Timing the 3.5

Locky1978 · May 19, 2014

Hi All,
I just thought I would check on this. When I set up my timing to the standard 6 degrees btdc it's pretty gutless. I'm able to advance it up to 12 degrees before pinking. Does this sound right? I'm not using the pulley marks. I've marked tdc and I'm using my electronic timing light.

The only thing I could think is because it's a low compression I may be able to run more advance. Is this correct? Should I just advance it to pinking then back off slightly.

zen · May 20, 2014

yes..low comp designed for crap fuel,as using decent uk fuel will take more advance..

Locky1978 · May 21, 2014

Ok i'll stick with my 12 degrees then. Reason I asked was I bought a Shiney new electronic distributor at Beaulieu at the weekend so I'm going to have to do the timing again. I'm all for keeping things original and I've been running points for ages but I was offered the whole kit at a price I couldn't refuse.

norseman · May 21, 2014

You don't give the year of your safari, but pre '86 there was only 114 bhp with a lot of weight to pull. I recently posed the question of how did LR extract an extra 20 bhp from the 110's V8 after that date, but no-one seemed to know. The method of advancing the ignition until it pinks then backing off slightly always worked for mechanics prior to the days of timing lights.

chris200100 · May 21, 2014

You might find there are restrictors on the carbs that can be removed, I don't know if that's what made a 20bhp difference .

Locky1978 · May 21, 2014

Yeah mine has the restrictors fitted. I never really found out if they are restrictors or designed to give some turbulence to the air/ fuel mix. I always thought if they made them to restrict they would just reduce the bore size with the plate rather than having the toothed edge it has.
Oh and mines an 83

marccleave · May 21, 2014

I think the restrictor plate is quite thick and has four holes in it.

If the part you're on about looks similar to this:

Then I think you're correct in saying that they are there to put some turbulence to the air/fuel mix, mixes the air and fuel more and also prevents the fuel from dropping out of the air.

Taffv8 · May 21, 2014

I'm going to follow this thread with interest!
I've found my 90 quite lethargic compared to my old one so I advanced the timing a little & it is a lot better, but I cant slow the idle down now :scratching_chin:

zen · May 21, 2014

first thing you do with that restrictor plate is throw it into scrap pile!..both of them mind you..

Locky1978 · May 21, 2014

Yeah thats the ones. The toothy plates behind the spacey plates. My carb spacers are full bore like in the pic.
On a separate note I tried fitting my electronic distributor tonight. Omg what a hassle. It turns out the module on the side of the distributor hits the power steering pump bracket. I allowed an hour to fit the distributor. 2.5 hours later with the power steering pump sitting on the bench and brackets fabricated I'm ready to put it back together. Not to mention the trouble I had with the seized bolts in the water pump cover.

Taffv8 I've usually found if you can't get the idle down when you advance the timing its an air leak somewhere. Usually the throttle spindles in my experience. You should be able to get the idle low enough to stall it. Either that or you still have the poppet valves in the throttle plates which aren't shutting properly. Mine were leaking air past the throttle plate when I got it which gave the same symptom as yours. I fitted solid throttle plates when I rebuilt the carbs.

Taffv8 · May 24, 2014

Locky1978 said:
Yeah thats the ones. The toothy plates behind the spacey plates. My carb spacers are full bore like in the pic.
On a separate note I tried fitting my electronic distributor tonight. Omg what a hassle. It turns out the module on the side of the distributor hits the power steering pump bracket. I allowed an hour to fit the distributor. 2.5 hours later with the power steering pump sitting on the bench and brackets fabricated I'm ready to put it back together. Not to mention the trouble I had with the seized bolts in the water pump cover.

Taffv8 I've usually found if you can't get the idle down when you advance the timing its an air leak somewhere. Usually the throttle spindles in my experience. You should be able to get the idle low enough to stall it. Either that or you still have the poppet valves in the throttle plates which aren't shutting properly. Mine were leaking air past the throttle plate when I got it which gave the same symptom as yours. I fitted solid throttle plates when I rebuilt the carbs.

Thanks Locky,
I have sprayed carb cleaner around but couldn't find any air leaks,
I do have those poppet valves in the throttle plates, so I'll take a closer look at them

Locky1978 · May 24, 2014

You can solder those poppet valves shut. Or replace them for solid plates. The other thing you could check is that the throttle plates are actually centred correctly. Wind the idle screw right out and make sure the plates shut fully.
Then again if you go as far as taking the carbs off to check this I would be tempted to replace the throttle plates and spindle seals anyway. They aren't very expensive from Burlen.

Timing the 3.5

Locky1978

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zen

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Locky1978

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norseman

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chris200100

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Locky1978

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marccleave

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Taffv8

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zen

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Locky1978

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Taffv8

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Locky1978

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