Most liked posts in thread: New Classic Mini Project - Fuel Injection!

The fuel pump kit has arrived, but the EFI unit itself is still probably 2-3 weeks out yet. In the meantime I got some aluminum plate to make manifold adaptors, there are 4 different manifolds I can use - the standard SPi manifold of which I have 2, the 2bbl manifold used on the Weber downdraft conversions (the only one I don't have, and the most expensive), the side draft manifold used with the HIF44 carb like my current green Mini has, and a sidedraft manifold that's used on the small block engines with the smaller 1 1/2" carb - which is what I'm trying first.



So I bored a 1 1/2" hole in the center of the plate, then drilled two mounting bolt holes to fit the manifold studs. I don't have the bolt spacing for the EFI unit yet, but I know the bolts will be horizontally directly across from each other, where the Mini manifold has them at an angle. Once I have the manifold gasket I can locate, drill and tap those holes for studs to attach the EFI to the manifold, I will probably use bolts to hold the adaptor plate to the manifold.



I also bored a 1 3/4" hole in a second plate to mount to the SPi manifold, the bolt pattern on it is a little more complicated, but I had the gasket so it was easy to mark those out, then once again when I have the EFI gasket I can mark and drill and tap those holes too.

Of course once I get the EFI mounted I'll shape the adaptor plate, knock off the corners and so forth so it looks finished.

I have a 3rd plate to use on the sidedraft HIF44 manifold but haven't bothered with it yet as I don't know if the Holley EFI unit will work in that orientation - it's designed to be a downdraft setup, but I know a guy who has mounted the std SPi unit on a side draft manifold, and a guy who has an EFI Holey unit mounted sideways on a supercharged engine, so if it works for them I think this will too.

More as it happens.....the next challenge will be to mount and plumb the electric fuel pump on my stand as it has a return line that I'll need to plumb in and it's supposed to be mounted lower than the tank level. I usually just use a 2 gallon plastic lawnmower gas tank as my supply, and I can set it on a stool or something to get the height, but I also need to figure out how to attach the return line so it doesn't blow out and spray fuel all over the shop.

I also am going to have to make some modifications to the wiring of my test stand, so I can integrate the EFI wires and leave the test stand still operable for regular Mini engine runs. Probably can't do any of that till the unit gets here tho, as the trigger wire for the fuel pump for example comes out of the EFI harness. I also have to build an air cleaner, integrate a manifold pressure sensor and an intake temp sensor. Lots to engineer yet.....

 

The Nikki manifold is by far the best all around fit and function, so that's what I will use for the 2bbl setup, I may try and use the original side draft manifold setup for the single bbl on the small motors. I still haven't gotten the 1bbl EFI unit, but I did receive the 2bbl unit and I've been working on figuring out how to fit it to the Mini engines. I will do initial setup on the 1098 in the engine stand, but I plan to use my 1275 in my Green Mini as my test mule once I get it all figured out.



I drilled and tapped a plate to put the temp sensor in the back of the head where the heater tap would normally be - just for test purposes on the test bed engine. I think if I install this on the green Mini I'll bore and tap a hole right into the end of the cylinder head - if I wind up not using it on that car permanently I can always just plug it as it's a simple 3/8 pipe thread.



The 2bbl unit is almost a direct bolt onto the Nikki manifold, I will have to open up the throat of the manifold to match the throttle bores - I'm undecided whether to use a phenolic spacer under the EFI unit or the aluminum I already have - but I have some phenolic material coming in case and I have a friend with a mill to shape it correctly. I will need to slightly modify the stud holes to match the Nikki stud pattern, but it won't take much.

I also ordered a 6" pancake air filter to fit the 2bbl EFI unit, no idea yet what the smaller 1bbl will need. Delivery on that has been pushed back to the middle of the month - I'll believe it when I see it - or when they charge my credit card I guess!

I had hoped to set up the 2bbl unit with the accelerator linkage on the left, but it does not fit there, so I'll need a longer acc cable when I mount it on the green Mini. I'll also have to pull the fuel tank to install the return line bulkhead bung. You can see in the pic the fuel pressure regulator sticks out too far and will hit the valve cover.




I ordered a bunch of O2 sensor bungs to weld into the exhaust pipes - I'll need one for the header in the test stand and for the green car - then If I build one of these for a customer I'll need it for them too - so it'll be good to have some spares on hand - I found them 5 for $20 including the plug....shipped.

The weber 2bbl intake manifold I ordered simply does not work, the center pipe on the headers foul the manifold, and I tried two different sets of headers - neither works. It's going back.

More as it happens.

 

Me too, but I went ahead and ordered the small 2bbl version, it's in stock so I should have it next week sometime, so maybe I can make some real progress. I'm excited to fire one up and see how it works.

 

Well, looks like the rest of my project is finally getting into gear, as I've had an email that the single bbl unit has shipped at last. Tune in next week for some pictures!

Also got the weldable bungs for the O2 sensors, and an air filter assembly is also due today - I don't know if it will fit the single bbl unit yet, but I think it does.

 

I sent the Nikki manifold off to the machinists today, we decided it would be better to relocate the studs in the manifold rather than modify the EFI unit, so that what we're doing. He's also going to match the bore to the throttle plates, and make a couple of phenolic spacers for me.

I decided to weld the O2 sensor bung into the front pipe on the muffler, that way I can use it with any of the headers and I only have to do the one....the sensor just unplugs so it will be easy to move from one setup to the other.

