dabo12367

Does anyone know what the normal operational temperature for a tuned Hurricane Xp is? I bought a Venom smart temp/failsafe and I need to set the temperature parameter on the engine temp. probe. It is a gauge that wraps around the lower head fins. The engine is a .27. Other engines of different size probably have a similiar temp range. Can anyone help?

ehroof

set it for 280, anything above that for any nitro engine is tooooooo hot.

krazyk000

not that i'm an expert but i was going to say the same thing. listen to ehroof, that guy knows what he's talking about.

Popper252

Nah he actually makes up half the stuff he says. I say set it for 284.

krazyk000

well shut, youre the master of the photo so how could i argue with you. but i say 286.1234828y6592. the y is a variuable that you have to guess....

Popper252

LMAO, good stuff man

dabo12367

Is that Kelvin, Fahrenheit or Celsius? You guys are strange. Stanton.

krazyk000

its Fahrenheit

ehroof

actually popper, i flip a coin and make up some numbers or answers.

Popper252

Haha I see, my pet hamster actually does all my crunchwork for me. He's also pretty good at photography.

dabo12367

I kinda knew that, I was joking, dabo12367.

Team Knowitall

Anywhere between 220-300 is acceptable. keep it above 220, but under 300. beyond that, tune for performance and make sure there's a light cloud of smoke coming out of the pipe at ALL times.

ehroof

eric, your saying that 300 is an acceptable running temprature for a nitro engine?

Team Knowitall

I'm saying that 300 is right on the line of acceptability. I've run many engines WAY over 300 for a short time and they did fine afterwards, but you really don't wanna run your engines like I run my engines I seem to have the midas touch when it comes to luck with engines, and if your engine goes OVER 300 you should shut it down and let it cool off, and richen 'er up, then run it again.

chances are if it WON'T stay under 300, it's probably just worn out, or you have an air leak in the engine, OR you live in Arizona, LOL.

mozzzy_2000

Hi,
I've had the .27 for about 6 months now. It is an absolute fact that this engine runs at about 280F. It seriously WANTS to run at that temp I have found. Incidently the Hyper 21 8 port runs at 280F as well. Remember its a big block that pumps out heaps more than the average .21 does. Its designed to run at high temps. In summer here in Australia I would be lucky to get the engine UNDER 280F seriously. I have even had it at 300F. Not for long though. But as long as the engine is not running lean it should be ok. I have run almost 2 gallons through it already & it still feels it has the same compression when it was new. At those high temps my engine kept on cutting out.
Essenitally I feel the stock cooling head on the .27 is simply not big enough to give it ample cooling. Its smaller than some racing 21s in some case. I recently found a giant cooling head that fits the .27 & now I am running the engine at 180F!! seriously and it runs like a dream. Run all day if you wanted to & now never cuts out. I spoke with the GM of the company & he assured me he runs his cars perfectly at these lower temps plus you get superior engine life.
So anyway engine temps are not always the be all & end all when it comes to tuning. As long as its not too lean; a nice steady plume of smoke when put on the throttle and you should be fine.
In regards to the smart temp I use one but the temp failsafe never clicks in on mine. But in any case I'd set it for 290-300F as I said, 280 is its normal running temp and you want to set it higher than that of course other wise the failsafe will kepp on interferring with your throttle.
hope that sheds some light

Team Knowitall

A: Racing .21s create a lot more heat than the .27. engine size alone does not dictate its cooling needs-its design, porting, and materials dictate that.

B: at 180 degrees you're doing more harm to your engine than you are running at 280 degrees.

C: cooling head size ALSO does not dictate cooling capacity by itself. again, it's the design of the head and materials (for the most part)

They are never the be all/end all when it comes to tuning-IMO, temps are lowest on the priority list, but you DO need to make sure you don't reach the magic 300 number.

dabo12367

Thanks, That was useful information. An engine cooling head running under 180 degrees would have to have a compressor, condenser and lots of Freon. dabo12367

Team Knowitall

You can run just about any engine below 200 degrees...but I don't advise it for any reason.

dabo12367

Hey Mozzzy, Interesting info. But I have a question. Many people talk about how many gallons of fuel they have run through their engines but I have no idea how long a well tuned engine is designed to last. I'm aware that their are variables in this question, i.e. running temps, fuel used, driving habits, abuse etc.... What is your opinion on this and what happens when the compression is too low to support combustion. These engines are basically diesels where they are compression ignition (except during starting) instead of spark ignition. I know diesels have a compression ratio that starts at about 17:1 and can go up almost to 24:1 (depending on whether its a 2 or 4 stroke) So, anyway, our little nitro engines have a high comprresion ratio, how high I don't know but I'm sure it's well below what a diesels is because of the different fuel. When compression becomes an issue in our nitros, what do we do? fix or replace. Will a new sleeve work or do we need a new block? Any suggestions would be helpful, Thanks. David.

