R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 01-29-2009, 12:19 AM   #1
Tech Elite
 
dishsoap's Avatar
R/C Tech Elite Subscriber
 
Join Date: Jan 2009
Location: Tucson, AZ
Posts: 2,457
Trader Rating: 7 (100%+)
Default Hyper 7 Running Slugish But Temp Is Up

I got 3 tanks through on my sons hyper7 during break in at idle. Rich settings for the break in process. Break in went really smooth and I could here the engine settling in. I left all of the needles alone and ran figure 8s on the 4th tank with rich settings however the temp shot up to just over 200 degrees. I never got past half throtle on the trigger. When I would give it some quick burst of gas from the trigger it seemed extremely sluggish.

My questions is??? should it be running just over 200 degrees on a rich setting or is this to hot. I noticed that for the most part it was around 180 or so and didnt get that hot until the gas started to get low. When the gas got low the engine starting reving up past a normal idle sound. As the gas got lower alsmost running out the engine pitch kept getting higher. Is this normal. What is the ideal temp for the hyper 7 engine?

It just seems like there may be a problem as usually on my losi 8 b i never had this happen. Yes the temp would get higher when running out of gas but the engine would not change as mutch in pitch.
__________________
HobbyTown USA Tucson!!! HobbyTown USA SRS!!!!
dishsoap is offline   Reply With Quote
Old 01-29-2009, 01:17 PM   #2
Tech Master
 
Join Date: Jul 2006
Location: Sugar Land, TX
Posts: 1,169
Trader Rating: 9 (100%+)
Default

200 isn't too high during break in, figure the engine will probably run 230 or better once it's tuned. I assume it's sluggish like it's fat, and not like a lean bog, that should go away when you tune it. Not real familiar with the Hyper 7, but make sure that the fuel pickup is getting all of the fuel from the tank, it it loses contact as the tank gets low then it will lean the engine more than it should. You might also check the clutch and make sure you didn't break a spring, etc.
cjtamu is offline   Reply With Quote
Old 01-29-2009, 01:31 PM   #3
Tech Master
 
MassiveMods's Avatar
 
Join Date: Jan 2006
Location: Sydney
Posts: 1,977
Default

start getting heat into the engine before you damage it.

230 to 280f is fine ... if you dont get heat into it the piston will linnish its self into an unexpanded sleeve , this will cause you big problems later on.

what happens when the engine is cold is the shock of the piston hitting the unexpanded sleeve will damage the rod and rear bearing ... this will become apparent around the 4 to 6 litre mark ..

MM
__________________
Engine development manager Rifling Pty Ltd. Nitro fuel designer : Neo + World record title holder 2012 Austalian Nationals 147.6 KPH , 1 st 2 nd and TQ Australian National Buggy titles 2012. Victorian State title 2012 Neo + , South Australian state title ON and Off Road 1/8 2012 Neo + :-) QLD State Titles 2012 1st buggy & trruggy + TQ Neo + MG66 RX7 1st Sportsman Class Truggy QLD State Titles 2012 !! Nitro Addicts Australia . com
MassiveMods is offline   Reply With Quote
Old 01-29-2009, 02:17 PM   #4
Tech Elite
 
slaytanic's Avatar
 
Join Date: Apr 2007
Posts: 2,171
Trader Rating: 20 (95%+)
Default

You culd be way lean on the LSN and way too rich on th HSN. I had this problem yesterday at the track with a new mill. HAd killer low end but just not the top I needed. Every time I touched the needles temps shot up. I turned the HSN 1 full turn in and the LSN 1 full turn out. Still killer low end but now I have insane top along with a 40 dgree drop in temps.
__________________
Team Epic
Team Terribles~Answer RC~Fastlane Graphics~Torco Race Fuels
XB808 Mamba Max Pro/Tekin 1900kv RC-monster mount and tray 4s
XT8 Hobbywing 150a esc/2000kv combo KILLER! Full rc-monster e conversion. 4s
slaytanic is offline   Reply With Quote
Old 01-29-2009, 03:25 PM   #5
Registered User
 
UltegraSTI's Avatar
 
Join Date: Jul 2005
Posts: 7,171
Trader Rating: 20 (100%+)
Default

colder than 200 is generally believed to be simply 'wearing' the engine.

200 is a good place to break in an engine. do not let ur engine run colder than that. after ur breakin/heat cycling is done, go easy on the needles til it start gettin to max power. still smoking on the throttle.

dont get married to a temp though, it will be ur undoing if u do.

R
UltegraSTI is offline   Reply With Quote
Old 01-29-2009, 03:38 PM   #6
Tech Regular
 
ace921000's Avatar
 
Join Date: Jan 2009
Location: Southlake, TX
Posts: 437
Trader Rating: 7 (100%+)
Default

i like my engine to be between 220-240

the engine should raise its idle because its getting more air and less fuel. that equals more rpm

sounds like you have a lean bog. the weather changed on me and my cars tune was shot and it turned into a lean bog. the low end was wayyyy to rich and the high end was a bit too lean. my car would stall out. i leaned the low speed alot and richened the high speed. now she runs like a champ!
ace921000 is offline   Reply With Quote
Old 01-31-2009, 07:45 PM   #7
Tech Addict
 
layedbackguy's Avatar
 
Join Date: Mar 2005
Location: dc,md,va,nc,oh
Posts: 514
Trader Rating: 15 (100%+)
Send a message via Yahoo to layedbackguy
Default

Quote:
Originally Posted by ace921000 View Post
i like my engine to be between 220-240

the engine should raise its idle because its getting more air and less fuel. that equals more rpm

sounds like you have a lean bog. the weather changed on me and my cars tune was shot and it turned into a lean bog. the low end was wayyyy to rich and the high end was a bit too lean. my car would stall out. i leaned the low speed alot and richened the high speed. now she runs like a champ!
+1 on the lean bog i run my motors depending on make and model around 220-265.lean the bottom, and play with the top buy riching up it until you have a good results

good luck
layedbackguy is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:12 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net