Trygstad 872

byeatts said:

Been avoiding this thread because many wont be able to handle the truth.I get the opportunity to build up BB,s of many builders and have 860 and 880,s . Multiple motors of each. I,m a nut shell a cylinder with little porting will require larger mains and cylinders with extreme porting will run smaller mains, When an 880 well ported cylinder and the piston drops it flows much more air . That air in turn pulls more fuel with it since its a ratio.The same 880 without good porting has an air flow cylinder restriction and requires larger mains to compensate since air flow and signal are reduced. A well ported 880 also requires dropping the pilots to 15,s at altitude, The well ported 880 intake signal is much stronger than a 860 and is pig rich at idle/altitude with stock pilots.I have tuned many BB,s that love 480,s and 3 that require 540,s /560,s and larger.I,m not a fan of extremely lean jetting ,they have proven to fall off at the end of a climb due to excessive heat leading to Det. However they will be the snappiest motor off the line.Head design has some effect on jetting as well however not as much as the porting/bored carbs.the main jet size is not an indicator of HP.. Fact is a well ported motor with smaller mains can easily deliver more fuel than its counterpart,Yes there is a clear visible pattern as to the cylinder and the porting done and the corresponding jetting. motors that consistently run smaller mains are SHR.RKT , these have very good visible porting with exceptional air flow.,,,

Click to expand...

wow that is exactly the kind of explanation I was looking for, thanks! provides great insight to what sledsrock said about vacuum signal. this helps those of us that arent as experts make sense of what others say in regards to the jetting they end up running on their bb's. And it also supports a point that I think is important for consumers; that main jet size is not an indicator of hp as some say, and that its the airflow dynamics that play a larger role in the final jetting. disproving the statement that if it doesnt take more fuel than stock it doesnt make power.

Explanative, first-hand-experience posts like that, imo, helps to make us all better tuners through better understanding, I think the builders benifit as well; if owners are better informed about whats taking place inside the engine, then the owners are able to better tune their engine, make it run great, and showcase the builders fine engine work. the owners end up not second guessing things so much and end up with a great running sled as a result.

what a useful post, thanks again :yo:

now that you've all reinvented the bb......... I just gotmy 872 running last night and even though I only had it running in the garrage , I am quite impressed on how smooth it runs , I did have the crank trued and welded and the clutch ballanced this is the smothest running 800 I've seen, even though I did go back to stock exhaust except for the slp y pipe , I cant wait to get it on the snow this weekend!!

im still in break in mode !! not really doing a bunch of work on it until then, how about you cracker?

Lots of different clutching options/trials going on. I have a friend that has some radical gearing with 433 ramps and a ton of weight. I run the stock 441 ramps, arms and rollers with 16.5 grams and a 160/350 spring. Secondary has a QR 11 helix.

With my 3" and 7T drivers and stock gears I see about 50 mph in 3 ft of fresh pow and run about 1" from top of primary...about 1:1 ratio. On the hard pack it easily tops out at 70 mph and uses all of my primary.

Gonna try a couple of things with the clutching and then start playing with the gears.

433 ramps seem to be the most common with this engine.....according to the people I talk to. I am sure there are many more theories out there or people who are keeping it to themselves. I dont have 433's so i am just playing with what I have....and it seems to work !!!

Good luck !!!

r u all running stock exhaust or have you done some custom exhaust parts

MBRP.....but Dave suggests that stock is the best.

I just dont like it sounding like a sewing machine,I put on my slp can for tomarrows ride.

Be careful with SLP as i have been told by a few builders they are to tight for BB. and not to use them.

summit800 said:

I just dont like it sounding like a sewing machine,I put on my slp can for tomarrows ride.

Click to expand...

put on 55 miles with it and ran like a top

hivoltagesledhead said:

Lots of different clutching options/trials going on. I have a friend that has some radical gearing with 433 ramps and a ton of weight. I run the stock 441 ramps, arms and rollers with 16.5 grams and a 160/350 spring. Secondary has a QR 11 helix.

With my 3" and 7T drivers and stock gears I see about 50 mph in 3 ft of fresh pow and run about 1" from top of primary...about 1:1 ratio. On the hard pack it easily tops out at 70 mph and uses all of my primary.

Gonna try a couple of things with the clutching and then start playing with the gears.

433 ramps seem to be the most common with this engine.....according to the people I talk to. I am sure there are many more theories out there or people who are keeping it to themselves. I dont have 433's so i am just playing with what I have....and it seems to work !!!

