An interesting fact emerged many years ago from factory test papers on the
'breathing' properties of the six cylinder head. On the non-US TR's, as well
as the 2000 and 2500 saloons (with or without fuel injection) further
development took place on the gas-flowing and valve diameters. The outcome -
found on cylinder heads stamped 219015* and 219016* - was that reducing the
exhaust valve diameter from 32mm to 30mm gave greatly improved breathing. The
revised inlet tracts also created better air/fuel mix and vastly improved
'quench' to the extent that many on this side of the pond have been using this
head in preference to earlier versions. I've got a sneaky feeling that while
the two heads weren't fitted to TR's they did appear on US GT6. I've got all
the data I could scrounge on a spreadsheet if anyone's interested.
Jonmac
NB * You'll find these numbers stamped (NOT cast) on a flat plinth under the
valve gear between cylinders 2 and 3.
From: "glemon@neb.rr.com"
<glemon@neb.rr.com>
>To: triumphs@autox.team.net; Jonas Payne
<jagmog@hotmail.com>
>Sent: Friday, 6 September 2013, 4:01
>Subject: Re: [TR]
TR6 Cylinder Head
>
>
>You would get the most bang for the buck from shaving
the head 9.5/1 is usually considered a safe CR for a street car. A machine
shop guy told me a three angle grind was better for performance, but I always
thought it was more for longevity, will defer to other's opinions on that.
>
>Have definitely read that oversize valves are of no benefit unless you are
going racing or very major street mods.
>
>I would also smooth out the sharp
edges in the combustion chamber and match intake and exhaust ports and
manifolds. The Kastner competition prep manual goes into detail on this and
can be had on eBay and the various sources for $10 bucks or so.
>
>Greg
>
>---- Jonas Payne <jagmog@hotmail.com> wrote:
>> It would appear that I have
some bad seals/guides on my recently acquired
>> and running tr6 project.
>>
>> Looks like I'm going to have to pull the head and have some work done. Are
>> there any relatively low cost performance enhancements I should look into
>> while I have it off?
>>
>> 3 angle valve grind? Oversize valves?
Slight decking of the head to raise
>> CR?
>>
>> Jonas Payne
>> PBR
Consulting
>> 702-882-6711
>>
>> ** triumphs@autox.team.net **
>>
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