Shimming, nitro %, glow plug and timing
01-24-2007, 07:24 AM
#16
Tech Regular
Grinder Quote:
Originally Posted by Rich Browne
They are available in standard and turbo plug (Nova Rossi or Sirio only). Custom made and usually not in stock from local hobby shops - these are for the "ultra-racer"
Dear Grinder, that is the ONLY and correct way to measure the head clearance, only if you are serious about the hobby 
Have fun on the Winters!!!! and keep us posted with your engines
Originally Posted by Rich Browne
They are available in standard and turbo plug (Nova Rossi or Sirio only). Custom made and usually not in stock from local hobby shops - these are for the "ultra-racer"
Purchase from Ashford Hobbies:
http://www.ashfordhobby.com
I know Ace Hobbies had some in stock (They're closing soon - better call quick): http://www.acehardwarehobbies.com
I would prefer you purchase from these sources. I am happy to help with Tech Questions. Our phone number is listed on the Empire site.
I use mine constantly. It is the easiest way to accurately measure head clearance that I have found. Great tool. Thanks Empire!
http://www.ashfordhobby.com
I know Ace Hobbies had some in stock (They're closing soon - better call quick): http://www.acehardwarehobbies.com
I would prefer you purchase from these sources. I am happy to help with Tech Questions. Our phone number is listed on the Empire site.
I use mine constantly. It is the easiest way to accurately measure head clearance that I have found. Great tool. Thanks Empire!
Have fun on the Winters!!!! and keep us posted with your engines
01-24-2007, 07:37 AM
#17
Tech Regular
We should also state that the comments with regards to plugs and head shimming are when both are used together. Used alone a hotter plug will rev harder and a colder plug will make more torque.
As you know all of this is theory on a 4 stroke, can it be aplied on 2 stroke engines?
01-24-2007, 09:30 AM
#18
Originally Posted by ALG
AFM, I think this is vice versa. When you put a hotter plug, the ignition will be sooner, this is like advancing the cams of a car, if you advance the cams you will gain torque, and if you put a colder plug, this is like retarding the cams, making high end better.
As you know all of this is theory on a 4 stroke, can it be aplied on 2 stroke engines?
As you know all of this is theory on a 4 stroke, can it be aplied on 2 stroke engines?
AFM
02-01-2007, 08:32 AM
#19
I got a question..??
Is it ok to put three 0.1mm shims in order to use 30% fuel ?? I checked my engine and although I know it is supposed to come with a brass and a silver shim. However, my O.S. TZ 12 came with two brass shims. So I added one more. I think I have got the right head clearance in theory, but is it normal to have three shims clustered like that under the engine head??
Thanks..
Is it ok to put three 0.1mm shims in order to use 30% fuel
?? I checked my engine and although I know it is supposed to come with a brass and a silver shim. However, my O.S. TZ 12 came with two brass shims. So I added one more. I think I have got the right head clearance in theory, but is it normal to have three shims clustered like that under the engine head??Thanks..
02-08-2007, 12:37 PM
#20
I finally got a chance to thoroughly read Dennis Richey's article posted above and it is really awesome info.
Can anyone help me find tune this info into some type of procedure/guide? It may not be possible, but I sure would like to try.
1. Measure head clearance.
2. Based on head clearance, choose your nitro %: (Maybe thse should be ranges)
a) .36mm or less, use ??% nitro
b) .46mm or less, use 20% nitro
c) .??mm or less, use 25% nitro
d) .56mm or less, use 30% nitro
If you need to use a higher or lower % nitro, add or remove shims.
3. Choose your glow plug:
And this is where the fun really starts...
afm posted this a while back.
Is the opposite true?
- When the ambient temperature is low, we have to use a plug with thinner wire.
- With lower compression, we have to use a plug with thinner wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With low humidity percentage we should use a Cold (F) thermal range plug.
- If we have low temperature and low humidity, we should use a plug with thin wire and a Cold(F) thermal range.
Now there is also this info:
At this point clutch setting and gearing play a role - not just the fuel, plug and head clearance. What are the troubleshooting steps before changing any of the above?
