TD5 to V8

[elbekko]

2 hours ago, Bigj66 said:

It sounds like the Thor engine is the one to have. Will that run off MS too? Does the Thor have the same factory ECU as the earlier 4.6?

Thor has a Bosch ECU, not GEMS. A bit more complex with CANbus capability for the auto gearbox.

2 hours ago, RedLineMike said:

td5's run at 4 bar of fuel pressure, i would assume that a rover v8 would be similar, i know my LS runs at just under 4 bar,

Thor needs 3.5, GEMS 2.5 IIRC? Large enough difference to notice when not using the right pump anyway

[RedLineMike]

47 minutes ago, elbekko said:

Thor needs 3.5, GEMS 2.5 IIRC? Large enough difference to notice when not using the right pump anyway

fuel pressure regulator controls the pressure, not the pump

[Bigj66]

31 minutes ago, RedLineMike said:

fuel pressure regulator controls the pressure, not the pump

Just for comparison, do you know what pressure the 3.9 SERP runs at?

[FridgeFreezer]

IIRC most Rover V8's run at 40-50psi approx, it varies with vacuum (FPR references vacuum not outside air) and I think the Thors run a bit higher as Escape suggests but it's all ballpark - the MS doesn't care because you just nudge the fuel map up until the right amount of fuel is going in as long as the injectors aren't running out of time (duty cycle <80%) at max power you're good. Whatever lump you get will likely have the required FPR on the fuel rail anyway, the Thor I think it's on the pump in the tank (no return on fuel rail) but you can just mount an FPR externally and plumb the return back to tank.

MS can run anything with injectors. There's MS'd lawnmowers, tanks, and land speed record cars out there.

[elbekko]

3 hours ago, RedLineMike said:

fuel pressure regulator controls the pressure, not the pump

Unless the regulator is in the pump, as is the case with the Thor one.

1 hour ago, FridgeFreezer said:

the MS doesn't care because you just nudge the fuel map up until the right amount of fuel is going in

BTDT, does not work with Thor injectors and a GEMS fuel pump.

[Bigj66]

2 hours ago, elbekko said:

Unless the regulator is in the pump, as is the case with the Thor one.

BTDT, does not work with Thor injectors and a GEMS fuel pump.

BTDT??

[Bowie69]

Been there done that. 

[Bigj66]

2 hours ago, Bowie69 said:

Been there done that. 

Ah, ok 👍 

So just to clarify, a Thor engine will only run with its matching ECU which would be quite difficult to run as a standalone or even with MS due to fuel pump compatibility?

Next best option would be a GEMS 4.6 engine using either an unlocked factory ECU or, MS?

[Bowie69]

MS will run anything, including thor stuff. 

To be honest, don't muck about, while you can run using Rover ecus, MS is just better in every respect.

[Bigj66]

7 minutes ago, Bowie69 said:

MS will run anything, including thor stuff. 

To be honest, don't muck about, while you can run using Rover ecus, MS is just better in every respect.

Cheers, the argument for MS has been convincing chaps 😂

But, have I understood correctly that the Thor engine will not be compatible with the in tank pump as used on the 3.9 and 4.2 SERP engines? My idea was to replace the TD5 pump with one of those.

Here is a summary of what I think I need to complete this swap. Feel free to correct or add anything that I’ve missed.

R380 V8 bellhousing

R380 Defender V8 input shaft

Manual V8 flywheel

Spigot Bush

V8 Defender clutch and slave cylinder

V8/TD5 hybrid exhaust or bespoke stainless system

4.6 engine with MS ECU (engine to be confirmed but preferably a Thor)

V8 Defender radiator

TD5 airbox reused?

Engine mounts altered to suit

Power steering pipe work modifications as required

RRC 3.9 in tank fuel pump with adjustable FPR

Remote oil filter (Mocal)

[Bowie69]

Thor uses slightly higher fuel line pressure, that's it (I believe), the earlier fuel pump is more than capable of producing 100psi (around 40 more than is needed) and will flow plenty too. 

So it will work, you may have to twiddle the plumbing slightly but hey, you have a big project anyways, it is a tiny, tiny detail

[Bigj66]

8 minutes ago, Bowie69 said:

Thor uses slightly higher fuel line pressure, that's it (I believe), the earlier fuel pump is more than capable of producing 100psi (around 40 more than is needed) and will flow plenty too. 

So it will work, you may have to twiddle the plumbing slightly but hey, you have a big project anyways, it is a tiny, tiny detail

Excellent news. The only big challenge now is to find a suitable engine complete with all ancillaries...🙄

[FridgeFreezer]

TBH just buying a running P38 is a good way, that way you can test everything out beforehand.

[Bigj66]

Out of curiosity, do the later 4.4 engines also fit or are they a completely different engine all together?

