Fireball Glow plugs

Intlwaters

Help Support Intlwaters:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Does anyone think it maybe time to consider spark ignition? Today's ignition systems are very compact and have a lot of advantages. We ran a Quickdraw on boat fuel a long time ago. It ran fine on 15% nitro, but burned the electrodes off the plug with 40% nitro. We didn't adjust anything from the gas setup except the carb. We took out the diaphragms in a WYK carb and ran it like a nitro barrel carb.

It might take some small plug development, but quite a few 8mm thread plugs exist. That's only a little larger than 1/4". See 8mm Diameter - Car Spark Plugs It would require rule changes to allow two engine classes, gasoline and fuel. Either could run glow or spark ignition.

Lohring Miller
 
i could spout off allot of ideas and theories but ,,,esp 4 the ones saying lets try a new way lets try this --- blow a plug =richen it up.
dont argue,no theories/explinations,,,dont matter ,not relevant... just keep richening till u stop blowing

THEN or at the same time do WHATEVER it takes to get ur speed/handling/throttling/milling/whatever back where u want it. no leaning ,keep ur plug and get the boat working.
try it ,u might like it .

on a side note coldest thing i ran when i was first learnin was a mc9,,,dang i blew some plugs. figured it out ,with some 100mph club member help n then i pretty much gave away all the mc9s.
cant give me a plug that doesnt have super hot in the title now


From what I've seen most guys don't burn their expensive nitro very well. They run full water, a super cold plug like an OD289 then they havta lean the crap outta the needle to make it "go".

Cut back on the water, run a hotter plug and richen the needle a bunch, you'll go faster, mill better and will be a whole lot easier on plugs and motors.

Andy Brown put me on to this way back and it works!

10 thou restrictor:

full
 
Does anyone think it maybe time to consider spark ignition? Today's ignition systems are very compact and have a lot of advantages. We ran a Quickdraw on boat fuel a long time ago. It ran fine on 15% nitro, but burned the electrodes off the plug with 40% nitro. We didn't adjust anything from the gas setup except the carb. We took out the diaphragms in a WYK carb and ran it like a nitro barrel carb.

It might take some small plug development, but quite a few 8mm thread plugs exist. That's only a little larger than 1/4". See 8mm Diameter - Car Spark Plugs It would require rule changes to allow two engine classes, gasoline and fuel. Either could run glow or spark ignition.

Lohring Miller
I still have some NIB 1/4-32 Campion plugs I inherited.
I think there will be a considerable learning curve to run very much nitro through a small ignition engine. The best I’ve heard was in the 15% range but that was yeas ago. The key is like Lohring said the ignition systems.
 
CH ignitions are rated to 25,000 rpm. Powerspark ignitions are rated to 30,000 rpm. You need a coil and resistor plug with the Powerspark ignition but they are very programmable. CH uses a resistor wire and shielded plug cap so you can get away with non resistor plugs. Its timing is fixed, but has a low rpm retard for starting. My big question is how high nitro can the available plugs handle. It might not matter for the larger engines which run well on lower nitro.

Lohring Miller
 
Hi Tom,
I have run nothing but MC-9's in my Rossi .21s and Picco 45s (65% nitro) for more than 30 years. Two of my 21s are starting their 3 season on the same plug. I am currently sitting on about 90 plugs and you could not pay me enough to part with one of them. I honestly don't know how they perform in the big blocks and frankly I don't care because those dudes are too rich for my blood. You really need to anneal them first!!!
Who sells MC-9's?
 
Does anyone think it maybe time to consider spark ignition? Today's ignition systems are very compact and have a lot of advantages. We ran a Quickdraw on boat fuel a long time ago. It ran fine on 15% nitro, but burned the electrodes off the plug with 40% nitro. We didn't adjust anything from the gas setup except the carb. We took out the diaphragms in a WYK carb and ran it like a nitro barrel carb.

It might take some small plug development, but quite a few 8mm thread plugs exist. That's only a little larger than 1/4". See 8mm Diameter - Car Spark Plugs It would require rule changes to allow two engine classes, gasoline and fuel. Either could run glow or spark ignition.

Lohring Miller
Well thy would need a rule change for that.
Good luck.
 
Well I have some of the TCA #8 special plugs heading my way.
$10 each shipped.
Will see how thy work.
 
From what I've seen most guys don't burn their expensive nitro very well. They run full water, a super cold plug like an OD289 then they havta lean the crap outta the needle to make it "go".

Cut back on the water, run a hotter plug and richen the needle a bunch, you'll go faster, mill better and will be a whole lot easier on plugs and motors.

Andy Brown put me on to this way back and it works!

10 thou restrictor:

full
I make my own cooling cap and brass heads.
Thy have a small hole .060 in the cap and also drill a small .040 hole in the fitting on the rudder to release the pressure.
 