Good luck !!!

Click to expand...

Pulled .5 grams out and went for a rip tonite.....pulling 8000 to 8300 consistently. EGTS are a little cool, but thats a good thing.....can use a little less race fuel at 2200 ft and maybe even straight 91 at elevation.See around 1050 - 1100 in the pow at WOT and about 1000 on the trail....like to be closer to 1150 - 1200.

3" is a monster though....gotta get a longer snowflap.....running 2 sets of scratchers and nothing but steam from the coolers all the time !!!

Heading into Kakwa for 5 days tomorrow....gonna take my Dalton kit and play around with some weight in the fluff.

Damn TRA is a noisy clutch......really sounds like crap.

Awesome engine Dave.....there is a ton of freakin torque there man.!!!!!!!!!!!!

Hivoltage what jets are you running , I have all new parts in my tra and a new outer housing and ballanced and is also very noisy

At the end of the day you can make up all the different idea's on flow etc that you want. The plain and simple fact is a jet can only flow so much fuel, much like a garden hose. The orifice is only capable of having so much fluid pushed or pulled through it.

You can have a motor built to any specifications and if one motor builder's is built in the early stages of development and is trail ported to what is believed to be safe at that time and another builders motor is done after they have been able to watch and see what the competition is doing, they are going to go after their own porting a little harder because they have a SAFE guideline that didnt come at their own expense.

There is more to engine packages then just looking down the intake side and seeing how you perceive the porting to look, You have port heights that can be manipulating through base gaskets and head cuts. For me the proof is in the pudding when in comes to motors. Race wins and who does/has Ski- Doo trusted to build their race team motors and help with development? Not only for Sno-Cross but for hill climbing too. I can tell you for sure it is not with a guy that doesn't know what he is doing or copying others work and idea's. If a head design was that special or efficient a manufacture would have bought up the patent or found a way to copy it to gain the benefit of it.

I have been around and used other builders from the forums products and I have been useing Trygstad's products for a while, I have had more people ask me about them then any other builders. I have been asked for pictures of porting by a couple of engine builders on this forum and if SW had not revamped itself a few years back I would still have the p/m's. There is only one other guy I would trust to build an engine for me and he is not on this forum.

If you want the hardest running nastiest normally aspirated Ski-Doo's on the hill buy Trygstad's stuff.

My stuff has always ran hard on the hill and on the track.

Here is one of Dave's motors at work well above 10,000 ft

http://www.youtube.com/watch?v=R_ej...xt=C393d20bUDOEgsToPDskJYaDl7wd2SnYcf_ACG4WA7

byeatts said:

Been avoiding this thread because many wont be able to handle the truth.I get the opportunity to build up BB,s of many builders and have 860 and 880,s . Multiple motors of each. I,m a nut shell a cylinder with little porting will require larger mains and cylinders with extreme porting will run smaller mains, When an 880 well ported cylinder and the piston drops it flows much more air . That air in turn pulls more fuel with it since its a ratio.The same 880 with less porting has an air flow cylinder restriction and requires larger mains to compensate since air flow and signal are reduced. A well ported 880 also requires dropping the pilots to 15,s at altitude, The well ported 880 intake signal is much stronger than a 860 and is pig rich at idle/altitude with stock pilots.I have tuned many BB,s that love 480,s and 3 that require 540,s /560,s and larger.I,m not a fan of extremely lean jetting ,they have proven to fall off at the end of a climb due to excessive heat leading to Det. However they will be the snappiest motor off the line.Head design has some effect on jetting as well however not as much as the porting/bored carbs.the main jet size is not an indicator of HP.. Fact is a well ported motor with smaller mains can easily deliver more fuel than its counterpart,Yes there is a clear visible pattern as to the cylinder and the porting done and the corresponding jetting. motors that consistently run smaller mains are SHR.RKT , these have very good visible porting with exceptional air flow.,,,

Click to expand...

Dbook, since your sled r running so good ,do u have any clutch info for us 872 tunners?

Well I just got home form a 5 day trip into the Kakwa. The weather was not favourable so we did not get to see a whole lot, but the snow was deep and the trees were fun.

My 872 performed flawlessly !!!!! Never touched the clutching for the entire trip. The higher the elevation, the better the sled would run and the more power it would produce....I am constatnty amazed how solid this engine is.

