EA81 MPFI theory...

[El_Freddo]

Ok, since before Tweety's gone with the SPFI unit on his EA81 that I know is a tried an tested conversion I've been thinking of how to fit the EA82 MPFI setup on the EA81.

What I do know - the wiring can be cut down; the dizzy modified to fit the EA81 and how to do the fuel pump etc.

What I'm keen to know is how the injectors would need to be setup using the EA81 intake manifold - do they need to be squirting onto the "back of the valve" as such or can they be setup further along the intake manifold - would the angle of the injector be an issue or can they be set 90 degrees to the intake run - or would 45 degrees so they're pointing towards the cylinders be better?

Or "worst case" scenario - could the four injectors be mounted in an adaptor block on the intake manifold where the carbie used to live and still maintain good performance?

What I'm thinking is how this setup with the injectors in the block would effect performance. In my mind/theory it should still enhance performance to a degree better than the carbie and improve the fuel economy.

I've got a couple of MPFI wiring sets sitting around and it got me thinking it could be worth playing around with for shits and giggles more than anything - but I must admit that what EFI gives over carbies is what I'm really keen on these days

Any ideas/know methods I'd be keen to know about.

Regards

Bennie

[steptoe]

they are batch fire aren't they? so each bank squirts at the same time. If you need some S & G and not getting at home or work what about just one injector at each end of a carby manifold ?A bit like a single point injection but single point each side?

Fit it up should be easy - geting it to spray more often something for Dougy to help with ?

[Subydoug]

This should be cool. Easiest bet is probably all 4 in a throttle body. Next easiest is probably getting someone to weld some injector plugs into the heads. As far as having a single injector at each end of the intake manifold, could be done, but Im not sure how easy it would be to get it running well. The injector timing would probably be pretty critical and It would probably need to be a pretty small injector spraying for the whole duration of both cylinder's cycle, or firing twice or something along those lines. The 82mpfi manifold has dual ports so its not as bigger drama as the fuel cant cross over.

maybe best off starting with a series 1 ecu? The ignition curve for the ea82 is probable a little bit different to one for an ea81. As far as reprogramming the ecu goes, well, anything is possible.

DO IT BENNIE!!

Doug

[TOONGA]

you need a set of these Bennie






RSR555 owns them

TOONGA

[El_Freddo]

they are batch fire aren't they? so each bank squirts at the same time.

Yes they are batch fire in the way you've described.

If you need some S & G and not getting at home or work what about just one injector at each end of a carby manifold ?A bit like a single point injection but single point each side?

Probably wouldn't work using the subaru MPFI ECU and wiring - would most likely have to come up with a new ECU and wiring or go aftermarket...

This should be cool. Easiest bet is probably all 4 in a throttle body. Next easiest is probably getting someone to weld some injector plugs into the heads.

I've thinking the welding of the injector plugs into the heads - the pics below help with the placement for these - trick will be to clear the AC compressor and the PS pump if they're ever going to be there.

If that's too much to do/too difficult then I reckon the injector block will be the way to go. We'll see how it goes, I'm only looking for inspiration/ideas on how this could work as I think the wiring is only a secondary issue or something that can be nutted out without too much difficulty.

maybe best off starting with a series 1 ecu? The ignition curve for the ea82 is probable a little bit different to one for an ea81. As far as reprogramming the ecu goes, well, anything is possible.

Dunno, will find out about the ignition curve... But it will be the 4 plug/hotwire system as I have one or two of those lying around gathering dust...

DO IT BENNIE!!

Some day! Will have to see how things pan out. I got this idea when speaking to Tweety about EFI'ing his trike. I reckon it'd be a neat system to run an EA81 with and no nasty lifter ticking like the EA82s do

you need a set of these Bennie

Yeah I do! But this image is enough for me to modify a set of heads to fit the injectors I reckon. I doubt Paul would want to part with these, otherwise a part of his museum/library of parts would be incomplete!

Cheers

Bennie

[tambox]

Hang on Bennie, a set of heads like that sitting on a shelf or not being used is a waste.
Whats the point of having a set of "rare" heads, unless they are being utilised. In that case, photo's will suffice.
Are they going sit there forever, never used for what they were made for.
You only live once, maybe a loan to help with development would be a starting point.

[TOONGA]

Yeah I do! But this image is enough for me to modify a set of heads to fit the injectors I reckon. I doubt Paul would want to part with these, otherwise a part of his museum/library of parts would be incomplete!

Cheers

Bennie

He has a complete turbo engine in an MY coupe

(somewhere)

and yes the Americans drill holes in the same area and weld bosses into place for the injectors.

TOONGA

[El_Freddo]

Hang on Bennie, a set of heads like that sitting on a shelf or not being used is a waste.
Whats the point of having a set of "rare" heads, unless they are being utilised. In that case, photo's will suffice.
Are they going sit there forever, never used for what they were made for.
You only live once, maybe a loan to help with development would be a starting point.

Yeah true that! He might have a plan for them. I'm happy to give the boss weld a go some day, I think that would be the easier/better option for me.

Toonga, thanks for the info, I'll check out USMB and see what I can find there

Cheers

Bennie

[steptoe]

Hang on Bennie, a set of heads like that sitting on a shelf or not being used is a waste.
Whats the point of having a set of "rare" heads, unless they are being utilised. In that case, photo's will suffice.
Are they going sit there forever, never used for what they were made for.
You only live once, maybe a loan to help with development would be a starting point.

Given your parts stash sounds bigger than mine Mr boX, sounds like some hypocritical advice

[tambox]

Sorry, my parts stash is common stuff, running in my cars, ready to be used when required and my family is helping in their use.
Or more to the point I don't have the heads we are talking about.
It would be educational for all of us if this goes ahead, would think about EFI my Brumby, to stop it cutting out when on steep angles.

