....and talking about other manufacturers..just for Kev (as he's stuck on a desert island in the middle of nowhere), if you google Derbi Mulhacen 659, Kev (if you haven't seen it already),..sort of flatracker style...I like it (if you like that sort of thing..)

I did not know it snowed on a desert island, on my map Australia is in the middle & the UK is right on the edge of the world, heee.

Yes I have seen that before.

hehe...lol

I am very excited about getting this other engine, it means I can now approach the project in a more complete/comprehensive way.

What I was trying to do before, was to keep the short block uncracked. My engine is almost new, and it seemed the logical approach, as far as budget goes. But, not getting the rod-to piston balance was a downside.

Now, I can do a whole motor, but, the budget will increase.

I would like an uprated con-rod, so I can "up " the revs more safely, and get the crank-rod-piston balanced/lightened. I can also do a couple of other bits of fine tuning.

Its a growing project......just try to keep it within my realms of "sensible" (I haven't heard the two words together before...Richard and Sensible, sounds weird):deathmetal[1]:

Sounds like a better plan rebuilding the new motor & leaving the orginal one standard, that way you can sell the modded motor when you are finished playing.

Once you decide what mods you are finally doing we can talk, as you keep changing your mind as new ideas are put to you.



:darth:

yep...that's me......just been airing my thoughts on the forum!!

:sleep01:

..but my mind changed since I went for a chat/visit to the engine builders, re: still getting the pull/power low down with a big cam....and I think we can pull that one off, by experimenting.
Therefore, I will try some different cams.. long/short duration, different durations ........and lifts high..or not so high.
The 5050 will be a "Benchmark" cam, along with the standard cam of course.

Approve Kev?

Sort of changed my initial project ideas........haven't I??

Well the first part has arrived, all the way from America.

The wrong part! I clearly stated what i wanted on the heading of the order. donuts!!

grrrrrr.

Anway, for information, a Wiseco 103mm 11.5:1 Piston, with Pin and Clips = 506g.

I have found something!! I am going BIGGER BORE !!!
 

Since getting the wrong piston (! great thanks!) ..I had a look with the 103mm and the barrel.

I now think it is safely possible to go to a larger Big Bore......with the Standard XT660 Barrel/cylinder..

In this picture No.1, you can see the barrel, the correct way up, sitting on the engine, as it were.....with the Skirt on the bottom, that sits in the crankcase... it is this Skirt that is about 4mm. You can also see "inside" the Barrel, through this hole , the outside of the Skirt. This is much thicker than 4mm, its about 8.5mm. It is in this area the piston mainly moves, not in the Skirt.... http://i933.photobucket.com/albums/a...jpg?1283762821

In picture number 2 you can see the thickness of the Skirt, which is about 4mm....

http://i933.photobucket.com/albums/a...jpg?1283762962

In this picture No.3, you can see "inside" better... it definately thicker,its the inner wall of the water jacket...

http://i933.photobucket.com/albums/a...jpg?1283763040

And looking from the top, in picture No.4, you can see the inner wall of the water jacket , to the wall of the cylinder..its about 8.5mm

http://i933.photobucket.com/albums/a...jpg?1283763122


So, as long as the skirt is "meaty" enough...that would vary on differing opinions, you should be ok

So, how much do you leave on the skirt????

I am going to be maverick, and try a 104mm piston.(about 2mm left on skirt wall). I have a spare engine, and fast fingers " clutch-side" (but I don't think it will be the case), I think it should be ok with a 2mm Skirt wall......wait and see.....the 714cc Big Bore....

Brave man with a 2mm sleeve.

Can't see any photo's.

Why not fit one of these & go to 106mm.

http://cgi.ebay.com/ebaymotors/CYLINDER-SLEEVE-YAMAHA-06-07-RAPTOR-700-700R-YFM700R-_W0QQcmdZViewItemQQhashZitem20b212dc1fQQitemZ14042 6533919QQptZMotorcyclesQ5fPartsQ5fAccessories

Or if you have the funds.

http://cgi.ebay.com/ebaymotors/Yamaha-Raptor-700-Big-Bore-741cc-JE-Piston-106-Cylinder-_W0QQcmdZViewItemQQhashZitem4ceceb8961QQitemZ33039 2373601QQptZMotorsQ5fATVQ5fPartsQ5fAccessories

[quote=Kev;137822]Brave man with a 2mm sleeve.

