7 replies to this topic

[joyce1bro]

Hi all,
I’m struggling to find any info on this product for a mini.

I’m going carb to injection and want to know if anyone has used the above system on a 5 port or what’s everyone’s take on it for an A series and even injector sizing. It comes out with 2 x 350cc or change to 230cc or 730cc injectors.
I have emailed jenvey who said a few have them on minis and they do work fine but I can’t find anything.

Beneficial to run 2 extra injectors in the runners?

I’ll be running a fully programmable Link ECU.

And If you wondering why I don’t just buy an SC kit is mainly because I like the carb/heritage look.

Any info or thoughts would be appreciated.

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Edited by joyce1bro, 11 January 2022 - 09:08 AM.

[Tones61]

https://www.starchak...efi/siamese.htm

[timmy850]

As per the article Tones has linked, the Siamese port problem is the main reason why aftermarket mini injection is a single point style like the SC kit.

The Jenvey throttles would work great on a 7/8 port head with 2 of the units (so one barrel and injector per cylinder)

[joyce1bro]

As per the article Tones has linked, the Siamese port problem is the main reason why aftermarket mini injection is a single point style like the SC kit.

The Jenvey throttles would work great on a 7/8 port head with 2 of the units (so one barrel and injector per cylinder)

What about custom manifold with direct or semi direct port injection? 2 per runner sequential, Which is what my tuner was wanting to do? Still have starving issues? (I read the link which some of it is a bit beyond my pay grade lol)

Can I also ask what the difference is between the SC and the jenvey in terms of injector placement? They look to in the same place?

Edited by joyce1bro, 11 January 2022 - 10:32 AM.

[Indigo]

Injector size depends on expected maximum HP and number of injectors.

Using FuelTech Fuel Injector Calculator! - FuelTech USA

And with a target of 100HP gives a 328 injctor size.

So 2 x 350cc injectors would be on the mark.

My understaning is that if injectors are too large you can get eratic running down low as the injectors spend more time closed than open.

 

Regarding the Jenvey I would give it a go, but I think the SC would be lower risk.  I would start with batch firing as per the SC setup.

[Mini Manannán]

There are ECUs about with siamese-specific EFI code. Megasquirt is one, Canems is another, I think Polestar have one too.  I don't think Link do though?

  I've been looking hard at EFI recently...

[PoolGuy]

Some of this was covered recently, https://www.theminif...r-classic-mini/

 

Bobbins linked to this too, which was informative https://www.emeraldm...midget_Project/

[timmy850]

As per the article Tones has linked, the Siamese port problem is the main reason why aftermarket mini injection is a single point style like the SC kit.

The Jenvey throttles would work great on a 7/8 port head with 2 of the units (so one barrel and injector per cylinder)

What about custom manifold with direct or semi direct port injection? 2 per runner sequential, Which is what my tuner was wanting to do? Still have starving issues? (I read the link which some of it is a bit beyond my pay grade lol)

Can I also ask what the difference is between the SC and the jenvey in terms of injector placement? They look to in the same place?

The Jenvey uses a Weber manifold, which means each barrel feeds one port of the a series head. The manifold runners aren’t linked

The SC feeds both ports from the single throttle

The basic Siamese problem is:
Firing order is 1342 which is the same as 3421
Ports 1&2 are grouped on a mini and so are 3&4.
To get the injection timing right you need to fire the injectors in a very specific sequence (when using one runner per port) so that all cylinders get an even distribution of fuel. The only way to get this right is using a good known injection code, probably followed up with individual exhaust port O2 monitoring

A single throttle body like the SC is able to get decent results from a simpler injection sequence as the engine can consume the air/fuel mix from the single throttle. There will still be a slight bias between the first and second firing cylinders in each port