Hi All

Please move this if it is in the wrong section....... but all the interesting stuff seems to go on in this one.

I am in the (painfully slow) process of Megajolting my 3.5 v8 Disco (LPG).

Les has already fitted my trigger wheel, and I have been faffing about sourcing coil packs etc for ages, but now I am ready to get on. I have seen somewhere that someone has fitted the EDIS coil packs to the side of the plenum, and this strikes me as a good solution.

Is there any reason that this is a bad idea?

Would you agree that it is OK to get some ali square bar TIG'ed to the plenum, then tap it for bolts to hold the coil packs? (Not by me obviously, I am inept)

Would anyone have any measurements for the plug leads for this style of fitment?

Anybody have any experience of the 10mm 'quad core' racing plug leads?

(Oh cripes, I've just read the 'rubbish posts' topic)

Your wisdom is eagerly awaited.

Thanks

Damon

Geoff mounted his coil packs to the side of the plenum on his RR, which then became Zuz's, and is now Bill's, and is now parked in my garden... which means I can wave a camera at the mounts if you like?

Only thing to be wary of would be distorting the plenum casting, it's unlikely but if you got too much heat into it (esp. near the edge) you could warp it and end up with loads of air leaks. I'm sure a TIG-qualified adult could comment on this though.

Don't faff about with swanky pants HT leads, use genuine Bosch or Lucas, or bite the bullet and buy Magnecor. Most of the fancy ones are just brightly coloured tat. My HT leads are a Lucas set picked off the workshop floor, dizzy ends picked off and Ford ends crimped on. Work fine for me even in deeeep water.

Thanks Fridge'

I had thought of the potential for welding disaster, and have got a plenum off of ebay just in case.

I plan to beg Les to do the welding as I think he is a TIGmeister. I did PM him a while ago on the subject, but I think there was a PM problem at the time as have had no response and they aren't in my sent folder I notice.

A picture of the mounts would be most useful please. I think I've seen a pic of a blue plenum on here with chunks of ali welded on for coil packs.

A measure of the leads would be great too, so I can source them before strapping it all together. So standard 7/8mm silicone leads are adequate?... I thought the bigger the better given that I have LPG?

Damon

I too thought about mounting them there.

I decided against them as a mechanic mate advised me the coils can breakdown if they get massively overheated.

As such I decided the plenum was not to be the mounting point as it gets horribly hot


This was purely my thoughts from info given to me, it may be that they would be fine long term mounted there, but I thought "why take the chance" and mounted them at the front of the engine and others have done this too since.

The other issue you will have is the ECU, when I megajolted mine the spark was much more powerful, as such the spark meant a "Better" ignition, and the result was hunting as it then ran weak, mine was a tweaked system anyway, but if you find when it runs that it hunts as you drive then you'll need to have the ECU rechipped and programmed.

That was also another of the reasons I went from MegaJolt to full Megasquirt

Nige

if you are going to the hassle of megajolt then isn't it worth just going the whole hog and going full MS?

its not a huge amount more work after all andwould save you kicking yourself later when you decide to upgrade?

Hi Guys

I only start on petrol, for literally two seconds until the revs drop and it changes to LPG automatically. The LPG system is an old style 'draw-through' system (though with a stepper valve linked to a lambda to make it closed loop), which I can ramp up the gas flow on.

If this wasn't the case I would MS in a jiffy (or more likely several months of disasters!). I have a Unalite dizzy, which gives good sparks, but the vacuum module has gone kaput, so thought I may as well 'jolt it now that switchable maps is available.

Anybody got any good maps for LPG?? (I hear they like a very different profile)

Nige: I have read your threads with great interest and seen your mounting solution, which I have spoken to Les about fabbing me up, but then I saw the plenum mount and it looks really neat, so thought I would take the chance. If they start breaking down I guess I will have to re-think. They are often mounted on the block in ford applications I think?

Damon

Nope they are not !!!!!

