The V8 Owners Forum -

Hi folks

Engine swap is nearing completion. I had a 3.5 (knackered) and am going to a 3.9 from a Range Rover (it was on EFI, but I'm keeping it on carbs till the new cam is run in and then going to megasquirt).

I had to keep the new distributor as the oil pump drives were different. The old engine had a lumenition(?) ignition system. This new distributor has an amp on the side.

Can anyone advise what I need to do to get this wired up right?

I've seen the posts by Ramon such as at http://www.v8forum.co.uk/forum/viewtopi ... r+positive but I don't have the old connectors for whatever went on the new distributor amp so I'm kinda stuck a bit.

The old system is here:



New distributor is this type:


So, I'll be junking the amp in picture one (on the bulkhead) and running two wires from the coil to the module on the new distributor?

What's the wiring for the spade terminals on the new distributor? I believe coil+ to one and coil- to the other - but which is which?

Thanks for any help.

A

The one on the left in the photo is the -ve and the one on the right is the +ve.
Regards Denis

Thanks a lot !

So, am I right in thinking I can disconnect the amp on the bulkhead from the coil, and wire as you describe (from coil to new-amp) and it should just work?

Do I need any particularly hefty wire for that or is there not a lot of power coming down there? Anything else to worry about, cross-talk or interference etc?

Thanks

No hefty wires needed. No crosstalk to worry about.
Only worry is that these amps get hot due to the location and later models have a remote amp on a heatsink to improve the sitation.
However, I've not had any problems myself but always carry a spare amp.
regards Denis

DEVONMAN wrote:No hefty wires needed. No crosstalk to worry about.
Only worry is that these amps get hot due to the location and later models have a remote amp on a heatsink to improve the sitation.
However, I've not had any problems myself but always carry a spare amp.
regards Denis

Yup - I've had two fail in about 100,000 miles so it is worth carrying a spare given how little room they take. It's actually the only total breakdown I've had on my SD1 - apart from a seized water pump.

I didn't know there was a later version - earlier SD1s had a remote amp mounted beside the coil. But that is no better.

You also need to make sure you've got the right coil for that ignition amplifier. The amp will potentially toast the wrong type of coil (not immediately, but I toasted about 4 before I realised I was being supplied the wrong one!)

Chris.

Chris.
Good point about the coil. a points type coil or one that normally has a ballast resistor will deffo not suit.

Dave. I'm not sure at what date they mounted the ign amp on the heatsink but I had a 1995 3.9 which was like that and my mates 2001 TVR Chimera also has the amp on a heatsink. These have 3 connections instead of 2 but the centre connections is just an earth.

Regards Denis

Thanks for that, guys.

Bit worrying on the coil front then. Given that it's a lumenition at the moment with optical sensor in the distributor (so not points), do you think that sounds like the coil is suitable? I don't see a ballast resistor anywhere (though not entirely sure what one would look like...)

Failing that, I guess I just go and ask for another coil, suitable for a J-reg Range Rover...

lansalot wrote:Thanks for that, guys.

Bit worrying on the coil front then. Given that it's a lumenition at the moment with optical sensor in the distributor (so not points), do you think that sounds like the coil is suitable? I don't see a ballast resistor anywhere (though not entirely sure what one would look like...)

Failing that, I guess I just go and ask for another coil, suitable for a J-reg Range Rover...

Safe bet is to get the correct coil to match the dizzy.

Regards Denis

OK, will do. The less head-scratching I have to do when I turn the key, the better

Thanks for all the advice folks, I dare say I'll be back when it's not running

Oh - that reminds me - the old engine had a crankcase vent hose at the rear. It also had flame-traps going rocker-cover to carbs.

The port is blocked off on this engine and it appears I have a flame trap (big cylinder) on the left bank, and a little moon-shaped disc at the rear of the new one. I'll try and get a photo of it later. I hope it's OK breathing-wise with this arrangement? I don't have

I was thinking of using the old rocker-covers and keeping the existing flame-trap arrangement. However, I'm wondering where the ventiliation will come from, given the port is blocked off, if I do ?

New engine, flame-trap @ cyl 2.



(Ignore all the EFI wiring hanging about the place..)[/img]

A hose from the can (flametrap) near cylinder no 2 into the back of the air cleaner will do till you get the MS. If the engine is a high mileage unit then under wot throttle conditions you may get some fumes under the bonnet from the little moon shaped filter which nornally acts as a controlled vent inlet to the crankcase.

OR you could take the pipe from the can via a tee piece to the original breather points on the carbs.

Regards Denis

OK, carried on sticking it all back together today. Eventually spun it over to see if I had oil-pressure - light didn't go out, but as engine didn't start perhaps no wonder.

Only thing is, I haven't wired that amplifier yet. I tested the two poles on the coil and found one around 10.x volts, the other was around 1v I think.

Do I just wire the 10v one to the positive on the distributor amp, and the 1v one to the negative on the amp? Or do I wire the amp negative direct to earth? I got some of the old wiring loom off the donor, and it appears that perhaps the positive was actually coming from the alternator...

It didn't even sound remotely like it was going to fire, incidentally....

lansalot wrote:OK, carried on sticking it all back together today. Eventually spun it over to see if I had oil-pressure - light didn't go out, but as engine didn't start perhaps no wonder.

Only thing is, I haven't wired that amplifier yet. I tested the two poles on the coil and found one around 10.x volts, the other was around 1v I think.

Do I just wire the 10v one to the positive on the distributor amp, and the 1v one to the negative on the amp? Or do I wire the amp negative direct to earth? I got some of the old wiring loom off the donor, and it appears that perhaps the positive was actually coming from the alternator...

It didn't even sound remotely like it was going to fire, incidentally....

Taking your last comment first, Without the amp connected it will not sound like it's going to fire.
The coil should have + & - signs next to the terminals.
Positive to positive on amp and negative to negative on the amp. The negative dosen't go to earth.
The feed to the coil should be from the ignition switch not the alternator.
Regards Denis

Thanks Denis

I can't see marks on the bulkhead coil, but the donor coil says -1v and 15v written on it. I measured the bulkhead coil on it (ignition on) and obviously not running it showed around 10 and 1v on each pole.

Does that help? Many thanks for all your help

To put it another way, if I wire it back to front will it kill it?