Firstly I don't know how DI works but I had this idea;
I was looking at a mini head today and I thought would it be possible to drill through the side of the head, (from either the front or the back) into the combustion chamber, tap in an injector and run direct injection

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Respect mine and I'll respect yours.

The potential is there but the limitations will be the software/hardware to drive them. The 5 porter requires a few tricks to get the fuel mixtures correct, regardless of whether you inject into the port or directly into the cylinder.

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

You just need to buy a factory DI head. They did make them. *














*They were fitted to the BMC Mini Tractor with a diesel engine.

There is a lot more to direct injection than bolting some common electronic injectors onto the head somewhere.
Most (all?) of these systems for 4 stroke motors use mechanical injection to cope with the pressure in the cylinders.
See http://en.wikipedia.org/wiki/Gasoline_Direct_Injection


<edit> Mick, we need more than 16HP, please.
BTW the Mini tractor was indirect injection.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Near enough!

With direct injection the injector needs to be able to withstand the combustion pressure and heat. It also needs to be placed in the right spot and at the right angle to work correctly. This is not a backyard job.

The pumps are commonly mechanical, but the injectors are electronically controlled ala



This means the tuning requirements of the software would be similar to the port injection anyway (timing of the event and qty of fuel), i.e. if you think port injection on a 5 porter is hard - this will be just the same tuning-wise.

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

Doz, that is a good diagram of the late common rail type of injection.

The downside of direct injection is that the faster it revs the more fuel it uses but the shorter time is has to inject it.

It's got to be way cheaper to fit an 8 port head and decent port injection, than R&D direct injection on the old 5 port head.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

After meeting Mad Matt last week I reckon the twinky conversion would be the best EFI option. Having said that there will always be those who think these things will be an easy conversion - good luck is all I can say lol

The time problem vs rpm for injecting the fuel is the same for the DFI as EFI. My BINI has an rpm redline of 6500 - pretty sure the DFI is the main limitation there.

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

Someone has done the hard work already.

You can get "semi"sequential injection for a 5-port.

Just need a trigger wheel, map/lamba sensors, v.short manifold with injectors pointing right into the siamesed ports

and lastly the Canems ECU.

http://www.canems.co.uk/casestudy/1380inj.php

Mine has had port injection for 10 yrs now (Motec ECU) - and with plenty more power than that http://au.youtube.com/watch?v=Bp4W-0KsQ ... annel_page

The point is the difficulty in port injection will be the same with DFI I reckon

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

Very nice, but that's cheating! there's a whopping great snail sitting on top of it!

I thought the problem with port injection on a siamese port was outside cylinders running lean due to the firing order. Wouldn't direct injection fix this?

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Yes, DI would - but the effort and cost = better to change to an 8port/crossflow head

but the Canems seems to get around charge robbing by using very precise sequential injection. explaination here:

http://www.canems.co.uk/siameseports.php