I make my own cooling cap and brass heads.
Thy have a small hole .060 in the cap and also drill a small .040 hole in the fitting on the rudder to release the pressure.
I liked the old OD 099 plugs thy had good heat with a stout wire.
Thy new 289 are to cold for me.
 
I got a couple of these last year from Rick Baker. Istall in you water line. Take water temp. Adjust with your flow meter. Keep notes. Slicker than snot!
 

Attachments

  • IMG_0622.JPG
    IMG_0622.JPG
    128.9 KB · Views: 44
From what I've seen most guys don't burn their expensive nitro very well. They run full water, a super cold plug like an OD289 then they havta lean the crap outta the needle to make it "go".

Cut back on the water, run a hotter plug and richen the needle a bunch, you'll go faster, mill better and will be a whole lot easier on plugs and motors.

Andy Brown put me on to this way back and it works!

10 thou restrictor:

full
Apparently you need to be a bit prudent with controlling cooling water flow. Many years ago John Equi proved that if you slow down water flow thru the head it actually is able to gather more heat before exiting. What do you think?
 
Apparently you need to be a bit prudent with controlling cooling water flow. Many years ago John Equi proved that if you slow down water flow thru the head it actually is able to gather more heat before exiting. What do you think?

Hmmmm...

I find that hard to believe. I mean if you cut the water down the head should run hotter, I can't see any other scenario.
 
I would put the adjustment tee on the outlet
line of the head ... thereby keeping the water jacket full and time to absorb heat.

installing the tee on the inlet side will only allow
a trickle of water into the head and the water will take the path of least resistance and may not fully fill the water jacket...

but that's just my .02
 
From what I've seen most guys don't burn their expensive nitro very well. They run full water, a super cold plug like an OD289 then they havta lean the crap outta the needle to make it "go".

Cut back on the water, run a hotter plug and richen the needle a bunch, you'll go faster, mill better and will be a whole lot easier on plugs and motors.

Andy Brown put me on to this way back and it works!

10 thou restrictor:

full

[/QUOTE
One of the most critical tuning tips for nitro boat, pure gold!
Kinda ironic
From what I've seen most guys don't burn their expensive nitro very well. They run full water, a super cold plug like an OD289 then they havta lean the crap outta the needle to make it "go".

Cut back on the water, run a hotter plug and richen the needle a bunch, you'll go faster, mill better and will be a whole lot easier on plugs and motors.

Andy Brown put me on to this way back and it works!

10 thou restrictor:

full
One of the most critical tuning points for nitro boats, pure gold!
Kinda ironic reading through this post as I assemble a little 21 outboard for a small pond on my property after spending almost $100 for a gallon of fuel and thinking I'm f'n crazy.
Sad to see it come to this but it was inevitable, RC cars are big time electric now and nitro boats were only ever as healthy as the nitro car industry.
 
Hmmmm...

I find that hard to believe. I mean if you cut the water down the head should run hotter, I can't see any other scenario.
Back then some hobbyist was sell little 1/4 inch plastic dots with adhesive so you could stick them on the water jacket. I never tried them, but supposedly there were different heat ranges and they would change color accordingly. John stuck several different ones on a .21 ran it under various cooling conditions and noted the color changes.
I agree with you on cutting down the water, but I think you would have to really "starve" it to have any significant effect and that could get a bit tricky.
 
I would put the adjustment tee on the outlet
line of the head ... thereby keeping the water jacket full and time to absorb heat.

installing the tee on the inlet side will only allow
a trickle of water into the head and the water will take the path of least resistance and may not fully fill the water jacket...

but that's just my .02


Binder Dundat. I actually split Prather fuel tubing from the pressure.

Back then some hobbyist was sell little 1/4 inch plastic dots with adhesive so you could stick them on the water jacket. I never tried them, but supposedly there were different heat ranges and they would change color accordingly. John stuck several different ones on a .21 ran it under various cooling conditions and noted the color changes.
I agree with you on cutting down the water, but I think you would have to really "starve" it to have any significant effect and that could get a bit tricky.


You do havta cut it down quite a lot, if you have a flow meter you can start by flowing your whole cooling system to the same setting as your needle. Run the boat hard, bring it in and grab the head. If you can hold it more than a coupla seconds it's too cold.

I run an 0.030" restrictor in my 20 mono and 40 hydro and an 0.040" in my 90. Thought I might be overheating at Hunsville a couple years ago (warm air and water) & pulled the restrictor out of my 90 boat. The thing was so rich I didn't have enough range on the third channel to stop it from blubbering. :(
 
On my BZM motor the water outlets (2) are very large. I was concerned that the outlet was larger than the inlet and would not keep the water chamber full. So I got out the flow meter and dialed it down on both outlets. I was also able to get them equal so that one side is not hotter than the other.

I too have split tubing with too much pressure. It is a little of both. You need to restrict outlet and inlet. The outlet should never be bigger than the inlet. The temp will not be consistant.
 
Back
Top