Kris 007 XTX Stroker crank comversion - .: XT660.com

Kev · # 1 25-03-12, 11:39

778CC, well it has been done with full instructions & proof this motor dose exist. Well done Kris for taking on the project you have done well mate, it was mod I dreamed of 2 years ago & now it is a reality.

Quite a big project.

The parts that were needed to build this monster XT motor.

XT660 casings bored out to take the Raptor 105.5mm cylinder
Raptor 700 5050 cam. ground rocker arm to clear the cam
Raptor 700 cam gear & de compressor parts
+3mm Throttle Body & 565cc fuel injector (not yet when we get to steve’s Dyno to see if it works)
+1mm inlet valves
Ported head
+4mm headers
Raptor 700 cosmic 105.5mm gasket kit
Raptor 700 105.5mm barrel
Raptor 700 105.5mm 12.5:1 cp piston machined flat top
Rraptor 700 +5mm stroker crankshaft made by Hotcranks USA
Raptor 700 cam chain (same as XT
Raptor 700 fly wheel, nut & washer
Raptor 700 starter gear & thrust washer gear has been modified ( I had to cut the centre out of the XT starter gear and weld it onto the Raptor starter gear to get the idler gear to line up properly.
Raptor 700 stator, pulse pickup & harness XT stator plug
16mm spacer behind the stator, as the Raptor crank is shorter that the XT's
2 X 11mm off set spacer’s behind the pulse pick up to match the Raptor shorter crant & smaller diameter, the Raptor rotor is 2mm smaller than the XT660,s
Modified XT clutch with extra clutch pate + 10% heaver clutch springs
PC 3 & wide band commander
DNA stage 3 air box
Leovince x3 pipes

Today the motor came to life. Dyno results to come very soon after the bike has run in. I hope to be with Kris to see the gains & ride this beast first hand.

Raptot 700 +5mm Hotrod stroker crank

700 raptor stator & flywheel

XT660 starter gear left, Raptor 700 right.

XT660 starter gear right, Raptor 700 left.

XT660 Fly wheel left, Raptor 700 Fly wheel right.

Copper head gasket.

Raptor base gasket.

+1mm inlet valves

16mm longer stator coils holder bracket to hold the Raptor stator coils, + the 2 X 11mm longet brackets offset by 2mm to suit the smaller Raptor flywheeel.

kris007 · # 2 25-03-12, 13:41

Well another big job complete and running, it was a bit of a worry for a while not really sure if it was going to work out but it did. I have had a lot of help along the way from Kev for his advice & posting my mod's, Fran & Daniel (DL700) HDD Motorsports/High Desert Dyno USA, Who I highly recomend for anything raptor 700. I could not have done this without your help, Thank's guys. I will head to the dyno as soon as its run in.

CaptMoto · # 3 25-03-12, 14:32

Well done to you Kris and to Kev for his assistance. this is certainly a milestone of a project, I look forward to the Dyno results.

Kev · # 4 25-03-12, 23:28

This mod is a credit to Kris he is the one who put the cash up & did all the hard work, I think Kris had a few sleepless nights at one stage as it did not look like it was going to work.

See you at the Dyno Kris when she is run in.

Kev · # 5 19-04-12, 12:50

I met Kris at the Dyno today & he got 76.68HP & a wopping 62.39 FT/LBS of Torque from his stroker crank conversion, what a great result Kris well done mate, this would be the fastest XT ever built on record.

feck · # 6 19-04-12, 15:36

awesome work chaps, that torque curve is something else... what gearing is he running out of interest?

F16 · # 7 22-09-13, 19:39

Really admire your work, Fantastic!
Looking thru the pictures and comments and it`s very educational,but I wonder if it would be possible to just use the XT flywheel/stator? Would it really matter that stator fill up the cavity instead of taking the bother of making the spacers?
Just qurious,as I am in the mind state of doing something similar,thanks to this thread.I have now used hours reading of big bore raptors and other kind of tuning tips "over there"....

kris007 · # 8 22-09-13, 22:21

The only way that the xt stator & flywheel will fit is to send the xt crankshaft to DL and have it stroked at a cost of $1200 + shipping.
The raptor crank is not the same on the flywheel side as the xt and stator & flywheel will not fit, also a new hot rods +5mm is about $300 and DL can supply 2nd hand parts total cost deleverd $650.
The mods are well worth it you will love the extra power.

F16 · # 9 24-09-13, 00:14

Thanks Kris, another question to erase from the list..
If you where supposed to do the mod again,what would you do different? Like compression ratio , bore size etc...
I mean there is a big increase in both bore and compression ? how you think this will affect the engine in the longer terms?
what is your opinion off doing a longer stroke and reduce the comression ratio compered to your mod ?
But most important, are you still happy with this beast off a XT?
regards
Per

kris007 · # 10 24-09-13, 02:46

Very happy,
And I would build another in a minute it is a totally different bike just turn the throttle and its on the back wheel no clutch needed.
Things to keep on top of, compression ratio will increase with a stroker crank and it needs to be kept under 12:1 to run pump fuel (here in Australia the pump fuel is rubbish)
I would get the xt crank stroked next time to 8mm and a 105.5mm CP piston/barrel will make 804cc and run the xt flywheel & stator.
The DNA Stage 3 air box is a must.
And the clutch needs a lot of work to hold the power but it can be done, mine holds now.
The gear box is a worrie, will it hold ??? Ok so far.
And more, if you get serious about doing one let me know and I will help you out. But beware of

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