Jim:
While I can't tell if it is a GT6 head just by looking, the GT6
heads are much
higher compression when installed on a TR6 short block. The reason is
that the GT is a shorter
stroke version of the motor, so in order to keep the compression ratio
decent the combustion
chambers were much smaller.
It isn't worth much extra money however, because shaving the
stock TR6 head will give you the exact
same result. They use the same casting, and it is simply machined a bit
more to deliver the smaller
chambers for the GT6.
Now, if it has larger valves than the later TR6 heads, that
WOULD be something to pay a bit more
for. Higher compression + larger valves would be a significant power
adder. I believe (not sure on
this point) that the valve sizes were the same, however.
The power potential on the GT6 long block is actually higher
than the TR6, because the shorter
stroke allows higher revs, and the valves are proportionately larger for
the GT6 because of the
smaller displacement. The TR6 motor, being under square (bore is smaller
than the stroke) has a more
limited power potential. The longer stroke will deliver more torque, but
limits the rev capability
all other things being equal. For street the TR motor is better, for
racing the GT motor is the
ticket.
Cheers,
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Jim Jones
Sent: Friday, August 20, 2004 12:48 PM
To: 6pack
Subject: GT6 head
Listers:
The seller for this GT6 head on Ebay says it's from a late model car and
is in demand by TR6 owners because it's a higher compression head. I'm
not planning on bidding on it, but I am curious as to whether this is
true. Like many things we see on Ebay, I am fairly leary of used motor
parts and the statements of the sellers.
Jim Jones
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=24876
56499&category=34202
Check out the new British Cars Forum:
http://www.team.net/the-local/tiki-view_forum.php?forumId=8
|