Glow plugs

[Djph_RC]

I know glow plugs have a number that relates to heat, (hotter and colder)
But when would you change them?
Colder months warmer months? And then what do you go with cold medium hot?
Tips and tricks would be appreciated as I need to order spares as I only have the one that came with my car.

 

[ohsnap]

This is what Google AI says about glow plus heat range.
"RC nitro glow plugs are chosen based on nitro percentage and air temperature: use hot plugs for low nitro (<24%) or cold weather, and cold plugs for high nitro (>25%) or hot weather.
Medium plugs are ideal for 60–80°F (16–25% nitro). Match plug type (Standard/Turbo) to your engine head.'

I rarely run when the temp is under 60F (16C) and typically run 20% nitro.
I've found that the OS #8 (a medium plug) to be a really good all-purpose plug - even when our temps hit the 90's.

It seems that there are typically two circumstances causing me to change plugs.
1. Engine won't start.
2. It's been running and the engine dies when I'm off the gas / hit idle in the middle of a run.
Like when I get into a collision and the truck comes to a stop and then the engine just cuts out.
Then trying to restart - see #1...

 

[Djph_RC]

I’ve got 25% fuel as that’s what the previous owner was running it on.
It’s currently 5•c here in the uk now. I’ll get some medium ones and some hot.
I don’t think we have the temperatures to get cold ones

 

[ohsnap]

Besides OS, I've also had good results using McCoy glow plugs.
The OS #7 is medium hot (just pointing out options).

Personally, I would avoid the inexpensive N4 HSP plugs.
My buddy "scored a great deal" on them, only to suffer issues.
He's back to buying OS or McCoy.

 

[Djph_RC]

Besides OS, I've also had good results using McCoy glow plugs.
The OS #7 is medium hot (just pointing out options).

Personally, I would avoid the inexpensive HSP plugs.
My buddy "scored a great deal" on them, only to suffer issues.
He's back to buying OS or McCoy.

I’ll have a look for some.
Thanks for the advice.
We took the savage out today. It took a while to get started but it’s very fast.

 

[ohsnap]

I have a soft spot for Savages.
I have a robust 24 YO nitro truck that we can still buy parts for - some new production - and there is a lot of (but not absolute) backward and forward parts compatibility.
Well, there is no "backwards" for my 2002 (and I assume yours too) - they are bedrock.

Yeah, you can say that about a TMaxx which is older still, but I'll take a Savage over a TMaxx any day of the week.
I'll tip my hat to the Revo though - while it's "newer" than the Savage, it's had some shelf life...

So many other trucks/truggies/buggies (nitro and electric) have come and disappeared over the years, that it's hard to keep track of them.

Are you priming it right (putting your finger over the exhaust and using roto for a second or two - until the fuel just reaches the carb inlet and not flooding it)?

It may also be the glow plug - ones on their way out can often make starting difficult - but you have plans in that department.

 

[Djph_RC]

Yeah that’s how I’m priming it.
Mine has had a pull start put on it and it took a while.
I’m thinking the glow plug is on its way out.

 

[Vinni]

Yeah that’s how I’m priming it.
Mine has had a pull start out on it and it took a while.
I’m thinking the glow plug is on its way out.

Were bouts in the uk are you mate ? Bloweing down exhaust pressure line probs best way to prime it instant fual to carb n no stress on pullstart open carb blowe down press line n you hear it pop which savage you got ?

 

[Djph_RC]

Were bouts in the uk are you mate ? Bloweing down exhaust pressure line probs best way to prime it instant fual to carb n no stress on pullstart open carb blowe down press line n you hear it pop which savage you got ?

Newcastle under Lyme,
Staffordshire mate.

 

[Djph_RC]

Newcastle under Lyme,
Staffordshire mate.

Savage 21 F4.6 engine and 3 speed gearbox

 

[ohsnap]

Savage 21 F4.6 engine and 3 speed gearbox

????
A Savage .21 is not a F4.6 - it's a 3.5.
Can you post a picture or two of your engine?

All our cooling head conversation (at least from my side) has been using the assumption that you had a .21BB and not a 4.6 in it.
If it's an F4.6, one of those heads you asked about may work.

 

[Djph_RC]

????
A Savage .21 is not a F4.6 - it's a 3.5.
Can you post a picture or two of your engine?

All our cooling head conversation (at least from my side) has been using the assumption that you had a .21BB and not a 4.6 in it.
If it's an F4.6, one of those heads you asked about may work.

I posted a picture of it the other day but I’ll do it again. It’s an F4.6 and has the black crank case, where as the 21.bb has a silver crack case.

 

[ohsnap]

I'm caught up now. Sometimes it just takes a while.
Get some new glow-plugs in and enjoy your Savage!