Nice Holes in your hood.

[robert j. yates]

A modern engine can easily run at 300* if the head gaskets and so forth were able to withstand that level of operating temperature so the high number itself does not bother me per se, its the indicated lack of reserve.

The ECU on the TJ will dictate when it thinks things are to hot and sweep the guages. Having the guage sit in the middle of or to the right of the "0" on the guage, halves the indicated level of reserve which IMO, is not good. Yes they are designed to run hotter for emissions purposes and particularly so given that the 4.0 does not use EGR. Hot though is what the factory indicates as normal or 210. If my Jeep ran up to 210 and stayed there, I would be more comfortable.

A friend of mine has actually done some rather significant testing of underhood heat build-up on TJ's ( he runs an Avenger Supercharger) and subsequent results that could be expected from venting. For some reason, I cannot access his archive at the moment but once I do, I will post the link. I performed my hood vent placement as a result of his recommendations.

 

[Bayou Boy]

Just an FYI. A lot of vehicles actually have what are called "idiot guages". These gauges don't actually sweep as the conditions change. Say we are talking about a temp gauge. If the water temp is between 180* and 235* (random numbers that I pulled out of thin air) the guage will read dead center. any higher and it immediately goes to hot.

Manufacturers started doing this because idiot drivers would bring their cars in when the gauge went just a little above the center thinking there was something wrong. These "idiot Gauges" kept people from coming in when their car was running just fine.

So while you may think that all of the things you are doing to try and make your Jeep run cooler aren't working, they actually might be and you just don't know it because your stock gauge isn't capable of telling you.

 

[robert j. yates]

I know all about so-called idiot guages. I run a Scanguage to get around all of that.

Edit:......I have also done some significant testing with mechanical guages so I *know* exactly, the nature of my running hot problem. My *idiot* guage is actually quite accurate based on my results.

 

[toyrunner95]

did you look into the AEV conversions hood? its super expensive, you may have to sell a kidney but it might be worth it.

https://secure.aev-conversions.com/store/merchant.mvc?Screen=PROD&Product_Code=40303001AA

 

[RunninRubicon]

Heating

Just some thoughts here guys...BEFORE spending more money.

Are you boiling water into the overflow or worse blowing hoses?
Are you turning your crankcase oil black because of heat or just unburnt gas?

Does the "check guages" light come on because your heat guage is pegged all the way to the right side? 260+ degrees will melt babbit from your crank/rod bearings and knock the temper out of your cylinder rings.

Does your engine ping or knock because of the heat? Or is it the gasoline you run?

IF you can yes to these things THEN you have a problem. Otherwise, your Jeep is operating at it's designed specifications.

Keep the MOPAR airfreeze at the appropriate mix (50/50) and your 195 degree thermostat fresh (not-sticking partially open, preferably) and check your hoses for cracking and swelling.

Keep your rig tuned with fresh plugs and air filters and run GOOD motor oil.

You do this and your well on your way to NOT having issues.

Why are you worring about stuff that doesn't or isn't happening to you.

 

[PhulesAU]

Done!! I wasn't able to convince the first camera to give me the shots of the unfinished piece. but, here's what followed.

http://picasaweb.google.com/sandmaggie/20071211InstallingHoodLouver

 

[robert j. yates]

Why are you worring about stuff that doesn't or isn't happening to you.

...try running at 230* plus up a grade out on the 395 pulling a trailer and not worry about it

 

[ntsqd]

BT, DT & sympathetic, but that said the late Gene Berg wrote an article that has made me skeptical of numbers on gauges ever since. Unless calibrated against a high dollar std gauge I treat all gauge numbers with a grain of salt. Even those from electronic senders.

I don't put any importance on the actual number as long as the reading stays close to it's normal reading within a reasonable range. Even that, according to Berg, is asking a lot of a "low dollar (<$250) gauge" (his words).

 

[robert j. yates]

Arrrrggggg....as I have stated a few times on this thread...I am not relying on my *idiot* guage and have done some rather significant testing with mechanical guages.

Don't know who Berg is but I can say with alot of confidence that he has never put a wrench on my Jeep so while he may have some general points to make which should be considered, thats really all they are. At any rate...BTDT with testing the *idiot* guage for accuracy (with mechanical systems) and frankly, I was somewhat surprised that it is after all is said and done, rather accurate.

Plain and simply.....at 230* there is alot less reserve available to me and thats the real point....placing modifications onto my rig that build in reserve or make more available so that whilst on a long trip in extreme temps, I do not have an overheating condition. This spring, I expect to add a fan driven engine oil cooler into the mix and I have been considering ideas on how to reduce the heat generated by my AC condensor which I now consider to be the prime culprit in only getting a 10* temperature drop across my radiator.
Typical would be a 20* and I only have half of that which says to me that there is a reserve issue going on.

My addition of hood vents as well as many other engine cooling related mods followed this thought process to the "T".

 

[robert j. yates]

Here is the link from my friend Frank D on his hood venting process for his TJ. Note that his rig is supercharged....he is also a retired Air Force Colonel so I kinda sorta trust his judgement

http://oman4x4.com/hoodvents.htm#theory

 

[ntsqd]

Arrrrggggg....as I have stated a few times on this thread...I am not relying on my *idiot* guage and have done some rather significant testing with mechanical guages.

I knew that from your previous posting. I was relating my own take on gauges and relevancy.

Don't know who Berg is but I can say with alot of confidence that he has never put a wrench on my Jeep so while he may have some general points to make which should be considered, thats really all they are.

Gene Berg is legend in the Air Cooled VW world. His shortened treatise on gauges here: http://www.geneberg.com/article.php?ArticleID=239 It has been some time since he did his study, so aftermarket gauges may have improved since then but I somewhat doubt it.

BTW, it looks like your friend did a nice job of a scientific study. I'll have to thoroughly read it later.

 

[robert j. yates]

BTW, it looks like your friend did a nice job of a scientific study. I'll have to thoroughly read it later.

Yes he did. Frank is known to be rather *precise* LOL. Great guy

 

[RunninRubicon]

Hood vents

Hey I live in desert southwest. I understand heat. I pull a trailer and run a supercharger....I understand! I LIKE the idea of Yates' hood vents. I may very well include this on my rig.

 

[Andrew Walcker]

Done!! I wasn't able to convince the first camera to give me the shots of the unfinished piece. but, here's what followed.

http://picasaweb.google.com/sandmaggie/20071211InstallingHoodLouver

Nicely done, I got to give you credit as I would be way too much of a wimp to cut into my hood!

 

[ntsqd]

My original thot in posting was that if you can find someone locally that it would be less spendy and just as effective to have the hood louvered. Should be one or more guy(s) doing the work for hot rodders in any metropolitan area. PM me if anywhere close to the 93003 zip for contact info of my friend.

I'm particularly fond of inverting & reversing them. That way they function the same, but are flush to the top of the hood. Cosmetically much more subtle......