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Megajolt - another saga begins


ThreeSheds

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Introduction

I feel quite daunted starting this - after all I am standing on the shoulders of some pretty large giants in this forum, so what can little old (too old!) me bring to the party? Well I guess I can bring my noviciate status in many of the technologies and techniques that will be required for (hopefully) a successful assembly and installation of the kit. I have spent may happy hours trawling through the incredibly detailed and helpful accounts of both Megajolt and Megasquirt installations on this forum, and a load of off-world sites that I have found useful as well, and now I know it all think I know enough to make start... Well, at least: I know what I know, and I know some of what I don't know, it's what I don't know I don't know that worries me, but that's why this is a bit of an adventure isn't it :)

Now a couple of caveats:

  • I do have a tendency to do things my own way so please don't be offended if you offer advice (which I hope you will) during the course of this ramble and I ignore it - it's just that sometimes I have to make my mistakes in my own way :(

  • I am not in a hurry to get this done and this first part of The Plan (see below) I fully expect to take me until Christmas. So don't get your hopes up...

So why I am doing it? After all I am on a very limited budget and the RRC's engine is not really up to much (a bit rattly and leaky) and there are 101 more sensible things that I could have spent the money and time on (if I was sensible..). Well I guess that the answer depends on who I am talking to:

a] SWMBO: "The original system was shot and replacement components are expensive" (This statement is technically correct, but the original system could have been re-instated for probably 1/3 of the cost of Megajolt)

b] Car-nut: a] and: "It enables running on LPG with a more correct advance curve, thus improving efficiency and saving the planet"

c] LR-nut: a] and b] and "It has well known multiple benefits, but it's mainly for it's improved wet-conditions running"

d] Hobbyist: a] and b] and c] and "It gives me a chance to experiment with new technologies and techniques"

e] The truth: a] and b] and c] and d] and "yes... ok... it's bling and I want one" :D

The rest of this post will describe the first part of The Plan and future posts will describe how The Plan unfolds...

Stage One - The VR Sensor and Pulley Assembly

Remove crank-bolt

This was set to 280 ft-lbs at the factory 17 years ago and was expected to be a struggle... So it was first gear low box with the hand brake hard on and then:

First try was with the rattle-gun and impact socket.. Nothing :angry:

Next a breaker-bar on it with a copper mallet.. Nothing :angry: :angry:

Next a two foot extension on the breaker-bar - happily inched the rover along the drive... but move the bolt? Nah. :angry: :angry: :angry:

Having read about people who place the breaker bar on the OS chassis and then let rip with the starter so that the bar has a good swing before it hits the NS chassis, I sat and pondered this option for an hour or so... Didn't fancy having a breaker bar and socket flying off into the scenery, so finally discounted it. :(

Despairing now - back to the impact driver (apparently has a break-away torque of 500 ft-lbs IIRC) and this time I just ran it until the compressor cut in, gave it a rest and then when the compressor stopped again I repeated the cycle. After about eight or ten such cycles it came away! :D :D :D Lesson? Give the rattler a chance to do it's job! ;)

Remove the plugs and set engine to TDC No 1

Not strictly necessary at this point but I thought that I might as well.

Remove the crank pulley

After checking that the keyway was near the top (I once dropped a woodruf key into the sump on my Series 1 years ago) I gave the pulley assembly a little tug and away it came :)

Remove timing pointer and trim back

The timing pointer needs to come off since it rides quite close to the harmonic balancer ('HB' from now on) so it will need trimming back a bit to clear the trigger wheel, and since it is plated with something and trimming will remove the plating, it will need painting too.

Lever off thrower

With the pulley assy on the bench I now levered off the inside thrower. This is very flimsy and is easily bent, but came off ok, although care was necessary not to bent the 'catcher' while doing this.

Remove 6 pulley assy bolts and remove the catcher

In my scheme, the Transit trigger wheel (Ford part number 1 078 767) is going to sit between the catcher and the hub of the HB with the tangs pointing forwards over the outer part of the HB so it is not necessary to strip the pulley assy beyond removing hte catcher (what is it really called BTW - anyone know?) I have found that the internal diameter of the TW will just clear the six bolts when mounted in this position, thus removing the need for machining.

Drive out roll-pin (trigger wheel wont go on with it in place)

Actually it's only necessary to drive the pin flush with the HB hub and even then only because the trigger wheel won't go on with it there. Later (after timing the wheel) the internal dia of the trigger wheel (TW) will need filing to clear the roll pin.

