Has anyone got Bosch leads on a 3.5 & if so how good/bad are they?
Thanks in advance.

Cheers
Craig.

There was a thread on this recently where someone was having trouble with their leads (Top Guns). It turned into a conversation on what leads worked best and were most reliable. From memory the consensus was to stay with the factory leads. Do a search you should be able to pick the thread up.

Bosch or Mitsi leads seem to have less failures.

I've bought two sets of top guns as the first failed within 1000km, second set is going strong at 10 000km.....

I have used bosch for years

Used to use various silicone leads, had issues with them and ignition systems on the turbo rotaries.

The part number for the 3.0 and the 3.5 is the same, I have them on my TF right now.

You can either use bosch or NGK. Only thing is NGK are blue and I like the black ones

I also have Bosch on the V8, it had top gun when I got it, always played up on hot days, the leads fixed this immediately.

They are good.. I wanted them on my Pajero when i did the LPG conversion but they don make them for LPG & Petrol use.

So had to go with Crapgun..:)

What dont they make them for LPG use? I dont see why they would be any different. Maybe just because it doesnt have an "LPG" sticker on the box?

The only reason I could think is if it gave a crap/weak spark and hence wasnt good for LPG, but then they would be crap leads for petrol also. I need to change mine I think as sometime a cylinder has started to cut out on LPG, usually after idling for a while, and was going to go bosch from the consensus here. If anyone has any reasons why they wouldnt be good for LPG that I am not aware of please post up :P

Ollie

LPG tends to run hotter and the myth is that standard leads will break down.

To be hontest I have a few customers with LPG and they are using Bosch and have no issues

I have seen Bosch for LPG & for performance use in separate boxes but the leads look exactly the same even the writing on them.

Just use normal leads. As if LPG runs hotter, and as if teh leads would heat up more because of it. The only thing that heats up leads is radiant heat off teh engine and coil voltage. Coil voltage doesn't change, nor does radiant heat in an LPG engine.
If LPG ran so much hotter it ruined plug leads, teh cooling system would be a larger issue.
Seriously, there are some pretty bloody stupid and ignorant mechanics around these days.......
I have used the Bosch Super sport leads in everything I've owned, the ones with the spiral wound stainless core.

Regards, Andrew.

Just use normal leads. As if LPG runs hotter, and as if teh leads would heat up more because of it. The only thing that heats up leads is radiant heat off teh engine and coil voltage. Coil voltage doesn't change, nor does radiant heat in an LPG engine.
If LPG ran so much hotter it ruined plug leads, teh cooling system would be a larger issue.
Seriously, there are some pretty bloody stupid and ignorant mechanics around these days.......
I have used the Bosch Super sport leads in everything I've owned, the ones with the spiral wound stainless core.

Regards, Andrew.

Sorry for being so ignorant and stupid, I guess my 20 plus years of working on cars accounts for little.

The combustian temps on a LPG run car are higher, and the cooling systems on some cars do suffer. Fords are one example, AU faclons you need to ensure that you are not running too much coolant as the cores are very thin and the extra percentage of coolant can slow the flow. I have seen this happen, the fix was to simply use a thiner mix, (this was done by other stupid and ignorant mechanincs at Ford of a bulliten sent out by even more ignorant and more stupid engineers are ford!!!!)

As I stated above, I have used Bosch with no issues, some will recommend a more heat resistant lead as the engine bay temps do tend to be hotter on LPG due to more heat being disursed.

As if LPG runs hotterWrong (+1 to madmagna)

The reason why LPG-fuelled engines don't overheat is because the cooling system isn't designed with a 0% safety buffer (of sorts).

Just use normal leads. As if LPG runs hotter, and as if teh leads would heat up more because of it. The only thing that heats up leads is radiant heat off teh engine and coil voltage. Coil voltage doesn't change, nor does radiant heat in an LPG engine.
If LPG ran so much hotter it ruined plug leads, teh cooling system would be a larger issue.
Seriously, there are some pretty bloody stupid and ignorant mechanics around these days.......
I have used the Bosch Super sport leads in everything I've owned, the ones with the spiral wound stainless core.

Regards, Andrew.


Few quick points.

LPG is a dry fuel.
Petrol, is a wet fuel.

Petrol when entering a combustion chamber cools the engine.
LPG doesnt.

LPG engines do run hotter as LPG does not cool the combustion chamber.

Heat plays a part depending on the insulation thickness of course etc,but LPG also demands more from the igniton system than normal fuel as it requires a higher voltage to jump the gap of the plug as it is harder to ignite,so its more likely to cross fire,show up weaknesses etc,so a thicker jacket is the norm along with different core materials sometimes to maximise the effect

Also with the old vehicles (holden 253-308 etc),winding the static timing up and the tendancy to run camshafts with longer exhaust duration for lpg all added up to increased temps in the combustion chamber and the engine bay!,it certainly did on my car,and has been the cause of many a melted lead sets,so it can happen

Steve

Few quick points.

