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Re: Cold Starting

To: YeOldEd@aol.com
Subject: Re: Cold Starting
From: "Robert M. Lang" <lang@isis.mit.edu>
Date: Wed, 9 Oct 2002 10:59:54 -0400 (EDT)
On Tue, 8 Oct 2002 YeOldEd@aol.com wrote:

> Hi Listers!

Howdy.
 
> It occured to me that it might be a good idea to "pre-oil" the engine before 
> starting when you don't use the car as a daily driver.

Sounds like a good idea...

> For the periodic or occasional driver, would it make sense to pull a wire off 
> the coil and crank the engine for about 20 or 30 seconds before firing it up 
> for real? Might this help our notorious top ends? When I tried this, I 
> indicated about 85psi.
> 
> Any thoughts?

...however, grinding the engine over on the starter is not going to get
the oil to where you need it most - to the cam - when the motor is cold.
Most of the oiling to the cam  on the TR6 is done through "splash", and a
lot of the oil to the cam is flung onto the cam from the crankshaft. So,
turning the motor over on the starter is probably not going to spin the
motor fast enough to sling the oil onto the cam to do any good.

As far as getting oil to the top end of the motor... as soon as you get
oil pressure (actually, there is a small delay of a second or two), you'll
get oil to the rockers. But - if you use good quality motor oil, the
rockers can run without doing much damage because some oil will cling to
the parts and provide at least some protection while the system is
starting up.

If you really want to pre-oil your engine, you have two choices. Choice
one is to use the engine oil pump to prime the engine. Note: this only
primes the main bearings, the cam saddles and the rocker shaft - NOT the
cam itself... To do this, pull the distributor and the dizzy pedestal.
Yank out the distributor drive gear. Make a tool that can engage the oil
pump drive. The tool should fit in a standard drill. Run the oil pump up
'till you get pressure at the gauge... now put the drive gear and dizzy
back in, set static timing to 10 BTDC and start the car.

The other choice is an oil "accumulator". An accumulator is basically a
vessel of some sort with a "bladder" separating two chambers. One chamber
will have a quart (or two or three) of proper motor oil and the other
chamber has pressurized air. Connect the oil side to the main oil gallery
(there are a couple of good connection points like the oil pressure idiot
light sending unit (1/8 NPT)) and open the valve on the accumulator. You
should see oil pressure at the gauge. Run it like this for a while, maybe
10 or 20 seconds. Then pull the accumulator reconnect the idiot light
sending unit and re-plug the oil line. Start the car.

Racers like the accumulator setup, as they can plumb it into the oiling
system between the oil cooler and the main oil gallery. This gets them
engine pre-oiling with the added benefit of using the accumulator to
provide an oil pressure reserve in the system... this helps the system
maintain pressure should the oil pickup suck air on a long corner (or any
of a number of other oiling calamities that can occur when driving at the
limit).

But I should say that for a rare-driver (defined as a few times a year),
just making sure that the car will start properly without riding the
starter will be more than adequate. 

> Mike N.
> 
> CC75088L  (Looking good and running great!)

regards,
rml
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