Converting SPI to Carb

Started by MPlayle, March 11, 2016, 08:04:05 AM

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MPlayle

I know it has been a while since I did an update.  I have not had a chance to get back to finishing up the timing and tuning.  I'm hoping to spend some time this afternoon on it.


MPlayle

Got a little time on it yesterday.  I "think" I have the static timing set.  This new distributor functions a bit different in that the 'trigger' seems to be dependent on the passing motion of the point of the lobe past a very narrow band of the sensor.  Just positioning them in alignment does nothing.

I hooked up my static light per the manual - in parallel to the distributor (+ of light on the coil -, - of light to ground) and it is always on!

I hooked it in series with the distributor (disconnect distributor - from coil, + of light on coil -, - of light to distributor -) and when using the gear lash of the distributor drive to pass the lobe back-and-forth across the sensor makes the light flicker.  So I set the timing to have #1 at ~ 6* BTDC and aligned the lobe and sensor.

I then tried to ensure I still get oil pressure by cranking the starter (in neutral, no plugs in the head, distributor cap still off).  I get some sort of arcing near the starter.  I can't tell where for sure as it happens only when turning the key to 'start' and lingers briefly returning to 'on', but ends when turned to 'off'.  I can only see the reflection of the arcing on the inner fender when turning the key.  I can't reach to turn the key and see the starter at the same time.  A friend will help me check that out on Monday.

Once I get that sorted, it will be on to checking out the fuel system - does the relay properly trigger the pump, pump flow fuel, etc.

MPlayle

Got the arcing figured out today.  I had the cap off the distributor and also not connected at the coil when cranking to check for oil pressure.  It was arcing between A and B in the following picture (coil+ to the high tension out socket).



Testing for oil pressure was also successful: cranked it with the power to the coil+ disconnected to prevent the arcing while still keeping the plugs out for minimum load while trying for oil pressure.  It started building pressure nicely on the second attempt (10 second bursts of no-load cranking).

We then put the cap on the distributor, plugs in the head and connected up the plug and coil wires - no more arcing.  The sound of the cranking changed appropriately for the cylinders building compression, but no fuel.

When I get the next chance later in the week to get back to it, I will put some fuel in the tank, reconnect the power to the fuel pump and begin tuning the carb.

Then it is hope it fires up.


Vikram

I'm trying to do something similar.
Have an spi that being converted to twin 1 1/2 su carbs. I'll be mating it to a mk1 harness. What coil would I need to match it to the 59d4e dizzy?

MPlayle

It depends on whether there is a ballast wire/resister in your wiring harness.

The harness of the SPI on mine did not have any ballasting.  Jack at 7Ent recommended a 3.2 Ohm coil (the Lucas Sport coil) to go with the distributor.  If there had been ballasting, he indicated I could stay with the 1.2 Ohm coil of the original SPI.


94touring

He'll have a brand new mk1 harness, so this sounds like a low ohm coil and a later style dizzy will work just fine then.  Guess if the coil melts we'll know!

MPlayle

A little more progress. Put a couple gallons of fuel in the tank for a basic "leak test" of the lines and pump.  Got the pump to prime and send fuel forward to the filter briefly.  Then it looked as though it had quit flowing even though I could still hear the pump running.  Did some troubleshooting of the lines and was getting fuel to the filter and through the filter into a clear jug - although it did change colors a bit: from normal "yellow" to orange, then back to "yellow".  I suspect a small "clog" of old fuel scum in the hard line being reused from the fuel injection feed.  I also redid the line from the filter to the carb to ensure no tight turns to crimp the line.

I had already set the initial static timing and initial carb setting, so I got brave enough to try firing it up on those settings.  Cranked a bit without choke - did'nt start, but not "bangs" either.  Gave it a bit of choke and tried again - fired right up and idled smooth.  It would stay running smooth with dropping out the choke after just a few seconds even!

Just need to recheck the timing with a timing light and do the basic tuning of the carb, button it and and I'll be done!

Oh, and I put the boot lid back on since I won't have to be troubleshooting anything back there at this point.

I'll do a couple of final pictures once it is tuned and ready to drop of the jack stands.

MiniDave

Isn't that a great feeling, when they start right up and run nicely like that? Congrats on getting it buttoned up and on the road again...... 4.gif
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MPlayle

The "plan" is to do the final timing and carb tuning later this morning.  Then put the bonnet back on and put it on the road.


MPlayle

Got a friend to help a bit this morning and did the dynamic timing adjustment to 8* BTDC at 1500 rpm per the Haynes manual as the timing for a 59D4 distributor.  Also did the carb tuning and now have it set for a warm idle at 1000 - 1100 rpm.  Idles very smooth, revs nicely and smoothly by hand in neutral.  All buttoned up and ready for a road test.  Did not get pictures of the finished effort yet.