- If your engine overheats:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more top end speed:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more bottom end:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- Not enough run time (< 5 min.):
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you increase or decrease your nitro %
Go back to step 2 and adjust your head clearance
Can anyone help me find tune this info into some type of procedure/guide? It may not be possible, but I sure would like to try.
1. Measure head clearance.
2. Based on head clearance, choose your nitro %: (Maybe thse should be ranges)
a) .36mm or less, use ??% nitro
b) .46mm or less, use 20% nitro
c) .??mm or less, use 25% nitro
d) .56mm or less, use 30% nitro
If you need to use a higher or lower % nitro, add or remove shims.
3. Choose your glow plug:
And this is where the fun really starts...
afm posted this a while back.
http://www.rctech.net/forum/showpost...9&postcount=22
How to select the proper plug:
- When the ambient temperature is high, we have to use a plug with thicker wire.
- With higher compression, we have to use a plug with thicker wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With high humidity percentage we should use a Hot (C) thermal range plug.
- If we have high temperature and high humidity, we should use a plug with thick wire and a Hot(C) thermal range.
* Thermal Range: F (Fredda = Cold) C (Calda = Hot)
How to select the proper plug:
- When the ambient temperature is high, we have to use a plug with thicker wire.
- With higher compression, we have to use a plug with thicker wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With high humidity percentage we should use a Hot (C) thermal range plug.
- If we have high temperature and high humidity, we should use a plug with thick wire and a Hot(C) thermal range.
* Thermal Range: F (Fredda = Cold) C (Calda = Hot)
- When the ambient temperature is low, we have to use a plug with thinner wire.
- With lower compression, we have to use a plug with thinner wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With low humidity percentage we should use a Cold (F) thermal range plug.
- If we have low temperature and low humidity, we should use a plug with thin wire and a Cold(F) thermal range.
Now there is also this info:
The best instrument to determine which Turbo Plug to use, is those weather panels they sell for Yachts, that have Temp, Humidity and Barometric Pressure on them. Have it calibrated at your local weather station, and bingo, you’re ready like the Pros.
That is the key to success or failure tuning engines with Turbo Glow Plugs, because they are so sensitive to weather variations that is unbelievable.
Following is a selection chart for Novarossi Turbo Glow Plugs:
That is the key to success or failure tuning engines with Turbo Glow Plugs, because they are so sensitive to weather variations that is unbelievable.
Following is a selection chart for Novarossi Turbo Glow Plugs:
Code:
Type Thermal Range Nitro% Temp C / Temp F Humidity% C5TC Hot/hot wire 10-20 0-10 / 32-50 70-100 C6TC Hot/average wire 10-20 10-16 / 50-61 70-100 C7TC Hot/cold wire 20-30 16-25 / 61-77 70-100 C8TC Hot/ultra cold wire 20-30 25-up / 77-up 70-100 C5TF Cold/hot wire 20-30 0-10 / 61-77 40-70 C6TF Cold/average wire 20-30 10-15 / 61-77 40-70 C7TF Cold/cold wire 20-up 16-25 / 61-up 40-70 C8TF Cold/ultra cold wire 20-up 25-up / 77-up 40-70
- If your engine overheats:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more top end speed:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more bottom end:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- Not enough run time (< 5 min.):
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you increase or decrease your nitro %
Go back to step 2 and adjust your head clearance
02-08-2007, 01:41 PM
#21
Originally Posted by nitro_moe
I got a question..??
Is it ok to put three 0.1mm shims in order to use 30% fuel ?? I checked my engine and although I know it is supposed to come with a brass and a silver shim. However, my O.S. TZ 12 came with two brass shims. So I added one more. I think I have got the right head clearance in theory, but is it normal to have three shims clustered like that under the engine head??
Thanks..
Is it ok to put three 0.1mm shims in order to use 30% fuel
?? I checked my engine and although I know it is supposed to come with a brass and a silver shim. However, my O.S. TZ 12 came with two brass shims. So I added one more. I think I have got the right head clearance in theory, but is it normal to have three shims clustered like that under the engine head??Thanks..
Yes 3 is fine , what you want to check is that once you have shimms in place check that you have some meat left in the head button to seat into the cylinder.
