[chrisp]

Anyone familiar with Water Outlet Restrictor Kit Moroso ? Trying to lower operating temp. just a tad , runs @200 , idle sitting 210 , turn engine off about 1 cup fluid comes from the overflow hose a few minutes later , 180 stat .461 Kauffman headed tri-power , roller cam . 10.43 comp. 4 speed , 354 rear , 7 1/2" crank pulley , 8" water-pump pulley ,desert cooler rad. 18" clutch fan with full shroud 15 lb. cap . Divider plates proper as well as cast impeller . Seems to run good . Any suggestions to lower a tad ? thank you

[02Hawk]

I would try a couple of things

1) verify temperature reading. Where is temp reading coming from. I have in the past spent a lot of money replacing stuff when the guage itself was giving erroneous readings.

2) try a smaller pump pulley to get the pump spinning a little faster.


3) what is timing set at?

4) have you tried switching T-stats?. I like the ones that are about 1 inch thick that sit solid in the housing cup. Verify the stat opens at 180 degrees.

5) what does it rn without a thermostat?

[torqjunki]

What type of thermostat are you running? I have a similar combo and have tested several t-stats. The balanced type made by steward or moroso have a much larger flow area and always cooled better than the stock style. Get a quick action liquid thermometer at the grocery store and check the t-stat on the stove to verify that it operates at or near stated rating. Running with out a t-stat may get you closer to your goals, but at the expense of excelerated engine wear due to longer warm up times. Make sure you have a good quality Hayden fan clutch. I think you have the rest up to par. If all else fails, a aluminum radiator is not too expensive now days. I got a four core aluminum Champion for $175 from a store on e-bay. I would go with the traditional 2 core, as I believe the air flow through the four core is not as good due to the thickness of the core. Mine runs cooler at idle than going down the road.

[chrisp]

Temp is coming from rear of driver side head , timing is 32 total , have never removed the t-stat , have all air rubber flaps on core support , with hood closed seems to pull fair amount of air through the grilles . Tri-power was sucking air / fuel through the end carbs. being too rich but ran @ 180 , now carbs are fixed going hot . Plugs do not look lean . May try a different stat 160 ? thank you

[kilkm68]

I'm having a problem also with the motor running a little warm, similar engine, mine is a 474 with aluminum heads and pistons and roller cam. It runs down the road at 185 but will heat up idleing to 210 or higher. I also considered a restrictor plate. I pulled the thermostat to check the flow, water seemed to be running through the radiator fine. Going down the road on 100 degree day it would only run about 158 degrees, but at idle for an extended time would heat back up to 210 and going higher before I shut it down. I discovered tonight if I rasised the idle from 800 rpm to about 1200 rpm temp would drop to 190 and stay there. PROBLEM IS THE WATER PUMP! There is much discussion here about the impeller clearance on these Pontiac motors, they must be correct or they don't circulate the water properly and I'm sure it must be my problem, maybe yours also. This pump was put on when I had a water pump failure out on the road and took it to a shop for repair. I had a similar problem with a Buick Nailhead a couple of years ago and put a smaller water pump pully on so the pump so it turned faster at idle, and it fixed the problem. I may try the same fix, or Ames Performance has some Flow Kooler pumps for $89 they say increase water flow at idle by 100%. I may just do that, I hate to think about pulling the radiator out again, but oh well, spending time with the old goat in the garage is one thing I like to do.

[rad400]

8" Crank pulley 6 1/2" or samller ie 5 1/2" wp pulleys.

[kilkm68]

my car has a 7 1/4" crank pully, 6 1/4 water pump pully. OD measurements. should I try and find a smaller wp pully?

[HWYSTR455]

I'd say yes, try to find the smaller, A/C setup or 'towing' package pulley. 9 times out of 10 though, all the idle heatup issues I've seen are related to 2 factors, fan clutch/shroud, or timing at idle. Total timing isn't the issue, with your case, obviously, it's timing at idle I bet. Lemme guess, you're running 10 or 12 initial? Try limiting total by 4 and run 16 initial.

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