Topic: Timing chain

[sharpxmen]

dunno about overdrive but my '86 camaro won't lock the t/c until it warms up (the relay is controlled by the ECU), same idea i think.

[dwtaylorpdx]

So wouldn't it make sense to:

1. Get it as low as you can and still keep the computer happy.
2. Lie like a rug to the ECO and fool it to making sure you can run in the
180 range where the fluid is happy?

I know my jeep runs at 210 with the stock 195 stat and 190 with a 180 stat
(Yes I have the stuff to make sure, I just fought a doa guage sensor last week... )
Yes lower temps at the bottom of the radiator.. BUT the relative heat transfer has to
be higher to cool the fluid, so the water in the radiator would have to be down around
160 to get the tranny fluid to 190.. the "delta T" has to be
about 30 degrees to get significant thermal transfer.

I test this kind of stuff for a living. Part of my job is making sure IT spaces are cooled correctly.


Cheers.
Dave

[firebrick43]

When you say loss of power, where at in the rpm range and how drastic? 
You can retard or advance a cam a few degrees to move the power band.  Retarding moves the power higher rpm.  As you timing chain stretches it retards the cam slightly.  And our engines need the power in top.  I would use a good wag to say we are talking about 2 or 4 horsepower.  We are talk some where around 4-6 degrees.

The stretch of a chain the the difference in power for our engine would be spaced out over years and nearly 100000 miles as it would not be noticeable to people until you replace it and even then it will be small in this size and type of engine.  The only way a power loss could be sudden from a cam chain would be that it became so loose that it skipped a tooth but by that point it would be making a hell of a racket at idle as it slapped the cover.  If it's not slapping the cover your problem is most assuredly else where!