Cheers Guy
thicko question coming..... On the RF car injection....why are the injectors in the bells rather than slightly lower down in the inlet runner??....... Does it give better mixture or finer spray ?
saw an Alfa 12v engine once which had two sets of injectors (second set came in at 3000rpm)
I'lll leave that question to an engineer Phil......
Phil ... with mecanical injection is sometime advisable to have injectors on top of butterfly throttles in order to have an equivalent ratio of air and fuel but also prevet on cold start to fill too much fuel directly to the cylinders causing misfiring and spark missing !
On the 908 Porsche tested both postions and finally the best result at Le mans for fuel comsumption was on top of stack and not directly onto the head ( watch how high my red stacks are in my RSR 3 l engine
Modern engines with ECU management can have those very close to the valve because there is always a plenum giving plenty of air into the stacks and fuel quantity is driven by ecu and lambda of course
Last edited by LM mic; 30-06-2016 at 21:56.
Thanks for the explanation Michel....they are really long bells on the Porsche engine !
That's a thing of beauty isn't it! I assume the chains on the tennis balls are for retrieval if you forgot to take them off before cranking the motor?
Chris,
KKL 54N Im sure used to be Christian Hrabalek's car. Used to be in storage just down the road from me.
Went to Italy when he 'sold' some of the cars and the plate never changed.
Tom.
'Hrabalek', of course.Originally Posted by tomsredstratos
The Pirelli liveried car. There's lots of photos of it parked next to a his red Stradale, from that time.
I think they were maybe from an AutoItalia article?
Some one was writing somewhere ; Big toys Big B... !!!!!!
And many thanks for all your pics !!!!!
It's all about getting a better mixture of fuel and air. With a road car, it spends the bulk of its life at low Rpm which mean low air flows down an inlet runner or manifold. Best place for the injector is at the back of the valve. If it was further out, you can have fuel drop out, basically the fuel ends up running down the manifold wall. Once airflow increases, with the injector at the back of the valve, the fuel spray doesn't have time to mix properly with the air so at that point, it's better to inject the fuel further up in the air stream to get a better mixture. On a race engine you may see dual injectors, one behind the valve, the other outside of the trumpet, the injection will be staged, lower one spraying at lower rpm, the outer one either adding to or taking over from the lower one. All superbikes now have dual injectors as standard. The outer injectors normally have around 12 holes to create a more atomised spray pattern.
I have the secondary shower injectors on my Alfa engine, untried yet, might add a little power, might not butshould clean up the fuelling. More of a tinkering or pub bragging rights thing TBH.
Other thing to note is its not safe running showers and having wasted spark ignition, chance of a big bang or fire. They need to be fitted inside a closed environment, like a yellow fibreglass cold air box, while the injectors spray, you can get fuel standoff which if you've never seen, it's like a big cloud of semi atomised fuel, above the trumpets.
Pic shows hurricane racings modified busso, 400 HP, 10,000rpm, slide throttles and if you look carefully, I think a total of eighteen injectors.
Last edited by strat24v; 01-07-2016 at 10:59.
Another good video https://www.youtube.com/watch?v=kWKf...gnfNkhhzVzzhhA
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