MG-Cars.info
MG MGB GT V8 Factory Originals Technical A new source of engines? BBS discussion at MG-Cars.info
MG-Cars.info
Welcome to our Site for MG, Triumph and Austin-Healey Car Information.
Parts
MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.
|
|
MG MGB GT V8 Factory Originals Technical - A new source of engines?
| With the 2004 Formula One racing season over for an other year I couldn't help thinking about the fate of all those lovely V10 engines that will be outlawed next season. F1 is moving to a V8 instead. Just think of it, 985 Horse Power, 18,000 rev.red line. Whew! Probably just twist my little Brit into a pretzl. |
| Christopher Trace |
| Interesting thought, but the V10's were only designed and built to last for a few hundred miles before needing a complete strip down and rebuild. For next season the engines have to last for TWO race weekends so you might get nearer to one thousand miles out of an engine! I believe the 2.4 litre V8 specification is not now coming into effect until 2006 season as the teams managed to convince the FIA that to develop a reliable V8 unit for 2005 was out of the question. Of course what they really meant to say was we need longer to wring 1000bhp out of 2.4 litres!!!! For 2005 I believe it is proposed that the cars will lose some of their aerodynamic bits, launch control and traction control - however, lots can happen over the winter and the industry giants like Fiat (Ferrari), Mercedes Benz (McLaren) and BMW (Williams) have a lot of clout. L. Webb A mile down the road from BMW Williams factory! |
| L Webb |
| this might sound stupid but how do they get so much power out of a comparitively small capacity? |
| J P Connor |
| My basic idea would be rediculous amounts of compression ratio and alchohol fuel...?? |
| Larry Embrey |
| JP VERY high revs (up to 19,000 in 2004 probably 20,000+ for next year), 5 valves per cylinder and very efficient porting (no turbo to force the mixture in), and that's just the start of it! An F1 engine is designed to operate between about 7,000rpm to 19,000rpm and would be totally impractical in a road car - despite all that power it is very easy to stall an F1 car as you may have seen a few times on TV and without launch control next year there will probably be a few more "slow" starts when the lights go out! Roadgoing supercars like Aston Martin, Ferrari, Lamborghini, Porsche etc rely on more c.c. for their power 5 or 6 litres at least and usually producing around 100bhp per litre non-turbo and 150bhp per litre if turbo fitted - way short of the 300+bhp per litre of an F1 engine. L. Webb 75 BGT V8 Teal Blue - 137bhp (at the moment but more to come!!!) |
| L Webb |
| i guess that all makes sense really, i know that F1 engines dont use a cam, the valves are operated by pnuematics (or is it hydraulics??) not sure how efficient and reliable this would be. i buy retro cars (magazine), a few months ago there was an MGB in there with a crossflowed 2 litre B series engine kicking out 200bhp. love to learn more about porting (i swear i'm not a geek!) |
| J P Connor |
| "this might sound stupid but how do they get so much power out of a comparitively small capacity?" JP, They do it by sacrificing low end torque for rpm. This creates the illusion of a very powerful engine, but one that is entirely unsuitable for our application. Search through the archives for the "Cyclone 2.0 vs Ford 302" thread for some of my thoughts on this. I believe the thread is under the "MGB General" heading. I just hope this post doesn't generate the bitterness here that it did over there. |
| Dan Masters |
| As long as we're not trying to say a V8 is better than a V6 there shouldn't be any bitterness.... ;-) Justin |
| Justin |
| F1 cars still have pretty dam quick acceleration so there must be enough torque there to launch them that fast. obviously they weigh as much as i do wet. i'll have a look at that thread. |
| J P Connor |