I was seeing 8000-8100 rpm CONSISTENTLY throughout the climbs or boondocking or deep powder carves. We got to play on one hill at about 6000ft.....45 sec to 60 sec climbs in the deep snow sidehilling left to right, straight up, right to left, WOT....48-51 mph track speed, 1180-1238 egts and not even so much as a burp in the engine or throttle response. No overheating, no codes, no anything...just pull and freakin ride !!!!!

My clutching is working great and I am very pleased with this engine. I have about 500 miles on it now and still loving it.

Oh, I did manage to break the torque plate/arm (whatever you want to call it) that is on the left side of the engine behind the primary clutch !!!

How...dont know....just know the bolts are all broken....I am going to say it is because of all the freakin torque this engine makes.

Also, it is probably a 60 km ride on a trail, each way, towing a skimmer with 5 days supplies and fuel.....awesome test for my machine....very pleased.

No issues with the 3" track, drivers or anything else. I dont know why people say you must go slow on a trail with the 3" track, but i say....No way...unless it is icey or bare(obviously), but I it drive like a noraml machine and have no issues.

All in all.....a successful trial run for my build and I am very pleased with this combination of parts.....it is a much better handling machine than the stock 09.

The ONLY downside is the fuel consumption...it does like to drink fuel....a lot of it. I will be contacting Dave to see if there is something I can do about it...but i doubt it....it is a big bore !!!

Way to go Dave.....I am probably 290 lbs with all my gear on and I guarantee you that I dont "BABY" this sled....it is working great and I can keep up with guys on stock machines that are 100 lbs lighter than me and even highmark them once in a while !!!!!!

Happy New Year and safe riding to all !!!!!!!!!

Just pulled off my primary to check out the damage from the broken engine stopper. All the bolts on the stopper were sheared off and it is obvious that my ring gear has been cutting away at the aluminum plate. My engine mounts are all good and no cracks in the pyramid. Gonna have to do some research on the stock motor mounts and possibly get stiffer ones.

Will call Dave and see if he has had any issues of this kind.

Will need to clean up my primary sheaves and hopefully buff out the scatches and dings from the stopper hitting it after it was broken.

Will keep u posted.

hivoltagesledhead said:

Well I just got home form a 5 day trip into the Kakwa. The weather was not favourable so we did not get to see a whole lot, but the snow was deep and the trees were fun.

My 872 performed flawlessly !!!!! Never touched the clutching for the entire trip. The higher the elevation, the better the sled would run and the more power it would produce....I am constatnty amazed how solid this engine is.

I was seeing 8000-8100 rpm CONSISTENTLY throughout the climbs or boondocking or deep powder carves. We got to play on one hill at about 6000ft.....45 sec to 60 sec climbs in the deep snow sidehilling left to right, straight up, right to left, WOT....48-51 mph track speed, 1180-1238 egts and not even so much as a burp in the engine or throttle response. No overheating, no codes, no anything...just pull and freakin ride !!!!!

My clutching is working great and I am very pleased with this engine. I have about 500 miles on it now and still loving it.

Oh, I did manage to break the torque plate/arm (whatever you want to call it) that is on the left side of the engine behind the primary clutch !!!

How...dont know....just know the bolts are all broken....I am going to say it is because of all the freakin torque this engine makes.

Also, it is probably a 60 km ride on a trail, each way, towing a skimmer with 5 days supplies and fuel.....awesome test for my machine....very pleased.

No issues with the 3" track, drivers or anything else. I dont know why people say you must go slow on a trail with the 3" track, but i say....No way...unless it is icey or bare(obviously), but I it drive like a noraml machine and have no issues.

All in all.....a successful trial run for my build and I am very pleased with this combination of parts.....it is a much better handling machine than the stock 09.

The ONLY downside is the fuel consumption...it does like to drink fuel....a lot of it. I will be contacting Dave to see if there is something I can do about it...but i doubt it....it is a big bore !!!

Way to go Dave.....I am probably 290 lbs with all my gear on and I guarantee you that I dont "BABY" this sled....it is working great and I can keep up with guys on stock machines that are 100 lbs lighter than me and even highmark them once in a while !!!!!!

Happy New Year and safe riding to all !!!!!!!!!

Click to expand...

If you run higher track speeds on the trail the lugs don't seem to be happy. Alot of lugs have came off due to delamination and heat.
Good luck and good to hear things are working great.

Ahhhh yes.....forgot about the delamination. Definately want to keep that in mind on a hard packed trail....thanks for the reminder.