Hopefully, I will get to do the road test and rad flush this weekend.


MPlayle

Pictures of it all finished and ready for the road test:









MPlayle

Got it out for a "shake down" run this morning - a little bit of neighborhood driving to go fill the tank all the way (no leaks!) and then some highway runs.  Accelerates nicely up the band - no more dead spots from stand-still or mid-range cruise.  Temperature gauge working nicely as desired.  Temperature comes up to the middle black mark and stays.

I did need to lower the idle a bit more once fully hot after coming back from the highway runs.  Otherwise, running sweetly.


94touring


MPlayle

I drove it a bit more this afternoon.  Took it to a car wash and cleaned all the dust off.  I think I may want to add an extra return spring to the accelerator cable at the carb - it is a little slow to return all the way to idle, but 'blipping' the throttle will get it to drop.

Unfortunately, I also realized I have to make a tough decision about trying to keep the Mini.  I'm spending a lot more time providing care to my parents than expected (the reason the conversion took so long).  I'm also not doing as many hours on the contracting, so income is down a bit.  Neither "toy" is getting much time (Mini or the sidecar rig) and I am looking at needing to change my daily driver as well.    :(




MiniMike

I read through most of your thread here and am looking to do an SPi to carb conversion. I am piecing together parts but basically following the Mini Mania instructions on their website... I wanted to use this relay in the conversion but not sure if it is the same (the pins are the same but I don't know about anything else). I liked it because it came with the connectors for it to clean it up a bit. Any thoughts if this will work? https://www.amazon.com/GOOACC-Automotive-Interlocking-Harnesses-Warranty/dp/B01M74X0ZK/ref=sr_1_1?ie=UTF8&qid=1538522075&sr=8-1&keywords=ar201+relay

Thanks!
'93 Mini Cooper SPi

MiniDave

What are you going to use the relay for?

And yes, they will work if wired correctly...which is very simple on these relays and they all wire the same way. terminals 85 and 86 are for the coil in the relay. 85 is the power from your switch, 86 goes to ground. When you apply power to 85 it pulls in the coil which then connects terminals 87 and 30. 30 is your fused supply, and 87 goes out to the load - fog lights, fuel pump, or whatever.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MPlayle

I don't remember the details of the Mini Mania article, but I believe they leave the ECU and all the no longer used sensors in place.  When I did mine, I completely removed the ECU and all sensors no longer necessary.

I seem to recall the relay in the Mini Mani article is to replace the fuel pump relay function of the multi-relay box that goes with the ECU (big black block usually mounted on a bracket above the brake unit).


MiniMike

Thanks guys. The mini mania instructions call for removing the ECU and wiring the fuel pump and starter to the relay.
'93 Mini Cooper SPi

MPlayle

I think I did separate relays for the starter and fuel pump.

The earlier posts from when I actually did the conversion should clarify.

MiniDave

#69
Do you need a relay for the starter? Isn't there already one there? (AKA starter solenoid mounted on the fender?) If not, the pull in voltage for the starter is minimal so it shouldn't need a relay but it doesn't hurt. It would wire up exactly the same - the wire from the ignition switch is the trigger wire to terminal 85, then the load or output terminal 87 goes to the starter. Easy peasy.

In the instructions they say to take terminal 30 to ground - the only reason to go to ground with this wire is if that's how the system runs - I doubt it works this way but I don't know.....if the wire you hook to 87 is hot, then taking 30 to ground means a direct short.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MiniMike

I was mistaken it says main relay and fuel pump relay will be run by this relay. Here is the wiring diagram they have in the instructions. Looks like 86 and 30 go to ground
https://www.minimania.com/images/articles/AR201_lg.jpg
'93 Mini Cooper SPi

MPlayle

It sounds like their instructions have you retaining the factory "relay box" and the replacement relay gets wired to the ECU harness to shuttle power to the factory box.

My approach was to remove the factory relay box as well as all unused wiring.

The MM approach leaves behind all of the unused wiring and connectors.


MiniDave

I agree with Mplayle, eliminate all the ECUs and sensors and wire it normally. Simple is always better.....
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

MPlayle

In the middle of page 2 of this thread is where I outlined the wiring changes I did.  If I remember when I get back from the dyno day, I will look to see if I still have any of my hand notes detailing the wiring changes.  If so, I will scan them and upload here.


MiniMike

Mplayle,

Thanks for the info! I am going to try to tackle it like you have described... if you have any more notes you can scan i would be greatly appreciative. I am always nervous about wiring...also What is the 4 pin relay you used.. i have the 5 pin ones is that usable with your method.. sorry for the stupid questions... I've been going between your thread, mini mania instructions, and haynes manual schematics. about to tackle the front harness to get rid of all the unnecessary connections.
'93 Mini Cooper SPi