More as it happens - getting closer to seeing if it will run now.

 

Over the last few days I cut the adaptor plate out for the single bbl EFI unit to fit the Nikki manifold. I sent the manifold off to a machinist friend who reset the mounting studs to fit the 2bbl EFI unit so I had to modify the mounting holes I'd already drilled to fit the original Nikki spacing to fit the single bbl unit to the manifold. My plan is to run the single on the test stand first to figure out how to make it all work, then put the 2 bbl unit on my 1275 motor in my Racing Green car to see how it all works in an actual car, since I can't put any load on the motor in the engine stand so the unit can "learn" a run map.



So I now have both the single and 2 bbl units fit to the manifold so I can switch them out easily. My machinist buddy also has the maps saved in his mill so he can cut spacer plates out of aluminum or phenolic material for me, as well as convert the manifold stud spacing easily. He also matched the opening in the Nikki to the bores of the 2bbl.



All of this is just preliminary to actually fitting it to an engine and a car. An SPi manifold can be made to work with a little bit of surgery here and there, but the Nikki is even easier and it fits better. I was able to lop off a water jacket boss on the bottom of the SPi manifold and now it will work with either exhaust header too.

So, single bbl units for the small engines - 998 and 1098, 2 bbl unit for the "big" motors is the plan - Holley says the single can support up to 200 hp but I dunno, it doesn't seem like it could flow enough to really build some HP in a 1275 or 1380 motor with a nicely flowed cylinder head.

My buddy forgot to cut the phenolic spacer for the 2bbl unit - it's only needed to provide clearance for some of the linkage and other bits - who knows maybe it's a good idea to have it for heat insulation too? If so, i can make one for the single bbl version too, there's plenty of room between the top to add an air cleaner too so, another 1/4 or 3/8" of height won't matter.

At this point both projects are on hold for a while. I have a car coming in the shop the 26th for a suspension overhaul and an engine being delivered around Nov 1 that will need to be torn down and parts sent off to the machine shop, and I'm back working on the Inno to get it up and running. I'm down to a short amount of time before I'm laid up in January with my knee replacement. I'm still only able to work a little here and there, but I'm determined to get these projects finished.

The EFI project will have to wait.

Linkage on the single bbl is going to be interesting, and I may have to build some brackets and such to get it to work - no real idea how to do that yet, I tried the single bbl on both ways as it will fit either direction and it looks like having the linkage off the back of the manifold will work the best but I won't know for sure till I try it in a car - and right vs left drive may make a difference too. The 2bbl unit will only fit one way, so I'll just have to engineer for that mounting position. I'm excited to see it run and work, but I have to finish the other commitments I made first.

 

Lets keep it on the down low till I get it working, OK?

One of the big advantages of FI is automatic compensation for temperature and altitude....

also, it plays nicely with turbos!

 

Yes!

 

I've been looking at the different manifolds I can use - one came to my attention recently that I had never heard of - in the 60's and later there was a downdraft carb and manifold for the Mini sold under the name Nikki. I've recently found no less than three of these units! The intake looks very promising to use especially on the smaller 850, 998 and 1098 engines, and even the lower HP stock1275's. I have one of these now to experiment with - but I'm still waiting on the EFI unit itself to ship - probably another 2 weeks out. IN the meantime I'm working on adaptor plates and exhaust system mods so I can install the wideband sensor.



I have been planning to use a manifold used by Mini for the factory fuel injection as they are plentiful cause people take them off and switch back to carbs when they can't find parts or anyone who knows how to work on the Mini EFI.



The only issue with this manifold is that it won't fit with certain exhaust systems, where the Nikki will work with any of them. I also found a Weber manifold that may work when I go to the 2bbl unit for the larger, higher HP engines.

 

Me too! Perfect winter time project.....too bad it has to go on pause for a while.

 

I would happily pay someone to create new ones for me if it could be done for a reasonable price, something similar to what I would have to pay for a Weber manifold, they could use one of the ones I have now to use as a template, 3D scan it in and cast from there. I wonder if they could "adjust" the casting a little bit - to have 1 1/2" pipes and openings instead of 1 1/4"? I'm thinking it would be a little more complicated than a sugar scoop in that the surface at the head and under the EFI unit would have to be straight and square - which would probably mean some machining of the casting, plus they would need to be drilled for the EFI unit and/or adaptor plate.

But first I would probably put out a call to see if I can acquire any more originals cheaply - if I easily found 3 so far when I didn't even know they existed, surely there must be more of them lying about?

 

Just got notice that my EFI unit will ship on the 15th......

 

And it still hasn't gotten here yet - a call to Holley and now it's supposed to ship the 30th.....sighs.

 

Thanks guys, more projects in the works.....newest one set to arrive Monday - on the coldest, rainiest day we've had all fall, and the second one on Tuesday - the second even colder and rainier day! Then Wed it's supposed to be nice again - typical fall KC weather.

We had 85* Thursday and a high of 41* today!

Lots to do before the Knee date, but I doubt it will all get done in time - none of these projects is time critical fortunately.....if done by Springtime it will be soon enough.

Did you all know the hottest it ever was in Reykjavik was on a July day where it hit 76*! And yet the usual lows in winter are high 30's and low 40's due to the gulfstream waters that go north along the coast and out to the northern sea.

 

I doubt I can afford to have them made up, I have the three and when those are gone I'll buy the Weber and use it.....