rear gear change advice

[JOZW30]

New (last spring) aluminum "performance" water pump.

New modified t-stat (tested before install).

Had 4-core radiator recored and tested.

Lower hose not collapsing.

Same (correct #s) pulleys as on car before rear change.

Moving the initial timing up or down hasn't really made much difference to the thermals. It can sit there at idle after start up and not go above 160-170 degrees all day. Start moving and it slowly creeps up and up and up and will stabilize pretty much just north of 200. Obviously hotter on hotter days.

I thought maybe we didn't get the block cavities cleaned out real good and it's clogged up? has anyone ever tried to pull the lower block plugs while the motor is still in the car? Guessing it's a bloody mess.

One last question about the fan clutch, when the motor is hot, and I shut the car down, should the clutch be tight, or should it spin by hand pretty easily?

Thanks again for responding the 800th &quot;my enigne's running hot post&quot;! [img]<<GRAEMLIN_URL>>/smile.gif[/img]

[RPOLS3]

What about the sender or the guage? NJSteve documented issues with temperature senders with his T/A.

I agree with everyone else that the gear should not be an issue. I run a 3:73 in my Big Block/Auto/A-C Chevelle and last July (80's and humid day) it made the 200 mile round trip to SCR15 with the A/C on full tilt and ran 185-190 degrees on the road and ran up to 200 occasionally at a stop light.

[Plowman]

You don't say what your coolant mix is at,antifreeze protection. I found that any richer than -34 deg is to thick. This will cause the car to run hot down the road and not hot at idle. I would replace the fan clutch too.

[Salvatore]

I agree with everyone else...its NOT the gears.

[olredalert]

----Messy or not I would pull all the lower plugs I could get to. You may have only marginal flow thru the block.......Bill S

[ssl78]

when its at 200 did you ever take a infra red gun and take a reading going into the radiator and out of the radiator to see the temp drop

[Tommy]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ssl78</div><div class="ubbcode-body">when its at 200 did you ever take a infra red gun and take a reading going into the radiator and out of the radiator to see the temp drop </div></div>

I was going to ask the same thing. Those little heat guns are cheap and work great. I think they are still around 20 bucks at Harbor Freight. I check my header tubes, radiator, t-stat housing on my stuff with them. I agree with the Masses, it shouldn't be the gears. I ran 3:73's up and down the interstate for hours at a time without issue. I also don't think 200-205 is hot either... If your fan is flattening out at the higher RPM is won't push as much air as did before. I have experienced that with flex fans and tall gears. They would run cool around town but flatten out while flying up the interstate and my temps were higher then. Still, 200 isn't bad in my opinion. I do have large box fans in the garage that I run in front of the car with the hood open after hard drives. That's only because I don't like to watch the temps skyrocket after shutting off these old engines. I worry about cooking the bearings sometimes Hope I helped some.


Tommy [img]<<GRAEMLIN_URL>>/[/img]