What a difference Timing makes... (Engine warming up)

[Kingofthehill]

I advanced my timing from 15base to 22 base (Still not getting any knock at 36* total)...

The throttle response was noticeable... it felt better... everything was great till i looked at my temp guage... dang, it jumped up about 20* at cruising speed...

i go re-timed it back to where it was and sure enough.. 20* drop, back to where it should be...

So im see'ing that as i need to upgrade my cooling system.... would this be a fair assumption???

new pump, new radiator but only a 3 core vertical flow (Always thought Cross flow was more efficent?)

any tips? im running about 30% coolant, water wetter and distilled water with a 160* t-stat.... but 3 core, flex fan with a so so shroud...

JOe

[rumblefish360]

Upgrade the fan and shroud. Re-advance the timing. Test, then report back.
Can I get an engine bay/engine shot on the board please?

[dwc43]

Put the coolant mix back to 50/50 with the water wetter. Also, just increase your rad cap to 22 lbs and that will fix it.

[rumblefish360]

Cap pressure increase, good idea.

[dwc43]

Thanks.

Just for reference we use a 22-24 lb cap on our race cars. With plain water,2 row rad,pulley reduction,6 blade plastic Flex A Lite fan (good to 8000rpm) and no T stat. Runs too cool at times. moslty 180* so I have to tape it off to keep it around 200 so I can get the most out of it.

[Kingofthehill]

Did'nt even think about the cap.. Currently im running a 16lb cap... i'll increase to a 22lb tomorrow...

She's a little dirty... she has gone through a new fuel system and a lot of carb tinkering... not as clean as she normally is

[Kingofthehill]

I know, I know..... the black engine compartment is a Chebby thing... it was painted black before i bought it, lol

JOe

[dwc43]

Look at the third pic.

Did you take that while the engine was hot? Look at the top rad hose. It's sucking it'self closed. I don't think it's optic, cause the other picks the hose looks full and round. It would not hurt to cut an 1" out of it at the rad to pul it around straighter than it is now. Sure looks like the upper hose is sucked shut.

[rumblefish360]

Black, thats OK. Not my car. What ever floats your boat.

Now, on the cooling, try a viscous fan from MoPar since you have a shroud.
I was hoping for a look at the pulleys. Under driven or regular pulleys?
Because an underdriven pulley will be slow, then the pump will be slow, cooling would be slow or not enuff.
Refitting the engine with a high flow pump with under drive pulleys will (Probably) cause a problem at higher speeds, like Hwy driving. The water/coolent cavitates. (sp)

[Kingofthehill]

Nice observation, but i assure you its the picture.. although i do have room to cut an inch out and re-attach, there is no pinch there...

What exactly does a higher pressure cap do? any chance its gonna be too much internal pressure and just find a way out somewhere else?

JOe

[rumblefish360]

DW, I think it's just the shine/glare/angle on it.

[Kingofthehill]

The pully's are factory size.. no underdrive pully's on her

JOe

[rumblefish360]

The higher the pressure, the higher the boiling point of liquid.
If your system has a short fall, the higher pressure will show it. But I doubt it. Everything looks very good from where I sit. A hose will go first.

[Kingofthehill]

Originally Posted by rumblefish360

The higher the pressure, the higher the boiling point of liquid.
If your system has a short fall, the higher pressure will show it. But I doubt it. Everything looks very good from where I sit. A hose will go first.

Thanks

[rumblefish360]

No problem, Thank DW as well.
I guess hes off starting a thread about his cam/engine.

[dwc43]

The pressure cap raises the boiling point of the coolant. As long as the rad and hoses are in good shape there is no damage that can occur. Like I said in my other post I have run as high as 24lbs with no problems.

You could do an underdrive pulley set up. This helps it if it is over heating while running high rpms like my race runs all the time. The water pump starts to cavetate at 4000rpm. If it's getting hot at idle you have to adjust other things. Like the cap pressure,timming, fuel as well. You may want to toos the T stat as well or at least run a 160* high flow. It opens at 160*, but it has a larger hole to allow more water to flow through. Also there are steam holes that need to be added to the heads in most apps to prevent this as well.

[dwc43]

Originally Posted by rumblefish360

No problem, Thank DW as well.
I guess hes off starting a thread about his cam/engine.

I did start a post. But I got back in here. lol. I swore that one pic looked like that hose was sucked closed, but I'll take your alls word on it.

[dirttrackracer]

Top hose pressure bottom hose suck. Thats why the bottom hose has a wire reenforcement. Water cools better than antifreeze the added pressure of a high pressure cap will increase the boiling point also a higher pressure in the system will help redose the chance of steam pockets. For factory type heads the 36* total timming is about right so if its getting warm vers less timming you may have a lean fuel curve.

[dwc43]

Originally Posted by dirttrackracer

Top hose pressure bottom hose suck.

Not always so. For instance my '85 4x4's clutch fan went bad and the old 7 blader was not turning very fast at idle or any speed for that matter. I could actually stick a piece of cardboard in teh fan blade and stop the engine and I could hold the fan still. No way you can do that with a cold engine and a functioning clutch. Mine was sucking the top hose closed when it started getting hot.

[peg leg]

Royal Purple coolant additive? The stuff works wonders, assuming you have no other contributing issues. Here in HOT country, the stuff usually drops coolant temps 20 degrees.

Ron

[cageman]

I have seen the top hose get closed shut when a thermostat was bad.

[dirttrackracer]

Well it stands to reason that if you have a big enough restriction on the pressure side of the pump before the radiator you could calapse the upper hose.In that case you should definitly look for the source of the restriction.

[cageman]

closed thermostat.
wasn't my car, was a chevy, if that means anything.

[Dick]

I question the 22lb cap. As long as he is not boiling over, a higher pressure cap isn't going to do anything. A higher pressure cap will just let coolant pressure increase to that point at which it will open and let the excessive pressure escape, either through the overflow tube or into an expansion tank.

DW, where do you get this stuff?

[dwc43]

Originally Posted by cageman

I have seen the top hose get closed shut when a thermostat was bad.

I thought that was what was wrong with the truck too. 1st thing I changed and it still collapsed the top house and over heated. Then I got to watching the fan and replaced the clutch and it was fine. Still running today.

[dwc43]

Originally Posted by Dick

DW, where do you get this stuff?

Well known stuff that most all racers like me use. Works well. Our cars run too cool and have to be taped off to get the propper amount of heat in them.

[WCLARK]

All a pressure cap does is raise the boiling point of whatever coolant you have. It does nothing to cool your engine.

[Dick]

Originally Posted by dwc43

Well known stuff that most all racers like me use. Works well. Our cars run too cool and have to be taped off to get the propper amount of heat in them.

No, no, I meant where do you get all this "stuff" like a 22lb cap will cure his overheating? Been into the 'shine tank again?

[dwc43]

Originally Posted by Dick

No, no, I meant where do you get all this "stuff" like a 22lb cap will cure his overheating? Been into the 'shine tank again?

Nope. No shine. It's a simple fact that chaning the pressure changes the boiling point of the coolant. You raise the point it wont be overheating. That'
s why they make caps with different pressures so you can tailor your cooling system to your needs.

[Dick]

Originally Posted by dwc43

Nope. No shine. It's a simple fact that chaning the pressure changes the boiling point of the coolant. You raise the point it wont be overheating. That'
s why they make caps with different pressures so you can tailor your cooling system to your needs.

I'll let someone else argue with you on that.