Thread: cutting down on valve burning

Originally Posted by hesguitar

We've got the 2.6l 6 and from what I hear it would be fair to assume future issues with burning exhaust valves- which got me thinking, the cylinder head re-conditioner we use at work taps into a coolant passage at the rear of falcon 6 heads (that tend to warp around cyl 5) allowing coolant to flow faster to reduce captivation and keeping the rear of the head cooler.

Has this method been tried before on land rover heads? If the head was already off to replace the valves and a blueprint was available it's a pretty easy modification.

The Falcon mod is to reduce head gasket failure and head cracking. I think I've only seen one single burnt exhaust valve on a Falcon alloy head in 20 years. Tons of cracked heads though.

You are better off running Flashlube in a drip feeder or with your petrol.

its the #5+6 exhaust valves your trying to save and in the long term no there is nothing you can do to save them
running a touch rich and on qood quality leaded fuel helps.

They are completely different heads but they both have a problem with heat, i just thought something similar might help with cooling the land rover head.

Any issues with carbon build up on the valves with the flash lube? I've got one fitted and was wondering about that too, never had a car with a drip system before

Originally Posted by hesguitar

They are completely different heads but they both have a problem with heat, i just thought something similar might help with cooling the land rover head.

Any issues with carbon build up on the valves with the flash lube? I've got one fitted and was wondering about that too, never had a car with a drip system before

Temperature of the head isn't the problem as such. It is more a lack of lube at the valve faces causing poor contact at the valve seat and the overheating of the valve head edge. Regular tappet adjustment is also very important as it maintains valve closing for longer.

I have seen a badly adjusted Morey's set-up cause inlet valve failure on a Holden 308 with massive carbon deposits. But then the owner was a dip stick. He just kept pouring the Moreys in instead of adjusting it down.

So far I haven't seen that kind of damage with Flashlube. It should be checked regularly to use about 1ml of Flashlube per litre of fuel. It isn't hard to check with the sight glass on the dripper.

G'day Hesguitar

The 2.6 Litre 6 cyl IOE motor was originally from the Rover sedan which had a vastly longer engine compartment,when this motor was shoe-horned into what was basicaly the 4 cylinder hole,they had to modify the firewall backwards to fit the motor, so, the rear 2 cylinders get starved for cooling air, that, with the difficulty in adjusting the rear exhaust valves lead to them being to tight and burning,set the Exvalves at .002 more than specified,that will help, these motors were designed to run on leaded fuel so ULP is unkind to them, use a lead replacement treatment.

Note: the rear head studs are hard to tighten to the correct tension when in the vehicle without a "crowsfoot" spanner,this under-tension can lead to oil and water leaks at the back of the head

When set up and tuned correctly these are a smooth motor BUT thirsty. lots of torque at low revs


cheers

I just did a valve adjustment on one of these engines yesterday afternoon. I had no trouble getting to numbers five and six exhaust valves. They were correctly adjusted, but I added .002" to try and extend valve life. There is a slight pop in the exhaust, so I suspect that it may have had tight clearances in the past. I will now conduct a compression test to find out if it has a burnt valve. I will also apply compressed air into the spark plug hole and listen at the exhaust pipe for escaping air.

Aaron.

G'day Aaron 11A

It may well be worth investing in a compression tester, reasonable qualityones can be purchased at places like Repco etc. they usually have a selection of plug thread heads, i have had mine for about 20 years, remove plugs, place in selected hole turn motor over about 4-6 times and it will give the mean compression reading for that cylinder, or turn over as before but wait until the selected cylinder has compression, then while stopped in that position any drop in pressure will indicate poor seating valves


Hope that is of help


cheers

That is exactly what I would normally do, except my compression tester was in my shed, while I was on the other side of town. If a low reading is found, I will then do the compressed air trick, while listening at each manifold to determine if it is head gasket or valves. This check is redundant, as if the compression check shows a fault the head has to come off anyway.

Aaron.