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MG MGB Technical - Superchargers, Crossflow, Engine Swaps...
I thought some of you might be interested in the upcoming seminar John Twist (University Motors LTD) and I are hosting October 28, 29,30: Tuning for Speed. The first day at University Motors covers in-depth tuning for any type of MG, modified or stock. We take a seminar participant's car (usually a dual-carb MGB) and torque the head, adjust valves, disassemble and inspect the distributor, and go through the induction/emissions/exhaust system. Then we set timing and carbs and make the car hum. The second day starts at our local chassis dyno (Baker Engineering) and we put up to five participants' cars on the dyno. Then we head to my shop, Eclectic Motorworks, and discuss and look at all of the power-adders available. These include ported stock heads, crossflow heads, superchargers (Judson and Moss), carb conversions, engine swaps, exhausts, cams, distributors, and more. The third day follows-up with more in depth discussion of modifications and moves to chassis, tires, brakes, etc. We supply handouts with information gleaned from John's 30 years of tuning experience and my 1000+ dyno pulls. Participants also get a chance to drive my supercharged 1978 MGB. I hope this is an appropriate post--feel free to e-mail or call if you'd like a brochure or more information. A quick synopsis and contact info is at: [http://www.eclecticmotorworks.com/events.html] Thanks! Carl |
Carl Heideman |
Hi Carl. Sounds good, wish I could make it. The link didn't work for me.. ?. Don |
Don |
Trim off the square brackets. |
Matt Kulka |
Carl, sorry that I can't attend. I thank you for your great web site and the invaluable information you share with us out here in the hinterland. I'm sure everyone who attends will leave with a wealth of information and experience. |
Bill Young |
Whatever happened to the Aussie kit using the more effecient OPCON twin screw supercharger? The twin screw design is supposed to be smaller and take less parasitic drag, resulting in equivalent horsepower with less boost. Nobody seems to be talking about it any more, -- just the Moss/Eaton blower. Barry |
Barry Parkinson |
Barry The screw type SC from Hanns Petterson in OZ is still alive and well. There is not a lot of difference between the screw and Eaton roots blowers up to about 10lb boost but from then on the screw type is more efficent therefore cooler and takes less HP to drive. There is a drawback however. As it is a true compressor it takes power to turn it even when not making boost, which is most of the time. The Moss setup with the bypass valve however uses little or no power when off boost and is more efficent at cruise. I quess it depends how you use the car as to the type to use. Denis |
DENIS H |
Denis has hit the nail on the head regarding superchargers. One of the things we try to teach in Tuning for Speed is a practical approach to questions of this type. Over the years, we've found people worrying a bit too much about one theoretical aspect or another and missing the point of a more important item. (I'm not saying Barry has done that--I've read Barry's posts in the past and he is always posting great information and questions.) For example, I've seen it time and time again that people spend a lot of time and energy finding the "perfect" cam without any consideration of RPM range they drive, their compression ratio, and cylinder head porting. The "perfect" cam in theory will fall flat (and actually lose HP) if these other issues are not addressed properly first. Anyway, sorry to keep the shameless plug going for Tuning for Speed, but we try to help people make good, well-informed decisions through our experience and dyno data. We hope you can all make it! --Carl |
Carl Heideman |
Want to clue us in about your findings and what does and doesn't work? Timing? Advance curves? Since I live in NYC I won't be coming out and it's a bit of a drive to get my car tuned which I like to do myself. I will install an aluminum head that has been ported by a well regarded 'head' guy who works at a race shop which specializes in high-end and race cars. I will also be installing roller rockers too. Grassroots did a similar thing a year or so ago. Thanks. |
Mike MaGee |
Carl I don't hear anyone talking about combining water injection with supercharging. Back in the '80's I used a windshield washer pump to kick in water through a spray nozzle at the carburetor with a turbo charged 4 cylinder Ford Mustang. I was able to run full spark advance at full boost and saw a major increase in power. (over 40% increase with a few other mod's thrown in) (The turbo from a physics point of view is an unstable system, as more power produces more boost which produces more power, etc.) This should work well with a pull through system with an unpressurized carb such as the Moss system. At a minimum it would permit a higher compression ratio and better part throttle mileage. Getting the water properly metered is the hard part. Barry |
Barry Parkinson |
The cheap and cheerful way of doing water injection is to use the water pump from the high-pressure headlight washers found on modern cars - these can make about 75psi which atomises the water very well. Make a jet by just drilling a small hole in something. The cycle of ever-increasing boost on turbos is avoided by using a wastegate which opens once the target boost is achieved - running without a wastegate results in swiss pistons! fwiw, -- Olly |
Oliver Stephenson |
Mike, A lot of the information John and I discuss in the seminar has already been published in stories in Classic Motorsports and Grassroots Motorsports Magazines (I write regularly for both of these magazines). air filters, ignition systems, supercharging, etc., have all been in past stories. I just covered timing and advance curves, with dyno data, in a 3 part ignition series in Classic Motorsports. A bunch of the information is still in queue and will be published in the coming years. For example, I've got an MGB cylinder head shootout where we put 6 different heads on an engine and dynoed them all--that will be a story in the next year. Similarly, I put 1.5" and 1.75" SUs, DGV, DCOE Webers on an MGB engine and dynoed them all--yet another for the next year. There is also more stuff coming on tuning, cam timing, fuel injection and more. In the seminar, we cram everything into three days and put all this stuff in perspective to give people solid advice they can use in context. So, if you're patient, you can get it all on the cheap via the magazine stories--but it's way more fun to hang out at the dyno shop!!! By the way, most of the people who come to the seminars don't bring a car, but just a notebook and camera. Again I hope I haven't made too much of a shameless plug here... Barry, You are correct that you don't hear much about water injection anymore. I've been meaning to play with it some, but have had plenty of other things to play with and just haven't had time for it...I know of a few people on the supercharging board and Judson listserve that have. --Carl |
Carl Heideman |
Thanks Carl. Being unemployed again makes the trip rather unaffordable and ill advised at the moment. I remember water injection kits being sold by Jackson Racing for Miatas. The problem in the 80s were injection kits were crude and somewhat undependable but modern technology improved them a great deal since then - and their price has gone up to show the improvements. I do believe WWII Spitfires used a crude form of water injection to boost their power temporarily. When someone is shooting at your ass you can never have too much power :) |
Mike MaGee |
Mike, I think the injection system in Spitfires you are referring to was nitrous oxide. |
David Overington |
I think the Germans used nitrous. The Americans used water/alcohol mixture. Not sure what the Brits used. Everyone used superchargers. In fact, some used a combination of turbo and superchargers, the turbo feeding the super. As stated, never enough power. |
Edd Weninger |
This thread was discussed between 13/09/2005 and 17/09/2005
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