As a side project, I'm thinking through a basic budget motor project and thought I'd grab some input from you guys.

The idea is to put together a efi motor using an L series bottom end and CA18 computer, loom ecu etc.

The thing I'm now undecided on is whether to use an L series head, or go down the path of a KA24e series head.

KA24 head would give me cross flow design and more room to play with on each side of the motor. L series head keeps it simple and cheap.

One other consideration is whether to use an L16 block or an L20 block. Looking through the writeup zac510 did on ozdat, he mentions he calculated an CR or 7:1 when using a L20 block and KA24 head, that isn't going to be good news as I'd probably prefer a NA motor at this stage.

Anyone know how to calculate the CR using an L16 block?

Also if anyone has any other input with fors and againsts for any components please feel free to voice your opinions.

cheers

Hi All I believe that the most cost effective way to efi any 4 cyl engine is to use the GM set up off Camiras/pulsars This system is very basic and very cheap and the ecu can be reprogramed with a laptop [and connecting cable]. From memory these systems only use air/engine temp/map /throttle position sensors and ignition signal and come in 1.6 and 2.0 litre versions. I've often thought of going down this path but L series sound better at full noise on carbs!! and i'm old school. Cheers OMD

Click to view attachmenthi guys , just a thought got a photo of a cheap efi l series manifold, ive had it for about 10 years but all they did was cut the manifold flange off a original l series single carby manifold and weld on his own runners, the injector bosses can be bought .
if i was ever going to use this manifold id cut the pleunem off and weld a bigger 1 on
it all depends if you can get tig welding done cheap though

Thanks for the reply guys, OMD there is a guy on ozdat that is using the Camira gear, from all reports it is a good option. I'll be using all CA18 gear modded to suit the L banger, as I have a friend who has a real time nistune board so can put together a basic tune for me, plus it's something different as well.

Wayne, thanks for posting the pic, I can see what you mean about making a bigger plenum, ha! But good to know you can purchase the injector bosses, I wasn't aware that you could do that, that makes things even easier.

But I'd still like to look into using part of the L6 manifold, at least the flanges and injector bosses. then just fabricate the runners, trumpets and enclose them into a plenum with a throttle body attachment.

Here is a pic of a L6 manifold that has been cut down, got it off a US forum, but bear in mind that I've been told there are 2 types of L6 manifolds, one that tapers back, and one that is straight all the way through, so people attempting this at home, make sure you do your homework.



Also stumbled across this link which is good for a bit of inspiration;

http://cmy510.tripod.com/efi/efi.html

is that a exhaust turbo manifold be-neath it ?

are you useing it ?

HI All When we were buggerizing around with factory efi back in the late 70s we used 280zx cut down manifold gaskets as L4's were never avaiable.Therefore if you cut down a 280zx/R30 inlet manifold you have a manifold for any 4 I'd imagine the 280zxturbo one would have the better plenum. Dont forget to drill/grind around the top of the inlet port[use the manifold gasket as a template] to inject the fuel into the the port .If you dont do this the Lseries efi manifold wont bolt up as the injectors foul the head. Cheers OMD

Caveat: I have not tried this!

It seems to me that a cheap alternative to quad throttle bodies (QTB's) would be to find 2 TB's to suit the twin SU manifold from the SSS. The TB's could be anywhere from about 38 - 45 mm ID, with a little manifold porting ... but that seems like a fairly capable (and direct) induction setup.

I figure drilling or welding in bosses for injectors would not be too difficult. I suppose you could even graft on the flanges and injector sockets from an L6 EFI manifold (?)

An aftermarket ECU would be needed - and I do not know enough about them to know whether you could/would run it off one or both TB's. I would have thought there are enough dual throttle body set up's around to find out pretty easily.

This setup may give "the best of both worlds" ... EFI, but with 'that' side draft induction noise.

Just a thought ...


Garry

That manifold looks pretty good, is that a cut down 6 cylinder efi manifold as well?

Yes it comes of a 6 cylinder manifold. The runners were cut of from the original plenum and a new aluminium pipe were welded into position the front part is for a BMW throttle body as this engine is going into a BMW E30 318I. We are trying to run it with all the electronic goodies from the original motor. So everything will be BMW except the engine.