R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road > Onroad Nitro Engine Zone

Like Tree8Likes
Reply
 
Thread Tools Search this Thread
Old 05-19-2009, 02:43 PM   #3241
Tech Adept
 
Join Date: Jun 2005
Posts: 100
Default Head Shims

I am still trying to get a grasp on understanding engines and I'm sure a similar question has been asked but after reading quite a bit of several threads I still have to ask. What, if any, are some general guidelines for shimming a head for the different nitro contents? Are there somewhat specific shim ranges for a certain nitro content? I run at sea level and anywhere from 80-100F degrees air temp. Novarossi .21 engines.
automator is offline   Reply With Quote
Old 05-20-2009, 02:27 AM   #3242
Tech Champion
 
Roelof's Avatar
 
Join Date: Aug 2007
Location: Holland
Posts: 5,736
Send a message via ICQ to Roelof
Default

Quote:
Originally Posted by Arboleda View Post
Roelof, I'm the one asking about avoiding one of the pitstops in my 15 minute races. The thing you have to understand is that it's a small track with lots of corners and very short acceleration time until the next corner.

Basically, the engine has waaaaay more than enough power for the track. So that got me thinking that maybe I could do thing like go down to 16% fuel, put in a venturi, etc, etc - and maybe just maybe it could all lead to me going 7.5 minutes on a tank and still have enough power for such a small track.

It's just club racing and I'm just experimenting and thinking out loud
OK, as I mentioned before. Go to 5% nitro and lower the tank pressure by using a TeamOrion CPD and use glowplug 5 to work with the 5%. If there are ways to cheat (no tankvolume is checked) you can make the tank bigger and use a large fuel filter (some even mopunt a Mugen pressure chamber in the fuelline).
__________________
Speed is only fiction but a 130+km/h MRS4 is for real.
Roelof is offline   Reply With Quote
Old 05-20-2009, 07:48 AM   #3243
M7H
Tech Elite
 
M7H's Avatar
 
Join Date: Dec 2004
Location: The Netherlands
Posts: 2,193
Default

Quote:
Originally Posted by automator View Post
I am still trying to get a grasp on understanding engines and I'm sure a similar question has been asked but after reading quite a bit of several threads I still have to ask. What, if any, are some general guidelines for shimming a head for the different nitro contents? Are there somewhat specific shim ranges for a certain nitro content? I run at sea level and anywhere from 80-100F degrees air temp. Novarossi .21 engines.
As a general rule you can say that .21 engines come from the factory shimmed for 25% nitro at sea level.
- every 10% increase in nitro content, needs an additional 0.1mm headshim.
- every 10% decrease in nitro content, needs 0.1mm less headshims.
__________________
Serpent
M7H is offline   Reply With Quote
Old 05-20-2009, 07:53 AM   #3244
Tech Elite
 
dameetz's Avatar
 
Join Date: Mar 2003
Location: The Sky
Posts: 2,535
Default

Anybody has any experience with Nova Flash .21 engine for 1/8th onroad? My last Nova was Plus 21-3 7 ports. I had bearings durability issues with that engine. After that I wanted to buy the 359, but heard durability issues as well like conrod, pin and bearings too...Now I see that 359 is being discontinued by Nova...So maybe they too realised about that problems. Now I m really interested in that Flash model and wanted to know if it is worth buying it. And what Nova pipe is best to match it?

Thanks in advance.
__________________
Dudududududuuuuuu.....
dameetz is offline   Reply With Quote
Old 05-24-2009, 05:50 PM   #3245
Tech Adept
 
Join Date: Sep 2006
Posts: 246
Trader Rating: 2 (100%+)
Default Need Some Help

I Need To Get a Couple Novarossi R1 Cranks #85005 Can Anybody Help
dfilo456 is offline   Reply With Quote
Old 05-24-2009, 07:21 PM   #3246
Tech Fanatic
 
Join Date: Mar 2008
Location: Virginia
Posts: 937
Trader Rating: 21 (100%+)
Default

I have a 08 353 and just noticed today it seems to like to run with the Hsn at around 1 1/2 turns out and the Lsn at less than 1/2 turn out. Is this fine for this engine? I just put a new conrod in and its only had a gallon of fuel total through the engine. It just seems a little weird that it likes to run like that and it came out of the box with the hsn 4 turns out and the lsn 1 1/2 turns out. It puts plenty of smoke out and really dosen't run over 250f. Any thoughts?
VA_Racer is offline   Reply With Quote
Old 05-25-2009, 07:11 AM   #3247
Tech Elite
 
