This is an indirect quote from the original thread
Any 1050/1200 Polaris watercraft crank case will work for this job. All you need is the two case halves. If you get a complete motor to rob it from, hang on to the domes, water covers, reed cages w/stuffers and water rail. You may want to use them later for your motor.
If you go with a 1200 you will need to have the case fly cut out to accept the 800 (or 85mm) cyl's . If you are building a 1050, this will not have to be done to the case.
You can use a twin recoil/mag housing. Is a bolt on deal. However, you may need to work the inside of it where the stator plate goes depending on what type of ign system you decided to go with. Union Bay Racing has a billet mag housing that will allow you to use several styles of ign stators and incorporates the use of a v-belt driven water pump found on older Fuji motors from Polaris. Very reliable and inexpensive water pump. Note: the shock tower on mag (right) side may or may not need to be notched if the domestic twin mag/recoil housing is used in conjunction with a 12.5" Center to Center belt (same as any Gen 2 twin ###1065 Pol p/n).
The front of the top case has the provisions cast into it the same as the twin for a water rail. Having this milled flat and two holes taped with the water passage in the center of them will allow a bolt on style water rail. If you still have the water rail from the top of the motor, this can be used as a template. It can also be used for this application. All of the billet water rails that I have seen are basically identical as far as bolt pattern. I have seen home made rails that use a 0-ring just like what comes on the twin. This works if you chamfer the passage for the O-ring.
If you decide to use the UBR mag housing, there are a few things to discuss on the use of it.
Mock up, mock up. You can never mock this thing up too much. To make sure everything fits perfectly. You will have to make sure the hole in center of stator plate will be big enough for the crank. Make sure you get the water pump pulley from UBR when you purchase the housing. Starter cup, depending on what type of flywheel and or ign system you use, you will need to make sure the starter cup will contact the pawl.
One thing to look at when selecting a case is to make sure the crank bearings have not worn into the case. Feel the edges for "knifing" and make sure the bearing surface is smooth. It is OK to see the places where bearings have been living, just not feel impressions in the aluminum. This will ensure you have a good "bite" on the bearings when the case is mated with the crank.
One last thing before assembly, you must chamfer oil hole on the PTO side with a small carbide. The object is to make it give oil to the sides of the bearings as the bearing with the snap ring covers up the factory oiling hole. The mag side is done in this fashion from the factory. Bottom line, make the PTO end oil hole look like the mag end oil hole.
There are several different ways to go about this.
One is to purchase a new crank that is built for this purpose. Many shops out there can supply them, I can supply anyone a new OEM crank.
Another way is to send two twin cranks to a shop like SLP in Idaho to have them rebuilt into your application. From some of the experts on these I have been told that the 70mm cranks do not need to be welded but the smaller 68mm ones do when buying new. Something about the "glue" on them is just as good as welding. I did not have my 70mm crank welded.
The PTO end should have a wide bearing (5207-ILT) and a narrow bearing (6207NX18). The narrow bearing being closest to the end should be of the type that incorporates a crank locating snap ring on it.
There is another snap ring (crank locator) that goes on the mag end. It sits in the case and not on a bearing. This is ring is needed if a twin housing is used and is used with a watercraft crank as well.
On the UBR style, a pto seal is used (Being a metal seal coated in rubber) and the little square nubbies cut off flush with a razor blade.
Several different direction to go on ignition. There are many that have not been tried or are being tried as I type this. The two most common ones used to this point that I am aware of are 1984-1989 Indy 650 (I am told that the old Polaris Centurian is the same) and XCR/Ultra ignitions.
Pros/cons of these two systems:
-650: Pros. Easy to find, lots of aftermarket support, low cost.
Cons: 120 watt lighting coil, timing curve is conservative in low RPMs.
-Ultra: Pros. 280 Watt lighting coil, better low end timing curve.
Cons. Expensive, harder to find, aftermarket support is sparse.
I went with the 650. I got a complete system for under 100 bucks on ebay from a '89 650. As far as the timing curve goes, once you find the peak torque on these motors, set 16* BTDC at that RPM. I didn't use a dyno, I just set mine at 16* @ 8000 RPM. This is a good base line setup. These motors make so much torque on the bottom (even without VES jugs) that the little extra timing and lighting coil power was not worth the cost to me. I am able to run my hot grips on high and a PIAA head light, LED tail light with power to spare. Hot Grips pull 15 watts, the headlight pulls 65 watts. I did use a Autometer brand temp gauge set up with a rectifier from Radio Shack ($3) but it pulled way to much power to run the rectifier. So I went with a dummy light instead. A XCR/Ultra alternator would do it with power to spare.
