778cc XTX, Kris 007 Stroker crank comversion
 

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.

http://i201.photobucket.com/albums/a...x/P1010631.jpg
Raptot 700 +5mm Hotrod stroker crank
http://i201.photobucket.com/albums/a...x/P1010633.jpg
Raptot 700 +5mm Hotrod stroker crank
http://i201.photobucket.com/albums/a...x/P1010634.jpg
700 raptor stator & flywheel
http://i201.photobucket.com/albums/a...x/P1010635.jpg
XT660 starter gear left, Raptor 700 right.
http://i201.photobucket.com/albums/a...x/P1010665.jpg
XT660 starter gear right, Raptor 700 left.
http://i201.photobucket.com/albums/a...x/P1010664.jpg
XT660 Fly wheel left, Raptor 700 Fly wheel right.
http://i201.photobucket.com/albums/a...x/P1010661.jpg
XT660 Fly wheel left, Raptor 700 Fly wheel right.
http://i201.photobucket.com/albums/a...x/P1010662.jpg
http://i201.photobucket.com/albums/a...x/P1010658.jpg
http://i201.photobucket.com/albums/a...x/P1010629.jpg
http://i201.photobucket.com/albums/a...x/P1010630.jpg
Copper head gasket.
http://i201.photobucket.com/albums/a...x/P1010639.jpg
Raptor base gasket.
http://i201.photobucket.com/albums/a...x/P1010638.jpg
+1mm inlet valves
http://i201.photobucket.com/albums/a...x/P1010620.jpg
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.
http://i201.photobucket.com/albums/a...x/P1010684.jpg
http://i201.photobucket.com/albums/a...x/P1010686.jpg
http://i201.photobucket.com/albums/a...x/P1010687.jpg

778cc Xt
 

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.

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.

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.

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.

http://i201.photobucket.com/albums/a...tx/XT784cc.jpg

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

Now thats a lot of HP,blimey!!!

Absolutely amazing job!!! :wave:

feck, running STD gearing.

Good Job on the motor !!!!! very strong power,,, that is a large job with a lot of unknow problems, but good to hear u got it worked out and im glad to be of help


Send me the OEM crank and ill get it made 8 mm stroke,,,, cost will be around $1250 + shipping... but drop in conversion with proper piston used

Looking at the run files after Kris's Dyno run I was wondering what all the spikes were, clutch slip or wheel slip on the Dyno, so I asked a good friend to have a look at the run files & he said the clutch was slipping, so Kris pulled his clutch down today & the clutch was fried & that is with the uprated clutch.

http://i201.photobucket.com/albums/a...--TEXT-WEB.jpg

what clutch is in it? and what oil is being used?

we have heavier clutch springs available, but their are some modifications available to make it hold the power

Kris was running an extra clutch plate + heavy duty springs at the time, the XT's clutch is quite different to the Raptors, Kris could not adapt the clutch hubs from the Raptor to the XT's motor.

We will wait for Kris & he can explain further.

Clutch Mods
 

Thats right Kev

I had removed the half fibre plate and replaced it with a full fibre plus heavy duty springs,but thats not enough I have now fitted a new complete raptor700 set of clutch plates with 2 steels back to back and have ordered some heavy springs from DL700, see if this holds.

have u ridden it yet?

yes DL, but not hard yet its wet here.

xt 778 cc Clutch Mod's
 

I have been playing with the clutch and have had a win, I have been able to fit the raptor 700 complete clutch presure plate assy, clutch fibre & steel plates, clutch springs inside the xt 660 basket, with an extra steel and fibre the same as a raptor, all fits and works inside the xt 660 clutch cover.

New clutch mod list:

xt 660 clutch basket
xt 660 clutch pushrod lifter with new spacer
raptor 700 complete clutch pressure plate assy
raptor 700 full set of steel clutch plates x 7. STD xt 660 x 6
raptor 700 full set of fibre clutch plates x 8. STD xt 660 x 7
raptor 700 full set of clutch springs x 6 (DL700’s heavy springs ) STD xt 660 x 5

Nice work Kris.

NICE !!!

the OEM 04-05 yfz 450 atv fibers hold power a bit better and a bit less cost they are the same size and fittment just larger puck sizes

5TG-16321-00


if anyone needs i have access to good used Raptor parts and international shipping isnt too much flat rate

Thanks Daniel.:sbike:

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"....

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.

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

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 :gsmile:

Thanks again Kris,
second time now when trying to post my reply,I was logged out during my writing and my message went missing.
Try short now and come back later,with more to ask :)
Bedtime work tomorrow morning..
Per

Hi Kris!

I apologize in advance for my bad english))

I have several questions for you:

1. You changed the balance shaft or it native?
2. Strongly to change the thrust at low engine speeds?

I need to replace the crankshaft in the engine. The cost of the original crankshaft - insanely huge (due to dollar exchange rate), and the value of the crankshaft from the raptor - much nicer.

So I'm trying to understand how much really to transplant the crankshaft from the raptor in the T�n�r�. And how much will all this construction is reliable and stable

Thank you in advance for your reply and good day!

Hi Korrh
Why do you need to replace the crankshaft ? Big end - connecting rod damage ? or crankshaft badly damaged - broken ? or want to stroke it ?

If its just a connecting rod there are kits available to repair.

If you change the Crankshaft (to a Raptor 700 type) the balance shaft remains the same, but you will also need to change to the Raptor 700 flywheel, stator & pickup plus mods to the mounts of the stator and change the stator connector plug, but the big problems are with the starter gear/clutch major mods needed you will need to use both the XT and the Raptor 700 gears, the centre needs to be removed from the xt gear and welded to the raptor gear a very delicate job.

It dose become a little jerky down low it the revs because the Raptor flywheel is about half the weight of the xt flywheel, the engine will rev much quicker though.

It is a very big job and well worth it if your looking to stroke it maybe not if your going to go the same stroke.

Sorry for the delay in replying

Kris