Rover distributor amplifier

hirot · March 10, 2013, 01:39:13 PM

Hi, my baby started first time, an unknown engine with a complete rebuild and a 35DLM8 distributor that that was a complete mess originally. I was stunned....However, and there always seems to be a however, it only ran 5 short times before the brand new Amplifier Module failed. The car had no bonnet and there was a healthy cold breeze blowing through my garage.

I had expected the Amplifier to fail as they are affected by heat (so I had read), but I had hoped at least to have driven the car and for a few thousand miles.

So as I see it I can either : 1. just by in a lot of spare Amplifiers. 2. change to the 35DM8 Remote Amplifier 3. change to a different electronic gizmo. or 4. go to a Mallory points system.

Option 2 is my first choice as it it the second cheapest. Does anyone know if it is a straight fit onto the 35DLM8 or do I have to make wires and plugs or even get the 35DM8 base plate.

Option 3 is looks ok but I have no idea which is the better electronic system and I want to stick with the 35DLM8 as the base ditributor and would prefer to use its magnetic pulse system.

Option4 is expensive, although I had read that someone had had an intermittent problem with one and then returned to electronic.

I like the idea of real points as at least you can tell what is wrong when they fail.

Any help will be gratefuly recieved.

Regards Ian

BlownMGB-V8 · March 10, 2013, 08:12:00 PM

I vote for option 1 ;-)

No really, how about a Pertronics module?

Jim

WedgeWorks1 · March 10, 2013, 09:30:45 PM

I would look into Petronics and stay away from the Mallory dual points.

Moderator · March 10, 2013, 10:41:08 PM

I'm not knowledgeable about the differences between amplifiers. For that sort of question, I contact Jeff Schlemmer at "Advanced Distributors". You'll find him to be extremely helpful.

Pertronix Ignitor systems are extremely popular in North America, but I believe most UK users choose Lumenition instead. Those two options should be fairly comparable.

hirot · March 13, 2013, 10:52:07 AM

Thanks for the feedback. Looks like it will be a Petronix and I will keep the Rover Amplifier just in case.

Simon Austin · March 13, 2013, 09:29:01 PM

Ian,

What make of amplifier did you have? Reason I ask is I had a brand-new aftermarket amp fail after about 600 kms on my RV8 (same set-up you have). I switched to a Lucas unit and although a good unit, there was still some minor running issues to deal with.

I installed the remote ignition module kit which uses a Rover amp. This has proven to be the best one yet.

You do get what you pay for especially with ignition amps.

hirot · March 16, 2013, 08:01:25 AM

Simon, I assume it was an aftermarket amp as it did not have Lucas written on it....and it only cost £24. It can't have been the heat as there was no bonnet, the doors were wide open and it was blowing a hooley.

I looked into buying the remote one but again didn't know where it would have been made, so I have gone for a Petronix and a spare aftermarket Rover and a very old (1995 at least) genuine Rover amplifier. The second aftermarket one, which was to be my spare, gave a great spark compared to the old Rover amplifier. I got my aftermarket from Rimmers and I believe that Clive Weatleys are the proper ones.

On my previous Roadster I took out the Lumination ignition as it occasionaly misfired and put back points which I changed every 2000 miles or less. On removing the Lumination I found that the previous owner had knicked the wire in the distributer which shorted occasionaly, hence the misfire.

As you rightly say you get what you pay for and it pays to be careful.

Regards Ian

Simon Austin · March 25, 2013, 03:29:01 AM

I'd agree Clive's modules would be Rover units. Can't imagine him selling anything else.

hirot · March 26, 2013, 04:27:22 AM

Simon, as I am struggling to get correct Petronix unit I may go the same route you have.

You sent me the jet and metering sizes that you changed to. Was this for your RV8 or your V8 and is the V8 a 3500 or larger ?

Simon Austin · March 27, 2013, 12:20:03 PM

The jets and needles are for the V8, Ian. It has a 1980 SD1 3.5 with the Edelbrock 500 carb.