The flywheel for either system will have to be re-tapered to match the crank taper. I do all flywheel tapering in-house for $75.
There are some folks out there that use the twin recoil housing and water pump with the twin stator. I don't know which flywheel and CDI they are using, but I think this route has some real advantages if you consider using a stock mag housing. I say this because the stock twin mag housing needs to be machined slightly to make the stators from the triples fit. If I were to go this route I would be curious on where the flywheel would need to be in relation to the stator, how deep do you cut the taper? Not rocket science, but would have to be addressed. These little things (among the hidden ones, air gap on a triple flywheel for example) along with using the proven V-belt pump is why I went with a UBR mag housing. It is as "bolt on" as you can get.
You can use a twin stator in a twin mag/recoil housing with an XCR re-tappered flywheel.
Part number of old 650 ignition should be 4060071.
And if you are using the new 650 / RXL ignition the part number is 4060092.
In one word, ELKO. You cannot beat the stock Polaris piston. It is well worth one's while to buck up and spring for the stock ones. This can be a subject of great debate, but this is my recommendation. As far as the new coated pistons go, unless you have issues with sticking pistons, the older non-coated will work fine. Plus they are much, much cheaper as a kit (rings, pin and piston).
Stock, valved or non-valved. Doesn't mater, however, I would highly recommend the newer valved jugs. Better design all-around.
I had Doug Ruth do his "race port" on my brand new non-VES jugs.
Always check your port timing. What you should be shooting for, believe it or not, is as close to Polaris twin as possible.
Polaris 900/1050/1200 Crankcases
Polaris 600/700 or 800 twin cranks
650 Mag Cover and waterpump
P/A or UBR mag housing
29mm ID stingers for CS pipes at low altitude
32mm ID stingers for CS pipes at high altitude
Last edited by Powersledder : 11-17-2009 at 11:11 AM.
Bill I have the entire original thread in PDF format. I tried to upload it but it didnt work. I will ask Bryan if we can get it uploaded. Here are some pictures I poached off SW. The link is to ninjaplumbers build pictures and there is also a video of his 254hp dyno run.
I will try to get some of the good tech info (clutch set ups, etc) moved over here this weekend.
Also good to see you got the stinger size correct for the CS pipes.
I used sea level stock watercraft domes and cut them to fit. I ended up with a 0.063 squish and 12.7:1 compression. Very happy with this so far, I don't ride much over 7K. I used a 1pc water cover from Randy at WATCON.COM. It is built for the watercraft use but worked perfectly for me. It was cheaper than UBR. There are many ways to over come this parts issue. Kelsy at RKT, Brad Wursten (1200psi on the 4m)would be good sources.
Several was to go on this one. First off, the reed cage is slightly larger on the w/c cases than the snow cases. You can still use stock boots by modifying the bolt holes. However you will need the reeds from a watercraft. Advice, if you have a ported motor, there is a 10HP delta between V-force and stock. If V-force is too rich for your blood, then there is always Carbon Fiber reeds. Fantom carbon fiber reeds are proven and much cheaper with the contact listed in the Vendor section.
Round slides, flat slides and D-slides have all been used on these motors with great success. It all depends on what you want to do with your sled. In my case, I used the UBR carb adaptors and 42mm flatslide rack. This is the easiest on your thumb and has a very light pull. The D-slides would be 2nd place for every day throttle pull. I would call the roundslide big bores more of a racing application. There is not as much performance gain for the trail to overcome the need for Popeye arms to run them.
I picked up a set of 38mm 2001 Thunder cat flatslides. I had SLP bore them out to 42mm. Had to modify them to fit the cyl spacing on the watercraft. The outer two carbs needs to come in 2mm towards the center one. I was able to do this by purchasing two of the fuel inlets that Polaris uses on the twin and mock up to the motor. I based the jetting off the 2001 Polaris 800. The mid ranged ended up being very lean and had to order the richest needles that Polaris sells. The needles that came in the cat were already the richest, but they didn't do the job.
I installed my own power jets and have been very happy with them.
I found two brand new Mikuni hi-flow 70LPH, 3/8" inlet fuel pumps on eBay for $20 each. They are used on the XCR for sure. I mounted them below and in between the carbs on the bulkhead. I used a 2" raised tunnel so it left a perfect place for them. I looked for a long time to find two fuel shut offs in the 3/8" flavor. They are hard to come by. The only sleds that I have seen them on were newer 800 twins. I use a P/N from the Polaris manual and got two 5/16" sent to me. Go figure.........