I know Kev....don't !!!!!

2mm on the skirt it is.....its actually 2.5mm......

I have a whole spare engine to play with, AND an extra barrel.....

oh ..and by the way....like my rebuilt Oak Bay Window? .....taken bloomin' ages......

Have know idea what you are talking about.

I have found out...that a Raptor 700R 2008MY Con Rod, is the same as a XTR 660R, 2008MY. (1S31165100)

A Raptor in Standard Spec, revs to 9000 rpm
A XTR in Standard Spec, revs to 7250 rpm.

....I s'pose you can guess what I'm going to do next.....yep, my XTR is going to rev, safely, why not?, to 9000rpm....another 1750 of revs!..

Working on the rev limiter now....Dynojet are helping me (they are really good guys, always been really helpful, thanks Richard by the way,at Dynojet, and of course, the only place to go for a Dynojet product, Powertech!!!!!).
And there is an alternative to Dynajet, which is being looked into. ( more difficult..so rather the Dynojet way)

:rotf[1]::rotf[1]::rotf[1]::rotf[1]::rotf[1]::rotf[1]::rotf[1]::rotf[1]::rotf[1]::rotf[1]::rotf[1]:



:family::partyondude::family:

fingers crossed we get the rev limiter sorted out......................if we can get there on the rev limiter, then this opens up a WHOLE NEW WORLD in XT engine mods....with an uprated con-rod, we may be able to rev higher than even 9000rpm......

We already know how to move the rev limiter on the XT, with a few members having done it on their bikes last year. Lets see what dynojet come up with as one person is already using one their products to move the rev limiter.

Well I don't know Kev.....anything on the forum about it?

Dynojet are doing something at the moment, hopefully be good news..

Well, I can comfirm that the rev xtend on the PCV doesn't work with the XT.

Just makes it ride horribly.

Daz, Dynojet UK are working with the Americans very hard on this rev limiter/Dynotek Ignition stuff....we will have an answer in a few days....

here is a link to our recent Rev-Limiter discussions...

http://www.xt660.com/showthread.php?t=14915

Well, the project is moving forward, there has been alot of things to consider, but I have been talking to one of the very best Raptor engine builders in the States, Dan at High Desert Dyno.

He thinks the Raptor engine is so very similar to the XT engine, and I think this guy would be the best man for the job.

He doesn't put much on his website, though, I guess engine-building keeps him busy, but here is a link..

http://www.highdesertdyno.com/

I have now decided to not do a 104mm piston (leaves very little piston skirt), and neither a 103mm piston (reports of unreliability)..
So I am going with Kev and dl700's (Dan's) advice, and I am going with a 102mm piston, a CP.

The engine is going to the engine builder on Saturday, so a strip down will start soon....I will send my crank to Dan at High Desert Dyno, so he can have a look at making a Stroker Crank for the XT's.......

Dynojet are still working on the rev-limiter, and this is my build spec (so far! I may change!!)

High Desert Dyno/ Cuervo Racing Gas flowed and ported Cylinder Head with
Larger Valves (+1 mm)
Uprated Valve Springs and guides
High Desert Dyno 5050 Camshaft
Rev limiter
102mm CP 11.5:1 Piston (686cc)
Nikasil Cylinder Barrel, bored to suit piston
High Desert Dyno +3mm Throttle Body

my existing mods are:
DNA Stage 3 Airbox
Power Commander
Carbon Cans Exhaust

My aim is: Not to lose any power at all in the lower revs,hopefully gain a fraction, and to have a driveable bike, that will pull through all the revs.

You will be fine, with that set up its going to fly.

I am very interested in the stroker crank, once Daniel can see one, hopefully he will be able to make them up for us as a straight bolt in crank.

Sounds like a good package. Could you keep an account of the costs? Always interesting to see the price/power ratio.

(No problem if you don't want to)

Thanks Kev for your comment...

I have a feeling I may lose 1-2 hp around 3500 rpm...but thats not a really big deal, but totally against my original plans....(no laughing Kev!!! lol)

I think the 103mm bore would have offset any small losses with the 5050 cam, but a well built/spec'd 102mm may even be better! We'll see....


As for the Stroker crank, I hope there will be some interest from other forum members, in tuning their bikes....or from people who wouldn't consider buying an XT before, who were maybe looking at Husky/KTM, or from MT-03/Derbi Mulhacen/Aprilia Pegaso etc. owners ..........

