From: John De Armond Newsgroups: alt.autos.rod-n-custom,rec.autos.rod-n-custom, rec.autos.sport.nascar Subject: Re: A really, really little V-8 Date: Sun, 19 Nov 2000 00:29:57 -0500 John McCoy wrote: > No, but if the Japanese motorcycle companies can routinely get 110hp > from 600cc in a production engine, a one-off built for competition, with no > requirements to live for several years, run cleanly at slow speeds, or > comply with fuel economy, emissions, or noise requirements, ought to > be able to do better. > > You'll note also that my original post mentioned that I didn't know if > Formula SAE has an inlet restrictor - if they do, then 80hp may be a > very creditable number. There is an intake restriction of 20mm for gas (don't know what it is for alky) but a clever intake manifold design can work around that. In 1992 or 3 (full-blown CRS syndrome at work) I served as a consultant to the Rutgers FSAE team, assisting them with engine management. We achieved approx 120 hp on the rear wheel from a Kaw Ninja engine on gas and operating through the 20mm restriction. We used an Electromotive engine management system. The engine breathed through a very slick barely sub-critical venturi manifold. The venturi, modeled by the CFD guys on the team, was about 3 feet long. It fed from a Volkswagen Golf throttle body (120mm, as I recall.) We lost only 3% flow over what the throttle body itself would flow. Looking at those pictures sounded numerous alarm bells for me. First off, it looks like SAE has completely lost control of the competition or else they're just turning their heads. The objective of the competition is to build a car for a specified budget ($8k back then). There was some wink, wink, nod, nod going on back then, things such as allowing donated parts to not be counted in the budget, but this is thoroughly out of control. Man-hours must be costed in the formula. Unless they figured a dime an hour or something thereabouts, there is no way to build a car with such an engine and stay within budget. The next thing that bothered me is that from what I could see of that engine, it is not a very good design. I would anticipate the crank to be far out of balance with no more counterweights than what is shown. The intakes are far too large for such small cylinders. Machining a crankcase from billet gives one almost no control over expansion, something that is easily done with castings. Casting the crankcase would have been easier, cheaper and faster than hacking it out of aluminum billet. The engine sounded sluggish and not particularly well tuned in the audio clip. This would fall in line with a really lousy BMEP computed from the HP at speed. I suspect that there was very little academic supervision of this project. The SAE rules call for the competition to be primarily a learning experience with proper supervision required. Unfortunately many universities treat this competition like a bastard step-child (Rutgers certainly did) so lack of supervision and direction would certainly feasible. This opinion is based purely on what I saw on their web site. I don't know any of these guys and have not been to a competition since 92 so there is an ever so slight possibility that I may be slightly wrong here and there :-) From: John De Armond Newsgroups: alt.autos.rod-n-custom,rec.autos.rod-n-custom, rec.autos.sport.nascar Subject: Re: A really, really little V-8 Date: Sun, 19 Nov 2000 04:33:21 -0500 Batman wrote: > Judging from the eveloution (sic) of their cars including the advance from > normally asperated (sic) bike motors to turbocharged alky burning motors up to > know (sic) with an in house designed and built 16,000 RPM V-8 effort, I find it > hard to believe how you can describe this as a unsupervised basterd step > child type of program? Wow, batman. Kid spends 15 minutes at a web site and he's an instant expert. Why would I call it a bastard step-child sort of program at many universities? Well let's see. When I arrived at Rutgers about a month before the 91 competition, the scene was dismal. The team was working in one corner of an equipment room in and amongst stored junk. Even though Rutgers had a wonderful engine research laboratory complete with multiple dynos and motor dynos, they were not allowed in. Ditto with the machine shop. They had been spending their own money - because the university had none for the program - to go to an off-campus machine shop to have work done. They had gotten the Electromotive ECU donated but they could not come up with a PC to tune it with! Obviously little engine development work had been accomplished. I brought one for them to use. They had built a dyno using an automotive torque converter as the absorber. This even though a wonderful GE motor dyno was just on the other side of the wall where they were working. Probably the worst part was that none of this work was for credit course work. They had to do all this in their spare time. Probably corrupting them for life, I showed them how to pick the lock to the MechE machine shop so that we could sneak in at night and over a long weekend and do some emergency machining. We rigged up jesus cords to power the lathe and mill because the power was locked off at night. I went to talk to the department head to see if I could solicit some support. I thought that perhaps since I was a sponsor and contributor (and old enough to be their dad) I might make some progress where they could not. Brick wall. I was told in no uncertain terms that the school did not sponsor the FSAE effort and that they'd have to make do. Sounds like a bastard step-child program to me. The torque converter dyno didn't work very well and burned out as we hit 100 hp during our tuning. We managed to get in the dyno lab at night. (I'll never tell how.) The guys removed all the hazardous waste drums that were stored on the chassis dyno and I got it working again and calibrated it. The team caught holy hell from the dept head for that bit of initiative. Yep, bastard step-child. Jerry Grandov, their composites whiz (seen on the right here: http://coewww.rutgers.edu/fsae/images/gallery/1994/94jerry.jpg ) made the carbon fiber fairing for the 91 car. Using grocery bags for vacuum bagging and cardboard refrigerator boxes and heat guns for the curing oven. That despite Rutgers' having a world class composites and ceramics department. He got NO help from the school. He got carbon fiber prepreg donated to the project and then had to go buy a freezer to keep it in. Apparently the school could not even come up with a friggin' freezer. Those guys did an absolutely outstanding job, more so because of the obstacles the university tossed up in front of them. From talking to people on other FSAE teams, I learned that this is not uncommon. While some schools such as Cornell give the fullest support to their teams, most don't. The students have to scrape and beg and do with what they can. And without university oversight or guidance, one ends up with things like a from-scratch V-8 that will only produce 80 hp. John |