AMMO Posted August 2, 2002 Share Posted August 2, 2002 The Le Rhone Gnome engine info stuff was from memory and valve train info incorrect. I did a search for Rhone Gnome in Yahoo. There are lots of interesting sites. These were truly wonderful engines of the First World War period. Only had a short life as better stuff came along. If you are interested in engines it is definately worth a look. Contact. Chocks away. AMMO Link to comment Share on other sites More sharing options...
hugh Posted August 4, 2002 Share Posted August 4, 2002 to answer peter carmichaels query as to why an alloy crossflow head is being produced in this day and age the reason is, the americans could not get new crossflow heads (for old formula fords)from ford and decided to make their own, so if you have to make them yourself, why not make them out of alloy, as he probably knows the crossflow formula ford is the most popular single seater race car in the world and the demand is such that new cars are being built for the crossflow formula ford overseas market. Link to comment Share on other sites More sharing options...
elie boone Posted August 5, 2002 Share Posted August 5, 2002 AMMO, Ah the great war, those where the days when people where not afraid to try something radical. However what puzzels me is why nobody seems to try a combination of a 4 stroke bottom end with a 2 stroke top together with a compressor or turbo and direct fuel injection or am i wrong ? Link to comment Share on other sites More sharing options...
AMMO Posted August 5, 2002 Share Posted August 5, 2002 Piaggio / Innocenti the people who make Vespa scooters had a four stroke bottom end with two stroke top end and direct fuel injection running a few years ago. This was to reduce emissions. As legislation tightens up it may go into production. Who knows? Wars are great for developing new technology. Shame really that mankind seems to be at it's best when they are trying to destroy each other. AMMO Link to comment Share on other sites More sharing options...
Eugene Posted August 6, 2002 Share Posted August 6, 2002 I have a Vegantune crossflow that produces 170+bhp at 7,000 rpm with 1700cc with the line still rising. The best thing is the torque which with 2 valves per cylinder is better than for 4! It make Eugene a very impressive car to drive (Roger King will vouch for this) when compared to alternatives. It also sounds great and looks the part (see link below). I could have gone for something more modern but as has been said before I didn't buy a Caterham because it looks modern and wanted an engine to match but with interesting perfomrance. That's what I got. VX lumps are too heavy and K's too silent. My engine talks to me and handles like a dream! (Live axle too!!). Ammo, you should know better. The twincam setup produces far better breathing than the pushrod crossflow and as a whole is a lot lighter. Small Boy - with Loud Toy! See Eugene here and Lotus@Herts here Link to comment Share on other sites More sharing options...
AMMO Posted August 6, 2002 Share Posted August 6, 2002 Eugene I agree with you. But the pushrod design I had in mind was an ali hemi-head one not a Crossflow. Don't know if any car engines have this but there are bikes that can produce good horsepower from this simple design. Fitting twin overhead cams would add weight and probably not produce any more power than a properly designed pushrod set-up. Of course a Vegantune or Lotus twin cam head is better and more desireable than a Crossflow head. Regarding torque, I also agree with you. My knackered Crossflow felt like it could pull taller gearing than my fresh Zetec. Bottom line is that the Zetec has given me 25 mph more top speed. I don't like noise as I find it very tiring and distracting. So two valves with the type of cams they require to make horsepower are not for me. People who bought 16V Volkswagen Golfs after having owned 8 V ones were dissapointed in the more powerful 16 V engine. They though they did not pull as well. Each to his own. Life would be boring if we all liked the same stuff. Generally speaking we all end up buying or building what we like or want. My point was just that if outright horsepower is what you want, four valves per cylinder is the way to go. There is no escaping that fact I'm afraid. Hope I did not offend anyone. Saying you don't like someone's coice of engine design is as bad as telling them their kids are ugly or stupid. I should be more careful how I put my points across. On a different note are you still in Rome? How are things going? AMMO Link to comment Share on other sites More sharing options...
Peter Carmichael Posted August 6, 2002 Share Posted August 6, 2002 The best thing is the torque which with 2 valves per cylinder is better than for 4 This is demonstrable nonsense. Link to comment Share on other sites More sharing options...
Old Septimus Posted August 6, 2002 Share Posted August 6, 2002 I suppose the BMW/Bristol engine is good for pushrod fans with 18 of them. Didn't the Humber Snipe have a clever hemi head with diagonal pushrods that passed through tunnels between the cylinder bores? Was that ever successfully tuned? Link to comment Share on other sites More sharing options...
elie boone Posted August 6, 2002 Share Posted August 6, 2002 BTW AMMO, If money is no object then i rather have a Voisin aerodynamique than a Bug. Ho else would have a propeller driven ( by airflow )waterpump Link to comment Share on other sites More sharing options...