Riketsu's Avatar
 
Join Date: Aug 2004
Location: Puerto Rico
Posts: 2,414
Trader Rating: 29 (100%+)
Send a message via AIM to Riketsu
Default

Quote:
Originally Posted by VA_Racer View Post
I have a 08 353 and just noticed today it seems to like to run with the Hsn at around 1 1/2 turns out and the Lsn at less than 1/2 turn out. Is this fine for this engine? I just put a new conrod in and its only had a gallon of fuel total through the engine. It just seems a little weird that it likes to run like that and it came out of the box with the hsn 4 turns out and the lsn 1 1/2 turns out. It puts plenty of smoke out and really dosen't run over 250f. Any thoughts?
I was tuning a friend's engine, and it was a bit weird. If it wasnt around what you are saying: HSN = 1 1/2 and LSN = 1/2, it wouldnt run fine. I tried resetting the needles back to stock and work my way from there like I always do, but no, it didn't work.

My suggestion is take the engine apart and inspect everything, dismantle the carburetor and look for damaged o-rings. When you are mounting everything back together, be sure to seal correctly neck of the carburetor since this is primarily where it leaks.

You can also slap in another carburetor if you can get your hands on one to start eliminating suspects.

But as a friendly advice, I currently am running 3 different novarossi engines (2 SCT and 1 353), and all of them are no where near 1 1/2 and 1/2. So it may be something wrong or it may be just that your engine runs there. Either way check it out to be safe.
__________________
eBay user id: riketsukirai
Riketsu is offline   Reply With Quote
Old 05-25-2009, 07:36 AM   #3248
Tech Champion
 
Roelof's Avatar
 
Join Date: Aug 2007
Location: Holland
Posts: 5,736
Send a message via ICQ to Roelof
Default

The best way to start with is with the flush setting. The main needle is always setted arround there and the LSN mostly 1 turn in fron flush.
__________________
Speed is only fiction but a 130+km/h MRS4 is for real.
Roelof is offline   Reply With Quote
Old 05-25-2009, 08:19 AM   #3249
Tech Fanatic
 
kitracer's Avatar
 
Join Date: Sep 2001
Location: hong kong
Posts: 986
Default

Quote:
Originally Posted by dameetz View Post
Anybody has any experience with Nova Flash .21 engine for 1/8th onroad? My last Nova was Plus 21-3 7 ports. I had bearings durability issues with that engine. After that I wanted to buy the 359, but heard durability issues as well like conrod, pin and bearings too...Now I see that 359 is being discontinued by Nova...So maybe they too realised about that problems. Now I m really interested in that Flash model and wanted to know if it is worth buying it. And what Nova pipe is best to match it?

Thanks in advance.
I saw one and know another guy doing really well with the Flash .21 (std, not tuned). The conrod is the Plus model, not 359.

I have been running 2 x 359 with no problems (other than my tank leaks) Careful with the ceramic bearing because it will take at least 1 litre to break in with slow acceleration otherwise they could skip.
I suggest stay with Nova and I like #9886 with the conical header, 5 to 7 fin depends on your track.
__________________
Nitro-x Tomorrow Fuel today
Blitz body the champion choice
kitracer is offline   Reply With Quote
Old 05-25-2009, 09:27 AM   #3250
Tech Fanatic
 
Join Date: Mar 2008
Location: Virginia
Posts: 937
Trader Rating: 21 (100%+)
Default

Quote:
Originally Posted by Roelof View Post
The best way to start with is with the flush setting. The main needle is always setted arround there and the LSN mostly 1 turn in fron flush.
That would be great if it would run like that but it wont. I have a 2630 pipe one it and I'm going to try a diffrent pipe to rule that out.
VA_Racer is offline   Reply With Quote
Old 05-25-2009, 07:16 PM   #3251
Tech Elite
 
Riketsu's Avatar
 
Join Date: Aug 2004
Location: Puerto Rico
Posts: 2,414
Trader Rating: 29 (100%+)
Send a message via AIM to Riketsu
Default

Quote:
Originally Posted by Roelof View Post
The best way to start with is with the flush setting. The main needle is always setted arround there and the LSN mostly 1 turn in fron flush.
Sure that aint picco carbs? None of my engines have a flushed HSN nor a flushed LSN.
__________________
eBay user id: riketsukirai
Riketsu is offline   Reply With Quote
Old 05-25-2009, 08:05 PM   #3252
Tech Fanatic
 
Join Date: Mar 2008
Location: Virginia
Posts: 937
Trader Rating: 21 (100%+)
Default

Quote:
Originally Posted by Riketsu View Post
I was tuning a friend's engine, and it was a bit weird. If it wasnt around what you are saying: HSN = 1 1/2 and LSN = 1/2, it wouldnt run fine. I tried resetting the needles back to stock and work my way from there like I always do, but no, it didn't work.

