'66 912 resurrection

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chud
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Re: '66 912 resurrection

Post by chud »

So engine in, all easy from here right? Nope.

The Motronic loom was in a pretty shitty state but was good enough for the time being to run the motor, so it was loosely run in and by the time I was finished she looked like a test rig of some sort. An oil pressure gauge from a 924 was bought to keep it all VDO and temporarily rigged up and we were ready for a test fire. With shaky hand and king lead from the coil off I went for the oil pressure crank. Instead of the sound of a freely turning flat six with no spark plugs fitted all I got was a hefty clang and that was that. Damn.

A brief swing on the crank pulley nut would confirm that we were locked solid, so I replayed the engine/gearbox union in my head. Gearbox span free. Check. Engine turned. Check. Did you try test the engine turned with the clutch fitted.......? No. You spanner.

So you remember what I said about things being thrown if the motor had to come out again - well it did. Instead of throwing something though I took a breather then set to it. Thankfully with the experience from my first attempt behind me the whole process was a whole lot less painless. Anyway, back to the problem - the only hunch I had is that the bolts I was given to fit the clutch were too long, and the third one I pulled would prove me right with a slight witness mark on the end where it'd bottomed out - thankfully not very much but enough to lock it out. So shorter bolts in, and problem solved.

With that done, you know the drill and with help from the wife one afternoon we were back to where I was a week previous.

This time the noise made when cranking was a lot more cranky-esque and we had good oil pressure. Lovely.

Fuel next, I ran the pump direct to check for leaks and we were all good. I'm running an external FPR and adapted the end of the rails to AN6, they meet at a T and then back to the FPR. Fuel pressure set.

With that, I thought it was about time I stopped procrastinating and tried to make it go so king lead reconnected, we gave it a go.

Nothing, just cranked. Aaah, flywheel sensors were back to front.

This time we have pops and farts and an attempt to start but nothing more than that and some impressive flames and that's pretty much all we mustered out of her all afternoon, try as we might she just wouldn't go. We had all the ingredients for it to happen, but just didn't happen. I bought some noid lamps and this showed that my pulse to the injectors was very weak. I sent the DME off to get bench tested and they diagnosed a few issues that were sorted there and then, £250 later I had my 'ready to go DME' back with me. I added a heap of extra earth straps and had another crack. This time, marginally more successfully. She'd fire straight away, but not attempt to run or even idle. After some more head scratching and reading I checked the impedances on the flywheel sensors and they came back in spec. Running low on options I took the flywheel sensors off to take a look with a view to regap, and I found the end of the speed sensor had been ground down by the teeth. Not gapped right then eh.

I bought the BMW equivalent sensor which is far cheaper but identical all bar the length of the cable and regapped to 0.8mm, which anyone who has carried out this task with the engine and box in the car will testify is, an absolute twat of a job to get right especially when I wasn't blessed with a spare full length sensor to glue a 0.8mm washer to. Cue smug chortles from the carb guys.

Anyhoo, with that done - she runs albeit not very discreetly with the special home made exhaust it currently has, but still - small victories and all that. Now that I have verified the motor runs I might bin the Motronic completely but we'll see.

I'll take some up to date pictures at some point but up till now when I've been out there I've not been in the frame of mind to be operating a camera.

Anyone want to buy a recently refurbed DME?
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911hillclimber
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Re: '66 912 resurrection

Post by 911hillclimber »

Well done, and if it helps I've done battle with that 0.8mm job too.....
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chud
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Re: '66 912 resurrection

Post by chud »

Oh it’s a delight isn’t it!
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Re: '66 912 resurrection

Post by Ollie »

Great update!!! One step at a time!
chud
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Re: '66 912 resurrection

Post by chud »

Image



More later, but first - coffee.
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Re: '66 912 resurrection

Post by Bootsy »

Everything must stop for coffee
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911hillclimber
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Re: '66 912 resurrection

Post by 911hillclimber »

Sod the coffee, more pictures!
Stop slackin' and reveal all. :wink:
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
chud
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Re: '66 912 resurrection

Post by chud »

Ok here we go.

So I battled on with the motronic and all the while in the back of my head had me doubting it. Shoddy loom, 30 year old sensors and an idle bypass valve that looked like it'd been used as a projectile at some point didn't fill me with confidence. So one day I just thought sod it and pulled it all off and put it on ebay - it sold within the hour and with that I ordered a set of Jenvey bodies and a Canems ecu. For those not familiar with Canems they do a couple of options but I went with the clubman package which uses a crank angle sensor on the pulley end instead of the stock flywheel sensors, it does spark and fuel utilising a GM coilpack which comes with a bracket that plugs the hole up where your distributor once lived and comes with a nice fresh set of magnecours leads - which may I add seem to have been measured by a 5 year old.

