Lead additive for Kent head?

[Steve L]

I have been driving an old (1989?) Kent engine for about 3 years now. Recently someone was shocked that I have not been adding a lead-substitute to the unleaded petrol that we have in Germany.

No one mentioned the need to me before.

Do I need this lead substitute?

Thanks in advance.

Steve

[pincher]

Hi mate, always put Millers lead substitute and octane boost in mine. Dont know it does anything though. Ian.

[Hammy]

there are a lot of posts on this subject, use the search.

Basically the exhaust valves will recess into the head over a period of miles as the valve seats are soft and  the lead prevents wear.

How much recessing depends on usage.  An additve may stop this and may also allow a more advantagous timing advance to be set without pinking.

keeping an eye on the exhaust valve clearance will tell you if the exhaust valve is sinking into the head as the gap will close up.

[Asterix]

Add it. I've done likewise since we lost lrp locally.

[amgas]

Use castrol valvemaster plus in my "other" classic car - has been tested by federation of Historic vehicle clubs so hopefully works ( plus I think Castrol would be unlikely to put name on anything that did not work too well ).

I believe if you have run an engine on leaded for years you could get away with unleaded for a while without too many problems ....

[Martin Keene]

My Xflow has been running on unleaded almost since they dropped 4 star for LRP, no signs of trouble yet. It was running on leaded for ~25 years before hand, so there will be a hell of a lot of lead in the head already.

Incidentally, if the worse does happen and the valves do start to recess. Then the cure is exactly the same as the prevention would have been. The difference being, if you wait until it *needs* doing then you get the interest on, or get to do something else with, the money while your waiting...

[blankczechbook]

is the 89 still a kent engine BTW.... or is it one of the HCS heads on an otherwise simialir block....

..is that the reg year of the car

what is the engine code 711M....... or what have you got in there??

[Steve L]

First of all, thanks for all the answers. A Ford expert (a professional Ford mechanic) was the one that told me I ought to be adding lead substitute. Apparently there is no way to tell if hardened seats have been installed without taking the head off. And for 80 Eurocent per tank fill, it seems like cheap insurance. I'll just do it until I have concrete proof that I don't need it.

As far as the engine type goes, I once copied all the information off the block that I could read:

Top front left side:

14H90AX

Below that:

8316 6015 R(?)34

Rear, left side:82038 782 084

The mechanic said to me, that's an "AX" you've got there. It's a good engine.

If anyone out there can add to that, I'd appreciate it.

The registration papers say that it has 1.6 litre displacement and 125 horsepower. (about 123 british horsepower). A couple of people told me that if the hp rating is correct that it *has* to be bored out to 1.7 litres. Again, I'm interested in your thoughts.

The engine has double Weber 40s and a "297°" camshaft (mentioned in another recent thread).

Yours,

Steve