[Bowie69]

Anything fits, but won't fit your current gearbox

[Bigj66]

43 minutes ago, Bowie69 said:

Anything fits, but won't fit your current gearbox

Ok so is that because they have a different bell housing bolt pattern to the earlier V8s? Maybe a different crank bolt pattern for a flywheel too...🤔

[Bowie69]

Completely different engine! 

[elbekko]

12 hours ago, Bigj66 said:

So just to clarify, a Thor engine will only run with its matching ECU which would be quite difficult to run as a standalone or even with MS due to fuel pump compatibility?

No, MS will run it without issue. You just need slightly higher fuel pressure.

The Thor in-tank pump has an internal regulator and return, which means there is no return from the Thor fuel rail. The Thor in-tank pump fits just as easily as a GEMS or Serp pump, they're all the same top anyway.

[Bigj66]

1 minute ago, elbekko said:

No, MS will run it without issue. You just need slightly higher fuel pressure.

The Thor in-tank pump has an internal regulator and return, which means there is no return from the Thor fuel rail. The Thor in-tank pump fits just as easily as a GEMS or Serp pump, they're all the same top anyway.

That’s great information, thanks very much.👍

If using MS then, I will only need to find a complete engine and don’t really need to worry about things like the ECU and loom do I? There are some out there on EBay etc but some are high mileage and some are exchange only so it might take a bit of patience before I find a suitable one. If I can find a complete vehicle then that’s great but I don’t want to be paying over 3k for a vehicle just for its engine.

[Escape]

You should be able to find a running P38 for a good price. That will give you an engine and wiring loom, as well as the correct fuel pump and enough parts to sell on to buy you a MS.

It is possible to run MS directly from the P38 flywheel and crank sensor, we have one in a Classic auto (with EDIS) and a 'prototype' on a P38 manual, with direct coil drive (thanks to @FridgeFreezer). The later Thor was never mated to a manual, so only has the flywheel for an autobox. You can mix and match, though manual flywheels for the later engines aren't that easy to find. Older flywheels don't have the timing teeth for the crank position sensor, which is why MS often uses a separate timing wheel.

Filip

[Bigj66]

54 minutes ago, Escape said:

You should be able to find a running P38 for a good price. That will give you an engine and wiring loom, as well as the correct fuel pump and enough parts to sell on to buy you a MS.

It is possible to run MS directly from the P38 flywheel and crank sensor, we have one in a Classic auto (with EDIS) and a 'prototype' on a P38 manual, with direct coil drive (thanks to @FridgeFreezer). The later Thor was never mated to a manual, so only has the flywheel for an autobox. You can mix and match, though manual flywheels for the later engines aren't that easy to find. Older flywheels don't have the timing teeth for the crank position sensor, which is why MS often uses a separate timing wheel.

Filip

Thanks Filip

I have a CPS on my Cosworth engine but it’s fitted to the crank pulley. Is this where the MS timing wheel is located on the V8?

[Bowie69]

It is cheaper if you get the original loom and modify, up to you really.

[FridgeFreezer]

48 minutes ago, Bigj66 said:

I have a CPS on my Cosworth engine but it’s fitted to the crank pulley. Is this where the MS timing wheel is located on the V8?

P38 has crank sensor on the flywheel, sensor is mounted opposite side to the starter motor. It also has a cam angle sensor in the front cover but MS doesn't need that.

There a couple of ways of doing the MS which I'll mention just to avoid confusion;

1. MS & Ford EDIS ignition module. This is/was an easy & robust way of doing the ignition bu the EDIS module MUST have a 36-1 toothed wheel for the crank sensor which means mounting a trigger wheel somewhere, usually the crank pulley. This system is what I run on both of mine.

2. MS with direct coil drive - 4 additional high-power transistors are soldered into the MS ECU and wired to spare outputs to drive coil packs directly. The MS reads the crank sensor itself so can handle any number of teeth / gaps / alignment. The drawback is full coil current (and back-EMF) going through the ECU which can cause issues if it's not done well. This method can re-use the standard P38 coils & sensor. This is what Escape is running. I did solder it for him on the understanding that I think it's not as good as #3 and any problems are of his own making

3. MS with ignitor-type coil packs - MS has 4x driver chips soldered in and drives (for example) Volkswagen coil packs which have the high-power transistor built in. This is the same as #2 but avoids big heavy current going through the ECU which is IMHO a nicer way of doing it. Lots of the MS crowd are using the VAG coils now I believe. I also believe Nige at Megasquirt V8 is moving to this method as EDIS modules get harder to find. I made a PCB which puts the ignition drivers on a plug-in board which makes life much neater so do ask if you're going this way

[Bigj66]

5 hours ago, Bowie69 said:

It is cheaper if you get the original loom and modify, up to you really.

Do you mean fit the MS ECU plug to the existing loom?

[FridgeFreezer]

5 hours ago, Bigj66 said:

Do you mean fit the MS ECU plug to the existing loom?

Yep - the engine end can stay mostly the same depending which exact route you go (option 1,2,3 from my last post) it's just the ECU end has a different plug and may swap or ignore a couple of things.