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-   Onroad Nitro Engine Zone (https://www.rctech.net/forum/onroad-nitro-engine-zone-71/)
-   -   OS TR engine thread (https://www.rctech.net/forum/onroad-nitro-engine-zone/40966-os-tr-engine-thread.html)

afm 09-01-2004 05:33 AM


Originally posted by sean
i have been doing a little more experimenting and getting some better results,although my TR still wants to be a little on the hot side for the best performance. this may sound like a really stupid question and i think i know the answer but i will ask anyway. if i ran 30% nitro would i be better off as far as temp? i was thinking that with a higher nitro content i could put more fuel through the engine(run it richer) hoping that maybe the increased fuel through the engine would help keep it cooler-yet not bogg it down because i have a higher nitro content which burns better? i dont know, just a thought
My suggestion would be to check your head shimming. Sometimes having to much or to little head clearance can generate heat.
For a .12 engine on 30% nitro, the ideal head clearance should be .021 inch. For 20% nitro it should be .017 inch.
Measure the recess distance between top of cylinder sleeve and piston at TDC, then measure actual head recess distance between chamber and shim surface, then subtract those to measurements and put appropiate shim to get suggested total head clearance.

AFM

sean 09-01-2004 05:54 AM

that would be interesting info to have anyway- i have the appropriate micrometers at work that i use for shimming outdrives,altthough my digital calipers have a depth reading- i can probably just use that. another thing i noticed was the body i am runnig sucks. it seems to get hot much quicker with it on. all they had at the hobby shop was a VW JETTA. when i run the car without it it doesnt get hot so quick. that body also seems to slow th car down considerably-plus i was worried about ventilation so the whole body looks like swiss cheese.

sook 09-01-2004 06:44 AM

Sean, the jetta body is fine. Just remember that if you are just driving it up and down a parking lot, your temps are always going to differ from those that actually race these cars. The only holes that are actually needed in a lexan body are those that you use for adjusting the carb, 2" hole in the front and rear windsheild. I do not even cut out any of the side windows for vent. Most of us that race use 30% nitro content. I did not shim nor change the glow plug using 30% nitro on this R-Spec. I realized that when I made the switch from a 20% to 30% that the temps on my RB's came down a bit due to the nitro cooling the engine down a bit. Besides it produced more power on the track. I gave up a little run time per tank with 30%, but it does not hurt when you have a good pit crew.:D Just keep in mind that you should use the low end needle to adjust for punch acceleration (timing) and the high end needle for power (temp control). If your car boggs a bit before it takes off, you could lean the low end a bit till it just blast off the ground. Then adjust the high end needle to readjust the temp settings during high speed runs. I usually just adjust the high end as the car is lifted from the ground at WOT till it sounds like it is at its best high rev.

Darkseid 09-01-2004 06:48 AM

Sean, in my experience, my engine always runs about 15-20 degrees hotter when I run a sedan body compared to the Lola style shell I usually run. So if your running a sedan style body, your engine is really right where it should be on temp. Cause if you stick on a Lola and go running, you'll lose at least 15 degrees from air flow alone.

Like I said, just go have some fun!:D

sean 09-01-2004 09:51 AM

hey a lola style body sounds great. i dont race yet, just drive around for fun. could you recomend a good lola body for the NTC3? i really appreciate the help with my engine guys. i may not race but i still take my hobby pretty seriously. i am very big on maitenence and proper set up. i find it very challenging and relaxing at the same time. i also dont like to abuse things for no reason-thats why i ask so many questions. thanks again, sean

sook 09-01-2004 09:56 AM

Its always good to hear that people still treat this as a hobby.
here you go Sean.
http://64.70.208.72/speedtechrc/3.html

I think that the only ones that Steve has left are from Yokomo. Check it out. You will have to do some cutting around the front shock tower (the body) to get it to sit down farther for lower effect. Good luck.

