ElbyMoto formula three

[Elby]

Hi everyone in Morini Land.

I am John Green from Elbymoto and have been very interested in the site having just found it, as a guy called Mat has just discovered my old formula one Benelli I entered in the 1981 Isle of man TT. Not knowing how he found me I did a search for Elbymoto and found the morini site as well. Back in the seventies I became a Morini dealer and my love of racing made me look long and hard at the 350 engine. I was not maybe as experienced an engineer as I maybe now but I hold fond memories of that particular engine. I have read some interesting things on your site and was surprised to find my old turbo bike I built.I will have to add a picture of the formula three morini at the Isle of Man TT in 1981. Looking back now it is easy to see mistakes and of course correct steps. I was responsible for the building of the formula three bike. It was bored to 400 cc and due to a carb rule we were able to run from memory 38 mm delorto pumps. The rule stated that the carb size was controled by the size of the front mounting flange internal diameter. The older 350's as some who own them will know had a slide over carb that fixed over the top of the inlet stub. When I approached the technical committee they accepted that under the rule the largest carb we could run on the Morini was 40mm. This gave us a real advantage over the two stroke Yamahas that used the normal jap rubber boot to hold the carb, later morinis did the same. So the yamahas were stuck with stock size carbs. I took this as being a serious advantage so worked on how to make the massive jump in carb size work for us. The problem was simple in one sense, the inlets are awfull and ports even more so. I got weslake and cosworth to look at the heads and they both came back that the valves were a nightmare. A penny on a stick was their comments to increase gas flow. I took stock valves and machined them down until they resembled a penny on a stick and it upped the flow rate considerably especially at low lift. Unfortunately doing this led to major flat spot lower down the rev range so I understood for road riding this was why they are shaped the way they are. We used pump carbs of the F3 to overcome this and it would lift the front wheel at 1500 rpm with a little blip of the throttle. The low lift was important because the Morini head set up allows for massive valve overlap. Valve overlap basically allows an engine to rev higher in one sense but also allows for ram filling under the exit of the exhaust,this combines to allow the engine to rev higher and as BHP is directly linked to engine rpm just 1000 rpm giving power makes a world of difference. Big carbs in this situation helps as well as I remember I lengthed the total inlet by using 10 inch long rubber pipes to increase the ram effect at high rpm stopping the gasses from reversing in the inlet when the valve was closed. I ground some cams and I can't from memory remember the valve overlap but just remember it being huge compared to the normal valve overlap used on 45% angle engines. The reason you can't use huge overlaps on 45% angled valves is the valves collide. Because of the penny on a stick the inlet gasses did not flow like the tulip valves, some gas went out of the exhaust port but just the small area between the ports, the rear three quaters of the inlet bounced down the bore hleping clean out the exhaust gases. This made for a pretty thirsty engine but it made power. In its 350 version it suffered chronic crankshaft over heating. When we eventually bored it to 400cc the crankshaft was a real problem as the main big end journal would turn blue. For the Isle of Man we were pretty convinced the engine would not last because of the crankshaft problems. What I did discover during the Isle of Man was how important the squish area is. This area is the distance between the top of the piston and the cylinder head. We would take the heads off each run to look at the gas flow over the piston and also the head. This allowed us to get the perfect squish and power by shimming the base gasket. How much power you may ask. I never had it measured but I can tell you it was quick. Trevor Wise who road the bike was having bad handling problems at speed, only the island has these high speeds. We decided to head for Jurby airstrip on the island as it was used for testing. I had bought Tim Revics highly tuned Laverda Jota with me as a pit bike. He had been banned from riding as the Jota had gone through a police radar trap on the A12 at 155mph. I told Trevor that we should take both bikes on the strip at Jurby, Trevor would ride the Morini and me on the Jota, the plan was once we got to high speed I could see the wobble and see if I could solve the problem. We both took off from the start and I never saw the Morini again the Jota was not quick enough to keep up with the F3 Morini. Someone would have to find the records but as I remember the Morini in the race was clocked at 158mph. Unfortunately the rear piston gave way before we had completed a lap of the race. The fact was and still is that if the rear piston hadn't gone the crankshaft would. I had new roller cranks built for the 1982 TT as well as spun pistons as I was sure with the correct mods we could win. Unfortunately the 1982 formula three world championships were dropped so we never got a chance to prove it. I would like to say all these years later that the ACU were excellent, the Morini broke the sound limit but rather than make us alter the exhausts their technical team just moved the sound meter and blocked of the exhaust with a bit of wooden board and gave us the OK. The rear piston was blamed at the time on the american who helped us with support from the whore house in Nevada called the chicken ranch. The truth was it was fifty fifty, when we had the oversize bore done they didn't make a long enough liner so the bottom of the piston was exposed by 10mm at BDC. When I sent the non destroyed piston to cosworth they said it was only good for 5,000 rpm. It didn't make much difference as the crank even by then was starting to fail. We all just wanted a lap time and that was our biggest dissapointment of the whole project. We honestly thought we would claim fastest lap before it blew to pieces.

I don't know much about Morinis but I do think I built the fastest one so far, well at least in the TT. Any questions comments ask away. If anyone knows were the 325 morini I built from a 250 is I would like to know as well as the 500 I exhibited at the Earles Court show, I am sure the seat on the turbo was the same as the five hundred and made from aluminium. Any other specials I built I would like to know if they survived as well. Unfortunately my photgraphs were pretty much destroyed through my own stupidity so I don't have that many. I also built a flat tracker 350 based on the old side valve harleys, wonder where that is?



John Green

P.S I now live in Cyprus.

P.S.S why no spell checker I am an engineer so naturally I can't spell or do grammar.

[MickeyMoto]

Hi John,

I was just about to go to the garage for a fettling session when I saw your post. What a wonderful story.

Just think if you can get a 3 1/2 to 158mph what could you do with the new 1200?

Mike.

[Wassuck]

Hi John

Just to say that I have that seat (see my previous post). However it was not aluminium it was glassfibre.

Cheers

[Elby]

The seat on the Formual Three was fiberglass made by my own dirty fingers. The turbo seat was aluminium as were most of the road bike seats I made, no need to make moulds, just a pair of tin snips a hammer and a bit of welding. Imagination also helped along the way. Not always pretty I should say!!!