Jeff,
I rebuilt my TR4 engine to original spec except for 87MM pistons
and liners, Teflon valve guides, hardened seats and modern rear
seal. I used the stock TR4A cam fro BPNW. The engine came out
great.... strong and smooth.
I did experience a pronounced roughness above 3500 RPMs and
thought that the moving parts in the engine were off balance. I
also had the huge, heavy 4-blade TR fan. It had a knick in one
blade was not balanced by anyone.
I bought one of those "tropical" 6-blade fans on Ebay and
balanced it with bicycle wheel type balancer with new balance
weights from TRF. This was a pure speculation move... before
moving to no fan and an electric replacement. Well... It fixed
the problem completely.
The engine revs over 5000 without any vibration. I still think I
could improve the situation with one of those TR250 yellow
plastic fans... if I could get it to fit without hitting the
radiator.
Brian Sanborn
62 TR4 CT16260L - Groton, MA
My TR4 Restoration Web Site
http://www.net1plus.com/users/sanborn/Home.html
E-Mail: sanborn@net1plus.com
-----Original Message-----
From: owner-triumphs@autox.team.net
[mailto:owner-triumphs@autox.team.net]On Behalf Of Jeffrey J.
Barteet
Sent: Monday, August 21, 2000 12:36 PM
To: triumphs@autox.team.net
Subject: Making a TR 4 Rev Up
Hi, Folks,
So my new engine has accumulated around 1500 miles on it and I'm
exploring
the upper RPM limits a bit in second and third gear.
The crank, rods, pistons, pressure plate and flywheel were all
balanced. New AE 87mm pistons were used. The crank was turned
down .010",
and I had the cam reground by ISKY, and I have the TR 555 grind
which was
supposed to be a 'fast road' cam. It has 268 degrees of
duration. The
flywheel was lightened by a few pounds, but it still weighs a
country ton
with the old-style ( many little coil springs ) pressure plate.
It runs quite well and pulls like mad from 1800-4200 rpm. I have
an OD, so
I'm guessing I have the 4.10 rear end.
In my 20/20 hindsight, I would have done a couple of things
different, and
I probably will when it starts raining some time in December.
They are:
1) Shave the head to get the compression higher
2) Ditch the '4' flywheel and gone with a 4a flywheel or perhaps
even an
aluminum one with a 'modern' diaphragm-type pressure plate
So briefly, that's the drivetrain.
What I'm noticing is that the engine is quite smooth until you
get up to
around 4800-5000 RPM when a vibration sets in. I haven't tried
going past
5000. It feels unhealthy.
In that article recently posted
http://www.speakeasy.org/~mgendron/Kastner_TR4A.html ) by someone
on the
list about Kastner doing salt flats racing and drag racing, he
was pulling
six grand on his motors.
.....and Terry Ann Wakeman, who is also on the list, has a
hot-rod TR3
see her nice web site at:
http://www.cruzers.com/~twakeman/TR/index.html )
and I believe she has a harmonic balancing pulley on her car. I
seem to
recall her saying once that she shifts at 5700 on on-ramps.
I'm jealous.
So here are my fears, questions:
When I had the motor balanced, the machine shop guy got a little
beady-eyed
when I asked him if he had balanced the crank with the front fan
extension
on the crank. I'm wondering now if that's the problem? It's a
fair-sized
chunk of cast iron.
Or
Do these motors really need a balancing pulley to rev? Did
Kastner have these?
Or
It it just impossible to make them rev with a 35-40lb flywheel \
pressure
plate combo?
What steps should I take to make 'er rev?
Once again, I'd appreciate any first-hand experience from the
racers out
there.
-jeffrey
Jeffrey J. Barteet, System Administrator
National Center for Ecological Analysis and Synthesis
735 State St., Santa Barbara, CA
barteet@nceas.ucsb.edu 805.892.2508
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