Assemble the TW into the pulley assy

Lightly clamp the TW between balancer hub and catcher, true it up (I used my venerable old dial calipers) to the HB outer (which I assume is pretty centered) and position it back on the crank and check clearances. In my case I had a bolt head that was a bit close but nothing fouled. Checking around with the VR sensor showed that the only place it can really go is at 3 o'clock looking from the front. Conveniently there are two decent bolts available for mounting it's mounting bracket on at this position :)

Design/construct sensor bracket

Like most people I made the bracket out of a bit of right-angle bent metal which I fixed onto the front of the engine using the bolts previously mentioned. I positioned the bracket so that the part which will mount the VR sensor is vertical, then I found where to put the hole for the sensor by lining up a ruler with two of the cross-head screws that hold the crank oil-seal cover in place. In this manner I ensure (as far as possible) that the VRS would be radial to the axis of the crank. I marked and drilled for the VRS (two holes - one for the working part and one for the 6mm bolt that will hold it). Again - in common with most people I will use washers to position the sensor radially to get the correct clearance to the TW.

'Time' the trigger-wheel

Note: In the next bit I am always viewing from the front of the engine, the engine turns clockwise and No 1 is the nearest cylinder on the right hand bank (when viewed from the front remember!)

With the sensor and the crank pulley assembly in place I checked again that No 1 was on TDC compression. Then I slackend the six pulley bolts a little and moved the TW around until the VR sensor was central to the fifth tang after the gap in the TW (that is - the gap has already passed the sensor 50 degrees ago with the engine going clockwise) In summary, with No 1 on TDC (compression), the VR sensor is at 3pm and the gap is at just before 5pm (viewed from the front of the engine. Once checked again I then nipped up the six crank bolts to hold the TW still (it's not necessary to true up the wheel at this point)

File a timing nick and clearance for the roll-pin

With the pulley assy back on the bench I filed a small nick in the TW at the position of the TDC mark, then stripped the six bolts and catcher off, and marked where the roll-pin goes. The TW needs a small area filing in it's inner diameter at the roll-pin position to clear said pin. I didn't even try to make the notch a fit on the pin, but left a little clearance so that the TW would be able to move a little for fine tuning later.

And THAT is where I am at the moment. Still to come is:

Paint the bracket, TW and the timing pointer

Assemble VRS bracket and timing pointer to engine

Assemble pulley assy to mark, true up and nip up tight. Insert the roll-pin.

Check run-out of TW and clearance to VRS. (less than .020" run-out and .040" clearance will be aimed for)

Remove the crank assy and pot the TW with Sikaflex to prevent anything getting behind the tangs. (don't worry - I'll grease the HB outer ring so that the potting won't stick to it)

Replace the pulley assy to engine and do up crank-bolt (280ft-lbs!)

Mount and adjust sensor to just clear worst of run out ( by .020"?)

Temporarily wire up the EDIS system, turn the engine and watch the sparks light the night sky![/b] :D :D :D

Stage Two: Assembly of the Megajolt Kit (including extra circuit to drive the original ECU)

Stage Three: Mounting/Wiring/Assembly/Testing of the rest of the system

Well that's it for now - I'll edit this and put some pictures in soon.

TwoSheds

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Megajolt i easy peasy to build and to fit. The hardest bit to get yor head around is where to time the trigger wheel in to. Once you've got your head around it its easy. What takes the time is making all the brakets for everything.

It does exactly what it says on the tin. Its fit and forget -it just works. Only thing I'd say is make absolutely certain you've got a good earth and its tight. Mine used to intermittantly cut out for no apparent reason, which i evenetually work out was cos the earth connection was loose!

Sounds like somebody needs a more powerful rattle gun...........

Cheers

Jon

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Good for you !

Why did you choose MJ over Full MS Then ?

Nige

Two things really - one is I use LPG 99% of the time, and the other is cost - with the weak dollar, I have got a Megajolt kit for £52 including post, but I may yet get stung for vat and apparently a 'handling charge'... :(

Well, TBH there was another thing - I find the thought of doing the MJ daunting enough - I think that MS would be a step too far.

I'll try and get some photos done tonight...

TS

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I tried to take some informative pictures tonight - it's harder than I thought! Hats off to you guys who get great shots of WIP...

Anyway - here they are...

First - so you know what I am talking about - the 'catcher' and the 'thrower':

catcher_thrower.JPG

Next the main part of the pulley assembly (without the catcher and thrower) showing how the trigger wheel will be positioned and how it clears the six bolts. (sorry I already painted it - makes it kind of hard to get a picture :( )

pulley_assy.JPG

This shows the loosely assembled pulley on the crank with the VR sensor in place. You can see that with the pulley on TDC the VRS is nine teeth round clockwise.