[steptoe]

should try LPG in the Brumby for steep angels

[Subydoug]

Well looking forward to whatever you come up with. What I want to build some time may be of interest to you.

Regards

Doug

[tambox]

Cant afford to pay the gas tanker to stay at the farm, apart from that LPG would suit.
Maybe LPG injected EA81.

[El_Freddo]

Well looking forward to whatever you come up with. What I want to build some time may be of interest to you.

What Tweety uncovered with some research on USMB might be of some interest to you:



I don't know if you've seen it in his revamp thread - it's a Single Point Fuel Injection body with twin injectors from a Nissan D21 pickup with a VG30i engine. We've since found out that this engine didn't come to Oz in that model, but there should be something similar in the Pathfinder of the 1989/1990's era. Could be worth looking into?

The other things I've found through a thread dig in USMB is that there are quite a few of those heads available that Toonga posted about earlier. They're considered rare over there but still seem easily available?

Either way I most likely wont be able to get a set over here for cheap - as that's what this project is set to be all about - kind of like Steptoe's "Project Cheap Grief". So further talks with a mate and some further non-forum research found this product that would allow you to drill a hole where you want the injector positioned - no welding required:



Can be found here

Things I now need to find/sort out are:

1) if EA82 injectors will fit, or if EJ18 injectors can be used
2) how to keep the injector fitted to it's boss as there's no screw base like the stock injectors have - thus some sort of rail configuration would need to be sorted.

Currently I'm liking where this is going. It really gives me itchy feet to do it!

Cheers

Bennie

[Tweety]

This is interesting.

In my internet surfing I saw EA81 heads that had twin spark eg 8 plugs. This is done regularly with VW engines by the great Stan Pobjoy of Sydney. The second plug was mounted under the head. Originally made for more reliability in light aircraft I've seen such a VW engine with its 8 lead dizzy cap.

Wondering two things

1/ What if your injector was mounted in the lower plug hole. Or the upper standard plug location and the spark plug in the hole under the head.

2/ wondering if anyone has had twin spark plug mods done to eA81 heads and what the result was like. I recall in the 70's a spark plug that came out with multiple electrode contacts. Looked like they would make more power but didnt in my view.

[steptoe]

Goes to prove there is more hot up stuff for VW engines than EA81 eh !

[Venom]

How about making your own ECU? To some extent the factory injection setup is antiquated and inefficient compared to what modern EFI can do. If you built your own though you could swap out the MAF for a MAP, program it to run more modern injectors, use an O2 sensor on each bank, etc. It wouldn't need to be any more complicated, it would just be able to take advantage of more modern components.

[El_Freddo]

Wondering two things

1/ What if your injector was mounted in the lower plug hole. Or the upper standard plug location and the spark plug in the hole under the head.

2/ wondering if anyone has had twin spark plug mods done to eA81 heads and what the result was like. I recall in the 70's a spark plug that came out with multiple electrode contacts. Looked like they would make more power but didnt in my view.

This is interesting thinking Tweety, but (always a but!):

1/ I'm not up with direct injection systems yet. The injectors I'll be using are batch fire and not designed to be subjected to the combustion chamber environment. To do this I'd need sequential injection - something that's only hit factory markets in the last 5 or so years!

2/ Dunno. The twin electrode spark I think was more about getting a better burn in the chamber - or to make sure you got at least A spark in there. Either way I'm not spending the extra coin those plugs or a set of those twin spark plug heads - I believe they're a new item with the second plug cast into them, not a stock head modification...

How about making your own ECU? To some extent the factory injection setup is antiquated and inefficient compared to what modern EFI can do. If you built your own though you could swap out the MAF for a MAP, program it to run more modern injectors, use an O2 sensor on each bank, etc. It wouldn't need to be any more complicated, it would just be able to take advantage of more modern components.

I think I'll crawl before I start running! Aim is to do this with parts I have lying around. While this system may be antiquated and inefficient compared to modern EFI I'm sure it's a marked step up from the current carb systems (or even the weber systems) living on top of many many EA81's.

I was thinking maybe the way to go would be an EJ18 management system - no cam angle sensor, only a crank sensor required on the timing side of things.

The possibilities are endless - which is a good thing. Building an EFI system might be the next step if I feel the need - would be good to get to know how to do it but it's not essential to what I plan to do at the moment. Using the MPFI is something I want to have a crack at as I have a system or two gathering dust and in light of the SPFIs not being readily available in Oz I think this is the way to go and a good tinkering exercise that wouldn't be hard to reverse if ever the need arises.

Cheers

Bennie

[steptoe]

Funny how somethings make a comeback - like hoola hoops, yoyos - even skateboards were an in thing until they just stayed ( and taken 35 years+ to shrink back to near original size and materials )

Golden Lodge were a twin or maybe four electrode plug in the 70's and noticed the design has made a come back for car engines. I think they stuck around with bikes ??

Harder to alter plug gaps,and comment in one enguine building book from the 80's was that the authors opinion was that really only created an alternative path for the spark - not extra spark for more bang, so no more bang for the extra bucks

[Tweety]

like putting lipstick on a pig and its still a pig (Obama). You can have 20 electrode arms but spark I imagine is limited to the volts delivered to the plug. So darn good leads/dizzy cap and rotor etc is the best investment.

The Stan Pobjoy engine rebuilds for VW's can include his own crank. The twin spark heads allow good power at low revs with a high performance cam. Worth a scroll of his website

http://www.stanpobjoy.com.au/#!dual-ignition

But it comes at a huge price. I was roughly quoted at beyond 10 grand for a good rebuild of my 1916cc VW with the custom crank and twin spark heads etc. The Ea81 cost under half that with adapter custom exhaust etc bits that the VW wouldnt have needed.