02-08-2007, 02:06 PM
#22
Originally Posted by rmdhawaii
I finally got a chance to thoroughly read Dennis Richey's article posted above and it is really awesome info.
Can anyone help me find tune this info into some type of procedure/guide? It may not be possible, but I sure would like to try.
1. Measure head clearance.
2. Based on head clearance, choose your nitro %: (Maybe thse should be ranges)
a) .36mm or less, use ??% nitro
b) .46mm or less, use 20% nitro
c) .??mm or less, use 25% nitro
d) .56mm or less, use 30% nitro
If you need to use a higher or lower % nitro, add or remove shims.
3. Choose your glow plug:
And this is where the fun really starts...
afm posted this a while back.
Is the opposite true?
- When the ambient temperature is low, we have to use a plug with thinner wire.
- With lower compression, we have to use a plug with thinner wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With low humidity percentage we should use a Cold (F) thermal range plug.
- If we have low temperature and low humidity, we should use a plug with thin wire and a Cold(F) thermal range.
Now there is also this info:
At this point clutch setting and gearing play a role - not just the fuel, plug and head clearance. What are the troubleshooting steps before changing any of the above?
- If your engine overheats:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more top end speed:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more bottom end:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- Not enough run time (< 5 min.):
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you increase or decrease your nitro %
Go back to step 2 and adjust your head clearance
Can anyone help me find tune this info into some type of procedure/guide? It may not be possible, but I sure would like to try.
1. Measure head clearance.
2. Based on head clearance, choose your nitro %: (Maybe thse should be ranges)
a) .36mm or less, use ??% nitro
b) .46mm or less, use 20% nitro
c) .??mm or less, use 25% nitro
d) .56mm or less, use 30% nitro
If you need to use a higher or lower % nitro, add or remove shims.
3. Choose your glow plug:
And this is where the fun really starts...
afm posted this a while back.
Is the opposite true?
- When the ambient temperature is low, we have to use a plug with thinner wire.
- With lower compression, we have to use a plug with thinner wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With low humidity percentage we should use a Cold (F) thermal range plug.
- If we have low temperature and low humidity, we should use a plug with thin wire and a Cold(F) thermal range.
Now there is also this info:
At this point clutch setting and gearing play a role - not just the fuel, plug and head clearance. What are the troubleshooting steps before changing any of the above?
- If your engine overheats:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more top end speed:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more bottom end:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- Not enough run time (< 5 min.):
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you increase or decrease your nitro %
Go back to step 2 and adjust your head clearance
With respect to 1 and 2.....actually you first have to determine what Nitro% fuel you will run, because mainly it is determined by rules, like EFRA & IFMAR which only allow 16%. In the states most top drivers run on 30% nitro.
Once you have determined that, you measure your actual head clearance without shims, and then add neccesary shims to adjust your engine's combustion chamber accordingly.
Now this rough figures apply for .12 engines.
16% Nitro .36mm - .40mm
20% Nitro .40mm - .50mm
25% Nitro .50mm - .60mm
30% Nitro .60mm - .65mm
Then you select appropiate plug according to table , and yes opposite is true.
Then you have to set your clutch with initial reccomendtaions from manufacturer and the adjust your carburator on the track.
When you feel the engine is not fast enough, but working fine, first thing you should think about is ....
1.- Are the tyres sticking? Is the track clean without to much dust?
2.- Do you have the right gear ratio?
3.- Is the clutch properly tuned?
4.- Are the transmission and bearings smooth?
5.- The last way is to lean a bit your engine, and here are some key points:
* At first do not lean the low-speed needle keep it rich. If you want more low end torque, change to a thicker clutch spring or tighten the clutch nut.
* Always use the tallest 2nd gearing your engine can pull. No need to worry about if the tallest 2nd gearing makes the acceleration slower. If you find the car slowing down a bit when it changes to 2nd speed, then you may need to delay the timing of 2nd speed clutch.
* Just remember when you lean the HSN, you may need to rich the LSN at the same time. When you lean the LSN, you may need to rich the HSN also. If you move HSN for 5 mins, then move the LSN 10mins(double). Then you will find a balance point between HSN and LSN.
