Run time?

[UltegraSTI]

was out 2day 2 shake down the buggy, cool temps low 60s.

and i just switched to odonnell fuel (20%). runnin stock hyper8 motor. and i can barely eek out 5min on a tank. of course 1 might think too rich, but motor is free 4 most part (has been broken in already and after initial warmup really goes, i wonder if i'm even lil lean). cracked tank, leakin gas? a clog? any1 else know anythin that could cause this?

i'll have vids up soon so u can look at the track and even listen 2 the engine if it helps. our track takes 30-32sec for a buggy.



-Ult

 

[UltegraSTI]

whats ur buggy's runtime? *video*

i'm barely makin 5min. hyper 8 in my pcr. thing is runnin too strong and maybe even a lil hot 2 be too rich (it does run lil phat 1st lap or 2 of tank). wonderin if there's a crack in the tank or leak at the top w/the filler. idk

help suggestions?

-Ult

 

[ZANDOR]

If your only geting 5 miniuts on a tank and running hot you have a problem.

Air leak comes to mind!!! Iam not running an 8 port now but when i was i was getting about 15 miniuts @ 260 to 280 degrees F.

while its running take some wd40 and spray it around the areas that are sealed if there is a incress in rpms you will have an air leak in that area. check around your carb and the head and back plate. Did you loctite your head screws and back plate and your carb?????????

 

[jon2]

Think Zandor means use Loctite blue on the backplate screws but use RTV silicone on the backplate and on the carbs neck right at the top.

 

[ZANDOR]

:smoke: thanks jon

 

[CorradoPsi]

i get about 8 minutes of racing at 230* using my vspec, 10-12 just bashing around.

id say you got issues man.

 

[Rolex]

If you have a leak somewhere, you'll notice a lot of extra oil and/or mud collected somewhere. That's a very short run time, so it might be too rich, or the engine is blowing a lot past a worn piston and sleeve. What's your temp after a few laps?

 

[jon2]

Then lets keep it here. Before I started having glitching on my PCR PRO, I would have close to 15 minute runs on one tank then re-fuel then back out again.

Rules I have learned to adhere to:
- Seal the backplate and carb with RTV silicone and let cure for 24 hours.
- To take it slow during break in!
- Get a temp gun if you don't know how to use the spit test or the pinch test.
- Don't keep running it too long if you know you have an oddity in run time.
- Come here for help.Lol

Read it,Learn it, Memorize it. then do it again!

Jon

 

[ZANDOR]

good advice jon

 

[UltegraSTI]

will the engine note tell u anythin out of a video perhaps? the thing was really movin, but idk...was thinkin maybe somethin wrong w/the tank. i just switched fuels from trinity to odonnell. it does take a long time 2 die from that 1st bruuppp when outta gas. temps were about 23x or so after it died and i ran over to it.

thx 4 the help, i'll get more info.

http://thewarf.com/ryan/RC/RCvids/

choose 'ult1'

http://thewarf.com/ryan/RC/RCvids/ult1.wmv direct.

just a quicky i pulled up, but if helps any1 decypher this, then thx!

-Ult

 

[CorradoPsi]

i watched the vid, i dont know if its the poor resolution or not, but i usually like to see more smoke than that. especially when you first apply the gas. you should get a nice puff out of every corner. your top end sounds ok, so long as you have a good stream of smoke as well. go through and look for airleaks and check your tank for cracks.

 

[UltegraSTI]

just bought a new tank (and pull start lost recoil last wkend, if i'm gonna tear this thing down 4 leax might as well) 2 cover myself on that end, b/c i'm suspicious about the tank's conditions and the filler seal. i put fresh fuel line on the car last wkend after i ran. checked the filter and cleaned it then. i'll make sure thats tight.

yes i was lookin 4 smoke and i didnt get it after 2 laps or so (leanin out b/c of fuel load) in slow corners, there was a good chunk of wind, idk how much that effects seeing it, but i hear ya. i did lean it a lil at beginning despite the colder temps 2 get it 2 warm up some initially. i did start 2 richen it when the issue of barely makin 5min on the track (maybe another 30sec in gettin it started and warming) came up. still i knew it should go longer, but i didnt want 2 go any leaner b/c it sounded really mean on the backstretch, especially at the end of the tank. but goin richer i knew my runtime was already short. so i wondered bout the tank or leax. so i stopped runnin early. only real temp refs i did after gettin her warmed up were that she was at 22x/23x after it ran outta gas and i ran over to pick it up (i know i shoulda checked it thruout the run, 1 time i did at the beginning after 2 laps and it was 217).

i do have a temp probe thing, nice piece as seen above. my issue 2 a point is that i'm goin by what the previous owner had said in that the engine was broken in. was it sealed, i honestly havent looked-will 2nite. how many tanks b4 me, didnt ask him.

all the help is more than appreciated. btw, have another track member askin me and almost inciting in front of others that i'm scared goin into sundays big bash and kickoff races at the new track. hmmm, last i checked i'm just doin this 4 fun gettin back into it. should i be sorry i didnt spend the same amount on the engine as i did the car? last i checked even w/this runtime issue my lap times are faster (and i'm rusty still).

thx

-Ult

 

[CorradoPsi]

why not ask him "why is driving toy cars so competitive, does he make a living at it?" I've got a nice buggy, but i dont throw it in peoples faces, i offer to let them drive it. so long as they prove they are a good enough driver with thier own car that i dont have to worry too much about major damage, ill let pretty much anyone drive my cars.

 

[Team 17]

If your fuel line is short going to the carb then u will burn fuel quicker.

 

[mikeburgin]

Hard case normally if you have leak in the motor you can see it, ie wet patches, and if its in the fuel lines, blow down the lines and see if it has preasure, one of my rbs after my recent weekends racing is blowing fuel between the piston and liner but thats real noticable, oil everywere, there is the thought that maybe your running to rich and its not running clean enough to smoke and is actually blowing unburnt fuel out the pipe instead of smoke!!!!!!! but your car doesn't look slllloooooowwwwwww,

 

[UltegraSTI]

hmm thats a thought and i have seen that outta this b4, spots of liquid/fuel on the table while warmin up or gettin another tank full. hmm

sealed the engine and put on new pull start. didnt have rtv on it b4hand (prev owner). will check the lines 2mrw. also goin 2 check cooling head for threadlock and perhaps some grease 4 the needle orings . didnt notice that the fuel filter need some tightening (i did take it apart when i put the new fuel line in wk b4). as i said earlier i have a new tank, gonna put that in regardless, clean everythin up and prolly lean the low end a lil bit and see what happens

-Ult

 

[mikeburgin]

How olds the glow plug, that can also make em use fuel,

 

[CorradoPsi]

if you lean the low end, use the 4 second rule to get you in the ballpark.

 

[UltegraSTI]

using mccoy mc8s, this 1 is about about 2 sessions old, had only 4-5 tanks b4 this last session. i spent most time u/s'g how these engines work and gettin it 2 run decent b4 i put a fresh plug in.

on this pinch test, i've seen so many ways 2 do it, some plz clarify the entire process.

-Ult

 

[CorradoPsi]

i clear out the motor by reving it a few times. then pinch the line as close to the nipple as possible and count till the motor dies. mine runs till about 3.5 sec's then revs up at 4 and is out by 5. that is after I've tweeked the bottom end by running it, my vspec likes the bottom a little fat. your engine may differ, so the 4 sec rule is only a starting point, but it should get you pretty close.