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Triumph TR6 - Unleaded Fuel Mods

Hi Folks:

At the risk of being repetitive I'd like to ask a question I could not find an answer for in the Archives. Does a US spec 1976 TR6 need to be reconfigured to run properly on unleaded fuel or were they set up that way from the factory? I'm in the process of refitting a 45K '74 engine to my '76 - 6 as a temporary fix and plan to rebuild the original pretty much to spec with the exception of shaving the head about .030 thou and using some better quality after-market bits. No other power mods anticipated.

Bob E
76 - 6
Bob Evans

There is debate on wether you do or do not need to add lead substitute to our engines that are factory design/built to run on 94 octane leaded petrol. I personally add lead substitute to my fill ups. It may be the case that a head that was designed for leaded fuel and is subjected to uinleaded will show very little (nothing to worry about in our life time) valve seat recession.
In your case, since you are rebuilding an engine and doing a hair cut to the head, you may as well go the "lead head" route. I would think just upping the compression would say yes do the head to run on unleaded. You will be redoing the head anyways so go for the valve train parts that are designed for unleaded. It is a little more but you may as well.
Rick C
Rick Crawford

Thanks Rick. Definitely food for thought. It's only money!

Bob Evans

I'd say do the valve seats, but only take the minimum that you need to make it flat. Just me. They run hot enough.

This thread was discussed between 17/04/2005 and 19/04/2005

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