When I liberated mine from a couiple of M*ndeos I noticed they are mounted on the END of the block on a strnage shaped bracket like a wedge of cheese, the top being level, and the angled base for triangulation / strength. ie they are in air flow all about

That did it for me, and the thought of Looooooooooooooooooooooooooooooooon leads to 1 3 5 and 7 from the other side of the plenum

Nige

Ask and ye shall receive - it's as if I've got nothing better to do




And my setup (in the prototype stage ):

OK, not my finest hour of fabrication but this was about 2 weeks to Russia... butchered a pair of Mondeo coil mounts to save faffing about.

Doesn't look too bad covered in mud the gunk on it is white grease, with the Ford ends and some grease round the lip they're about as waterproof as can be.

Nige: Thanks for that. I know nothing and so am prepared to be led. Do you think a mounting like the photos above will get over this heat sink effect? Are the leads that much longer than from the front left side option?

Fridge: Those photos are great, and another option (as opposed to mounting straight to plenum) that might get around the heating fears. Looks not important for me particularly, just thought a plenum mount was neat as no leads need to cross etc.

I have wavered between plenum and water-pump cover mounting (shameless rip-offs both!), and am back in no man's land again now, DOH.

D

Funnily enough I found my original plans for those coil pack mounts today - could scan them if you like? The finished article was modified a bit from the plans, but I can modify or annotate them to show that.

The coil packs didn't seem to mind being alongside the plenum at all, and it was a nice tidy solution (would have been even tidier if I'd got as far as trimming the HT leads to length and putting in some clamps for them). It does mean quite long HT lead runs to the LH bank, but this isn't really a problem. The leads from the EDIS controller (mounted on the inner wing) run across the bulkhead then neatly up the valley alongside the injector leads and straight up into the bottom of the coil packs.

The one in the photos is made from ally but when I do another I'll use steel (stainless if I could afford it, just 'cause I'm a tart and it doesn't rust), for two reasons. One, I can't weld yet, so the chances of me successfully welding ally are slim (Geoff Greenwood did that one for me). Two, the lugs at the top where it attaches to plenum bolts are thin and too weak in ally. I'll also grind out the areas around these bolts to allow straight lugs instead of the narrow necked ones the original has (if you look at the plenum it wraps round the bolt heads, leaving only a narrow opening).

In order to avoid expansion problems and making fitting a lot easier the bracket has open slots at the bottom where it locates on the three plugs in the side of the plenum base. The plugs are nigh on impossible to tighten with it place so they are fitted with loctite on the thread and backed off just enough to allow the bracket to slide behind the head.

Nige,

Your leads are the neatest looking, ideally positioned NON factory job I've ever seen, and surely this thread deserves a piccy of your coilpack/lead arrangement, I was certainty well impressed at Bordon.

Boothy

Nige's coil wiring, unfortunately with my doodles all over them:

Please excuse my late response........ I think I stopped getting an email alert when the thread was moved? and have been busy digging my vege patch on the first decent weekend of the year round these parts.

Geoff: Your plans would be very useful if you could dig them out. I haven't welded for 15 years, but I know a man who can. I would really appreciate the HT lead lengths also if you have them.

I have found the image that first sparked my Plenum mount idea:
http://forums.lr4x4.com/index.php?act=atta...ost&id=5502
Would heat transference be an issue with this option do we think?

Damon

I attached mine to the bulkhead just behind the plenum (LR 90, no airbox). Drilled and tapped holes in the bulkhead and made aluminium brackets for the coilpacks to sit in. I figured less heat soak & vibration. Can take a pic if of interest?

Hi Tom

Sadly my engine (Disco) is tight to the bulkhead and no room either side on bulkhead due to LPG emulators and other bits and bobs.

I do like the plenum mount,for tidiness, but am also worried about heat damage, but then coil packs are v cheap so I suppose I could carry spares and just suck it and see.

Damon

Well, Im in a similar situation, on board air and lpg pipes in the way, mine are just mounted on the side, drilled and tapped through (sealed) the plenum. I just used the P38 coil bracket and folded the tabs up.

Never had any issues with heat / breakdown.

(for the more astute amoung you, I dont have a coolant leak, Ive just changed the thermostat).

Heres a pic for you:

Click to view attachment

My solution, tin bashing.

I wanted the coil packs low and out of the way but still be able to use
off the shelf Ford leads.