The edge tank I was using had one 5/16" bulkhead fitting in it already, so I ordered up a bulkhead fitting and made my own pick up. (hoping they wouldn't send me 3/8 stuff after I decided to go with 5/16)
Using the polycarbonate fuel line in a 5/16 size, I had to heat it slightly to get it over the 3/8 inlets on the pumps.
Primer system was simple, however I would not trust the check valve in the Mikuni primer. I highly recommend installing the one Polaris used in the 99 twins. The Mikuni built in check valve has been known to fail. I installed knock in's for the 3/32" fuel line AFTER the carb and T'd them all up nicely. This took a while to get everything to route perfectly. Take your time.....
Engine plate: Brad Wursten (435) 753 2661
Brad makes all type of motor plates, ignition stuff for many big name shops.
He also makes carb adaptors, water rails, and domes for our motors. He is a
builder of watercraft based motors as well. Around $200 for motor plate is what I
paid. Very important part of the install. You can use the XLT style straps instead, but is a
good idea to tie them together. Brad's plate makes it simple and he has been making
them for Tison, UBR and many others for years.
Mag housing: Union Bay Racing (360) 659-6840
UBR makes a ton of parts for these and build one bad to the bone motor.
They also offer all the machine work you need done to the case.
Carb adaptors, water rails, heads and domes and so one.
Machine case for mag housing
Machine case for water rail
Turn a 1050 into a 1200 case.
Pipes: CrankShop (877)-878-9692
Not as intended as a plug, but it is very, very hard to beat the performance
of the CrankShop pipes on these motors. They will build your pipes if you send them
your motor plate.
Clutch: HRP (616) 874-6338 HRP This is an area of discussion. My opinion is that anything making over 200
HP at elevation, should have a quad cam clutch. IMO, the HRP is very hard to beat and
customer service is very, very high.
Heads: 1 pc for VES motors:Union Bay Racing and Brad Wursten
1 Pc for non VES motors: WATCON.com
Powerjets: Jagged Edge Customs/4Z (253) 709 9097
Fantom rope. Super strong and light.
Plug wires: Superbeast baby! Mike is a builder of his own DIY watercraft as well .
Good button setup for 3-6000 ft was a 52/36 SLP Mountain helix and the Polaris Grey spring.
Good Team setup for same elev was 58/38 and Black/Purple.
My TRAIL 1050 pulls 8400rpm (digatron) with this setup:
Pri: Polaris p-85 with 82gram weights and SLP 160-300 spring
Sec: Polaris button with r12(50-36) and Polaris grey spring (20-84)
second hardest setting.
Gear: 24-40 and 8 tooth(2.52) drivers.
Track is a 151x2 fingertrack with 500 kold kutters.
Chassie is customised 1996 aggressive, and I weigh 240 suited up.
This is at an altitude of 1000'
Woody1050 (Mr. Krovoll) used this set-up on his 2001 RMK 1200ves last summer on the grass-drags:
Pri: Polaris P-85 with 78 gram and pol black/green(120-340)
sec: Polaris button with SLP 50/40 and pol blue/orange(56/90)
Gear: 23-40 and 9 tooth drivers.
Track was a 159" with 250 picks.
He runs pro-stock, so sled and driver was about 750 lbs
This motor was built and ported by himself.
Stock RMK chassie and fully trailable with 12.5 compression!!
Bored stock 800 carbs.
Runs a steady 8400rpm with this setup.
With this setup he did 103.8 MPH in 500'
Altitude was sealevel and temp was 50 degrees.
I would list my setup but im still working on a good combination. So far its 68 gram weights, 140-340 primary and 59-52 helix with some unknown red/white spring on a cat button driven clutch. Riding at 8-10k ft. turns about 83-8400 rpms.
all the other things like rider weight, track length, gearing, riding style all play a role in which weight works for you. I am running 70 grams, geared 2.05 19/39 with a 162 2.4 track and I weigh about 300 dressed for the snow. I would like to be geared in the 2.26 range when boondocking in 4-5 ft of powder in the deep dark trees, but dont want to sacrifice the track speed on the big hills.
On another note, I have found a spring last year that absolutely rocks for the primary, its a grey 120-360 from HRP. It has a low 3500 engaugement for the deep dark trees, but has a tall finish rate so you can really swing some weight for wicked belt squeeze.
Deep and steep is 2.15:1 gearing, SLP MOUNTAIN 50/36 with Polaris gray spring in middle hole.
Spring time is 2.00:1 gearing, SLP MOUNTAIN 52/36 with same spring.
I ride from 4200-6000 feet polaris primary with the black green spring, team secondary with the black white, 70 gram weights. rack mounted 40s unbored Mag 350,360,360, 03 needles, 55 pilots runs at 8550 after the pipes are warmed up.