Technical SBC 350 Getting Hot on Highway

Can't seem to help yourself , just keep diggin' !

 

Just so you know (because you are doing everything in your power to show us that you dont know.....)-vacuum advance doesn't come into play at Wide Open Throttle, like say..... during a dyno pull.


You wrote:
"Vac advance is just a crutch to get you from base(easy to start) to full advance and is not needed to drag race where your only concern is total timing, the last ting you need is for the vac advance to go hay wire"

You finally admit vacuum advance is separate from "full advance"

-rick

 

My Fucking head hurts trying to read this.

 

Just rewriting thermal dynamics and how timing has been done since the dawn of time.

 

I haven’t learned anything, but it has been entertaining

 

Of course Moriarity is correct. Millions of cars built in the era we like to deal with were built with distributors set the same way. No surprise there.

Vac advance is NEVER included in a discussion of "full advance" or "all-in advance". The reference in this trade is "X degrees all in at XX rpm plus X degrees of vac advance".

Anyone not familiar with this should sit down and get familiar...

 

It's like a circle... No beginning-No end...

 

I wish we were still trying to help the original poster.
Yes, some here need to install a vacuum gauge in their street driven rod to learn how throttle position and engine load affect vacuum.

 

You're right. The OP sure seemed to have a radiator that isn't doing its job under engine load. His previous in-town heating problem was fixed by a new radiator and fans, but now it gets hot on the road under load, where it never did before. Seems like something is either blocking airflow at speed or the radiator core isn't doing its job when more heat is produce by a loaded engine.

 

I have a 350 sbc .060 over with a mechanical advance distributor, no vacuum advance, 14 degrees initial 34 degrees total at 2500 set with my 40 year old timing light, half a radiator, because the grill shell won’t hold a full size. Mechanical fan. Goes down the highway @180 all day long. Sitting in traffic is another story. I personally think he has a restriction in the cooling system. Could also be air flow restriction Just my ten cents. (Inflation)

 

There are two in the last 14 words of your run-on sentence(?) below.

1. For someone who claims to be a 40+ year master of A/C, and the resolution king of overheating problems, you should know how to spell coolant by now.

2. Coolant moving too fast through the radiator to cool is an absolute fallacy, and directly contradicts proven physics and principles of thermal dynamics.

 

The newer rides I worked on would have a code popping up for running at these low temps claimed here

 

The option to ignore a member is something I almost never do but today was a exception.

 

I agree on going for a ride without the fans and shroud. Although I have a clutch fan on my 62 Bel Air, if the system moves enough air through the rad, it shouldn't matter whether it's electric or mechanical. I know guys here don't like electric fans because they're not traditional, but I don't think the electric fans alone are his issue and it doesn't sound like he has the mechanical setup and shroud.

I do agree that the shroud design is probably doing something funny with the air through the rad at speed. Since 59-64 GM cars have a lot of places for air to go around the radiator, if there's a restriction at speed then some of the air will probably bypass the rad. I'd focus on getting air through it, as your experiment suggestion alludes to.

One thing I noticed was this is a less expensive rad/shroud/fan combo. The cold case is about 25-40% of the cost of comparable products from Be-Cool and Griffin. The biggest visible difference comparing to those other higher-priced options seems to be shroud thickness, flaps (to allow air through at speed), and fitment of the shroud to the radiator (some have air flow gaps). With a hole saw and some rubber material, I bet he could solve a lot of his problem. Probably better done with the shroud off the car too . Example configurations of other rads for the same application below for comparison.

 

Except for the fact that GM specified that complete combustion on that engine happens at 205°F+.

If it is not much over 180ºF, it is NOT tuned properly.

My target is 215ºF.

 

Yes. Plug reading on E10 and E15 is now a fairly useless practice.

I switched to a wideband O2 sensor when MTBE was phased out.

Anything jetted for E0 (14.7:1) will be running a little lean on E10 (14.13:1), and even moreso on E15(13.8:1).

Lean mixtures and late timing raise temperatures.

 

Cue the "hot rods aren't built for economy!" guys.

If you are putting unburned fuel out of the exhaust, you neither got good mileage with it, nor did you make power with it.

Some still somehow think this is a merit badge.

 

I can think of 2 good reasons: Power and reliability.

Anyone think NASCAR runs their stuff at 180F ?
Oil needs to get above 210F to drive off condensation.
You get less wear, when the motor runs warmer.
Motors that don't get hot enough, build sludge.

 

Exactly, and thank you!

 

It has been proven: at 30 degrees "too hot" you get less friction, than at 30 degrees "too cold."
Some people seem to think their motor will suddenly explode at 212 F.

With a 12 lb rad cap, the boiling point of water, is around 244 F.
A 50/50 coolant mix, the boiling point is around 259 F.
And as long as the coolant isn't boiling, it is carrying away heat.

 

Typo on E15? Appears richer in your numbers?

 

Is there a direct correlation between coolant temperature and oil temperature? Would a 195°F thermostat allow the oil to be 15°F warmer than a 180°F thermostat, or is there more involved to it? Has anybody ever ran a temperature gauge in the oil reservoir and compared the readings?

 

The difference being that we're not running our engines at WOT for hours and don't have anywhere near the wear environment that Nascar engines do. For all-out race applications where even a tiny amount of wear loses horsepower and therefore can lose races, every little bit matters. For our street cars that are usually driven from A to B and not tuned for 100% all-out full throttle performance, any wear will be negligible due to more frequent maintenance and rebuilt intervals. If you're doing 20,000 miles on your car a year as a daily, maybe you'll notice.

I find this article from Summit interesting. If you read to the end, they talk about the benefits of lower coolant temperature. In semi-performance engines like many of ours that create more heat than stock, it gives you more time for the cooling system to work since the cooling process starts sooner. IF your cooling system cools effectively, this gives you much more of a buffer before it gets too hot.

It's not direct 1:1, it's a complex heat transfer equation between the engine block, oil, coolant, flow rates, rate of heat generation, and air flow.

 

I would try putting a piece of tape across the gap where I put the arrow in the picture, and also at the bottom if there is any gap there. The fans may be sucking air thru there and not as much thru the radiator. I would also get an infrared temperature gun ($30) and check the temperature of the hoses as water enters the radiator and compare it to water exiting the radiator. I also wonder if coolant in the pump is bypassing and returning rather than flowing thru the engine. Your temp sensor is in your engines head, so compare your guage reading to what the hose readings are and you get an idea how much temp drop occurs in the radiator, and how those temps compare to your head. If the radiator is producing sufficient temp drop but its not getting thru the engine to cool it, I'd look at too much bypassing.If the radiator is not cooling the water, I'd work on that part of the system.

 

I think OP may have given up on this discussion a couple days ago.

 

With 94 posts in about 17.5 years, he probably doesn't check in very often.

 

With the ego arguing between the other members (as per usual) you'd understand why he doesn't post.

 

If this is the kind of response he gets every time he does, I don't blame him for not coming back!

 

IIRC: Oil usually runs 20 degrees hotter than coolant, once the motor is up to temperature.