Painting Parts = bad? help

[DALUVIAN]

Hi there, i Have a 2uz. I was wondering if its ok to paint under the intake, on the block, Mine was rusted some, so i cleaned it up. I don't know if it was painted before or not. My mechanic buddy told me that its bad to paint certain parts due to the heat it keeps in. Any inlightment on the subject is much appreated! :006:

 

[Anaema]

the paint shouldnt hurt anything, but i woudlnt paint the intake, you never know what might happen.

 

[cribbj]

It used to be one of the "in" things to paint the valley with glyptol or other tough, heat resistant paint. Nearly all of the HPBooks from the 70's had a procedure for doing this, and for SBF's, SBC's, etc. it's said to improve the oil drainage, however I don't think many modern day OHC Vee engines have need for better oil drainage in that area :boggled:

 

[DALUVIAN]

Yea i don't plan on painting the intake :no: . I don't know but i was told by another source not to paint it???, I think rust would do a better job at holding in heat no?

 

[Anaema]

how did you get rust on an aluminum block? and i dont think rust(Fe2 O3) is really good for anything other than red dye.

 

[DALUVIAN]

I have a 2UZ It has a iron block.

 

[cribbj]

Retaining heat in the block and especially the heads is a good thing. Higher temps in the combustion process is considered good for efficiency, however if that heat spreads to the intake system, the engine aspirates less dense air & makes less power.

Another trick of the 70's (and earlier) was to use phenolic spacers between the carburetors and manifolds, and between the manifolds and heads in order to keep the heat in the engine, but out of the intake system, and especially out of the carburetor. Hot fuel is NOT a good thing, as it's less dense and definitely makes less power.

For my 2JZ-GTE engine, I used a heat insulating coating on my heads, and on the intake manifold, however when I built the motor, there were no phenolic spacers available, so I'm not sure of the efficacy of the coatings.

Anyway, this is the long version of why it's OK to paint your motor. If you paint any of the internal areas, just make sure it adheres very well and isn't liable to peel off and block any oil or coolant passages.

 

[Anaema]

thats not true. Smokey Yunick proved that heating the intake manifold and intake charge to a certain point is a viable way to make HP. mostly by heating the fuel to the point that it is nearly fully atomized, so that it burns incredibly fast.

 

[cribbj]

Don't bring Smokey's adiabatic engine into this. You're comparing apples and oranges because Smokey's engine was a completely different design than what we're talking about here. I worked for an industrial engine manufacturer that developed 22:1 AFR lean burn gas fueled engines in the 80's and I did the control systems for them. These engines worked, and achieved great BSFC and made good power, but they were also NOx monsters, just like Smokey's......

The density of any fuel decreases as it's heated, and so does its calorific value. This has been proven time & time again in engine testing labs, and is the reason OEM's went to voltage controlled fuel pumps, and eventually to returnless fuel systems.

If you want to redesign your 1UZ to be an adiabatic or lean burn engine, and try to copy some of what Smokey did in the 70's then you might find that heating the fuel/air charge might be a good thing. For the rest of us, running conventional engines, heated fuel is NOT a good thing if you want to make power.

Here's a schematic of Smokey's engine; although it's in the public domain at the US Patent Office, credit goes to the Gale Banks website:

 

[Anaema]

Don't bring Smokey's adiabatic engine into this. You're comparing apples and oranges because Smokey's engine was a completely different design than what we're talking about here. I worked for an industrial engine manufacturer that developed 22:1 AFR lean burn gas fueled engines in the 80's and I did the control systems for them. These engines worked, and achieved great BSFC and made good power, but they were also NOx monsters, just like Smokey's......

The density of any fuel decreases as it's heated, and so does its calorific value. This has been proven time & time again in engine testing labs, and is the reason OEM's went to voltage controlled fuel pumps, and eventually to returnless fuel systems.

If you want to redesign your 1UZ to be an adiabatic or lean burn engine, and try to copy some of what Smokey did in the 70's then you might find that heating the fuel/air charge might be a good thing. For the rest of us, running conventional engines, heated fuel is NOT a good thing if you want to make power.

Here's a schematic of Smokey's engine; although it's in the public domain at the US Patent Office, credit goes to the Gale Banks website:

i know all that, i was just trying to say that heat can make power, if horrible emissions along side.