Injectors places above inlet trumpets
Injectors places above inlet trumpets
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del mar

Original Poster:

2,838 posts

223 months

Friday 13th July 2018
quotequote all
Evening,

Mondeo touring car at Goodwood today.

The fuel rail and injectors were above the trumpets, when the car was started you could see the fuel being squirted down the trumpets.

Never seen such a set up before, what would the advantages of this be ?

Thanks

Del

227bhp

10,203 posts

152 months

Friday 13th July 2018
quotequote all
Old school, I don't think you'll see it these days due to injectors being much more advanced. Two things:
1. They used to use two sets for high and lower rpm because one wasn't good enough and
2. The upper set was generally for high rpm as it allowed more time for the fuel to homogenise.

Now we inject it directly into the combustion chamber.

GreenV8S

30,999 posts

308 months

Friday 13th July 2018
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Also gives significant charge cooling to the intake duct - which might be especially valuable if the intake is restricted. Down side is wall wetting will make it harder to tune.

tapkaJohnD

2,000 posts

228 months

Saturday 14th July 2018
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Are you sure these were the only injector set? Possible to fit and set up these 'offset' injectors as accessories to supply extra fuel at high revs.

Normally injectors work best when pointed at the back of the valve, but at high revs, the extra time between injetcor and chnaber allows more vaporisation and additional cooling of the charge.

JOhn

Inline__engine

199 posts

160 months

Saturday 14th July 2018
quotequote all
for maximum effort engines the injectors further away make more power. the thought is the added evaporative cooling reduces the air inlet temps to improve VE and better atomisation (the fuel takes time to atomise it is not fullyt atomise within the first inch or two after being injected so if it hits a hard surface then like port wall or valve then its no longer atomised). You really need to phase the injectors with respect to the piston position and port flow. the school of thought of spraying at back of hot valve works good for OEM engines for idle, low speed and cold starts and driveability but for maximum effort its not going to be the best for outright power