| JP Yes, valves are pneumatically operated - occasionally you will see an air line being plugged into the side of the car to top up a reservoir (I think McLaren in particular had a few problems with this in the 2003 season and loss of air pressure caused Raikennen to retire from a couple of races). The system seems to have been more reliable last season. Torque: as Dan mentions, and I alluded to in my posting, F1 engines rely on high revs so torque is sacrificed. Check again my comment about possible "slow" starts when launch control is banned, at least until the drivers have done a few race starts to get used to being without it. To add to that, yes acceleration from the startline is extremely quick, but the drivers can only do that by using 10/12,000 rpm before letting the clutch in (hand operated) and lighting up the back tyres - not done for show like a boy racer but to prevent the engine bogging down. F1 cars are fitted with an anti-stall system which disengages the clutch when revs get too low but F1 viewers may remember a few "slow" getaways after pit stops last season due to insufficient revs. Finally, I think (and I am open to correction here) current F1 cars must be minimum 500kgs with driver and his helmet at end of a race. Just think what that means in bhp per ton (or even tonne)! Laurie Webb 75 BGT V8 137bhp and 193ft/lb |
| L Webb |
| i think its a good idea that these new rules are coming into place. in my opinion F1 was getting to a stage where they were driving high tech go karts and letting a computer do the rest. i dont know if everyone will agree with my view here but i'm sure you can see my point. dan, i read a good majority of the "Cyclone 2.0 vs Ford 302" thread and i think it got a bit personal for an mg forum!! you had some very good points though, i must agree that horse power is a bit of a nonsense figure if it is out of context, torque is the only way! L webb, just out of curiosity, if the current F1 engines have 5 valves per cylinder how many are inlet and how many are exhaust? just another thing, is your V8 a factory fitted V8 or a conversion? just that the 3.5 Sd1 puts out 198lb/ft and 158bhp (i think). |
| J P Connor |
| JP My V8 is a genuine factory car - number 2190 - which makes it the 90th R/B V8 and the 23rd car built in 1975. Rover/Buick V8 engine for the BGT was the downrated version used in the Range Rover (8.25:1 CR) rather than the Rover saloons (10.5:1 CR). Factory figures are as I stated at end of my last posting - 137bhp and 193ft/lb of torque. This has proved to be plenty in a car which weighs only a few pounds more than my other 4 cyl R/B GT! Comparative bhp per ton figures (based on C/B models) are 79.06bhp/ton for 1.8litre GT and 128.56bhp/ton for the V8 - an increase of nearly 63% over the 4 cyl GT. The best bit is that the peak torque figure is at 2,900rpm, perfect for 3rd/4th gear overtaking with minimum effort. OK, so some modern turbo diesels like the VW Golf TDi with the latest 2 litre engine of 140bhp, 240ft/lb (I think) and 6 speed box can probably match or even better the V8's acceleration - but I know which car I would rather be driving! Regarding F1 valves - sorry, I don't know whether it is 3 inlet/2 exhaust or 2 inlet/3 exhaust. Some engines may also have gone back to 4 valves per cylinder with some very clever positioning to provide maximum inlet/exhaust area. L. Webb 75 BGT V8 Teal Blue 77 BGT 1950cc Flamenco |
| L Webb |
| Justin A V6 will always be 3/4 as good as a V8....... |
| Mark |
| They also use a tightly controlled specially made for the event, petrol blend. High octane stuff. |
| Peter |
| L, they're some quite impressive figures. the VW Gti Tdi is just a little short of 1.9ltrs. its pretty quick but sounds like a straining tractor. the 5 valve arrangement is propbably either way round, it's most likely that the 2 valves are enlarged to match the surface area of the 3. have you got a pictures of your V8? or a website maybe? cheers joe |
| J P Connor |
| Joe Photos of both my BGT's are at http://uk.photos.yahoo.com/laurie_mgb Enjoy! Laurie |
| L Webb |
| very very nice. i'll get to that stage one day with my B! i still havent been in a MGB V8 yet, even though i own an MGB and a V8!! i've only driven my B in and out of the garage, on the second time i did it (my girlfriend didnt believe it worked so i had to prove it) it ran out of fuel then we had to push it back in the garage. she wasnt too happy :) anyway, like i said very nice you must be very proud. the V8 looks a bit more sneaky now it's on miniltes, i bet alot of boy racers dont know what they're messing with. nice one, joe |
