Engine and Transmission Tech

Hi Folks,

Sorry for asking a bunch of questions. I thought I had this site memorized and then I come across speed bumps that caused my first stumble. When I got this 4.0 I thought I was on my way. Now I've discovered (Ha-bought a Discover) that having the A/T is going to cause me to lose the flywheel, and consequently the flywheel trigger for the GEMS ignition that I wanted in the first place . . . AARRRGH!

I've been reading all the posts about the crank trigger wheels available and such. Would you all suffer a newbie's plea for suggestions?

If I were to change to a distributor ignition and use the 14CUX FI, what front cover do you recommend as I don't want to lose the crank driven oil pump?

What do I do with the ignition wires from the ECU to hook up the dizzy?

If I wanted to keep the GEMS fired ignition what are my options?

Thanks again,

Tim

P.S. I'm thinking of using a GM T5 tranny and S10 rearend if that makes any difference.

Tim, you do have some options. Provided you really want to keep the GEMS you might consider modifying your flywheel to provide the necessary trigger. I haven't looked at the Rover piece but I understand it has imbedded magnets. If so, there is no reason why you couldn't embed magnets in the flywheel. Supermagnets are available in nearly any size and configuration you could want, so installing them should not be a problem, such as by drilling the rim and pressing in the magnets. They could even be retained with small cross pins if you need them in order to feel secure.

The new oil pump would be a plus but I understand it takes some room and maybe interferes with the steering rack. But the rack can be lowered, or the engine raised. What year car was it, '76? If so you have an extra inch anyway.

The most important part of the system you got is the induction. You can run it with a Megasquirt controller, fit a front crank trigger, run an EDIS ignition or drive COP's with MS. Those are just options and there are plenty more. You did good.

Jim

The intermediate covers from 96/97 era have provisions for a distributor, but the cast holes did not get machined out. You can have the hole for the distributor and the hold down bolt machined to accept the distributor and still run the crank driven pump. The later covers are narrower because they did away with any provision for the distributor. The earlier covers didn't have the crank driven pumps. You also have to consider the camshaft and distributor drive gear. On the early engines, the cam was held in place by the distributor. The later ones had a cam retainer essential if you go distributorless. I have a couple of these covers kicking around the garage if you need pictures of one.

Hey Tim,

Retaining the GEMS system is doable it's just some extra work.
The flywheel pickup can be done a couple of ways. One is to retain the thin auto flex plate and remove the ring gear. This can then be sandwiched between the new flywheel and crank. Another is to grind off the rivets holding the trigger wheel on and have the new flywheel drilled and tapped to accept it. Or just use a std trans flywheel from a 96 or newer Disco.
You will need to retain all of the sensors. That includes all 4 oxygen sensors and the evap valves.
You will also need a digital speed input.
The hard one is keeping the security system from the Disco. It sends a digital signature to the fuel injection computer to allow it to start. The security module in the truck is matched to the fuel injection so you need to keep them together.
There are some firms that can delete the security feature from the injection system but it's cheaper at that point to go to an aftermarket system like the Megasquirt or SDS, etc.
You could I suppose also use the 14CUX computer and a separate ign controller for the rear coilpacks. But you would still be better off with an aftermarket system.

Jim,

I haven't bought the MG yet. I'm just in gathering stage and lost out an MGB GT close by last week. My wife was still home-bound after surgery so I couldn't make it in time to have a look at it. BTW, took her to lunch today so we had a good first outing and she walked around fine, just limping from nerve damage.

I'd LOVE to keep the GEMS ignition. I really like the neatness of the package. I'm not sure I'd have the skill to get the mags placed exactly on point in the flywheel, tho. I don't think I'd have a problem machining the flywheel on a degree table if I knew what the outcome was supposed to be. As for keeping the mags in, there are some pretty decent epoxies available that I'd be comfortable with.

Also, I'm not going to worry about the firewall mods yet but will put the engine low and back to clear the rack (I covet Pete's Fast Car front suspension, excepting the rack ratio) because I will be installing A/C for the lovely bride and this will be for cruising to the beach (hot & humid).

Cheers,
Tim

Todd,

I'd like to see pics, and maybe if you're willing to part with a short one since I really don't want to do a dizzy.

Thanks!
Tim

Fred,

Thanks for chiming in. I love the idea about using the old trigger wheel on a new flywheel. I'll see what I can find around here on a Disco flywheel. I couldn't find a five speed Disco around here to save my life, let alone an engine for one.

Sensors, I think can be grouped and the local LR guys know a work-around on that.

The security feature is a head-scratcher. I have a friend who owns a LR/Jag specialist shop here and he might be of some assistance in this area. I sure don't know squat about it.

The digital speed input is another speed bump I had no idea about. Can you tell me more?

Thanks, Fred!
Tim

I think I'm starting to understand this. I realize that I have the GEMS system (that had to sink in) and the fuel injection cannot be segregated from the rest of the system. Sooo, basically I bought an engine and my plan to buy the whole vehicle so I could make sure I got everything I needed failed. My buddy at the Rover shop had a front cover with the distributor boss drilled out and I can swap him for that.

Anyone want a dealer maintained Disco with not a nick or scratch on it minus the engine? I don't think this thing ever traveled more than 8,000 miles a year.

Now I need to know what you guys like in a distributor. Mallory or Delso?

I'm going to see if I can find a junk yard that'll let me scavenge a CUX FI to use. I'd love to be able to remove it myself so I know that I'm getting everything and can label as I pull. We'll see.