That is very neat Paul!

What Standard Ford Leads can you use from that position?

istruggle2gate11: Like that one too, but I am way too scaredy to drill the plenum.

I have now spoken to uncle Les, and 'we' are going with the water pump mount. If it looks as neat as Paul's setup I will be v pleased Les!

Damon

Damon, the leads came from M & N reg Escorts (with the coil packs).

The short leads are too short but the rest are usable on a V8.

Thanks for that. I will get hunting.

Paul - if you swapped the right hand pair from both coil packs (and the LT wires accordingly) your leads would have less crossovers. Do you use the standard long moulded Ford plug ends?

Click to view attachment

I used standard Escort leads from the scrappys, got a couple of sets cleaned up with gunk or similar and they're perfect, fantasticly tight fit on the plugs and definatly made for the coil pack with the rubber 'o' ring and snap fit.

Coil packs mount like H'F'Hells side by side over the water pump.

Worked all day on Howlin Wolf round 1 at Bordon, underwater and never missed a single beat all day in the swamp, absolutely amazing.

Best bit did not cost a penny and if needed I've got a spare set.

I find it very hard to justify a set of Magnecor or similar when these work perfectly well.

John, leads were only thrown on for photographic effect!

Plug end suits a V8 rather well.

Should only be marginally worse than my bracket, which hasn't caused any problems. It looks very neat - I'd say like it left the factory that way, but it's a bit too neat to be Solihull's handiwork!

I'll take the plans to work and scan them - might be day after tomorrow as I need to make some phone calls tomorrow lunch time.

Tom - I thought about mounting the coils on the bulkhead, but aside from being a bit short of space (would have been one each side) I was worried about losing the really good earth to the block, especially as I'd had a fair bit of trouble with dodgy earth straps with the original ignition. I take it you don't have any problems?

Dont worry about that, have you seen the length of spark these things will do? Just let it jump from the bulkhead to the engine
(Joke)

I have just fitted a Thor manifold (to earlier engine) i have mounted mine quite nicely down the back of the manifold.
Will post some pics asap.

No problems at all. As far as i know the mounting bolts the coil packs use don't need to be separately earthed. They are supplied with a 12v ignition switched live feed and to fire the coil, the ECU grounds then releases the negative side of each coil.
Vis (for direct drive coils): http://www.extraefi.co.uk/Drawings/8cy_Coil_Pack_Wiring.JPG

MS is fussy about the quality of earthed connections (for sensors, etc) so best to bring them all back to the same point which has a good connection to the negative terminal of the battery. This ensures there's no voltage difference between the different earth points (otherwise it gets wonky readings from the sensors)

I amused myself comparing sparks from the EDIS and (still present) standard ignition when I first fitted it. It wouldn't be exaggerating to say the EDIS was heavy artillery to the dizzy's damp squib... I think someone managed to get some passable photos and post them on here a year or two back?

I feel that heat is no issue with the coil mount on the r/h face of the plenum:
pic: http://forums.lr4x4.com/index.php?act=atta...st&id=11034

When you measure the inlet air temperature at the throttle disc position (with an IAT sensor that rests in a bung welded to the plenum; not the best position admittedly) you´d get about 30°C in operation at these. Maybe it´s a little hotter at the other side of the plenum as the fresh and probably cooling air will dissipate in the plenum.
OTOH I cannot remember having had a problem in putting a hand on the plenum housing when the engine is hot and even in summer. So the temperatures are safely below 50°C or even below 40°C.

I chose that position before I saw alternatives like above the water pump. At least it´s very vibration-proof like that

Apologies - work's been manic this week and I haven't had a chance to scan the plans. I'll do them as soon as I can.


Looking forward to this How does the Thor manifold compare for height to the earlier EFI plenum? I've an idea it's lower? Wondering because I'm planning on putting the old Range Rover engine in an MGB, and saving a bit of height would be a very good thing...

wasn´t there an extra plenum chamber for use in the MG-B V8 ? On the last pages of David Hardcastles second book there is a pic.