Team Knowitall

I'm not Mozzy, but a new piston/sleeve is what you replace when you're not getting any compression. at times the culprit could also be a poorly seated head, a bad glow plug washer, etc etc.

the crankcase will usually be perfectly good unless your engine takes a hard hit and breaks off the mounting tabs at the engine mount.

mozzzy_2000

don't write off something you obviously know little about hey. No offense dabo or redcatracing but if you haven't used one you wouldn;t know how effective they are. The temp could be higher but since the head is so dam tall the temp gauge obviously is further away & henced the temp given could be lower than actual temperature. 180F is what my guage reads but I guess it could be more realistically like 200F at the glow plug. In any case do the math. This cooling head is described as gigantic. And that may be an understatement. It totally dwarves the stock head. Its easily 50% bigger than the infinity .27 head and with that comes 50% better cooling. Its quite logical really. Its much larger than other racing heads like Nova,werks & o'donnell head. Not sure why you don;t beleive me as all these racing heads are designed to reduce engine temps drastically.
The important thing is that now my engine idles more consistently and has more grunt, never cuts out at high temps & quite litterally has zero drop of compression after almost 2 gallons.
Proof's in the pudding, my friends!
And here's the link to the head I purchased if anyone's still with me on this:
http://cgi.ebay.com.au/ws/eBayISAPI....tem=6046904685

cheers

dabo12367

Thanks Eric, I knew this was an expensive hobby when I bought the Xp and I'm glad to know that an engine replacement isn't needed because it lost compression. dabo12367

dabo12367

Hey Mozzy, If I can find that cooling head, I'll buy it. The link to ebay says it was sold but did have others. I'm not knocking you but 180F degrees does seem on the low side. Anyway, as I said, I'll do a web search and try to find one. dabo12367.

Team Knowitall

And I suppose I've never even seen one in person


2 of the 3 LHS's of mine in Memphis were American CNC dealers. the head made nearly zero difference on my XTM .247...I bought it because of the severe beating the head on my buggy took and this one was built way stouter...and the head didn't make a noticeable difference in running temperature, at least on my XTM .247.

I'm not saying that you don't know what you're talking about, and the difference in climate may make a big difference, but in 99% of cases, replacing the cooling head on an engine with a bigger one is usually a band-aid fix that masks something that's actually wrong...i.e. an air leak in your backplate, a leaky bearing, or something like that.

mozzzy_2000

thats interesting hey. I am very supprised that a larger head didn;t give you any extra cooling what so ever. Is it possible there was a leak which would have artificially leaned out the engine which would counteract the temp? Ie. the temp stays the same? Just a theory. What brand head were you using? Nova raceheads are significantly different from Amercian CNC.
To me it seems logical hey that you get cooler temps with a larger head. But obviosuly thats not the case in every situation. It was only stated as dropping temps by about 40F I think but In my case its more like 90F!! When I first used it I was immediately concerned that it was perhaps now too low in temp so I spoke with the GM. Not really knowing who he is exactly he said that he had several nitros and they all ran similar temps & he had been running them at those temps without any problems for years.
This head i found was just a gamble to be honest. I thought the sirio 27 looked almost the exact same mill. They gave me the hole dimensions & everything lined up ok and bolts on perfectly I found. I think there are other heads that will fit too.
Now as you mention there are other factors like climate, leaks, nitro% etc & I'd agree there too. Its cooling down here and I am considering swapping back the stock head over winter as its so dam hard to start when cold. The above temps I was getting was whilst its been warm so I think it may get too cold outside now to use the larger head. At first we thought the engine was leaking somewhere but the engine has been checked about 3 or 4 times and everything seemed in order. Incidently I am using 15% nitro which may account for higher temps than if I was using say 25%. I have also found that the team infinity & team orion use the same mills & the .27 s are apparantly identical to the orion wasp. The orion wasp operates at 270F running temp so its not supprising the infinity acheives similar temps in the first place. Other engines like novarossi seem to operate at low temps like 230F eliminating the need of a larger head.
A few things to note generally about the larger head & the temps achieved, would be the fact as I mentioned before is that the temp gun I have is now about an inch further back and this could significantly distort the reading. I suppose if I put a smart temp probe on it may give a more accurate reading. The temp gun is reading the head temp not necessarily the engine temp I think perhaps.
This head is also made of the lighter alluminum alloy and apparantly its best property is that it disapates heat much quicker than other heavier alloy heads available. The denser alloy absorbs heat better but the downside is that it doesn't disapate the heat effeciently as the lighter alloy head. The other good thing is that in the event of a bad rollover the head is more likely to just rip off without damaging the rest of the engine. Well thats the theory anyway.
In any case with such low temps with this head, i certainly wouldn;t run a new engine in with it. I still think you need to heat cycle a new engine well when running it in with the stock head first.
But yeah i certianly wouldn't say they're a band aid fix though. If an engine runs normally at say 280F and you want it at say 230F, putting a larger head on is hardly a band aid. It greatly reduces engine wear & massively increases the life of the engine amongst other things. Preventative measures I would have thought?
And when it comes down to it, have you ever heard of anyone killing an engine by running it too low in temperature? I certainly haven;t!

Cheers guys