The RV8 uses the14CUX FI system on a 3.9.

hirot · March 30, 2013, 06:37:37 AM

Simon, many thanks. I have a 1995 3947 and the 500 carb and will buy the .083 and the .080 and try them both.

DiDueColpi · April 05, 2013, 04:01:15 AM

Hey Ian,
not sure how common it is in the UK. But over here, one of the cheapest options for a magnetically triggered module is the old GM HEI unit.
Mounted to a suitable heat sink, it will fire most hi or low impedance coils very reliably.
They are small, cheap, reliable and tolerate abuse well.
Lots of upgraged designs are also available if a hotter ignition is wanted, but the stock setup will fire just about anything that you can think up.
Hope that's helpful.
Cheers
Fred

hirot · April 10, 2013, 03:57:51 AM

Fred, many thanks for the info. I have just got the right Petronix kit. They sent me the wrong one twice.
I will keep your suggestion in mind if this kit is as successful as my last option.

My problem now is that I am going to fix something that is not broken....yet

hirot · April 11, 2013, 03:21:19 PM

I fixed what wasn't broke and it broke. Having carefully dismantled my Lucas 35dlm8 distributor I fitted the Petronix....and it ran like a dog missing and spluttering and stopping. It ran as though I swapped 2 or 4 leads. I turned the distributor in retard and advance and nothing changed. Checked everything and nothing got better. So I reverted to the original Lucas amplifier and without touching anything else baby just started and ran beautifully.
Clearly I have done something wrong but I have no idea what. Either the spark was too weak or at the wrong time.

Any suggestions will be very gratefully received.

Disappointed and disallusioned of Ashbourne.

DiDueColpi · April 11, 2013, 04:33:39 PM

Dear disappointed in Ashbourne,
sometimes women are just like that.
What you need to do is..........................OOPS!.......... Responding to the wrong thing.

Most likely the Pertronics pickup is out of phase with the distributor cap. This causes it to fire between cylinders.
The most common cause is getting the magnetic ring that fits onto the distributor shaft turned to one side or the other.
The other is having the wrong kit.
An easy way to tell is to check your current timing and then reinstall the pertroics without moving the distributor.
Re check the timing. If it changes by more than a couple of degrees then you will have a phasing issue.
The hard way but most accurate and visual, is to drill a large hole in the distributor cap so that you can see any one of the plug terminals.
Run the engine, you should be able to see the spark going directly to the terminal from the rotor tip. If it doesn't you need to do some re aligning.
If your kit doesn't use the magnetic ring (new style) then the clearance to the pickup becomes critical and can cause problems as well.
Hope that's helpful
Cheers
Fred

hirot · April 12, 2013, 04:39:29 AM

Fred, again many thanks.
I will carefully strip the distributor, again, and re-instal the Petronix making sure the magnetic/black ring is correctly aligned with its locating teeth.

The kit came with two rings the second was a spacer ring which I originally fitted, as per the instructions, but it caused the magnetic ring to foul the rotor arm. Maybe it requires the spacer ring and I had not seated them both correctly, which would give a vertical alignment problem and maybe not give a good enough impulse.

The other thing I noticed was that the rev counter seemed to wildly under read.

I suppose the good news is that I am getting quite good at stripping distributors and getting top dead centre.

Regards Ian

DiDueColpi · April 12, 2013, 10:54:04 AM

Just another thought based upon the tach reading low.
Possibly you have a magnetic ring for a 4 cyl.
Get a thin steel rod (small screwdriver etc.) and check the ring.
You should be able to detect 8 distinct magnets around it's circumference.
Cheers
Fred

hirot · May 05, 2013, 01:33:17 PM

Fred gave up on the Petronix as I was in danger of wrecking my Lucas bits which a t the moment work OK. I will however look into the GM option plus I read somewhere that there is a similar Bosch unit.

I think as I have a new spare Lucas module I will continue to run as is until it goes wrong again. At least I can swap the Lucas bits in a few minutes.