HoSS: Going slightly OT i know, but I'd be interested in how you did the Thor conversion and what the power / torque spread is like compared to the hotwire setup?

Don't think so - they never injected the MG. You could be thinking of the twin-plenum SD1 Vitesse.

The MGRV8 was injected - it had a hotwire system - and it did have an MG badged plenum chamber. I'm not sure it's dimensions were any different to the Land Rover one, though, as the RV8 had a bonnet bulge and in any case they're probably rarer than unicorn poo.

I was going to answer here, but best not to hijack. Started a new thread here:

forum link

Hi All

Update: I have decided to go for the water pump mount, as Les had already had a think about it and formulated a plan, mainly. I am sorting the loom ready for its return, and hunting down some scrapper Escort HT leads.

Will post photos presently.

Anybody out there have any proven ig maps for LPG??

Damon

I added '10' to all bins in the petrol map, seems to work ok.

Thanks HoSS

I was tempted to do that as this is all the RPi ignition amp with added 'advance' for LPG does. I will try that for a kickoff.

Damon

That would be about right ......................... maybe as much as 14 at above 2200rpm.............





Ian

Thanks Ian

I remember vaguely hearing that LPG liked a steeper map. I have also heard that detonation is harder to detect on LPG, so am a little clenched about dialling in too much on the gas?



Les is making my coil pack bracket as we speak, and I am finishing off the loom at my desk. Am running the MJLJ with a PP3 battery, and have the map switching working and all, so when I get the shed that is my Disco back I will get it fitted and post up an update.

Only anomaly so far is that the RPM guage in the configurator shows 228rpm with no inputs. Even shows this with the MJLJ unconnected to the laptop.

Damon

Pure detonation is hard to detect period ................ full detonation is different to pinking and will destroy an engine in seconds............. but you are not in that territory.............


LPG has a much higher octane rating than petrol, but has a lower calorific value.................... it also burns much slower, hence the reason to light up the pot a bit sooner. The lower calorific value is the reason why you get 10% mpg on gas...........and potentially 10% less power...........

I think you would have to go a long way past a std map +14 to get into pinking land ................... much depends upon the CR of the engine, if its std then fine, if its been played with then treat with a little caution.




Ian

I never finished my spark maps before I sold the truck , but my experiments suggested that LPG needs a different curve rather than a simple offset across the whole map (which is what you get by twisting a dizzy or, so far as I'm aware, with all of the plug-in magic boxes). I think it needs a lot more advance at the bottom of the map, but more or less the same as petrol at high revs.

I'll play....
Modified mondeo coil packs and holders in original coil position.

Crikey that's a long way from the far bank of cylinders!

I have gone with the water pump mount.......... nice bracket made by Les, EDIS-8 module on inner wing drivers side, MJLJ to left of binnacle. Loom mostly made now so will have it in soon.

Will post pics when I have finished rewiring all my fusible links!

Damon

Click to view attachmentAfter trying to fit my dizzy LR leads onto the 1st gen EDIS coils - I realised they do not fit - of course I should have searched and asked before....

Is it better to order full set of Spark plug leads (triggerwheels.com) - or just the connectors and replace them on the original LR cables on the coils side?

No usefull scrapyards here around - so I have to order new from somewhere - any suggestions on that as well?

The picture shows the connector that I think I need - am I right?

Thank you in advance.

Yes you are.
Magnecor will do a bespoke set with both the correct ends on from them.
I make them up myself, but I'm tight...

thank you. If you make them yourselves - where do you get the coil plugs from?

from the coil packs which I get from the scrappy.
The ends are easily recovered, are metal and and can be reused, with care.
As you said this is not as easy for you.
RR

yeah - thats a problem. Magnecor is too expensive (I havent found an exact pricing - but I think that it will be more then 70 pounds). So I will go for the set sold at triggerwheels. Do you (or someone else) know if the spark side on their leads is ok for the LR?? It is hard to see from that smal picture they have on the web shop.

Edit: Have found this in a local shop - will check - for cca 30 punds (2 sets of 4 cables) - it should work.
http://www.tesla-blatna.cz/en/ignition-lea...0-77-79,889,236

The pics i promised (on page 2, six months ago )