Has anyone ever heard of creating a bypass of the heater by using a "T" and both rear water outlets on the heads. I'm probably not being clear...but I am experiencing 220+ heating problems and have done everything mentioned in these posts including replacing the head gaskets in case they were blocking flow. I only have 4,400 miles on a newly rebuilt 69 400 block and 72 4X heads. I have got the highest flow water pump from Summit, High flow thermo, 11" pusher fan, 7 blade fan with thermo clutch and shroud, desert cooler radiator, upper and lower baffles, .025" clearance on my divider plate, and ALL parts are brand new. I can go about 15 miles at low speeds (40 and under) before 220 and about 5 miles at 70+mph. I hate to belabor this subject BUT this can't be what was designed in 1968! HELP!!!

There has got to be some problem that has not been addressed? You've made sure your gauges work correctly, and or used a Thermal temp sensor gun etc? You've made sure your timing is set right, and your not running too lean? And you've adjusted the devider plate to get it as close to the impellar of the water pump as possible? etc?

There has to be a mechanical cause that we are over looking?

But until we can figure it out, here are some pix from GTO Ken for that type of set up he tried:
http://home.att.net/~gtoken/birdwork10.html

I hope we can figure something out for you, and soon!

Good luck - Brett - 67 Drop Top 455!

Isn't 1/4" on the divider plate a little to large" Shouldn't it be closer to the impeller?

- Jake

Hi Rick,
my experiance with running hot had me check the temp at the radiator. I found the temp different, 15 degrees F from the sender and fill neck. Give that a go.

Tom

You've checked every block there is on working over-heat issues, thats for sure. This implies that either your temp gage is way off, or there is severe blockage somewhere in the flow. You've done more than most of us to fix the heat problem. Gotta check that true temp reading before you do anything else.

Are you just running the 11 inch pusher fan or is that in addition to the factory style clutch fan? Puller fans are MUCH more efficient that pushers. I'm running dual 12 inch puller fans with shroud from a 4th gen instead of the clutch fan and original shroud and have no cooling problems with my .060 over 455.

Pssst... is that 1/4" gap too large?

- Jake

I believe 1/4" is too large. I set mine for 1/8" or closer.

Just pulled my waterpump. There was at least 1/4 inch space between divider palte and impeller, maybe a bit more. I am adressing this in the next few hours.

Also, I measured my flex fan. It is 18". I have a 19" fan waiting for me, along with new waterpump gasket, at the parts store.

Tom, I also checked my radiator temp a week ago. It was 20 degrees lower than the gauge temp. I think this is normal.

I'll advise results...hopefully by tomorrow, if interested.

Greg

Great news... looks like you'll be cruising soon without worries...

i just wanted to say that he said he has a .025" clearance on the divider plate not .25"
.025" is closer than most of us have ours

Divider Plate manipulation: 1 hour
19" Flex Fan: $39.99
Cardone Waterpump: $29.99
10 degrees cooler running temp in the city: Priceless!

Question on the '69 water pump/divider plate: my timing gasket set came with 2 water pump gaskets for 11 bolt, and I installed them both, one on each side of the divider plate. I don't recall if there was a cast or stamped impeller. That was also before the divider plate modification showed up on the site, and it still has about 1/4" clearance and no overheating issues except extreme (3+ miles in gear, TH400, 0-5 mph) conditions. When I tear down this winter and reassemble, should I install gaskets on both sides of the plate? I have no leakage issues with the cast-gasket-steel-gasket-cast sandwich.

Hmmm??? Have I made an error? The plates on my '68 fit into a recess in the timing chain cover. Should there have been a gasket in there? There wasn't one when I removed the original(?) pump... It sounds like the '69 set up is different. Can anyone clarify this, please?

Greg, I know the '68s are different. You should be fine.

I looked in the assembly manual...the '69 does use two gaskets for the divider plate. So when I tweak my plate, I need to remember to install a gasket first.