My suggestion is take the engine apart and inspect everything, dismantle the carburetor and look for damaged o-rings. When you are mounting everything back together, be sure to seal correctly neck of the carburetor since this is primarily where it leaks.

You can also slap in another carburetor if you can get your hands on one to start eliminating suspects.

But as a friendly advice, I currently am running 3 different novarossi engines (2 SCT and 1 353), and all of them are no where near 1 1/2 and 1/2. So it may be something wrong or it may be just that your engine runs there. Either way check it out to be safe.
Ive tried diffrent pipes, and longer pressure line from the pipe to tank and if this 353 dosen't have the hsn at 1 1/2 and the lsn at about 1/2 turns out its not happy. It dumps too much fuel in the engine if its any richer. I want to try changing the hsn and the piece that it goes into but if thats dosent change any thing what then? Replace the carb and it might do the same also. Could the problem be too much back preassure and it is over preasssurizing the tank and forcing too much fuel?
VA_Racer is offline   Reply With Quote
Old 05-25-2009, 11:37 PM   #3253
Tech Champion
 
Roelof's Avatar
 
Join Date: Aug 2007
Location: Holland
Posts: 5,736
Send a message via ICQ to Roelof
Default

Quote:
Originally Posted by Riketsu View Post
Sure that aint picco carbs? None of my engines have a flushed HSN nor a flushed LSN.
It must be startable.

http://www.jpracing.com/en/products/...arbu_fx21r.php
http://www.jpracing.com/en/products/...carbu_fx12.php
__________________
Speed is only fiction but a 130+km/h MRS4 is for real.
Roelof is offline   Reply With Quote
Old 05-26-2009, 03:38 AM   #3254
Tech Elite
 
J.Gonzalez's Avatar
 
Join Date: Nov 2002
Location: connecticut
Posts: 2,409
Trader Rating: 16 (100%+)
Default

Quick question.

I am rebuilding a damage cordoba engine. The case got damaged when the connecting rod broke and sleeve is wedged in case. Sleeve will not come out and case appears to have small ship internal.

Is their any difference between offroad plus 21 case and onroad plus 21 case?

Seems to be alot of new offroad case on ebay cheap.

Thanks
Jamie
J.Gonzalez is offline   Reply With Quote
Old 05-26-2009, 05:36 AM   #3255
Tech Elite
 
dameetz's Avatar
 
Join Date: Mar 2003
Location: The Sky
Posts: 2,535
Default

Quote:
Originally Posted by kitracer View Post
I saw one and know another guy doing really well with the Flash .21 (std, not tuned). The conrod is the Plus model, not 359.

I have been running 2 x 359 with no problems (other than my tank leaks) Careful with the ceramic bearing because it will take at least 1 litre to break in with slow acceleration otherwise they could skip.
I suggest stay with Nova and I like #9886 with the conical header, 5 to 7 fin depends on your track.
What do you think of the Flash performance Chris? Which do you think is better the new 35 Plus 21 ver 09 or Flash? I do have the 9886 pipe, it is a very good pipe with tons of power everywhere but I m having fuel shortage problems with it, I m thinking of getting Nova 2015 or 2052 or Sirio 2013 pipe...What do you think? BTW this eng will be for the upcoming race in Kuching which I saw you name joining that race too....
__________________
Dudududududuuuuuu.....
dameetz is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sirio engines thread EVOLUTION Offroad Nitro Engine Forum 2824 04-29-2014 10:58 AM
Axial Engines thread Axial Racing Onroad Nitro Engine Zone 164 10-06-2008 05:48 PM
RB engines thread CraigM Nitro Off-Road 7 01-05-2008 10:57 AM
JP Engines Thread DOMOisCOOL Onroad Nitro Engine Zone 2 02-16-2004 05:00 AM
OS engines thread EVOLUTION Onroad Nitro Engine Zone 44 02-11-2004 06:28 PM



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 03:46 AM.


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