AFM
02-08-2007, 02:54 PM
#23
Sweet! Thanks Alfonso 
02-08-2007, 07:09 PM
#24
Question? I have a .21 ninja that I just broke in, I added a third shim for this process. Should I remove it now that it's broken in? When you measure the distance between TDC in the piston what are you sopposed to subtract it from? Where do I measure ? I'm a newbie 
02-08-2007, 10:42 PM
#26
Originally Posted by rmdhawaii
I finally got a chance to thoroughly read Dennis Richey's article posted above and it is really awesome info.
Can anyone help me find tune this info into some type of procedure/guide? It may not be possible, but I sure would like to try.
1. Measure head clearance.
2. Based on head clearance, choose your nitro %: (Maybe thse should be ranges)
a) .36mm or less, use ??% nitro
b) .46mm or less, use 20% nitro
c) .??mm or less, use 25% nitro
d) .56mm or less, use 30% nitro
If you need to use a higher or lower % nitro, add or remove shims.
3. Choose your glow plug:
And this is where the fun really starts...
afm posted this a while back.
Is the opposite true?
- When the ambient temperature is low, we have to use a plug with thinner wire.
- With lower compression, we have to use a plug with thinner wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With low humidity percentage we should use a Cold (F) thermal range plug.
- If we have low temperature and low humidity, we should use a plug with thin wire and a Cold(F) thermal range.
Now there is also this info:
At this point clutch setting and gearing play a role - not just the fuel, plug and head clearance. What are the troubleshooting steps before changing any of the above?
- If your engine overheats:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more top end speed:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more bottom end:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- Not enough run time (< 5 min.):
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you increase or decrease your nitro %
Go back to step 2 and adjust your head clearance
Can anyone help me find tune this info into some type of procedure/guide? It may not be possible, but I sure would like to try.
1. Measure head clearance.
2. Based on head clearance, choose your nitro %: (Maybe thse should be ranges)
a) .36mm or less, use ??% nitro
b) .46mm or less, use 20% nitro
c) .??mm or less, use 25% nitro
d) .56mm or less, use 30% nitro
If you need to use a higher or lower % nitro, add or remove shims.
3. Choose your glow plug:
And this is where the fun really starts...
afm posted this a while back.
Is the opposite true?
- When the ambient temperature is low, we have to use a plug with thinner wire.
- With lower compression, we have to use a plug with thinner wire.
- Humidity determines if we use a Cold (F) thermal range, or Hot (C) thermal range.
- With low humidity percentage we should use a Cold (F) thermal range plug.
- If we have low temperature and low humidity, we should use a plug with thin wire and a Cold(F) thermal range.
Now there is also this info:
At this point clutch setting and gearing play a role - not just the fuel, plug and head clearance. What are the troubleshooting steps before changing any of the above?
- If your engine overheats:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more top end speed:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you need more bottom end:
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- Not enough run time (< 5 min.):
Cluch/gearing?
Troubleshooting?
Engine Tuning?
- If you increase or decrease your nitro %
Go back to step 2 and adjust your head clearance
02-10-2007, 02:19 AM
#27
Originally Posted by gashuffer
Question? I have a .21 ninja that I just broke in, I added a third shim for this process. Should I remove it now that it's broken in? When you measure the distance between TDC in the piston what are you sopposed to subtract it from? Where do I measure ? I'm a newbie
Ultimate Nitro Engine Tuning DVD: "Checking Head Clearance"
http://videos.radiocontrolzone.com/n...ng_sample1.ZIP
Since you're running a .21 and not a .12, I'm not sure how the tuning info posted above applies to you, so just keep that in mind.
02-10-2007, 07:43 AM
#28
Tech Apprentice
how about some head clearance #'s for 21's maybe on 20% 30% nitro
02-22-2007, 03:44 PM
#29
Tech Addict
iTrader: (2)
Originally Posted by Randyc
how about some head clearance #'s for 21's maybe on 20% 30% nitro
0% -- .006"
10% -- .012"
20% -- .018"
30% -- .024"
these are conservative numbers and will get you in the ballpark safely.
