Ahaaaaa, better engines...we all love 'em. Not sure if you are a
vintage racer or an EP guy but from some of the items I'm assuming it's
vintage. There are lots of vintage race groups, some have substantive
rules, others do not. I've been generally trying to abide by the SVRA
view of life. Frankly, I'd love to abide by the VSCCA view of the world
but since they dont believe that a TR of any kind is a legitimate
vintage race car it doesn't make much sense to even read thier rules.
whoops, back off the soap box before I fall and hurt myself.
>
> I've just picked up a spare TR4 block to build a better engine--as you
> may recall, my current one is a bit of a dog. All I've settled on so far
> is a big bore kit with Mahle pistons and Deeves rings. I _think_ it's an
> 87 mm kit--whatever's the largest you can do without modifying the
> block.
>
I'd recommend that you stay within the displacement rules and use the
87s. Some organizations will occationally test engine capacity and ask
for a change to those that are oversized or at least boost you out of
the class and put you in a group with cars so fast that you beg for your
little engine back.
> I'd like your sage advice for everything. Like what cam, what
> compression ratio, any tips on porting, bigger valves, what should I do
> with the crankshaft, etc.
>
Another note has commented on balancing, polishing etc. The RPM match
with the cam mentioned in a previous note is also appropriate with the
addition of compresion ratio as a player in that decison. Compressions
in the range of about 12:1 can be achieved thru trimming of the head.
Combustion chamber rework to unshroud the valves is also beneficial.
The old TR competition manual has a starting point. Larger valves is
another of those tricky areas of what can be done vs what is appropriate
in gentlemanly competion where we do not do engine tear downs based on
protests against very tight rules that spec such items.
We have stock size valves but have had to go to harder seats and valve
material to put up with the pounding associated with high lift/duration
cams and the high spring pressures that go with them.
Another note asked about roller rockers. They are illegal in SVRA
competition. Other groups may not care.
> I'm completely open on the subject. I do intend to use the webers
> (45DCOE) I have on the current engine--is that wise?
Well, opinions vary. Webers give you a lot of flexibilty if you know
what to do, which way to move and when to do it. In SVRA they also cost
you a class bump or two. Glen Efinger (my partner/mechanic) and I do
not feel that we have the collective intelligence to do the right thing
with Webers. We've got the some old SUs the car was sold with, some
internal mods and custom needles. The carbs only get touched for
cleaning and re-building as a general rule. There is nothing sweeter
than the sight of a competitor with his box of Weber jets out in his lap
on Sunday morning!
>I've also got a
> nice stainless steel header--looks good to me, and mallory dual point
> ignition--should I add electronics?
>
We went to a stainless header after the second mild steel one eventually
rusted and broke up (on a race weekend naturally). I suspect the
stainless will pay for itself in a couple of years. Have no experience
with aftermarket distributors to pass along, haven't done that one yet.
> I want to build as nasty a motor as I can, I'm tired of getting
> out-dragged in the straights by midgets.
Surprize, there will always be some one guy that doesn't care what it
costs to make his midget the fastest car on the planet. He'll out drag
you. Come to the south and his name will be Dr. Jim Roberts.
>
> One last thing--what's the story on rear hubs. I've had mine magnafluxed
> and they looked okay, but several days ago I saw the end result of a
> failure on a TR2 with a stock motor! Yikes. I welded my wheel studs
> in--am I asking for it? I used gas and let them cool in a sandbox. And
> what's the story about rear axles? I've got a Detroit locker in the rear
> end--shouldn't be as nasty as welding the diff, but it gives a hearty
> bump.
The whole rear axle story is still in the process of comming together.
One member of FOT has a line on custom axles but we're waiting until
Russ Moore has a chance to inspect an old SCCA car that has a full
floating axle setup and we look into reproducing it if it's better and
doable.
I've seen both TR3's that rolled this year with axle breakage, one has
been cut up and thrown away and the other is severly bent and awaiting
the start of major work. I'm just as interested in a mod as the next
guy but I want to make sure we do it once, the best way. I've chosen to
not use the new hubs just now. I believe they are so strong that they
agravate the axle breakage by having very little flex.
Welding wheel studs. Shouldn't do, or need to do this. Studs have a
knurl on them and a spec for the diameter of the hole that they pull
into. It'll hold them. We use 1/2 inch studs from Moroso (the drag
guys) and cut them down to a reasonable length. Gently pull them into
the hole with a good quality wheel lug nut and a wrench while holding
the hub in a vise. That way there is no bending force placed on the
hub.
>
whew, hope you didn't get tired of reading
> Mike Jackson
Want phone consultations? Call Glen Efinger 561-283-7700 - introduce
yourself and how you got his name. He knows 100 times more than this
and will share it all as long as you are willing to listen.
|