significantly larger than the 1.5 inch diameter supposed in his paper. I know that F1 engines have become markedly oversquare in recent years in search of ever higher revs, so it is possible (probable?) that valve sizes ARE sugnificantly larger. Does anyone have any data?

[PDA]

Firther thoughts on why Mr Judd could be correct:
1 as stated above, valve sizes may be larger than 38 mm.
2 In the parallel valve set up, higher than .35*diameter is beneficial because the flow is not around the valve circumference, but across the back of the valve. It is not beyond the realms of possibility that F1 engines introduce some kind of swirl inducing shape to the inlet port encouraging the flow to "bend", making higher lift beneficial