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what glow plug should I run?
- Thread starter robn69
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- Messages
- 4,790
Run a medium heat range plug.... outta be just fine.....
- Messages
- 4,790
There are 2 main types of glow plugs, Turbo style and Non Turbo style. the savage uses the NON turbo plug and works best with a medium heat range plug for most all bashin needs
https://www.hpisavageforum.com/threads/turbo-glow-plug.569/#post-8078
Read thru that thread and hopefully you will have more understanding on glow plugs and their types and uses....
https://www.hpisavageforum.com/threads/turbo-glow-plug.569/#post-8078
Read thru that thread and hopefully you will have more understanding on glow plugs and their types and uses....
N713TL
Active Member
- Messages
- 76
My experiences it depends on the temperature outside were you are running and if it is dry or damp . Example I'm in Chicago so a great heat range is medium. Went to Kentucky for a week and it was 90 with 90 humidity and it keep burning up that medium range plug went with a r5 was fixed the week after I was in Alaska and it was 50 had a hard time starting a r3 was great . I keep a r 3,4,5 in box
- Messages
- 2,627
- Location
- Dekalb, IL 60115
Glow plug temperature affects to the timing of the combustion in the engine. The hotter the plug, the earlier the fuel/air ignite, the cooler the plug the later it ignites.
Also, the higher the nitro content, the earlier it fires, the lower the % the later it fires. The same This is why shims are usually added when running higher than 25% nitro.
If an engine is firing too early, then it's fighting with itself by trying to push the piston back down as it's coming up. This causes damaged glow plugs, con-rods, high temps, low power output... If it's firing too late, then the piston is already on it's way back down when it fires, which causes lower power output.
Ambient temps play a part as the temp of the air around the engine changes how hot the engine gets which causes the ignition time of the fuel/air to change. So, a cooler ambient requires a hotter plug, warmer ambient requires a cooler plug.
That all said, if your running a big block and 20-25% nitro fuel, a medium plug usually does well. For a small block, a hot plug usually works well. I use odonnel purple plugs for most of my vehicles. In my revo with a 21TM (requires longer plug than normal), I ran the OS LC3 which is a hot plug. Break-in was fine, running after wards was fine. I changed to an LC4 (medium temp), power picked up quite a bit.
Also, the higher the nitro content, the earlier it fires, the lower the % the later it fires. The same This is why shims are usually added when running higher than 25% nitro.
If an engine is firing too early, then it's fighting with itself by trying to push the piston back down as it's coming up. This causes damaged glow plugs, con-rods, high temps, low power output... If it's firing too late, then the piston is already on it's way back down when it fires, which causes lower power output.
Ambient temps play a part as the temp of the air around the engine changes how hot the engine gets which causes the ignition time of the fuel/air to change. So, a cooler ambient requires a hotter plug, warmer ambient requires a cooler plug.
That all said, if your running a big block and 20-25% nitro fuel, a medium plug usually does well. For a small block, a hot plug usually works well. I use odonnel purple plugs for most of my vehicles. In my revo with a 21TM (requires longer plug than normal), I ran the OS LC3 which is a hot plug. Break-in was fine, running after wards was fine. I changed to an LC4 (medium temp), power picked up quite a bit.
Nitrodannyboy
Member
- Messages
- 24
Why is my piston hitting my glo plug unless i add extra copper washer?
- Messages
- 4,790
Got a pic and what model plug you are using???
Nitrodannyboy
Member
- Messages
- 24
"Hpi nitro star 21 bb" the purple 3.5 motor. And i till my glow plug out of my trx 3.3 traxxas
Nitrodannyboy
Member
- Messages
- 24
The Piston is literally smashing into the glow plug physically hitting it what would cause that? Are there different glow plugs with different depths?
Nitrodannyboy
Member
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- 24
Are there different length glow plugs?
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- 2,627
- Location
- Dekalb, IL 60115
Yes. Short (4 thread), standard (5 thread) and long (6 thread) I think. Traxxas plugs are long. OS sells some long ones for their TM engines, LC3 and LC4, not sure why they did that. Seems silly to make a special long plug just for a couple engines they make. Perhaps they were trying to cater to the traxxas engine guys too. Probably a few others that are "long" plugs too.
What plug do you have and what engine?
Short: Fox Short
Standard: OS #8, OS #6 (A3)
Long: OS LS3, OS LS4, Traxxas Super Duty
I use odonnel medium temp in my LRP's. Appears they are a bit longer than standard plugs. They tend to be cheaper than others and they run a good long while. I run OS LC3 in my 2.5 jato and LC4 in my 21TM revo.
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Nitrodannyboy
Member
- Messages
- 24
I just traded my traxxas slayer 4x4 short track for the the slightly older hpi savage 21 with the hpi nitro star 21 big block (3.5) the black and purple 1/8 scale monster truck. (With the purple engine head) Does that motor take a short glow plug? Because i put a few washers on the traxxas plug and got it to fire and run. But i didn't want to risk ruining the piston or sleeve so i shut it down without making Any pulls.
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- 4,790
Nitrodannyboy
Member
- Messages
- 24
I understand that it will take a short plug and medium heat range. But would a traxxas super duty cause clearence issues? I'm trying to make sure that is the problem i was having.
- Messages
- 4,790
Really the best way is going to obtain a short type plug and see the length of the coil chamber at the end, if you set them side by side with the hex shanks lined up it should be fairly obvious...
I checked my supply and don't have a long plug to compare myself
I checked my supply and don't have a long plug to compare myself
francis Labarbara
Well-Known Member
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- 456
- Location
- West Virginia
Compare the Threads on the LC4 and the R5
- Messages
- 2,627
- Location
- Dekalb, IL 60115
Take the head off the engine, put a single washer on the glowplug and see if the plug goes into the head button beyond flush with the expansion dome:
If it goes in further than flush, then it's too long. If it exceeds being flush with the flat part of the head button, it's close to hitting the piston if not actually hitting it. Typically, when the piston is at TDC, there is a mm or two of space between the base of the button and the top of the piston. However, if the plug is exceeding being flush with the dome itself, it's going to mess up the compression ratio a bit due to taking up extra space, which could give weird results on it's own regardless of contact with the piston.
