BDT 363 Sphynx Build

[Burns310r]

Okay fellas.

I have been riding my new DS 450XMX for the past 2 months in the Iowa D22 MX series due to some issues with my 250R motors. USPS thought it would be a good idea to drop my $2000 insured 2 day mail box containing a 310cc PROX, a ESR 330 PV (BRAND NEW) cylinder and my race BDT 350 ProX. The drop bent the sleeve's of both my BDT 350 and my ESR 330PV (so they where effectively junk). Nothing was wrong with either cylinder i may add when i sent them. Carlos was taking my 330 on trade for other stuff and my 350 was going under the knife for some more aggressive porting. Long Long story short, USPS paid me the Insured value......WOOOT

So now what to do.. Well after working directly with Carlos at BDT to get my 350 ProX dialed in for so long I naturally went back and asked for his help again. And he made a suggestion to me that I hadn't previously considered..... A stroker Sphynx motor.... Naturally I was giddy as a school girl hearing this as i know the Sphynx motors make more HP/Tq vs other cylinders.

So we ironed out what I wanted and after a short week and half, A box showed up on my door containing my brand new Sphynx.

This motor will complete 4 stroker killer. A lot of people say this, but its actually harder than most will admit in the A class MX world these days. It take a lot of work to beat up on the local A class 4 strokes here in Iowa if you havent seen my vids I have posted. These boys dont play around when building 4 poke motors.

So here are the build specs for the motor.

Sphynx 78mm Nikasil BDT Pro Port job running @220 PSI Comp
+4 stroker Hot Rods Crank(brand new good style)
Vforce 3 reeds
38mm A/S carb
ESR TRX5 pipe

This setup should be good for around 66hp and 45 ft/lb tq.

This will be the start of my build thread of this engine, and i will follow up with my thoughts on performance.

Starting.......
When i first got the cylinder, i must say... This thing is a piece of art. The porting is immaculate, the casting looks amazing... Carlos did a amazing job opening up the ports and blending the sleeve/ports.
http://i158.photobucket.com/albums/t82/BurnsMGT/DSC01833.jpg
http://i158.photobucket.com/albums/t82/BurnsMGT/DSC01839.jpg
http://i158.photobucket.com/albums/t82/BurnsMGT/DSC01840.jpg
http://i158.photobucket.com/albums/t82/BurnsMGT/DSC01835.jpg
http://i158.photobucket.com/albums/t82/BurnsMGT/DSC01837.jpg
http://i158.photobucket.com/albums/t82/BurnsMGT/DSC01834.jpg




I will update this thread as the build progress goes on. Should be able to race it after 2 weeks.. Takes me some time to build my motors and get them broke/dialed/practiced on before i race them. But you guys will deff see some footage of this motor tearing up some 4 strokes.

Stay Tuned.

[8686]

Wow. Looks amazing!

[chronicsmoke]

Looks good Burns!! Subbed. How are you riding on the DS compared to your R?

[Burns310r]

I have been finishing a lot better. But i have been getting better all season. Any my last 350 was giving up some HP to the local 450 guys so it was deff harder.

I cant wait to get both the DS and the R on the same track on the same day and compare lap times. Im hoping im faster on the R.

Regardless next season im giong to race the DS in the Production A class, and race the R in the Open A class.

[JackBrown1988]

Wow dude, that is awesome port work. Purdy-purdy-purdy.

[jhtrx250r]

What did bdt do port wise ?
That cylinder looks like they do un ported right out of the box from cp.
Calvin has got his casting down to a science.

[jhtrx250r]

I think you will like the performance of that cylinder, I have the 300 pv set up, it was a little pipey out of the box , so I had the ports droped with a resleeve , it made 55 rear wheel out of the box but that's the 300 kit.
Deadly has a 350 sphinx with a stock stroke I rode it a few weeks ago it pulls good , I think his was 62-65 right out of the box stock stroke.
You will like it, let me know how it works for mx?

[Burns310r]

BDT did there MX pro port on it. Its hard to see any difference becasue they sanded it down so well and put it through some sort of glass polisher for the nikasil process. Im no expert on it but I was assured that the port job on this thing is nasty fast.

Also he had to port it for the +4 stroke, it uses different port heights.

[wes350x]

Pics removed. Very nice Sphynx cylinder Kyle. get that thing running!