It comes with an unterminated loom - so has the multi pin plug on the ecu end but is down to the user to decide where he wants his ecu to live and so on. I've built looms before, and am an electrician so this wasn't an issue, I find it strangely therapeutic building looms actually. Weirdo.

I chose to have it live behind the drivers seat so made it an alloy plinth of sorts and there it sat.

Image

The ITB's themselves were simple to slap on but the throttle linkage required a degree in quantum physics to work out from the uninformative diagram you're issued as some sort of half arsed gesture.

Image
ImageImage
Image

The injectors are 350cc-ish units meant for a mini cooper S, this took a bit of investigative work to get the right part number but eventually found these bosch ones at a decent price.

Image

The ecu came with a base map after building a decent relationship with canems, and after calibrating the TPS she started albeit very lean - but a simple block increase of the fuel map had her a lot happier.

One part I forgot to mention between all this is fitting a 36-1 reference wheel to the lower pulley - they supply a ford crank angle sensor which you have to make a bracket for. Once you've mounted it you put the motor at TDC and measure the angle to the sensor. This angle is then fed into the ECU at the static timing stage and it works the rest out. It took a bit of fine tuning with a strobe to get it bang on but was easy enough.

So there we are, she finally starts on demand, hot or cold although obviously needs a good rolling road session.

In other news, I now have a working fuel gauge, oil pressure gauge and clock!

Image
ImageImage

The last pic shows the snazzy little box that converts the 6 cylinder signal to a 4 cylinder signal for the rev counter.
'66 912
'75 Mazda RX3
'80 Mazda RX7
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911hillclimber
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Re: '66 912 resurrection

Post by 911hillclimber »

Good going!
Tell Jenvey about those instructions. I live close to them and have chatted to them and their boss several times at shows, and I'm sure they will listen carefully and improve.

On the road soon!?
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
chud
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Re: '66 912 resurrection

Post by chud »

Cheers, I might mention it to them.

In the grand scheme of things not long till road time but still lots of time consuming jobs to do - most significant being joining the accelerator pedal to the throttle linkage on the ITB's which sounds simple enough if you say it fast but I think it might give me some problems.
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Re: '66 912 resurrection

Post by Mark A »

This is like space exploration! Fascinating stuff.

OCD me says please don't get rust flakes down those throttle bodies.
chud
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Re: '66 912 resurrection

Post by chud »

Mark A wrote:This is like space exploration! Fascinating stuff.

OCD me says please don't get rust flakes down those throttle bodies.
:lol: Yeah one of the items on my list - buy filters.
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Darren65
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Re: '66 912 resurrection

Post by Darren65 »

All looking good :thumbright:

I've been using a Canems ECU with my 2.5 twin-plug for a few years now and it's been absolutely brilliant, it does everything any other system offers at a fraction of the price and has been rock solid with regards to performance and reliability. Support wise David can get busy at times but once you get hold of him he's a great guy and extremely helpful. I've hidden mine below the passenger seat as I wanted to keep everything looking completely stock.

Looking forward to hearing the engine run 8)
chud
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Re: '66 912 resurrection

Post by chud »

Darren65 wrote:All looking good :thumbright:

I've been using a Canems ECU with my 2.5 twin-plug for a few years now and it's been absolutely brilliant, it does everything any other system offers at a fraction of the price and has been rock solid with regards to performance and reliability. Support wise David can get busy at times but once you get hold of him he's a great guy and extremely helpful. I've hidden mine below the passenger seat as I wanted to keep everything looking completely stock.

Looking forward to hearing the engine run 8)
That’s good to hear thanks Darren. I must say I have been impressed with David you can’t fault the service. Did you get yours mapped at the place David recommends in Warminster seeing as you’re in Wiltshire? Can’t recall what the place is called.
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Re: '66 912 resurrection

Post by Darren65 »

Nick Fulljames and Mick from Redtek did mine when they did the original build. The engine had to come apart for a fresh build last year which Gary Cook at GDC Automotive kindly sorted with Nick and Mick again setting everything up on the rolling road although I don't think much adjustment was needed from the original set-up and it's been pulling like a train ever since.

Cheers,
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