JLock 09-01-2004 02:12 PM


Originally posted by sean
hey a lola style body sounds great. i dont race yet, just drive around for fun. could you recomend a good lola body for the NTC3? i really appreciate the help with my engine guys. i may not race but i still take my hobby pretty seriously. i am very big on maitenence and proper set up. i find it very challenging and relaxing at the same time. i also dont like to abuse things for no reason-thats why i ask so many questions. thanks again, sean
Frewer also makes lola and can-am lola (enclosed cockpit) bodies as well.

sean 09-01-2004 04:58 PM

GOOD BYE OVERHEAT!
 
like i was saying, i thought that the jetta body was contributing to my high temps. i had run the car around with out the body and it would be fine, as soon as i put the shell on the temp would rise dramaticly. well today i went to a large parking lot and left the body off. i ran through about 3 tanks straight and my temp never went over 215-220. if i had put the jetta body on after 1 lap i would have been well into the 260's. the car spun out alot though. i have to get myself a nice Lola or GTP body now and i will be all set. thanks for the help guys!

sook 09-01-2004 05:42 PM

Sean,
since you are running the ntc3, you might check to see if the opening of the heatsink is rotated to the correct pass through position. For us ntc3 users, most of the heatsinks has to be rotated 90 degrees for air to pass through properly for cooling. Just a thought for you.;)

Racing4Evo 09-01-2004 09:15 PM

If you are looking for a wedge body, look for the Loletta I think from Frewer also. It has a bulgy front end to clear the front shock tower.

What kind of gearing are you using. If you have some low gearing down a very long street, the motor temp will be above normal. I find that the TR R-Spec can be geared a little higer.

Darkseid 09-02-2004 07:08 AM

Re: GOOD BYE OVERHEAT!
 

Originally posted by sean
like i was saying, i thought that the jetta body was contributing to my high temps. i had run the car around with out the body and it would be fine, as soon as i put the shell on the temp would rise dramaticly. well today i went to a large parking lot and left the body off. i ran through about 3 tanks straight and my temp never went over 215-220. if i had put the jetta body on after 1 lap i would have been well into the 260's. the car spun out alot though. i have to get myself a nice Lola or GTP body now and i will be all set. thanks for the help guys!
Sean: please don't take this the wrong way, but just for the sake of trying to help, I have to ask. Have you cut the proper air holes into your sedan body? When running a sedan style body your allowed to cut out a 2" diameter hole in the windsheild(inline with the heatsink head of course), cut out both front side windows, and cut out a couple 2" diameter holes in the rear window to let the air blow out the back. These holes are must for running a sedan body and if they aren't cut, they'll send your temps through the roof.

I'm not trying to make you out to be a nitro newby by asking this, but with the instant heat increases your getting by putting on your body, I figured that was a valid question to ask.

Just checking...:cool:

sean 09-02-2004 07:56 AM

i cut a 2" hole in the windsheild another hole in the rear window as well as a large hole in the roof. on top of the 2" holes i drilled a bunch of tiny holes through out the rest of the windows, front and rear. it looks like a car that tried to run a check point in Iraq it has so many holes in it. i know you may be thinking that the car has too much drag with all those holes, but i was worse before i drilled them

Darkseid 09-02-2004 10:49 AM

Cool, just checking...

As for the Lola body. I like to use the Frewer bodies because Speedtech sells them for $15. The Yokomo Lola's are just as good, but cost a bit more.

Lola's are hard to come by these days, especially the Frewer bodies. So you might have to pick up a Yokomo body.

Ricardo 09-04-2004 04:05 AM

Just got my OS .12 Tr-R Spec yesterday from my local hobby shop.
They still have 2 of them. Price $175

S.Stew 09-05-2004 09:34 PM

Just got back from nats.

Ron Atomic put his Kyosho with the TR-R spec in tenth in the A after qualifying and finnished 7th.

Looked real strong, though i wasnt impressed with his team mates cars.


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