ys sr dual plug head

[betta2500]

making a new prototype for dual glow head for ys sr.

email betta2500@aol.com

[Pulento]

Looking good.

Is it bigger than stock ? I've always think the stock head is a bit small.

[betta2500]

Is the same size as the original.
Thanks.

[HeliBenj]

Sorry if it's a stupid question, but what's the benefit?

[Jafa]

Cars and various engines use multiple spark plugs to get the flame front to travel sideways faster and then start pushing the piston down

You can get a smoother running engine

You can use two different heat ranges - makes the idle really smooth on one plug and the stunt mode really smooth on the other plug

Some argue that it's also a bit of a safety against a flame out due to loosing the plug in flight

[jake28]

Those look awesome

[betta2500]

I really appreciate your input,I'm making those heads for sale for 3 type of engines aling 91,ys 91 sr and st,maybe somebody got interested in the feature.

thanks.

[Jafa]

As a giggle, I even have two heads that have three plugs!
My friends give me a hard time saying a total flame out costs me $30

[ddracer]

I would love to see some power comparison results between heads. Follow me on this any set fuel will burn at a set speed. Surly the .91 head is not big enough for the second plug to make a difference in the flame head.

For example, My car is an Alfa 146 twinspark. This is my baby and used on trackdays and I pretty much know every nut and bolt. The inside of the cylinder is about 2.5" with a .5" squish. Right the car has a separate coil pack for each cylinder that powers both plugs. At a trackday for giggles we poped off four of the plugs just to see. Next to no difference at all and was on a head with say 5x the distance for the flame head to travel and a much lower octane fuel. OK the engine has a remapped ECU after market filters etc but that is because it was originally a road car, but our nitro engines are pretty well tuned to start with.

Please don't take this the wrong way as the work you have done look fantastic but it would be good to some stats.

Also with two different heat range plugs surely the hotter plug will alway ignite the mix first as glow plugs are always on?

[jake28]

.5" of squish.....lol really?

[ddracer]

That is an aproximation as the valve seats cut into it and I don't actually have the head off the car at the moment LOL

[Jafa]

It's not about power

Twin spark gives more efficient combustion and lower exhaust emissions,
but you probably wont feel this - you would need specialized gear to measure it

Twin spark also enables burning a leaner fuel mixer as well as using less ignition advance.
Just unplugging four spark plugs wont realize these benefits unless you remap the ECU

The Alfa 16V TS engines have had some debate and negative press

[ddracer]

OK cool so are you going to run the nitro engine leaner hence more power but of corse that would mean more heat.

Also your engine is a two stroke so timing is fixed by the port timing so really what are you going to gain? Again this is not a dig I love the work just want to know what your thinking?

PS your also right about Alfa 16v T-Spark mechanicly sound but the electrics are absolutly shocking and the standard ECU is one of the most unreliable ever made.

[jake28]

intake and exhaust is fixed but ignition is not why do you think they make glow plugs in diffrent heat ranges ??? DD if you are still not a believer why dont you do a search on a company called OMI that makes the Viperhead. Then tell us what they are thinking

[Jafa]

Originally Posted by ddracer

OK cool so are you going to run the nitro engine leaner hence more power but of corse that would mean more heat.

Not my thoughts - the manufacturers

I don't think they mean that lean - just slightly leaner I imagine

Originally Posted by ddracer

Also your engine is a two stroke so timing is fixed by the port timing so really what are you going to gain? Again this is not a dig I love the work just want to know what your thinking?

Again - not my thinking - the manufacturers
We were talking about four stroke twin spark cars

There is heaps of information on this theory - it's well known and understood
http://en.wikipedia.org/wiki/Alfa_Ro...n_Spark_engine

Originally Posted by Wikipedia

The two sparks on the 8V Alfa Twin Spark engines fire at the same time per cylinder and this makes the fuel mixture burn faster than single plug ignition because it is fired from 2 different places simultaneously. So less ignition advance could be used and also leaner mixtures could be burned.

I'm not sure that the burn faster comment is correct,
other references detail the flame front going sideways faster which is advantageous

With regard to our two strokes - there aren't many references supporting twin glow
But if you have actually used it - as I and many others have,
you can get a smoother hover (great for F3C but in 3D we don't care)
and with two different heat ranges you can get a great idle as well as good idle up performance
When you spool up you can really notice when it seems to key into the second plug,
it sounds like it's coming on the pipe
But do we care about the idle? Not really

Originally Posted by ddracer

PS your also right about Alfa 16v T-Spark mechanically sound but the electrics are absolutly shocking and the standard ECU is one of the most unreliable ever made.

I love Italian cars but their electrics have always been criticized
I had a Lancia Delta which was wonderful but when it hit 8 years old
something electric died every month for 6 six months before I sold it

[Pulento]

Jafa,

Why didn't you go with a slight bigger head as Viperhead did ?

[jake28]

jafa isn't making the head betta2500 is

[Jafa]

Originally Posted by Pulento

Why didn't you go with a slight bigger head as Viperhead did ?

As Jake said, I'm not making the head

I'm not sure if you can put the Viperhead on the SR

I think the Viperhead is made from different material also
Like the large OS heads which are alumite

[ddracer]

Originally Posted by Jafa

Not my thoughts - the manufacturers

With regard to our two strokes - there aren't many references supporting twin glow
But if you have actually used it - as I and many others have,
you can get a smoother hover (great for F3C but in 3D we don't care)
and with two different heat ranges you can get a great idle as well as good idle up performance
When you spool up you can really notice when it seems to key into the second plug,
it sounds like it's coming on the pipe
But do we care about the idle? Not really

Cheer mate that was what I was after, still not sure in my head how two different rated plugs will help, but that being said I my have ago at doing it to my TT50 and see for myself.

Originally Posted by jake28

Intake and exhaust is fixed but ignition is not why do you think they make glow plugs in diffrent heat ranges ??? DD if you are still not a believer why dont you do a search on a company called OMI that makes the Viperhead. Then tell us what they are thinkingI

As above but as you said if timing is done by the plug surely the hotter plug will always be causing ignition first? Even OMI dont have any information on their site on different rated plug in the same head.

[Pulento]

Originally Posted by Jafa

As Jake said, I'm not making the head

Sorry.

I'm not sure if you can put the Viperhead on the SR
I think the Viperhead is made from different material also
Like the large OS heads which are alumite

You cant. Is for YS91ST but they made the heads bigger to allow better cooling.

The new YS91SR3C has a bigger head also. I don't know if that fits YS91SR.