LPG is a dry fuel.
Petrol, is a wet fuel.

Petrol when entering a combustion chamber cools the engine.
LPG doesnt.

LPG engines do run hotter as LPG does not cool the combustion chamber.

Bull****. They have the same combustion temperature.
LPG is ingested into teh engine as an expanding/ just expanded gas. Look up aerosol, tell us what happens when you rapidly expand a gas. I'll give you a hint, it's the same principle that is used in air conditioning........
LPG and Petrol are both wet fuels, that is another dumb statement. LPG is stored as a liquid under presure then turned into a gas. Petrol is stored as a liquid and then atomised into a gas mixture, either by a carburettor or an injector. Whether a fuel is wet or not means nothing with regards combustion temperature or engine cooling. The temperature of the fuel and teh intake charge temperature are far more relevant.
DO some research before regurgitating the same pub rumours.

Regards, Andrew.

Bull****. They have the same combustion temperature.
LPG is ingested into teh engine as an expanding/ just expanded gas. Look up aerosol, tell us what happens when you rapidly expand a gas. I'll give you a hint, it's the same principle that is used in air conditioning........
LPG and Petrol are both wet fuels, that is another dumb statement. LPG is stored as a liquid under presure then turned into a gas. Petrol is stored as a liquid and then atomised into a gas mixture, either by a carburettor or an injector. Whether a fuel is wet or not means nothing with regards combustion temperature or engine cooling. The temperature of the fuel and teh intake charge temperature are far more relevant.
DO some research before regurgitating the same pub rumours.

Regards, Andrew.

Firstly, lol

No really, you made me laugh out loud (at your lack of knowledge on the subject)

Secondly, yes, LPG as it enters an engine expands, and the LPG itself cools......wait, hold on, we arnt talking direct injection as 99% of systems run a converter, which means this process happens some moments before the engine.....dont worry, your point is rather well, pointless. I know what happens when a gas expands, this has no bearing here. The gas expands and is mixed with air before the combustion chamber lol


LPG is a dry fuel, it has no lubricating properties either.

Anywho, here's some proof. Next time - how about YOU do some research. The first one is a crack up, its by Nulon......

http://www.nuloneurope.com/products.php?productId=LPG

"LP gas enters the combustion chamber as a completely dry fuel. As a result it burns very much hotter than does petrol, which enters the combustion chamber as air and fine droplets of petrol. The petrol droplets provide a cooling effect. The increased operating temperature in the upper cylinder area of an LP gas engine is extremely harsh on valves, valve seats, valve guides and top piston rings."

http://www.altfuels.org/backgrnd/altftype/lpg.html

"Because LPG enters the engine as a vapor, it doesn't wash oil off cylinder walls or dilute the oil when the engine is cold, and it also doesn't put carbon particles and sulfuric acid into the oil. Thus an engine that runs on propane can expect a longer service life and reduced maintenance costs. (Incoming liquid gasoline cools the combustion chamber and valves as it vaporizes, so you might expect, for example, that you'd need a valve job more often on an LPG-burning engine because the gaseous fuel doesn't give this cooling effect"

Wait...there's more......

http://www.uniquecarsandparts.com.au/LPG_Autogas.htm

"LPG Autogas is referred to as a dry fuel because there is no cooling effect on internal engine components due to vaporisation of the incoming fuel"

If we were talking about LIQUID injectino - then yea LPG would be injected in the manifold as a liquid - becmoe a gas causign the manifold to get icy cool - increasing performance - however it wil enter the combustino chamber as a gas and stil burn hotter - jsut increase performance because of the cooling effect on teh air in the intake manifold and density of the LPG. :)

HOWEVER NOONE has LIQUID injectino on a MAGNA (if you do please pm me i want to get it done but nowhere does it for magnas) - so the converter gets all the benefits of converting LPG to a gas - lol not the engine.

Petrol vapourises in the manifold cooling the intake air down -

Petrol also contains lubricants wihch LPG doenst - keeping the valve seats lubricated and help cool them down - however there are VALVE LUBE systems which most people use when using LPG to this isnt an issue anymore.

Agree with ERS on this one... N yea pretty ignorant ot ignore the fact that LPG does burn hotter - it also burns SLOWER causing more HEAT and less PUSH.

Hence, extractors tend to last ALOT less on LPG cars. thats why some warrrenties dont cover LPG wen run cars wen it coems to headers.

BTW my car ran fine too on standard leads - so i thought - increase mileage 50ksper tank wen i changed to BOSCH lpg compatible leads. Oh and it might help you people out there with LPG to use upper engine cleaner once a while coz of the GUNK that builds up with LPG use.- sorry off topic jsut a note.

there is a system moreys sell that drip feeds uppercylinder head lube (from memory) into the engine via carby or somewhere on the throttle body on injected cars, this seems like a good idea on a LPG to me, i want to fit one to my Diamante. About 460 here for the setup, pretty simple to fit. heres it is:
http://www.moreyoil.co.nz/product.php?catID=10cat=General