have 69 400 engine bored 20 over with 4,000 miles. Set up is a 4 core desert cooler radiator from Classic Industries, 11" pusher fan, high output water pump, have tried 170, 180,190,195 thermostats and the thing still runs at 210-240. Where's it supposed to run and how can I get it down to that temp? HELP!!!

Forgot...have 7 blade fan with clutch and shroud.

Check the divider plate to make sure there is less than 1/8" gap between it and the water pump impeller.

Also, what kind of gauge are you reading temps on? Factory? Or aftermarket?

You are way too hot, my friend. Check out PMIs comments but please verify your sending unit is accurate before you spend too much, or tear down the water pump. When mine gets HOT HOT its at 210 or so, then I need to pull over and let her rest. That has only happened 2-3 times in three years. If I saw my gauge get anywhere near 240 I'd have a heart attack. For grins, try a 165-170 thermostat.

Mine USED TO read 210-220, had faulty gauge, checked with two "temp pistols" bith read 190-195...
I checked w the 'pistols' (2 different to check them vs ea other too) AFTER doing the divider plate and it didnt help....if car HAD been running hot it WOULD have helped

Here is the detailed info Q, John and Bjorn are talking about:
http://www.wallaceracing.com/water-pump-mods.php

A good idea to have this set up right no matter what... can't hurt, and you know for sure your set there! My Stock gauge was way off too, faulty sending unit, and old gauge... I got a liquid filled Therometer that installs in the intake manifold, so I know for sure what temps I'm at, and it was 190 the whole time.
http://www.jegs.com/photos/55541000a.jpg
http://tinyurl.com/5z2lq for the description. They are usually $30, but sometimes are on sale for $20.

Perhaps the gauge is off?

Good luck - Brett!

Also note in the link that Birdman provided, using a water pump with the cast impeller makes a big diff over a stamped impeller, as shown in the pictures. Made a big differance for me.

Have aftermarket gauge and have had it pistol checked. It's definetly running at 210+. I've just converted from 50/50 anitfreeze to all water with "water wetter". It seems to get hot quicker. I'm thinking of going back to 50/50 and trying a new water pump. Any suggestions where I might get a good HO water pump?

Summit sells a Flow Kooler aluminum pump. I've put three of these on three motors and never run above the T-stat temp except for that one time on the way up to Mammoth Mountain. (288 miles in 3 Hrs. 12 mins. You do the math. 3.55 gears with 255-50x15's.) Then it sat about 5-8 degrees above the T-stat temp.

Flow Kooler

Oh ... and go to a 70/30 mix with good antifreeze.

Primetech,

Thanks. Just ordered it to be overnighted from Summit. Hope this solves the problem!!

Rick

It's still VERY important that you check the clearance between the impeller and the divider plate. Bend the plate if there's too much room.

I will. Thanks.

Rick,

My 400 ran hot until I had all the correct air baffles in place. Do you have the upper ones that only came on the 400. If your car was a 350 and upgraded to a 400 this could be a problem. also, there is a lower air baffle that is often removed and discarded on old birds. Until I added this to mine, it ran hot. This directs air into the radiator vs. under the car. The strange thing with my car was that without this, it ran especially hot on the interstate at speed. Now it runs 5 - 10 degrees cooler. Ames sell a fiberglass replacement as originals are nearly impossible to find. You may also want to advance the spark somewhat too. The original cars had a TVS (thermal vacuum switch) that was to advance the spark when temps got too hot.

Dave

Q, Will this also work on a 69 350? Didn't see 350 anywere.

bhiggins3,

The water pump should work for 350/400/455.

You just need to know if you have an 8 bolt or 11 bolt water pump, and also what your original water pump shaft length is so that your pulleys continue to match up.

mine runs around 210 to 220 should I be concerned or should I try to go to a different thermostat

Gary, see DRVMarch`s answer above, you have those fillers?
have you tested your temperature gague? mine was off 15F to the high side

Rick, what kind of configuration does your engine have? Eg camshaft, cylinder heads, distributor advance?

Bjorn, pistol the engine. gauge is off 17 to 20 degree so I guess I'm ok