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Works for me!! I think they are saying there is a threashold and once you reach it then there is a need for more spark. I don't think they are refering to the average everyday displacement increases. This is extreme stuff
 

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My bad, I just didn't give it a chance to upload. Sorry for the confusion.
 

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just think, if you go that extreme, you need to worry about good atomization, erratic f/a ratios. You'd almost have to force feed the motor to make it run right. Doesnt the ds650 have 2 plugs? Seems like a waste of head space and tunnel rerouting to me.
 

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We have a 3 plug head on our 794 drag frame raptor. I wont get into the politics but the heads are built byTim Barker. Terry has his own ignition setup he likes to use with it. There have been discussions/debates on other forums over this setup.
The DS/Rotax engine begins life with 2 plugs and that is one reason they respond so well to large bores.
Yes there are many big bore/stroke raptors running well with a single plug. I do however believe with the 3 plug head the numbers would be even better.If nothing else this design allows these big engines to rev and do so quickly.The quicker you can build power the faster your going to be.
 

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Id like to see pics of that 3 plug head ... curiosity...is it based on the 660 head at all? How many valves? People amaze me in what they can make. :thumbsup:
 

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danos660r said:
Id like to see pics of that 3 plug head ... curiosity...is it based on the 660 head at all? How many valves? People amaze me in what they can make. :thumbsup:
It's a modified 660 head.

Scholle, when you added the 3 plug head, did you add it as a single mod or was it done with other mods. Wondering if it made a noticable difference or if it was necessary for the motor you built and fuel you were running?
 

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I dont have any pics with the head off the bike. The 2 other plugs come in on the sides of the head opposite each other. I posted some pics on here of the enitire bike.
http://www.raptorforum.com/index.php?topic=7927.0
The other side doesnt have the bushing like the lest side its a little different since is goes through the coolant passage.
I think giesick has some on thier website.
 

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i don't think the ds650 has 2 plus. I can check with my buddy who has a ds650.
 

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Here is a link you can check out that has a ton of pictures of that bike: http://geisickperformance.com/raptor_pictures.htm It has pictures of the head from both sides. Can't show to much more detail than that to protect all Tim's hard work on how he installing those plugs.....

I will be testing and dyno tuning the engine some more hopefully before Easter weekend. It has shown some great improvments over a regular head. If you guys would like I can show you the difference between running it with three plugs firing, and with only one plug firing. (I have some dyno runs from before that show the difference between the two but I can't find them)

The main purpose of the three plugs is to burn more fuel and burn the fuel faster. MIT did tons of studies about how a hotter spark kernal will increase the combustion process. They also tested how multiple points of ignition in a combustion chamber increase flame travel quite a bit. It is pretty amazing how much flame travel speeds increase by adding an extra ignition point (spark plug). Now imagine what two extra plugs with more sparking energy at all three plugs will do......

So far it has given more power all throughout the power band, and it pulls like crazy on top end. I've never seen a Raptor hit the red line that quickly, or carry out the power that far in the rpm range.
 

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He said it all there in a nutshell. I like the new website layout. :thumbsup:

Yall have alot of stuff for the 700 to .Wow. Have you ben able to get them to rev and make power up top?
I have been considering the additional plugs on my small motor. I just hate to re-do the head yet again.lol
 

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Geisick said:
Here is a link you can check out that has a ton of pictures of that bike: http://geisickperformance.com/raptor_pictures.htm It has pictures of the head from both sides. Can't show to much more detail than that to protect all Tim's hard work on how he installing those plugs.....

I will be testing and dyno tuning the engine some more hopefully before Easter weekend. It has shown some great improvments over a regular head. If you guys would like I can show you the difference between running it with three plugs firing, and with only one plug firing. (I have some dyno runs from before that show the difference between the two but I can't find them)

The main purpose of the three plugs is to burn more fuel and burn the fuel faster. MIT did tons of studies about how a hotter spark kernal will increase the combustion process. They also tested how multiple points of ignition in a combustion chamber increase flame travel quite a bit. It is pretty amazing how much flame travel speeds increase by adding an extra ignition point (spark plug). Now imagine what two extra plugs with more sparking energy at all three plugs will do......

So far it has given more power all throughout the power band, and it pulls like crazy on top end. I've never seen a Raptor hit the red line that quickly, or carry out the power that far in the rpm range.
Definetly post some dyno sheets!
 

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That bike is sweet. If i see it in the dunes, i will come up close for a quick look, then run so it doesnt spank me... Where is the threshold in cc, requiring a three plug head for more power? Is it something you would do on say a 686 or 719? How is the reliability of the 794 with three plugs?
 

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I am wondering what this upgrade would cost when all is said and done? Head mod and ignition upgrade, everything done. If they offered some sort of kit for this with an exchange on the head (not easy I know) that would be great. On the other hand I am sure they don't want eveyone running this. Would sure make the bike stand out though :thumbsup:
 

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Discussion Starter · #20 ·
Geisick said:
If you guys would like I can show you the difference between running it with three plugs firing, and with only one plug firing
i would really be interested in seeing that :thumbsup:
 
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