Distributorless ignition help.

TVRTASMIN · Post by **TVRTASMIN** » Sat Jun 30, 2012 9:54 pm

Hi everyone.
My be an obvious topic somewhere but cannot locate it at hte mo.

I'm looking at fitting a 4.6 into my Rover P6 and keeping the serpentine set up.
This would mean using a toothed wheel etc plus megajolt or similar.
I'm only interested in a basic no frills set up to use the existing coil pack if possible.
Any info greatly appreciated especially sourcing the right toothed wheel etc.

Ian

DaveEFI · Post by **DaveEFI** » Sun Jul 01, 2012 8:42 am

Obviously, with only a crank trigger, you're restricted to wasted spark.
Trigger Wheels and others do toothed wheels and VR sensor kits to fit the RV8. You might consider using a Megasquirt in ignition only mode rather than a Megajolt as it's not much more expensive. Gives you the option to fit injection at a later date.
Injection might be easier anyway in the long run - given you can't use a factory carb setup for the 4.6.

TVRTASMIN · Post by **TVRTASMIN** » Sun Jul 01, 2012 10:24 am

I have a weber 500 and intake manifold i've had for years but not got round to fitting, so would prefer the carb route.

Where is the best source for the Megasquirt/jolt units?

Cheers
Ian

DEVONMAN · Post by **DEVONMAN** » Sun Jul 01, 2012 10:45 am

TVRTASMIN wrote:I have a weber 500 and intake manifold i've had for years but not got round to fitting, so would prefer the carb route.

Where is the best source for the Megasquirt/jolt units?

Cheers
Ian

I'm currently looking at a 4.6 project and intend to keep the non dizzy front cover for space and better oil pump reasons.
The engine already has Holley TBI injection so I will be fitting a megajolt unit and trigger wheel.
So far I have found a trigger wheel that can be machined to fit on the back of the standard 4.6 pulley/damper.
The wheel is 7.25" dia (From Trigger wheels) and it will need a center hole machined in it 51mm dia. Once you remove the mud splash ring, the back of the pulley also needs a minor bit of machining to form a flat surface to bolt the trigger wheel against and a dished spacer will also be needed.
I will also need to fabricate a bracket to locate the sensor.

Regards Denis

DaveEFI · Post by **DaveEFI** » Sun Jul 01, 2012 11:18 am

Not knowing the later engines, I assume the original trigger is on the flywheel which is being changed for an older one?

DEVONMAN · Post by **DEVONMAN** » Sun Jul 01, 2012 1:46 pm

DaveEFI wrote:Not knowing the later engines, I assume the original trigger is on the flywheel which is being changed for an older one?

If he using the P6 gearbox, then I don't think the 4.6 flywheel or flex plate will easily fit in the belhousing.

The 4.6 manual flywheel is thicker, heavier and has a different clutch and they are harder to find.

The 4.6 auto flexplate is attached to the crank by an assortment of spacers and bosses and the torque converter is attached to a separate plate which makes the whole assembly too thick for the P6 bellhousing.

Regards Denis

SimpleSimon · Post by **SimpleSimon** » Sun Jul 01, 2012 4:50 pm

ETA

TVRTASMIN · Post by **TVRTASMIN** » Sun Jul 01, 2012 4:53 pm

I'm either going to fit the P6 autobox or convert to manual using an LT77 already recond.

I also prefer to use the engine in it's original guise with the better oil pump .
I've also a 3.9 engine i could fall back on.

Cheers
Ian

DEVONMAN · Post by **DEVONMAN** » Sun Jul 01, 2012 5:19 pm

Just to clarify, I thing the initial post was concerning a 4.6 with non dizzy cover and the proposal to fit a trigger wheel to the standard 4.6 pulley/damper.

SimpleSimon, why have you brought the 3.9/5.0 type serp pulley into the frame?
These pulleys are different and have six bolt hole to fit a trigger wheel to and the trigger wheel is available off the shelf.
I don't think an "off the shelf" bolt on trigger wheel is available for the 4.6 pulley as current demand is small.

The 4.6 pulley damper does not have the balance weights you mentioned.

Maybe I have misunderstood your post.

Regards Denis

SimpleSimon · Post by **SimpleSimon** » Sun Jul 01, 2012 5:23 pm

Corrected Denis

just trying to help misread the initial post info

DEVONMAN · Post by **DEVONMAN** » Sun Jul 01, 2012 7:12 pm

SimpleSimon wrote:Corrected Denis just trying to help misread the initial post info

No problem,
I was hoping maybe you have found a way of putting a 3.9 dizzy type pulley on a 4.6 and maintain the correct multi-v position.

Regards Denis

ChrisJC · Post by **ChrisJC** » Mon Jul 02, 2012 10:13 am

There was never a 4.6 manual from Land Rover, all the 4.6's were auto. There were 4.0 manuals though.

I used the GEMS pickup on the flywheel with MegaJolt. I alsu used the standard pickup. Saves a ton of faffing around with the crankshaft pulley.

One issue is the position of the 'missing tooth', in my case I just rotated the flex plate:

I am sure you can do something similar with a GEMS manual flywheel.

Note that the Thor engines used a 60-tooth pickup, and are therefore no good.

Chris.

Eliot · Post by **Eliot** » Mon Jul 02, 2012 12:36 pm

Fitting a trigger wheel on the front pulley of a P38 gems is pretty straightforward.
triggerwheels.com makes one that suits IIRC - i made my own up from bits i had laying around (pucka original 90's escort edis wheel)

http://www.mez.co.uk/p38-megasquirt.html

DEVONMAN · Post by **DEVONMAN** » Mon Jul 02, 2012 3:06 pm

ChrisJC wrote:There was never a 4.6 manual from Land Rover, all the 4.6's were auto. There were 4.0 manuals though.

I used the GEMS pickup on the flywheel with MegaJolt. I alsu used the standard pickup. Saves a ton of faffing around with the crankshaft pulley.

One issue is the position of the 'missing tooth', in my case I just rotated the flex plate:

I am sure you can do something similar with a GEMS manual flywheel.

Note that the Thor engines used a 60-tooth pickup, and are therefore no good.

Chris.

But will it all fit into a non 4wd Land Rover bellhousing such as the LT77 SD1 type or P5/P6 auto type bellhousing

Regards Denis

ChrisJC · Post by **ChrisJC** » Mon Jul 02, 2012 8:45 pm

DEVONMAN wrote: But will it all fit into a non 4wd Land Rover bellhousing such as the LT77 SD1 type or P5/P6 auto type bellhousing

Regards Denis

No idea, I don't know how much the flywheels etc vary.

But one could fix the toothed thing from the Land Rover flywheel onto the SD1 type flywheel.....

Chris.