>From: Bob and Nancy <wises@mail.execpc.com>
>Reply-To: Bob and Nancy <wises@mail.execpc.com>
>To: triumphs@autox.team.net
>Subject: TR3A cam
>Date: Tue, 26 Sep 2000 19:32:29 -0500
>
>Once again I dip my bucket in to the well of the Triumph collected wisdom.
>
>My 1961 TR3A engine is in the shop getting a complete rebuild
>(balancing, 87 mm pistons and sleeves, rear crank oil seal, head
>rebuilt, etc). The old cam is shot, so I need to buy a new one. The
>shop owner tells me that unless I go for a wild racing cam, there are
>few ramifications of a "hot" cam on compression, carbs, valves,
>valve springs, and such. Given such latitude, what is the group's
>thinking about going with a little spicier cam? I don' t intend to
>push the car too hard when it is done, but I do have this one
>opportunity to tweak the engine a little. Any ideas?
>
>bob
>
>
>Carpe cervasium
I won't give advice... There are LOADS of folks who will... I WILL
give my observations on what I did. Many years ago when I was
redoing my TR4 for the first time I sent my old cam off to British
Parts Northwest for a "freshen up". It was just before Xmas and
about a week later, I got a call from BPNW asking me if I wanted
a "3/4 cam" for $7 more (Xmas special). "Go for it," says I ( my
vast mechanical experience to date had been changing sparkplugs on a
lawn mower and taking a TR4 completely apart). Any way when I got it
all together I must have done it right (I didn't have the dial
indicator to set TDC or a degree wheel to set the cam timing... I
got lucky). I found I had lots of power from 3200rpms to my self
imposed 4500 redline. Below hwere the cam really made the power
performance wasn't all that bad. Living with the semi-race cam was
my only option. At idle, it would be lopey. I couldn't get a
consistant idle at low rpms. Fuel economy was down but hell, it's a
toy car so who cares?
I liked to autox. Having the hot cam in effected how my car was
classed for competition. My local sports car club sort of over
looked the cam so I wouldn't get bumped in to a totally rediculous
class. Still, with the header they had to put me in DSP. Hell "D
Street Prepared" was a challenge enough... There was this guy with
Suzuki Sprint turbo who was always getting bumped into my class. Ya
know, it's REALLY embarassing to be running in the only true sports
car in the field and get the snot beat out of you by a Suzuki! Style
points don't count.
Anyway I the cam lasted about 11 years. When I rebuilt the engine
again several years ago I went to greater pains... I had the crank
and moving parts associated with it balanced, the flywheel was
lightened. I also switched out the stock tappets and got tappets and
sleeves from a Ford GT40. This time I opted for the "autocross cam"
from British Frame and Engine. This cam, while the specs seemed more
radical than the earlier 3/4 cam, gave me a better power band (from
about 2700 all the way to 5000). The cam is very tractible for the
street (its primary duty) and while I haven't yet autoxed the car
(the tranny needs some work) I have no qualms that I will run as
well as I did before.
The best part about dealing with BFE is you get Ken Gillanders who
is about as knowledgible on TRs as anyone in creation. He can direct
you to how to get the most from your TR3 and let you have the
greatest flexibility.
See? No advice... sort of...
Greg Petrolati Champaign, Illinois 1962 TR4 (CT4852L)
That's not a leak... My car's just marking its territory...
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