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Late GT6 Mk3

Alex Lowe

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HI all 

iv been using fuel additive in my late GT6 Mk3 registered 74 and have been considering having the valve seats hardened. I just read that these later cars had been adjusted for unleaded fuel for the american market is this also true for the British late Mk3s? If not is it worth having the seats hardened or just leaving it as i know of many people who do not bother with additive or harder seats

Thanks in advance guys

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I have a late Mk3, Feb 73, the last upgrade and no, it wasn't unleaded modified. I no longer bother with fuel additive, it turned my plugs pink :lol: so I couldn't see if I was running weak or rich. The received wisdom is leave it until you start to detect valve recession, don't do it until you have to. Your engine could run for 10s of 1000s of miles before it becomes necessary.


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I cant count how many thousands of miles i drove the rorty Vit6  1600   and many in my mk2000   with no recession or valve burning just using correct tappet cleaarances and

sainbugs 97ron fuel , the castings have high levels of lead memory from prior  years of leaded fuel burning 

i advocate dont buy must haves you dont need , buy fuel and drive them

any  chance of a head with exhaust inserts is probably ????   a  very late 1500  , dont think they were ever available on the 6cyl as a production fit.

(where's dave for some accurate history)


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5 hours ago, Colin Lindsay said:

Not on the GT6 anyway, and I doubt even for the USA market. By the time the last GT6 rolled off the line we were looking at the doomsday scenario of petrol running out!

Running out of petrol would have been an inconvenience,  instead we've had the actual doomsday scenario of petrol not running out.

For decades now I've single-handedly tried to use all of the remaining oil and petrol, to try and save the planet.😉


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