Cooling Problems

[Imacarguytoo]

OK guys i swapped an rpm intake anda holley 600 on my truck early this week. I put a 160 degree thermos stat in it. Its got the stock fan on it. It runs at 190 running down the highway at 50mph. At idle it starts to hit 200. But when i give it some gas it starts to cool off a little bit. Now should i put a clutch fan on it or maybe an electric fan on it. What do you think?

[matthufham]

200 even 205ish is perfect, 210 is fine aswell. a warm engine is a happy engine.

you should run a 185 or 190 thermostat.

i run the stock fan, and shroud with a 350, edelbrock intake too. i roll down the road at 205 to 210. i use a 190 thermostat

[BACKYARD88]

Theoretically, if you step up to a warmer thermostat it will hold the coolant in the radiator longer bringing the overall temperature down.

[Imacarguytoo]

Ok. Then why does it ping when i put a load on the motor. I set the timing at 8 degrees. It idles perfect. But when i have ran it and its warmed up. Its really hard to start. It acts as if the timing is advanced.

[rlm316]

What was your operating temp before the change? When you dropped the dist. back in could it be a tooth out? When you replaced the intake gaskets did the coolant ports line up? Did you install restrictor plates in the ports? Pinging/ hard starting are signs of over temp or/ and timing. Is your coolant level at the full range? Do you have good coolant flow with the thermostat open? Idle the truck with the radiator cap off until the thermostat opens and look at the flow rate and level. Coolant should move thru the rad. at a pretty good rate and just about an inch to an inch and a half below the fill neck. Also check your coolant mix. Should be about 50/50.

[Imacarguytoo]

Originally Posted by rlm316

What was your operating temp before the change? When you dropped the dist. back in could it be a tooth out? When you replaced the intake gaskets did the coolant ports line up? Did you install restrictor plates in the ports? Pinging/ hard starting are signs of over temp or/ and timing. Is your coolant level at the full range? Do you have good coolant flow with the thermostat open? Idle the truck with the radiator cap off until the thermostat opens and look at the flow rate and level. Coolant should move thru the rad. at a pretty good rate and just about an inch to an inch and a half below the fill neck. Also check your coolant mix. Should be about 50/50.

I really didnt drive the truck much till now. Its alot warmer out now than then. I am 100 % sure i have the dist in right. I had a friend check it also. I put the motor at TDC with mark on balancer at 0 Degrees. Made sure the piston was up with #1 plug out. The rotor button was pointing at #1 on the cap. Intake gaskets lined up right, coolant is full with great flow. The mix is good also. I am thinking the dist is just worn out.

[Longhorn Man]

what kind of fan is on it right now? You say stock, but I've seen lots off ppl think the wrong ones are stock ... a 4 blade fixed? A flex? A clutch?
Do you have a shroud in place?
Is the fan 1/2 in and 1/2 out of the shroud?

[WorkinLonghorn]

I don't think the coolant temp. is a problem. Here's a quote from the GM Service Manual from 1969; "Engine operating temperatures higher than the normal boiling point of water are in no way objectionable so long as the coolant level is satisfactory when the engine is cool."
>>Stock thermostat is 195 degrees.
>>Did your truck come with EGR originally? If so,it will knock like crazy if you disable this.

[piecesparts]

Is your T/stat a SUPERSTAT? Most manufacturers sell a standard T/stat and thenthere is what is sold as a SUPERSTAT. The superstat hasa better modulating pill init and the temperature stays more in the middle of it's cycling capability. A standard T/stat will cycle from that 60 degrees to a temp of 200 degrees, where the Superstat will tend to stay around the 180 degree mark better. NAPA and CARGUEST bo9th sell them around here, I amnot sure about other outlets.

Do you have a fan shroud on your radiator? Also the discussion of the flow rate on your coolant is important. If it is flowing to fast, then it doesn't have time to cool in the radiator, however a higher temp T/stat will hold the water in the motor longer and not let it out until the water is at a higher temp. The 200 degree temp is not bad, but there are many things that will bring it down, that you can do. Look into rlm 316's suggestions, also.

[WorkinLonghorn]

The 200 degree temp is not bad, but there are many things that will bring it down, that you can do.

Why would you want to?

[Longhorn Man]

There's advantages to both hot, and to cool.
When the engine is run cool, you can add more timing without preignition. You may notice less, or no vapor lock.
Less stress on cooling system

His system isn't working as good as it should. It sounds like an air flow problem. It works fine at speed, which, it has a butt load of air going through the rad at speed... but at idle, it starts to warm up.... lack of moving air.

How hot will it get if you let it idle?

[Imacarguytoo]

OK its a 4 blade fixed. Ok so what im gathering is the cooling is not the problem. So is it maybe the distributor?? I am very sure the timing is right. COuld the springs in it be worn out causing it to ping? I know with the timing being advanced it will ping and will be hard to start. But i am sure the timing is right.

[piecesparts]

If you are getting detonation at 8 degrees, then the problem is in the timing setup, somewhere. I have my engine set a lot higher than yours and am not experiencing the problem you noted. What type of dizzy are you running in your engine? Are you sure that the plug wires are all on the right plugs? Is the vacuum advance working in the dizzy and is the centrifugal advance free inside? You should be able to set the timing at 12 degrees without problem, but you are already experiencing detonation, so it appears that you are advanced to far. Do you have the right timing mark indicator for the balancer that you are using?

As for lowering the T/stat temp, I get a better performance with the engine controlled at 180 degrees, vice the 195 degree level. The losses due to heat compared to the gains for a warm engine and not having to bring it up to an operating temp, actually balances out at level somewhere just below the 190 temp. The amount of heat in the engine affects the cold air charge on the intake. The thought is to lower that to the point that the engine is running at an optimim level. On later model engines the T/stats are lowered to FAKE the computer into a richer charge on the intake, but there is also the cooler/denser air charge involved there, too.