a Wallace wrote:
>
> 1. Was the original head gasket copper both sides, yet a laminated
> type?
I believe so, but so are almost all replacement gaskets.
> Just wondering how to tell if this engine has been rebuilt before (the
> car
> was registered in 62, and has been sitting since 70, with 50,000 on
> the
> clock, which could be real...kind of rusty though).
Check out the pistons, the original 83mm pistons look pretty funky (to
me anyway). The skirt on one side has a large T-shaped slot, the other
side has a horizontal slot. The bottom edge of the skirt has a ledge.
Of course, these were available as replacements, but all the other
replacements I've seen don't have the expansion slots or the ledge.
> 2. In several places the coolant holes in the head gasket seem like
> they
> are much smaller, or even slightly in the wrong place, compared to the
> holes in the block. The most obvious example is the two holes just
> inside
> the front two head bolts, which partly cover the coolant passageways
> in the
> block.
> a) Is this the way it's supposed to be?
Yes.
> b) Would there be a benefit to having those holes enlarged in the
> (next)
> head gasket, or were they actually trying to restrict the flow this
> way?
I'm not certain, but I wouldn't want to mess with it. The balance of
water flow is important, in particular the front passages have to be
somewhat restricted to ensure the rear passages get enough flow. And,
although these engines do frequently suffer overheating problems,
insufficient flow does not seem to be an ingredient. IMO They get the
heat to the radiator fine, the problem is getting rid of the heat from
the radiator.
> c) Are the holes in those solid copper replacement gaskets the same as
> original?
Yes, unless you either special order them different (Mordy will make
almost anything you want) or modify them yourself.
> 3. Now I have the struggle of deciding how far to go with the rebuild.
> So
> far it looks like the cylinders are good; there's no scoring or
> anything,
> but it is 83mm....
> a) should I replace the pushrods with the hollow ones I've heard of?
Depends on your planned usage, and what pushrods it already has. If you
have the 5/16" ones, I'd replace them unless it's to be a trailer
queen. If you have the 3/8", I'd only replace them if you plan to drive
a lot, and have a lead foot. (I replaced mine <g>)
> b) how can I tell if the valve springs are up to snuff? I guess I
> could put
> a weight on them and measure the change in height - anyone know the
> spring
> rates for the 5 springs involved?
The service manual gives the following figures :
Outer spring :
Fitted length 1.560"
Fitted load 38 lbs
Free length 1.980"
Inner spring, inlet :
Fitted length 1.500"
Fitted load 33 lbs
Free length 2.080"
Inner spring, exhaust :
Fitted length 1.450"
Fitted load 36.5 lbs
Free length 2.080"
Auxilliary inner spring, exhaust only :
Fitted length 1.140"
Fitted load 10 lbs
Free length 1.540"
> c) unless they seem really perfect, I think I will replace the valve
> guides
> - are the upgrades bronze, or some other alloy, and what's the good
> source
> - BPNW?
Uprades are silicon-bronze, got mine from BFE. Note that the
silicon-bronze guides have to be reamed after installation, and require
somewhat more clearance than the original cast iron guides. If you are
looking for a little more performance, consider replacing the exhaust
valves with the 5/16" stem ones used on TR4A. There is a special
upgrade valve guide for this.
> 4. There are all kinds of things I could do of course, but I have to
> hold
> the (fiscal) line to some extent. What I really want is long-term
> reliability, even ruggedness, out of the engine. I would therefore
> appreciate a bit of guidance on where to direct my money - for
> example, if
> all is well with my 83mm pistons and liners I may not spend the $ to
> automatically move up to 87mm, if the same money could be invested in
> such
> a way that I could have enough confidence to take the car on a very
> long trip.
IMO these engines are already incredibly rugged, especially if you don't
try to get more power out of them. Cooling is really the only area that
needs improvement, I recommend an electric fan. (An alternator to power
it isn't a bad idea either <g>) Paper element air filters will add to
the longevity, and, along with adhering to the recommended maintenance
intervals (including changing the rod bearings every 30K miles), result
in a motor that will run 100K miles or more.
Somewhere, I've got an article on a modification to the oil pump pickup
screen which IMO is also a good idea. I think it was in Tech Talk #2
from TRSC, but I don't have my copy handy to check. It might be on
their web site at http://englishcars.com/trsc/ . The only time I've
ever had to walk away from my TR3 in over 20 years of daily driving was
when the oil pump sucked a bit of swarf (from a foolishly reused lock
tab) through a broken screen. Broke the pump driveshaft : no oil
pressure. The mod is basically to tie the body of the screen to the
pickup tube with copper wire, so that the screen wires do not flex and
break where they exit the solder joint to the tube.
Shameless plug : The entire Tech Talk series (currently 3 volumes @
$15/ea) is worth owning if you have a TR2-4A. (TR250 and 6 owners won't
be interested in Vol 1.) The one tip mentioned above would have saved
me far more than the purchase price. Proceeds benefit the Triumph
Register of Southern California (of which I am a member).
I'm driving to VTR (roughly 1200 miles each way, plus about 300 for
taking the scenic route to Portland) and I honestly do not expect any
trouble from the engine.
Randall
59 TR3A daily driver
|