Cooling tricks with iron headed hot rods?

[rgalajda]

Or a solenoid that closes the throttle plates

[dfarr67]

I don't use iron heads in anything BUT...... I was an Evans coolant fan for many years and found that in tuning the EFI on my 385 TPI I was logging knock that were giving me a problem addressing. For whatever reason I changed back to long life antifreeze with a container of water wetter and the ping has been greatly reduced. All my vehicles are now running antifreeze.

[RCJ]

Our dirt Cars ran cooler with about 20% anti freeze. Plugging the tstat bypass drilling a couple holes in the tstat helped. Polishing the chamber and piston top on an iron head would even up the hp difference. Themal barriers don't help there.

[Kevin Johnson]

Talk some more about the technique of pouring molten aluminium into the heads to block off passages. Do you need to have the head at a certain temp while doing this ...?

I ask because of the difference in coefficients of linear thermal expansion makes me concerned about stressing the casting and possibly causing cracks (?).

[PackardV8]

Back in another lifetime, I would fill the exhaust crossover passages with molten aluminum and then carefully port the exhaust end. Then, one time I didn't have time, so packed the crossover portion with scrungled aluminum tray and used a .0625" thick stainless steel shim at the intake gasket surface. I couldn't measure any difference in effectiveness.

[dannobee]

3rd gen camaro NEEDS the chin spoiler on, otherwise it'll overheat at highway speeds. One step up from the factory chin spoiler is to fabricate an aluminum chin spoiler with strakes on the side going forward to capture even more air. BTDT.

And find a circle track radiator that fits. AFCO, Griffin, even the Speedway specials. Not Cup level, but more like Late Model/Super late model. Adapt it to fit and close up the ends of the core support so that all of the air goes through the radiator.

[skinny z]

I've iron RHS heads. 10.4:1CR.
2" 2 row Griffin aluminum radiator. Conventional water pump and pullies. Electric fan. 195°-180° fan switch, 180° t-stat. Also run a full heater circuit for cabin defrost etc. 50/50 coolant, tap water.
No overheating despite being stuck in traffic at times. Yes, it gets hot in Canada. Texas summertime hot? Probably not. But hot just the same.

[Dan Timberlake]

1959 Mopar tech. BB SAE paper commented on the significant effect of inlet air temp on part throttle cruise knock.
Also the full throttle best torque timing variation with engine rpm.
Also their expectation that well done vacuum advance can improve fuel economy and driveability.

[skinny z]

... the significant effect of inlet air temp on part throttle cruise knock.

Also their expectation that well done vacuum advance can improve fuel economy and driveability.

I've experienced both of the above cruising my iron headed SBC posted above.
Subtle spark knock at very lean cruise and plenty of advance via vacuum. 45° or better under light acceleration.
I've been educated on that first sentences significance in Dan's post and would bet that had I sealed the cowl hood for a proper CAI, I'd probably have pulled better than 50° from the air inlet temperature. Plan is to do just that.
As it was, that advance and lean cruise gave a significant bump in fuel economy. I just had to avoid that load condition. (Unlocking the converter accomplished that).
I like my MPGs too.

[RobZ28]

Too bad your engine bay isn't the size of a dyno room

Didn't see the show, so can't comment if the heads were sim design/shape enough for a good test(don't care what they flowed).

Brzezinski(cast heads) talks bout some Dart cast iron heads, having coolant flow issues in one of their vids if i rem right.

Back to my first comment, are you using a CAI setup? So many factors to consider, especially when testing.

I've used the slowest UD pulley crank and Water pulley combo i could get with iron heads, ran 170 in summer. Some circle track guys like super HOT temps. Depends on how things are set up for your combo in total.

Heads are Dart SS 165's with a modern chamber. The Brzezenski heads he looked at were the 200's. Im ASSuming the larger intake ports were the reason they were so intrusive in the water jacket and the 165's might not have this problem... Dunno.

The car has outside cold air from the factory. Its got a tube that splits to 2 separate filters in front of the radiator. Its a really cool design that works.
Yup, air deflector underneath is good to go and that is a must have on any third gen camaro... Or else!

F-Bird... are you speaking about the coolant throttle body bypass mod? That is certainly something we all do in Texas. Theres no need at all for that.

I do put some extra barriers to make sure the air is forced through the fan and doesnt get around it.

I also run water wetter... it works some. I like that product.

Blocking the exhaust crossover... Hmmm... IF I am not mistaken, years ago in school they said that reduced combustion chamber temps to reduce NOX. But yes, that would indeed heat up the intake manifold. I am interested in hearing more about plugging this rather if I do it or not.

Polishing the combustion chamber? Does this not have any negative effects that would offset the benefits? I would assume that would/could cause some sort of detonation possibilities...

Thanks.

[Tom68]

Blocking the exhaust crossover... Hmmm... IF I am not mistaken, years ago in school they said that reduced combustion chamber temps to reduce NOX. But yes, that would indeed heat up the intake manifold. I am interested in hearing more about plugging this rather if I do it or not.

What, the passage across the inlet manifold, that's to help fuel vaporisation at cold temps for smoother running and better economy.
Block it for improved power at the cost of the above.

[Kevin Johnson]

...
The car has outside cold air from the factory. Its got a tube that splits to 2 separate filters in front of the radiator. Its a really cool design that works.
Yup, air deflector underneath is good to go and that is a must have on any third gen camaro... Or else!

...

Way back in time, on my Third Gen Camaro (actually Samantha's car), I scoured local wrecking yards to locate a second snorkel and created a dual setup with a second factory type CAI on the opposite corner of the bay. I found a better lid so that I could place a taller air filter. I just cleared the hood and insulation. I made a carb gasket/base by sacrificing a polymer cutting board. It seems like a Buick was the air cleaner housing and snorkel donor. It has been too many years now and gone are the days when you could easily scour hundreds of suitable cars at large Tampa area yards.

No money for dyno at that point in time. Butt dyno indicated a healthy improvement. Local police noticed me punching it and quickly accelerating from 45 to about 70 (per the officer). No ticket -- just cool it.

Negative comments about the Camaro RS in tropical Florida downpours -- very easy to hydroplane (but great dry weather handing -- compared to the 5.0 Mustang conv I previously owned). The windshield wipers were horrible and could not keep the glass safely clear in heavy rain. Rain-X helped some. At the same point in time I owned and drove a Mercedes 300 SDL quite 'rapidly.' Same types of weather. The Mercedes was far safer in the rain -- very noticeable in heavy rain (huge amount of development in that car series over time for high speed autobahn use).

[bobmc]

I thought the Z28 with Goodyear Gatorbacks had excellent wet manors but the only comparison I had was 1970"s Chevelles and Camaros, one of those front end "bra" bug covers was a no go, didn't get 10 miles on the highway before I stopped and took it off because the temp scared me

[V12MECH]

The 3rd. gen Camaro with TPI has an egr under plenum that uses cross over for exhaust feed. The egr function does reduce combustion temp, keeps NOX formation low, higher combustion temp equals more power, improvement to cooling system maybe required.

[PackardV8]

Blocking the exhaust crossover... Hmmm... IF I am not mistaken, years ago in school they said that reduced combustion chamber temps to reduce NOX. But yes, that would indeed heat up the intake manifold. I am interested in hearing more about plugging this rather if I do it or not.

What, the passage across the inlet manifold, that's to help fuel vaporisation at cold temps for smoother running and better economy.
Block it for improved power at the cost of the above.

Yes, cold weather east of the Rockies may need exhaust heat in the intake manifold. However, the discussion is how to cool iron heads in hot weather.