[atv fan 28]

Now thats a real port job!!! ^^^^^

[Thornfold]

Wow- acecarlos/bdtm port work looks much better-clean -n- perfect blend. Dont know much about porting- except by looks -n- seat of the pants. my bdtm motors rip. you can see on the bdt motor the 2 holes on each side of exh are bigger.

[CorvetteZ06]

Burns, Looks fantastic!!!!! Can't wait to hear the ride report. What main and pilot are you running in the 38 mm a/s ??

[wes350x]

Originally posted by Thornfold
Wow- acecarlos/bdtm port work looks much better-clean -n- perfect blend. Dont know much about porting- except by looks -n- seat of the pants. my bdtm motors rip. you can see on the bdt motor the 2 holes on each side of exh are bigger.

Yes, I did notice about the exh ports. I'm not sure on the specs of the shearer port work but this is supposed to be the same work as what he produced 82hp on alky with. These are 2 totally different port works, both from creditable builders.

[sangheraent]

Im no expert but isn't a port job not suppose to be smooth? Something about creating turbulence or some noise.

I remember reading about it on macdizzy's site.

[wes350x]

I know the exhaust has to be glass smooth, The intake if I remember right didnt have to be because roughness atomises the fuel or something...I may be totally off here.

[Burns310r]

Its not smooth there is deffinatly some surface roughness.

When people say they want rough intake for better fuel/oil/air atomization. They mean do not pollish it to a mirror. This is becasue intuetivly you would polish the entire motor to a mirror to induce the best possible flow. But on the intake side we need the turbulance for other reasons.

The exhaust can be mirror smooth because we want to get that air out of the motor as fast as possible.

smooth is a realitive term to what your talking about. Carlos's port work "looks" much smother than the drag port above. But both are more than sufficiant for creating turbulance. Also note, you can have to much turbulance in an intake.

the old moto "some good....mo's betta" does not apply in this case.

[derby]

The biggest difference is that the bdt motor was ported then plated. Then wes's motor done by shearer was plated then ported after. The plating process will smooth things out and make everything look smooth. The plating sticks to the inside of the ports thicker than on the sleeve. That is why the bdt is so smooth. But as far as port work the shearer cylinder looks like it had much more time spent. I could be wrong but that is what it looks like. All of my puma cylinder came back from millenium plating smooth just as the bdt cylinder. I had some work done after it was plated and of course it looked more like wes's cylinder.

[89rwfo]

Why are you comparing a drag port to a mx port and saying the drag port has had more time put in it? DUH no kidding!

[derby]

Originally posted by 89rwfo
Why are you comparing a drag port to a mx port and saying the drag port has had more time put in it? DUH no kidding!

So what makes a drag port more time consuming than any other port?

[KM250R-BDTM]

Let me just say the BDTM cylinder Kyle posted has +25 hours of Port & Flow work, and is a balanced cylinder as far as port & flow work goes. To say it does not have the amount of port work as the other cylinder shown, is simply wrong. Yes the Plating process smooth’s the surface, it does not however re-angle the roof or walls of the transfers and boost ports, nor does it change the shape & angle of the exhaust & sub-exhaust ports. Also our cylinder has had material added to certain areas by welding, and re-blended smooth…the other cylinder has only been ported, not Welded or Bench Flowed.

Simply looking at both sets of pictures shows the difference in porting, how clean and smooth the BDTM cylinder is, how much larger the sub-exhaust ports are, ect…. The BDTM cylinder is an MX port layout; however; it takes a lot of time to port/flow a full Drag cylinder as it does an MX one correctly…

[Burns310r]

Guys the pictures dont do this thing justice....


its a work of art. Cannot wait to get it running.. The cylinder is bolted together... need to do a leak down test on it tonight before dropping it in the frame rails. Hopefully have it purring by Sunday... Saturday is a race unfortunately and i wont be able to work on it.

[derby]

Burns the cylinder looks good. I am sure it will be a good running setup. I have been trying to get 250r enthusiast to open their eyes to this cylinder for years. I have been able to ride a couple different variations of the sphinx over the years. And this newest casting you have is going to be a hit once people catch on. I am glad BDT is building it, the 250r community needs someone to push the envelope on these motors. I will be looking forward to a ride report.

I promise the time it took to cut through the plating in those ports took some serious time. If you have ever tried to port on a plated cylinder you would know how hard it is to do.