Thanks for all the help.

Cheers,
Tim

I like EDIS pretty well but you need a crank trigger and an advance signal for that.

Jim

Hey Tim,
no need to throw the baby out with the bath water.
You have everything you need to make the motor run except for the computer.
All the sensors, injectors, manifolds, throttle body, coils etc are in the Disco.
Get yourself a megasquirt or similar computer and you're good to go.
You won't need a distributor as the megasquirt can fire your present coil pack.
There's a few of us here that can help out with the setup/tuning.
And I think I saw a company that sells one ready to go. If you aren't too keen about building your own.
Just plug it in to your disco harness and fire it up.
If you want the simplest system around and don't feel comfortable using a laptop for tuning check out Simple Digital Systems.
Rugged little computer that uses a hand held tuning box. And it is available to run your coil packs.
I've used quite a few of them and been pretty happy.
Cheers
Fred

There are many things you've never given a thought to that are advantages with a system like Megasquirt (MS). For instance, want to program your radiator fans? That's fairly easy. Have a burning desire to variable speed drive them? It can be done. It's a small thing of course, something you wouldn't give a thought to. But it sure beats messing around with temp sensor bulbs and external controllers.

You can use a wideband sensor to take full control of the mixture, EGT lets you fine tune the advance. It's even possible to control the individual mixture and timing of each cylinder. (Which can really help if your headers are not equal length. And they are not, are they?) Plus, there is an auto-tune feature that you can use to have the controller stay on top of things. Now admittedly it isn't going to automatically set up things like your enrichments and idle control but there are enough of us around to help with that by this point. Let's see, I've used them for over a decade, Bill Jacobson has about the most sophisticated system currently with 8 individual egt sensors, Bill Guzeman got into the game a few years back, Dan B has it on his TR-4 and there are others. (Fred? Jim?)

As attractive as keeping the OEM controller may seem, the truth is usually much harsher. They tend to be overly complex and invasive (Do you really need it tied into a secure key? Does it have to connect to ABS braking, traction control and ride control? Is it essential to connect it to the instruments?) These things are possible with MS but certainly not required. Would you really rather not be able to change anything? What if the engine runs differently with your exhaust? What if the changes you have to make to the induction system creates a glitch? It's more common than you think. How about an engine surge at 2000 rpm? Just live with it?

A lot of people have installed an OEM controller and a fair number have then pulled it back out to install something different. I may have been the first here. I used the Ford EEC-IV system with a TwEECer and felt like banging my head against a wall. Having a decent interface that makes sense and has most of the info that you need to be able to tune it is a world of difference away from the OEM systems where everything is a real big secret. As complex as the controller is, how could it be possible to tune it effectively if all you can do to change it is to vary the value of one or two resistors? And why would you want to do that if you could just plug in a laptop? And my tuning laptop is about a 20 years old IBM and MIGHT be worth fifty bucks but I wouldn't count on it. Having that lost, stolen (sure, like anyone would want it) or broken is no big deal yet it's all I need to tune the controller and gives me full instrumentation on user defineable screens and datalogging for performance analysis. Want to use your iphone instead? There are guys doing that too. In fact, I'm pretty sure that by now they've combined apps to get a rolling dyno worked out. Can't do that with the OEM controller.

Jim

Thanks for the encouragement guys. I'll check into the megasquirt system. Sounds like something I could figure out with a minimal learning curve. Micro-tuning carbs & ignitions isn't my forte. That's why I was liking the fuel injection. If the megasquirt will fire the coil packs I think I'll be good to go. I know you guys have all the answers.

Now I'm fired back up and ready to start rebuilding this 4.0!

Thanks!
Tim

Okay Tim,
I've got some stuff lying around so thought I could shoot a couple of pics to show you what you're in for.
This pic is of an unassembled MSII system. The bags are filled with resistors/diodes/capacitors/ICs etc. looks intimidating but assembled step by step is remarkably simple.

This is an assembled unit for a supercharged, turboed, nitrous injected MR2. This unit controls the cooling fans, the supercharger clutch, the waste gate, the nitrous injectors, coil on plug ignition and a slew more things. If you can solder you can build this easily.

This last photo is a SDS system.

I'm sure some will get tired of me promoting this system but for the average guy it really is very good.
It's easy to set up, easy to tune, and reasonably priced.
It's simplicity does forego some features but for the beginner or even an expert it is an attractive system.
Cheers
Fred



Edited 1 time(s). Last edit at 04/01/2012 02:17PM by DiDueColpi.

Fred,

This looks like the model car and radio kits I used to buy with my lawn mowing money. I've built quite a few computers so I'm not afraid of soldering printed circuit boards and dealing with tiny parts. My eyes might protest but if there's instructions I'll have a nice rainy day project.

Would you be so kind as to direct me to some of your sources for these components?

Kindest Regards,
Tim

For the Megasquirt there are a number of good sources.
The one that I tend to use the most is DIY autotune. Good website, reasonable prices and very helpful staff.

Fred,

Thanks so much for all the info. I'm very appreciative of this.

Tim

I build a MS system about 5 years ago. Not sure if it is a MSll
system. I am in the process of upgrading my old but newly rebuild 3.5 engine to FI.I ran the engine first with an AFB Carter carb. First I wanted to start with the original 14 CUX sistem but reading this post on FI I might go immediately to install the MS system. Not sure if I would go with the distibutorless option. I might need some help from some MS guys that know more about this set up.
Any info would be welcome.