4.6L V8 Fuel Delivery System?

[MrNick]

I've decided to just throw a carb setup on the 4.6L this summer so I can get it running again.

I will install an EFI system at a later date, but due to cost and work it would be far easier and faster to do a carb setup. (Thinking Megasquirt 3 EFI someday).

So right now I'm throwing together a list of things a need to buy for the carb setup and  I was wondering what kind of fuel pump I should look at.

I imagine the old SU pump will not be enough to feed a 4.6L? What are you guys using?

EDIT: Read my post below for more details.

[BlownMGB-V8]

Since you will be replacing the pump when you go EFI... The wife's 231 uses the old mechanical pump. Doesn't get any cheaper or easier than that. Pretty foolproof too. Same pump should bolt right up to your Rover if the cover still has the boss for it and the cam still has the eccentric. Otherwise, just about any generic pump should do fine.

JB

[MrNick]

I don't think it has the boss for the mechanical fuel pump. Being a 4.6L it came with the GEMS system (Why does nobody like the GEMS FI anyways?)

Let me do a quick recap - I got a 4.6L engine and T5 trans and got to where I was ready to start fitting it in. Having the time and money I sold the original MGB engine and set to work. Soon after this I hit some financial troubles and basically lost my funding for the project. Now my wife found a new job and I can afford to do some work again on my MGB, but her new job required us to move to a place without a garage. I can use another person's garage, but only temporarily.

Now I'm debating how to go about getting this old heap of steel moving again.

Here are the options I think I have:

1.) GEMS - Keep the GEMS setup, but I hear that the embedded security stuff will cause major headaches.
     Pros: Already on engine, have 90% of parts. Sequential Multi-port FI and Distributor-less Ignition.
     Cons: Little/no support and information can be found on this EFI setup. Would probably have to re-chip ($$$), need to conver car to FI (gas tank, etc)

2.) MS3 - Keep GEMS hardware, replace ECU with MegaSquirt 3
     Pros: Sequential FI, Distributor-less Ignition, Lots of online support
     Cons: MS3 = $$$, need to conver car to FI

3.) Carburetor - Remove all EFI stuff and put on Carb setup
     Pros: Simple use
     Cons: Will have to buy and replace a LOT of stuff (distributor, intake, timing cover, carb, probably camshaft)

4.) Hybrid (not the shitty Prius kind) - Remove Fuel Injection hardware for carb, but keep Distributor-less Ignition hardware and run it off of a simple ecu (MS2?) just to control the ignition
     Pros: Do not have to change out the more difficult GEMS stuff, still have simplicity of carburetor.
     Cons: Need Ignition management computer, will need to buy intake & carb setup (can resell later when going to full EFI)


I want to go with #2 and a full MS3 EFI setup, but I'm not sure I'll have the money for a full conversion. #4 seems like a good in-between as I can resell the major components later to fund the MS3 venture. Though as I'm typing this I'm realizing that the Hybrid setup would pretty much end up costing the same as the MS3....

hmmmm.... feel free to chime in as I roll this about inside my head here...

[mstemp]

Nick,

You may have a few issues coming up. If you use the standard 4.6L front timing cover, Oil Filter/Pump and the cast oil pan they may not fit due to Clearance with the steering rack and the cross member. Most people tend to replace these items with older 3.5L items. Also the GEMS is tall at the front I think and may hit the bonnet. On my Rover 4.6L I used an older Steel pan and a Buick front cover.

Whose motor mounts are you using?

For FI you could go back to the Older CUX14 setup from early 90's. I paid $150 for a complete setup from a wreckers. This way you can mill the mid and top plates and fit under the bonnet.

[MrNick]

I fabbed my own mounts to stuff the engine as far back and down as possible. the 4.6L is taller since the intake is rectangular, but I can switch it with an older CUX14 one that is curved and do some milling. Though I'd lament losing the big "4.6L" cast into it. Another option is to alter the hood, but I want to keep it as stock looking as possible.

The oil filter was a different issue. The front cover is a LOT different, having oil cooler lines and the position of the filter is right on top of the steering with almost no room. The pan fits fine though.

What I've done is gut an old oil filter, cut out several inches in the mid section and carefully weld it back together. Basically I have a 2" tall oil filter canister that's empty inside. Then I'm going to use the oil cooler lines to run to a remote filter.

I thought about going to a CUX14 setup, but the GEMS system has some awesome technology on it - Sequential injection and distributor-less ignition. The big one being the Ignition. To go back to a dizzy I'd have to change a lot on the engine just so I could run 50yr old tech as opposed to 10yr old tech. Doesn't make much sense to me.

[mstemp]

Nick,

Why not just replace the plenum cover and mill the trumpet stack? If you can't get the Rover ecu you have to work then use MS. What that's going to cost $300 or so?
Now the CUX14 may be a bit old but sure beets the hell out of a carb setup.
Gald it fits with the pan etc you have.

[MG four six eight]

Nick

I'm a believer in the MS3, it is fast (processing), tuneable to almost any engine and you can use alot of your OEM fuel injection componets.
Because it is a "universal" ECU there is some what of a learning curve setting it up and tuning it. However once you've played around with it, you'll find it very easy to tune. The good thing is that there is lots of on-line support as you mentioned, also the base settings that you download into the ECU are usually close enough to get the engine started. Once it's running you can begin tuning, the cool thing is you type in your laptop to tune!

I highly recommend getting a wide-band O2 sensor, it's makes tuning MUCH easier! The Innovate LC1 unit is reasonable in cost and there are settings and support for it in the MS tuning software.

Bill

[MrNick]

Yes, I will be replacing the plenum cover with an older one and mill it down some and changing the location of the alternator so that everything will clear the hood. I really don't think clearance is an issue.

Time and money are my problems. When I started this project I had plenty of both, but changes in my life have limited both.

I suppose I'll just keep going as I have planned. Plug in the GEMS ECU and see if it just works. If it doesn't work (which is what I'm expecting) then go the MS3 route. The pre-assembled MS3 runs $640 (yikes!), but I can save about $150 and get the unassembled one and do a ton of soldering, which I am familiar with just have never done that much.

First step will be to get the engine fit in, that way I can move it out of my friends garage and just tinker with the engine management as I have time.

Though I think the end product will be impressive - Potentially the only MGB V8 with sequential multi-port fuel injection and distributorless ignition

[BlownMGB-V8]

Um... I think maybe Bill might have you beat on that but don't let it get you down. He's out there on the technology edge and it's nice to have people leading the way.

JB

[MrNick]

Oh, wow. Just looked up his car in the photo gallery, I hadn't looked at it before. I like those wheel flares a lot.

Very nice. I may have to pick his brain on the MS setup later on.