wildchild45177

My Feedback: (11)

I use the OS typeF myself (just always trusted their product). This part is off topic, but do they tune the same as a two stroke? I just started running my first four stroke.
I have to say it sounds sweet, and runs good for break in. I can't wait to wring it out.

Bob

NM2K

My Feedback: (14)

Have you ever noticed that folks using one particular brand of glow plug are the ones stripping the threads out of their cylinder heads?

No, I'm not saying which brand, simply because there's nothing in it for me if I do except grief. Just think about which plug provides the most resistance to threading into the head when threading with your fingers initially.


Ed Cregger

RaceCity

Ed have you ever noticed the size of the wrench people use to install plugs?

I'm amazed they don't bust the firewall.

bla bla

For once I totally support and agree with Dude Zeelon.
Enr3's work great in just about every engine I've every used them in not to mention the ones i've told other people to use nr3's in!
OS F and Enr3's.
They're all the plugs anyone needs.

MatheusC20XE

I use Fireball hot plugs, and works good.. i don´t see any diference in performance to expensive OS "F".. turn the same rev.. and the Fireball appears have longer life..

The Raven

Interesting. Could it be they are doing something different with their head design to support a more common 2 stroke plug?

As a wild guess, they probably have the plug hole designed so the 2 stroke plug sits lower....in just the right position. Now if you put in a normal 4 stroke plug do you risk damaging the engine?

DarZeelon

No, Raven.

I saw an Enya .90-4C run with an OS 'F'.

I couldn't tell the difference. The Enya #3 is a 'normal' long reach plug - deeper than a normal OS (or Tower), but not quite as deep as the OS 'F'... Maybe OS make and recommend their 'F' plug for their four-strokes, because all their normal plugs (A3, #8, A5,...) have a 'medium reach', which may be insufficient for four-stroke...

MatheusC20XE

Well.. i measured the OS "F" and a Fireball normal HOT plug, and the diference of lenght of both is only 0,3mm. I didn´t feel any diference in power(measured in tach) using both plugs.. pretty same.

is more easy think, that OS made the "F" type, more to take money from customers with a diferent and specific product, than any other thing. You can use the OS "F" in a two stroke engine without problems too, only will make a little increase in compressio ratio, but is not a crucial diference..



I don´t spend more of my money in OS "F" plugs.. im very happy with the Fireball plugs in all of my engines(2 and 4 strokes).. i bought 3 cards of it..i will have plugs for all life




Cheers,



Matheus S. Almeida

NM2K

My Feedback: (14)

Good point.


Ed Cregger

The Raven

Without getting too technical, using a longer reach OS F plug (or any other similar 4 stroke plug) in a 2 stroke can affect how the engine runs.

1. Longer plug might hit the piston, unlikely but worth checking.
2. Longer plug raises compression, this could be good or bad depending on a number of other factors.
3. Four stroke plugs normally run hotter, at the very least this could change the ignition point (aka ignition timing) of the engine. Good/Bad, will depend on the engine.

I've only used an F plug on a 2 stroke once, it was a new inverted LA that just kept quitting (flooding on the way out to the runway). To avoid the increase in compression a second copper washer was used under the plug. It helped enormously but not as much as when the owner turn the engine upright, at which time a standard plug was used.

As for OS inventing an F plug just to 'take money' that's not a fair accusation. Sure, the company wants to make money (what company doesn't) but you don't invent useless products for the sake of taking customers for a ride. Customers will wake up to that quickly, no matter how loyal. If the OS F plug is a gimmick the same could be said for any other plug manufacturer.

MatheusC20XE

Well.. you are considering that OS "F" is a ultra long plug.. it´s not true.. is only 0,3mm taller than a default long 2 stroke plug. If you calculate, 0,3mm more of plug inside chamber, don´t makes any excellent diference in compressio ratio.. And i can say that, because i modified a small MDS 38 engine, increasing the compressio ratio of it to near detonation(max power can do using 15% of nitro and hot plug), and when i changed the plug for OS "F" one, it´s didn´t made any difference.. no detonations and no diferences in power(exaclty same rev range in tach).

The OS "F" appear to be much long, because have shorter thread and a big point.. the commom glow plugs, have bigger thread lenght, and no point. Because this, when you see the OS "F", you feel in your eyes that is very taller than commom long 2 stroke glow plugs.. but is not true.. Measure it and you will see that i talking.


About the temperature of OS "F", is pretty same termic range of hot plugs of 2 stroke(pretty same of OS A3 plugs).


Is much easy.. do the tests, use a tachometer, and then.. tell me..



And about the OS take money from customer.. well.. i agree, difficult to say that.. But, if you consider the very wrong tech informations about the engines of OS in website, you can believe more in it..

It´s always makes me laugh, when i enter in OS 55AX page and says: "Powerhouse engine.. max power 17.000rpm.."..

My friend´s 55AX don´t over 11.500rpm with the prop that OS said to use in Owner´s manual..


Is very easy create others diferent and specific products ranges.. in automotive factory it´s very commom too.. You pay 10 times more in the same part only because have some minor modification, that will don´t make any real diference in end.



In this hobbye.. if you follow all rules.. you lost your money..




Cheers,



Matheus

The Raven

Hmmm, I hadn't measured the plug or done any calculations to see what effect it does have on compression OR what temp the element glows at. In part, I was requoting the theories covered in a local R/C mag article. Although the theory sounds good, it probably is worth me checking with it in practice.

Engine speeds are dubious and I take them to be a design limit (aka redline) rather than a realistic operating speed. Look at the 40LA and 46AX, both are wildly different in design yet both are listed with 16000rpm. Neither will do that using sensible prop sizes. The 55AX is listed at 17000, yet it doesn't like to rev as hard as a 46AX (I consider the 55 a torque motor) using sensible sized props. 11500 is about right using the 12x7 recommendation, even though I find 12x8 is better for low down pulling power.

I'm still hesitant to use non-recommended plug types in engines and despite trying several brands (2 stroke) I have yet to notice any significant difference.

speedster 1919

My Feedback: (3)

Well lets look at Sonic Tronic 4 stroke plugs. 2 designs. 1 for OS engines and looks exactly like an OS F plug. And the 1 for Saito , Enya , Ect , Ect. thats looks just like the OS 8. I needed the shortest plug for a Webra T4 that recommended not to use a long plug like an OS F. This was the shortest 4 stroke plug I could find. I now use Hanger 9 plugs for my other 4 strokes at half the F plug price...........

MJD

My Feedback: (1)

"SPECIFICATIONS:
Stock Number: OSMG0556
Displacement: 0.545 cu in (9 cc)
Bore: 0.91 in (23 mm)
Stroke: 0.85 in (21.5 mm)
Practical rpm: 2,000-17,000
Output: 1.75 hp @ 16,000 rpm
Weight: 14.3 oz (404 g)
Includes: #8 glow plug, 40J carburetor, E-3010 muffler
Recommended Props: 12x7, 12x8, 13x6, 13x7"

The prop they recommend in the owner's manual is NOT the prop that will turn 17k on that engine, and it does not say that anywhere on their web page. It also offers a list of props that in their opinion are good choices for the most common applications. If you need logical for the application at hand. Maybe you are looking at a a retailer/distributor's web page, they have been known to be full of baloney.

MJD