Any suggestion as to what spark plug gaps should be. Engine is a 3947 running an Edelbrock 500 which I have jetted down and now gives all 8 plugs the same nice pale brown/grey colour.

Regards Ian

DiDueColpi · May 06, 2013, 02:16:48 PM

With a carb and the stock ign. I would run somewhere around .028" to .030" plug gap.
The spec for the FI. engine is .033-.038" but with a carb and the stock setup you will probably run into cold start problems at this size gap.
Plus the small gap is a little less stressful on the ign. system.
Cheers
Fred

hirot · May 07, 2013, 09:48:16 AM

Fred, again many thanks. I had guessed that my plug gap was a little too wide as they came at 35 thou which I suspect suits a better ignition system and EFI. So I will go down to 30thou and see what happens.

Reason for my question was that I seem to sorted out the carb jets in that I have reasonable plug colours and all 8 look the same, however, at low revs I get a slight hunting and very occasionally it runs on for 1-2 seconds which is why I looked at my plugs and whether they were to hot a plug.

When you have a non standard set up information is hard to find. But it is fun sorting it out.

Regards Ian

DiDueColpi · May 07, 2013, 06:37:10 PM

Re the "hunting" Ian. You may have the wrong springs in your carb. If they are too strong they lift the metering rods at part throttle and cause a surge. One way to find out is just take them out and run the car without them. Don't drive the car hard this way as you now won't have any enrichment. If the surge goes away then the springs are too strong and need to be replaced with a lighter set.
If the surge persists it could be the vacuum advance or just a lack of adequate timing. Disconnect the vacuum and set the total timing to 36 BTDC and see what happens.
Keep us in the loop and we'll go from there.
Cheers
Fred

hirot · May 08, 2013, 12:40:24 PM

Fred, thats along the lines I was starting to wander. I was thinking that at low revs I may just be switching from idle to primary so what you suggest sounds like a good idea.

I am first going to change my primary jet back to .086 and use the 1463 rod which puts me at 1st stage lean power/cruise. I currently have .083 and 1423 which puts me leaner on ist part of needle and then slightly richer on the second part of the needle.

If that has no effect I will try the spring thing. Stock spring is orange so I guess I will try a yellow. However, I will have to buy some springs first so I hope the jet/rod works.

The vacuum pipe is an easy test.

Its only a minor surge but its irritating when you are trying to drive in slow traffic.

Again many thanks.

Ian

hirot · May 16, 2013, 11:51:20 AM

Fred, sorted it and she's running real smooth. I was running with jet/rod which was a little too lean on the first stage of the needle and too rich on the second stage. Ran it then reset the idle mixtures. No more hunting/surging and she will cruise in 4th/5th at 30mph.

So, I am now running with .086 primaries and secondaries and using a #1463 (.067*.055) needle.

So all I need now is sunshine.

Cheers Ian

DiDueColpi · May 17, 2013, 02:33:47 AM

Good to hear Ian,
These carbs can be tuned to run fantastically well.
It just takes a clear head and some time.
As for the sunshine, I would send you some if I could.
Here on the west coast of Canada we are having some amazing weather this year.
Had some 30'c days already this year.
Cheers
Fred

hirot · May 18, 2013, 05:14:05 AM

Fred....and finally....gave up on the Petronix as it just wouldn't work and settled for the original Lucas amplifier module which has been superseeded by part no:- DAB118 and only costs around £25. I looked at making a remote unit as all the official one seems to be is a dummy unit to fasten on the side of the distributor, which gives a wiring connection, and an aluminium bracket where the original amplifier is fastened and connected by thin wires to the dummy unit.

Making a good and secure connection to the distributor is not easy. The irony is I should have kept one of my failed amplifiers....I had three fail one of which did't work out of the box....stripped it down and used it as a dummy wiring connection to the distributor. It seems a bit of a waste of money now to buy one and break it.

30 degrees now that seems a little greedy people over here would pay to get it up and over 20 degrees at the moment.

Cheers Ian