[Healeys] push rods too long

[Chris Dimmock]

Alan is 100% right.
The number one overheating issue in 100's is over skimmed blocks and heads.
The water galleries aren't vertical - they are angled. So every skim on either
surface moves the head gallery further away from the block gallery. And
skimming was the way to fit better/cheaper pistons and increase CR in the 50's
and 60's.
This was a well known issue 30 or more or so years ago, amoungst those who
raced 100's. Probably less well known today.
This is just another reason why plasticine and engineers blue are such
important tools in an engineers rebuild toolkit.
The number one issue in overheating 3000's is a tie. It's a tie between 2
issues,  between 50 year old blocks which haven't been cleaned, and huge
electric fans mounted on the "air" side of the radiator. Yep. Big electeic
fan. You can run in a parade all day, but you'll boil on a freeway at 100mph
in 20 minutes.
And not cleaning your block. Punch out a welch plug. Can you see between the
cylinders? No? How far below the welch plug can you stick a piece of wire?
It all boils (pun intended) down to what you use your car for.
Parade crawlers use huge big thermo fans ;-) (ducks empty thrown beer cans)
The rest of us who can do both clean our blocks, use modern core technology in
our radiators (with stock header tanks and frames) and use modern mechanical
plastic fans (e.g. Denis welch - where the whole bigger pulley starts off by
moving the fan mounting back 3/8 in or so from the rad)
Flame away. I'll idle beside you for an hour in a parade, and I'll run in
front of you for an hour in an Australian summer on a track at 100mph. My temp
won't go over 185 - 190. My thermostat controls my engine temp.
The only advantage of a thermo fan is when you stop. And I have a fix for
that. You restart the engine for a minute or so, to move the water.
A thermostat is the trade off for an engine running at the correct operating
temp. It's archaic, but works.
Best
Chris

On 10/08/2012, at 5:36 PM, Alan Seigrist <healey.nut at gmail.com>
> Just keep in mind then you start decking the 100 motor too much, the
> water ports don't line up properly and you can either get leaking or
> reduced coolant flow as a result.