AMMO Posted August 7, 2002 Share Posted August 7, 2002 Don't know about any hemi headed pushrod 2 valves. Maybe some yank V8. "Semi-hemi" rings a bell. Talking about propellor operated gubbins. Smokey Yunick, proprietor of "The Best Damn Garage in Town" at Daytona Beach, had a propellor operated alternator for use on the banking. They banned that. He was always great at bending or the rules. AMMO Link to comment Share on other sites More sharing options...
edmandsd Posted August 7, 2002 Share Posted August 7, 2002 I think the PT Cruiser/Bruiser that was in CCC not so long ago had an 8lt 2 valve per cylinder pushrod 'hemi' engine giving 150bhp per litre. Link to comment Share on other sites More sharing options...
AMMO Posted August 7, 2002 Share Posted August 7, 2002 Was it supercharged or turbocharged? Can't think it would make that normally aspirated. AMMO Link to comment Share on other sites More sharing options...
edmandsd Posted August 7, 2002 Share Posted August 7, 2002 Normally aspirated Ammo - high compression though running race fuel. Link to comment Share on other sites More sharing options...
cdg Posted August 7, 2002 Share Posted August 7, 2002 Toyota made a very nice 1600 hemi-head pushrod engine for the rear wheel drive Corollas (not the AE86 GT), which was also used in the 1600Celica. I'm talking late 70s early 80s. The pushrods traversed the block at some very strange angles when compared to a X-Flow, but it enabled a super port design, very similar to a Lotus Twink. Bore and stroke, if I remember correctly , were identical to the X-Flow. There was a guy at Curborough a couple of years ago with one bolted into the back of a single seater. It went very well indeed... Chris. Link to comment Share on other sites More sharing options...
Eugene Posted August 8, 2002 Share Posted August 8, 2002 Hi Ammo, No insult taken at all! I love a good argument. Just thought I would stir things a bit (can always rely on Peter to point out the errors!). I'm still working in Rome when I can get there but have been in LA, Auckland and am presently in Sydney for the past while (lots of air-miles!). However, to continue the discussion, I still think 8 valves produces better torque that 4 (regardless what Peter says) as most engine builders I have spoken to have told me so (does that get me out of attempting to explain why I think so?). Does this mean you can't get good torque from a multi-valve engine? Don't know! But I have yet to find one with a torque curve that show you can. Why is this I wonder? If its not the number of valves (something to do with air flow I guess) what is it? Other differences in engine design that a multi-valve setup demands? What ever it is, it is interesting that there is a general agreement or feeling that 8 valves are better for torque. Roger King, can you shed any light? At the end of the day I love my Seven, engine, and everything, although my wife has just ordered an MG ZT and I like that too! Small Boy - with Loud Toy! See Eugene here and Lotus@Herts here Link to comment Share on other sites More sharing options...
edmandsd Posted August 8, 2002 Share Posted August 8, 2002 I've had this discussion with Peter myself and from experience I can safely say that my BD cannot compete with the low/mid range grunt of an HTR race pinto. Peak torque isn't far different but my peak torque is around 2,000 rpm further up the rev range. That said my BD's torque curve is longer and flatter between peak torque rpm and peak power rpm. I know that the 2lt aspirated cosworth engines had to produce significantly more peak power than the pinto's they effectively replaced in the old Vecta Ford challenge cars (Mk2 Escorts and the like) because the pinto powered cars were faster out of the slow/mid speed corners. Link to comment Share on other sites More sharing options...
barry.h Posted August 8, 2002 Share Posted August 8, 2002 At the risk of spoiling a wonderfully non-specific discussion why doesn't someone overlay the torque curves from a 16 and an 8 valve engine - of similar capacity and equivalent level of tune to settle the argument? There must be the relevant info from a highly tuned 1800 x-flow around and say, a highly tuned 1800 k-series. My suspicion is that the discusssion revolves more around the shape of the curve rather than the absolute torque figure, which, after all is directly related to rpm and bhp. Barry Link to comment Share on other sites More sharing options...
Eugene Posted August 9, 2002 Share Posted August 9, 2002 Barry, a very good point. I am refering to the 'flatness' of the curve, not the peak power. Have a look at the diagram on my website (link below) to see what I mean. I would love to see a curve for a multi-valve engine of 1700cc to compare. Small Boy - with Loud Toy! See Eugene here and Lotus@Herts here Link to comment Share on other sites More sharing options...
Revin Kevin Posted August 11, 2002 Share Posted August 11, 2002 Hi all, People who need to justify their cause by using facts and figures usually have big wallets and no souls. Let them go racing and the rest of us can search out the emptier roads leading to NIRVANA. REAL SEVENS HAVE IRON BLOCKS GOOD WISHES TO ALL CHEERS CHRIS Link to comment Share on other sites More sharing options...
Casbar Posted August 11, 2002 Share Posted August 11, 2002 Girlie K's Link to comment Share on other sites More sharing options...
AMMO Posted August 11, 2002 Share Posted August 11, 2002 I have seen the errors of ways and am repentant. I have removed the Zetec head from my car and am melting it down so I can cast a new 2 valve hemi head with valves operated by pushrods. What a fool I have been for not seeing the light sooner. AMMO Link to comment Share on other sites More sharing options...
Taran Las Posted August 11, 2002 Share Posted August 11, 2002 Gosh AMMO it did a very long time 😬 Philip. D. Owen Membership No. 3976 Link to comment Share on other sites More sharing options...
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