Bruce Clough and Jack Brooks,
Thanks for the good info on the TR-3 bypass situation. I'm not going to
lose sleep over the fact that I blocked mine completely, but after reading
your well-reasoned replies I'm going to add a hole when I get around to it.
Sumner
> Bruce,
>
> Now you've got me worried. Some authorities (such as Bob Schaller in
"More
> BS About TR's") say to close off the bypass hose completely, and that's
> what I recently did. Is there a problem with that? Can it cause damage
to
> the engine? What's the collective wisdom of the listers?
>
> Sumner Weisman
> 62 TR-3B
>
Okay, here comes the debate. Some people suggest that a small passage be
maintained through the bypass for two reasons:
1. To let a little water circulate during warm-up to eliminate hot spots
caused by stagnant water.
2. To allow air to get out of the waterpump housing when filling the system
with coolant.
Bob thought the above was, in his words, "bullsh*t". He never had a
problem blocking it completely while living in Phoenix, so he reasoned that
nobody else would either. It was simpler blocking the hose completely
rather than providing a small path for water, so why bother!
Others, most notably Ken Gillanders, continue to believe that the bypass is
required for proper engine warm-up and continue to advocate skirted
thermostats (if you can find them) or reduced bypass flow with non-skirted
thermostats.
I have a functioning skirted thermostat, so the system is still "stock" in
our TR4. For several TR3s I've put together over the years I used a
restricted bypass simply because I had 1/4" fender washers that fit inside
the bypass hose perfectly. I've never totally blocked the bypass since the
original designers put it there for a purpose, and who am I to second-guess
them? Small flows through the bypass won't hurt (the skirt doesn't totally
block the bypass, there still is a little flow through the system when
warm).
Are you in trouble, naw, I don't think so. Go drive the car and have fun.
Of course, I have to add that the above in my opinion, and I'm not
telling/advocating/pushing anyone to do anything - yadda, yadda, yadda...
Bruce Clough
>Now you've got me worried. Some authorities (such as Bob Schaller in
"More
>BS About TR's") say to close off the bypass hose completely, and that's
>what I recently did. Is there a problem with that? Can it cause damage
to
>the engine? What's the collective wisdom of the listers?
Sumner,
I'd recommend a 1/4 inch hole in the restrictor, as you want some water
circulating through the engine when the thermostat is closed to prevent, or
minimize, localized overheating and boiling at the hot spots within the
engine, especially within the head.
I've considered putting a few small holes in the thermostat itself and
blocking the bypass, but whether this will work is purely conjecture on my
part. I haven't really thought it out well yet, but I think it may be the
best solution. It has the best of both worlds:
Thermostat open - no bypass flow at all, everything goes to the radiator,
Thermostat closed - minimal water flowing through the thermostat holes.
True, in really cold weather, the engine may have trouble heating up, but
how often do we take these cars out in really cold weather. I run mine
into the 40F's pretty regularly in the fall, but not much lower than that.
Although... New Years Day was my last ride last year and it was the low
20F's. ;-)
Later,
Jack Brooks
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