TDC.JPG

And finally - from underneath showing that the VRS is five teeth after the gap:

VRS_and_gap.JPG

I've been out there in the dark for a couple of hours and have had a bit of a set-back. There is a tubular support for the generator mounting that comes off the bolt that I am going to use for the top of the VRS mounting bracket. I had thought that I would be able to fit it on top of the bracket, but if I do that then it fouls on a bolt higher up, so I decided to chop the end off it and weld it to the VRS mounting bracket. It's a bit of a bodge, but I reckon when it's painted it'll be ok... And anyway - who's ever going to see it? :rolleyes:

I also had a go at pulling an EDIS coil-cap apart so that I can fit proper length leads. I have read that if you just pull then the inside (brass) bit would snap, so I took my time and got it apart ok. The technique I used is as follows:

1. Remove the clamping collar and cut the old lead flush.

2. Spray it with WD40

3. With a flat nosed 6mm pin-puch mounted in the vice - I pushed on the end of the old lead while winkling out the brass bit from the other end. The use of the word 'winkling' s deliberate here because you have to use a rolling-pulling sort of action so as not to straighten out the brass bit - something like extracting a winkle from it's shell. Once it is out, you are left with a bit of lead firmly clamped in the brass terminal.

4. Cut the HT lead flush with the brass.

6. Using a 5mm drill at low speed, carefully remove the remains of the HT lead from within the clamp.

7. Carefully force closed snipe-nosed pliers or a suitable tapered puch into the clamp to open it up ready to receive the new HT lead.

For a trial re-assembly I passed the end of a lead through the rubber outer (easy) and then trimmed it back to expose the core. I did this by first scoring deeply into the lead (but not as far as the core) and then I used a normal clamp-and-pull type of wire stripper which pulled the end off the lead leaving the core nicely exposed. A neat trick I thought - but probably one that everybody else has been using for years :lol:

After positioning the brass terminal on the end of the lead I pushed it back in to the rubber cap - again with WD40 - quite easily. I will wear gloves next time though because that brass is sharp - I got two nasty little bleeders from it :o

All together the coil-cap thing took probably half an hour for one. I will get a lot faster, but it has left me wondering whether it's better to just buy some made-to-measure leads... I'll have to think about that...

I'm off to bed now.

G'night

Twosheds

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  • 8 months later...

Eight months later and... IT RUNS!

I had only one false start - I had the EDIS-to-coilpack leads the wrong way round. Once I swapped them it immediately started and ticked over like a goodun.

With MJLJ out of the circuit the timing is nob-on 10o advanced - very pleased with that :)

With MJLJ connected there is a loverly smooth advance curve.

The engine is without a doubt running FAR BETTER now than it has ever done - even after the time I splashed out on a full service and 'tune up' by a reputable LR specialist - AND it has been laid up for 3 years and is now running on 20% diesel too (don't ask...)

Will post more later - I'm off to celebrate big-style now - with fish & chips and a can of Stella! :)

ThreeSheds

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Some pictures (I noticed that the ones above have all disappeared, sorry about that - perhaps it's due to me no longer having the web site they were on? :rolleyes: ):

The (partly assembled) pulley stack showing the positioning of the Transit trigger wheel prior to clamping it in place with the 'thrower' thingie. The inner diameter sits on the through bolts and the dowel required a little bit grinding out. In theory it could move if something hits it hard enough but once assembled and checked, I potted it with Sikaflex to stop mud/stones getting behind the tangs so I think it will be ok:

med_gallery_3439_602_62249.jpg

The stack mounted for checking. After confirming pickup operation and clearance, the stack was removed, nipped-up, potted and painted:

med_gallery_3439_602_21246.jpg

The view from beneath, showing the fifth (not)tooth and the pickup bracket

med_gallery_3439_602_12971.jpg

The coil pack and plug lead setup (shamelessly copied from FridgeFreezer - thankyou :) ). The caps with white tippex are the ones that DO work the strobe - the others do not.

gallery_3439_602_67324.jpg

And finally - the EDIS pack and it's associated wiring in the plastic box. The Megajolt box is mounted in the cab, but ALL power for the entire system comes through one relay (and the visible fuse box) and ALL earths for the entire system are taken back to the same point too. I may (one day) replace the castle connectors with crimped joints which will make it all a lot tidier..

gallery_3439_602_24224.jpg

Roger TwoSheds (I sold the third one)

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