| J P Connor |
| Joe, Can you drop me an email at Alexander dot Mph at gmail dot com with some more info on that crossflowed B? By the way, I presume the valve setup is 3 valves in, 2 out. It might be nice to see people's reactions when you drive by in the B with an F1 engine installed. I'd hate to pay for the petrol though... Alex (150+ hp crossflowed B) |
| Alexander M |
| alex, yeah course i can. what would you like to know? |
| J P Connor |
| Peter, Any idea as to what the "effective" ocatane rating might be? Dominic |
| Dominic |
| > I know that F1 engines dont use a cam, the valves are operated by pnuematics > (or is it hydraulics??) not sure how efficient and reliable this would be. Formula One cars still use cams to open the valves. It's the springs that are replaced by pneumatics. It's been that way for many years. Valve springs would lose pressure over the course of a race, leaving an engine with less revs at the end of the race. The pneumatics work just as well at the end as at the start. > F1 cars still have pretty dam quick acceleration so there must be enough > torque there to launch them that fast. You're confusing engine torque with rear wheel torque. It's rear wheel torque that accelerates an automobile. 250 ft-lbs @ 19000 RPM is a little over 900 HP. To make 900 HP @ say 3000 RPM would take 1575 ft-lbs. Torque is the rotary equivalent of force. It is what accelerates a vehicle but it's not the torque at the crankshaft that is important, it's the torque at the rear wheels. It just so happens that horsepower is the measure of how much RPM can be traded for rear wheel torque via gearing. If two engines have the same power but different torque, they will still accelerate the same if they both have optimal gearing. The engine with less torque will just have to spin a higher RPM to do it. This assumes the same average power over the RPM spread between gears, not just equal horsepower peaks. > My basic idea would be rediculous amounts of compression ratio and alchohol > fuel...?? Only small amounts of alcohol is permitted. They use gasoline with a tightly regulated set of additives. The regulations can be found at: http://www.formula1.com/insight/rulesandregs/14/486.html Dan Jones |
| Dan Jones |
| someone knows their stuff! i understand now, so i guess that F1 cars have a very low gear ratio and rev highly to get their torque? am i right or should i read it again? just out of curiosity, does anyone know what torque at the wheels a 78 Gt with standard engine etc would be? cheers, joe |
| J P Connor |
| > so i guess that F1 cars have a very low gear ratio and rev highly to get > their torque? Yes. F1 cars typically have 6 or 7 speed sequential shift semi-automatic gearboxes with ratios chosen to keep the engine in the high RPM power band. That maximizes the torque at the rear wheels and thus the acceleration of the car. The Williams team even tested with a Van Doorne continuously variable transmission (CVT) back in 1993 but the FIA banned CVT in 1994. > am i right or should i read it again? You got it right. For more on the subject, I did a simple derivation and write up on torque versus horsepower: http://www.mustangsandmore.com/ubb/DanJonesTorqueVsHP.html Dan Jones |
| Dan Jones |
| cheers dan, that write up looks impressive but i doubt i'll be able to get my head round it!! joe |
| J P Connor |
| Dan, Great article Torque vs HP. Regards Pete 1969 302 V8 |
| PJ Mantell |
| > that write up looks impressive but i doubt i'll be able to get my head > round it!! Nah, that's the easy one. The aerodynamics primer is a bit more involved but still no tricky mathematics. > Great article Torque vs HP. Thanks, see what you think of: http://www.mustangsandmore.com/ubb/DanJonesAerodynamics.html Dan Jones |
| Dan Jones |
| Dan, Awesome article also. Cheers Pete |
| PJ Mantell |
This thread was discussed between 29/10/2004 and 03/11/2004
MG MGB GT V8 Factory Originals Technical index
This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now