[hartwill]

Hey Kyle,
that thing looks like it's gonna rip.. Who Did your plating? I wonder if they can do a regular sleeved cylinder? If I keep my arens I want to get my 330 Neil built for me plated on the next bore.. either nikasil or the carbon lacing.. anyone have experience with carbon laced cylinders?

[Burns310r]

Carlos did all the work. I would highly recomend BDT to get engien work done. They have worked with me on getting my engine set up perfectly. I have sent my heads back and forth to get recut, my cylinders to get reported, and they have just done amazing work.

I have been really focusing on getting my motors to run the way I expect them to, and Carlos has backed me 100%.

You ever talked to Carlos at BDT Will?

[tbone250r]

Do all the Sphinx cylinders need to be Nikasil plated? What's the benefit of that?

[Burns310r]

Yes,
The sphynx cylinders do not have a pressed in sleeve. They use a hardend coating on the aluminum cylinder to act as a sleeve. The hardend coating means that you shoudlnt ever need to over bore your cylinder. As long as you dont have a catastrofic failure that is.

Simply put a new piston in and go. I believe it also has better heat transfer.

[tbone250r]

Hmm interesting. BDT will be doing my XC 330 that's for sure.

If you have a GoPro i'd LOVE to see some on-board footage of this bike when you get that motor in

[Burns310r]

Ya i will have some footage for sure. My wife will be putting some more promo videos together soon to. Unfortuanly the last to months are all on my DS 450. Which is a very nice bike.

But i cant wait to get the TRX back out there.

[Burns310r]

UPDATE!!!!!

Put the motor together and fired it up last night on the third kick. Then I did my usual break in process of... Warm up cool down 2 times. Warm up and half throttle run and cool down. And then Warm up and ride it like its meant to be ridden.

Let me tell you one thing fellas.... Your going to need more rear gear... Im running 14 on the front and a 37 or a 39 on the rear (cant remember what i had on there last) will check tonight...

This thing will straight blip 4th gear wheelies... idling along though my yard shifting smoothly up to 4th gear... Slam the throttle and it wants to throw you on your back... Im going to have to figure out a way to get some more gear for this baby.. And i still havent fine tuned the jetting. Im a little rich up top and running 3 month old race gas...

Its a damn freight train though i must say. We will be running it tomorrow at a District 22 MX race, so well see how we do.

more to come.

[tbone250r]

I'm suprised you dont do a longer break in procedure. BDT usually recommends running 2 tanks through the motor before you go whoopin on it. Everybody has a different break in procedure opinion tho.

But that's awesome to hear that it rips. GET SOME GO PRO FOOTAGE!!!!

[Burns310r]

I have been building my own engines for some time and its just the procedure i have had very good luck with.

I would never recommend going against what your engine build recomends with out there permission.

I have my theorys/ believes on ring break in wear. I believe that you break it in like your going to run it. It will last longer under those conditions.

Considering this is a race motor that is ment to 10-15 minute motos a few times a weekend, an entire season on a set of rings is great.

someone who runs trails for hours on end, probably should be a little more patient with there break in procedure to maximze longjevity of the seal.

[red88r]

My buddy that races snow x also breaks his sled motors in that way. He has never had a problem doing it this way. I never rebuilt my CT330 since I bought it from my cousin yet but he has 14/36 gearing on it. That was from running D16 races up here and he ran really good with it.

I believe on my Dad's Duncan 340pv we run 15/37? And for most tracks it seems to work pretty good. When you are competing hard like you on a mx track you those big motors can be a blast! Especially on the big tracks where you can really let it run.

Good luck to you and can't wait for some footage.

[mx91a]

Sounds good! 14/37 gearing is barely enough for a good running 265 with 18-19" tires time to get a 15 or 16 tooth countershaft sprocket pronto!!

[solid250r]

My bud runs a bdt sphinx 363 with 15-38. It will pull a 16, he rides tight trails and the 15 works awesome. Carlos told him to stick to the 15. Good luck racing Mr. Burns!

[Burns310r]

You guys running 15T fronts, what chain gaurd do you use. My ESR wont allow one that big.

[derby]

Pumashine has the best one. The ESR would be better if it went around the shift shaft. Pumashine makes them for the 15t, they are pretty thin where it gets close to the clutch arm. Still should offer better protection than the esr would.

[red88r]

All of ours for 15t are Duncan's.

[koh0001]

Sweet cylinder!! Can't wait to see it on the track!! Good luck.