It would be so much better if also a 105mm bore was a more cost effective/less labour intensive project......

you will get the whole price...when i have finally got there....including shipping etc.......no problem....

What I will say is,,,so far a DNA Stage 3 Airbox is highly recommended as an easy hp/responsive power improver.........and it looks dead sexy too...and exhausts should be a second priority if you are after a performance mod...

As you know I am trying to build a cheap fast XT at low costs.

A stroker crank, standard 100mm XT660 piston, re decked cylinder with a compression ratio of 11.5:1, stage 2 hot cam, ported head & hope to get around 60HP. We will have to wait & see.

I have all the parts lined up using a Raptor Hot Rod +5mm stroker crank, Raptor flywheel & stator. I will wait to see what Daniel says when he sees the XT660 crank before I do anything.

Yes, I like your idea.......a good project from behind the scenes, Kev...

All being well, Dan should have the crank in about 2 weeks, Kev....I haven't bothered with forwarding you anything Kev, as its just been sorting out the logistical (shipping) bits.....but you will be the first to know when the Crank is finally sent off.....

Of course, your shipping charges are totally different to ours, so I hope the overall package works out reasonably economical on the shipping front. I think it would be interesting for us two to compare the costs of our mods, for other forum members..

That's no problem, we will wait to see what Daniel says when he sees the XT crank.

Just remember all my modding & machining is labour free, or at mates rates.

you are going to be alot cheaper than me.....I wish the other Kev was my next door neighbour.....

He is a very good mate that has unbelievable talent in making anything. He even offered to build my stroker crank if I could source the +5mm bits.

He is at the moment machining up my coolant sensor mod to turn off the O2 sensor. He made one up in one day for me, we tested it on Monday, I changed my mind tonight & got on the phone to Kev2 & he will knock a revised version tomorrow for me that will allow for faster coolant temperature reactions. Now that is fast work.

hey, this is GOOD TIMES for us XT owners....we have on the menu coming up..

1. An 02 emulator- no more low rev fuel injection stutters...and being able to program the whole rev range, ..more news soon......

2. A low cost rev limiter...more news soon....

3. A stroker crank....more news to come......

4. Kevs OEM piston project.....more news to come...

5. And my project, using the High Desert Dyno Cylinder Head and High Desert Dyno 5050 cam....more news to come....

(and my DIY stage 3 when I pull my finger out)

Hurry up and get that thing on a dyno kev, wanna see that thing working!

:winner:

6. Daz's DIY Stage 3 Airbox....more news to come (when he can pull his finger out)

7. New DNA Airfilter for the Super Ten.....

I quite like the sound of kevs build with the stroker crank, stage 2 cam and a decked head with standard piston. Sounds more like something I'd be capable of doing myself money wise.

Stage 3 will come when I get time to do it, currently got a lot on from work and fixing up my fathers triumph vitesse.
Made a start, just need some money to get a few bits and time!

Woop, 'few bits' ordered! This'll probably be a complete flop but what the hell!

I think if you use Alu to make the DIY Stage 3 airbox, it will be the best solution.

I have a project too,the first project was with an xt660 renicasiled to 102mm,cp piston 12:1,ported head,kibblewhite valve springs,stage 3 xt camshaft,stage 1 & 2 filters,+2mm TB,power commander 3,termignoni exhausts and headers, the bike was 65-66 on the wheel and lots of torque but the nicasil wore off and damaged the piston so back to zero again.Now on to project second phase,made the damaged cylinder sleeved to 105.5mm with cp piston 12.5:1,racing ecu with rev limiter @ 9300 rpm,fcr like air inlet,+1mm inlet valves,dynajet ignition coil.I hope in about one month the bike will be ready(and more than 70hp on the wheel:unibrow:)

That is a good result...a pity the Nikasil wore out.... was that a Raptor cylinder, or XT cylinder you bored to 105?

Steve, have you found a way to increase the rev limit on the XT? In standard spec. it is 7200 revs.

xt cylinder bored to 105.5.Yeap the rev limiter is fully adjustable but i completely removed stock ecu and some wires(no more dash).The maping of the racing ecu is extremely difficult because you have to set the ecu from the beginning(advance,air pressure,fuel)but the result is quite rewarding, the rev limiter is where as it should be and the bike is far more agressive from the diffrent advance (huge diffrence even on a stock xt660)

are you leaving the Exhaust Valves at Standard size?