hey guys wondering of past 670 turbo builds and if they were properly tuned if they were a somewhat trustworthy turbo package-turbo kit is an aero 53-thanks all.
turbo 670
- Thread starter the sled shop
- Start date
yes the rotax motor is very solid. Oh how i wish that we had some of the old motors back without all the garbage straped to them.
D
670
They work really good dont overboost the 53 series 10lbs is about max.
They work really good dont overboost the 53 series 10lbs is about max.
nice,thanks guys-the engine has already had alot of upgrades done to it-RKT head, hd crank, crankseal savers whole package has already been run about 350 miles or so-owner sais its tuned real nicely-plan on running 50 av and 50 pump fuel at 500 to 3000 ft.anymore info or just anything on the 670 turbos would be great-thanks nick.
Wow old school!
There is an absolute known safe and effective high performance system for doing a rotax 670 turbo engine with the aerocharger 53 series turbo. I have a custom one...it's expensive and took years and years of development to get it right, be super high performance, and live! Oh and fyi dummy..it will make far more then 10lbs boost! I'm sure there are others and other setups but this one is 100% the way and proven.
Engine 99 HO jugs, crank, bottom end
97 rotax 670 fly and timing
pre 98 style pistons
custom head and hand lathed domes for rotax turbo by Union Bay with compression max of 125ft lbs at 3000ft.
custom rotary valve cut
pto seal plate
watercraft rotary valve seal
correct porting specs
custom air box and charge tube system with nitrous injection system
heavy duty fat boy pipe
custom carbs and settings for reliability and performance with power jets
special holly fuel pump
special fuel regulator and settings
highest volume 53 with wide throat and a screen...datalogging instrumentation..boost and fuel pressure gauges
Only runs 100% premix redline oil with 110 race gas...
you can run across a lake for miles at 10lbs with this setup. Fully boosted our record is 500FT! he he he
We've completely uncorked the boost to pull the full amount of air volume that this turbo and engine combo will suck through. You cannot sit and see with total accuracy a boost control on an analog gauge going that fast. But you can see it bouncing way over 14! We think in the realm of that is an accurate figure. The difference between 10lbs and 12 is mind boggling. This thing fully open and with the nitrous on is amazing as well for a small cc engine system.
There is an absolute known safe and effective high performance system for doing a rotax 670 turbo engine with the aerocharger 53 series turbo. I have a custom one...it's expensive and took years and years of development to get it right, be super high performance, and live! Oh and fyi dummy..it will make far more then 10lbs boost! I'm sure there are others and other setups but this one is 100% the way and proven.
Engine 99 HO jugs, crank, bottom end
97 rotax 670 fly and timing
pre 98 style pistons
custom head and hand lathed domes for rotax turbo by Union Bay with compression max of 125ft lbs at 3000ft.
custom rotary valve cut
pto seal plate
watercraft rotary valve seal
correct porting specs
custom air box and charge tube system with nitrous injection system
heavy duty fat boy pipe
custom carbs and settings for reliability and performance with power jets
special holly fuel pump
special fuel regulator and settings
highest volume 53 with wide throat and a screen...datalogging instrumentation..boost and fuel pressure gauges
Only runs 100% premix redline oil with 110 race gas...
you can run across a lake for miles at 10lbs with this setup. Fully boosted our record is 500FT! he he he
We've completely uncorked the boost to pull the full amount of air volume that this turbo and engine combo will suck through. You cannot sit and see with total accuracy a boost control on an analog gauge going that fast. But you can see it bouncing way over 14! We think in the realm of that is an accurate figure. The difference between 10lbs and 12 is mind boggling. This thing fully open and with the nitrous on is amazing as well for a small cc engine system.
WOW thanks f-bomb now thats what im talking about-definatly some good info to have and to read.i wasnt going to go that extreme,dont really need to over here in NH for groomed trail riding-this is my first turbo build,ive modified sleds before a bunch but never with a turbo ive been trying to read up and learn as much as i can in the last couple of years.the chassis is dam near perfect for its year but just needs more power if i gain 70+ hp that wiil be awsome i figure the 670 would be a good beginer project with not so much at stake if things dont work out.some of the stuff thats in your post has been done to engine,i guess what im wondering is if the engines were somewhat reliable if tuned down a little with about half of the tweaks that you descibed.THANK YOU nick-fyi the engine turbo package im looking at has already been run and pretty well tuned in so im not starting from scratch-pretty much bolt in chassis and go-i hope
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I've seen em eat pistons at 8lbs boost plus they run eradictly.
Here are the keys:
You must have low cranking compression
retarded timing (you can only get this with pre 98 fly componants) The HO system only retards to a degree which is not adequate)
exhaust (guys have tinkered with stock expansion with side dump but the facts are that no exhaust has been as consistant and reliable as the fat boy end dump single for this setup.
Internal engine: water craft seal keeps you from coking (burning, foaming, and reintroducing it to your system for a quick failure) your oil.
pto seal ...that seal is designed for 120hp not 180 and up. The pto seals will not stay in place long.
pistons...the old style pistons were all that would consistantly live...domed versus non domed so the heat sig is distributed correctly otherwise even at lower boost with a long duration run you burden direct areas and have failures.
head design..once again you have to have a correct squish and compression setup going against the timing spark to have this entire thing work. It's then got to be sucked out of the system correctly and in perfect time or things go CLANK. Understanding the basics of the 2 stroke as an air pump makes it easier to see why it's a complete system from start to finish that works. It really isn't as much I'll run it at low boost and it will be ok...even making small boost you can have incredible heat and stress and that equals hassle, frustration, and MONEY! Think in terms that you are simply asking your pump to work faster (therefore HP) ....while it works faster it all has to go in and out at the exact correct time or it's bad. You are also introducing a much wider variation of the pump requirement...before you pump has to work from low HP to 120ish. Now it has to work at low HP to 180 for 8lbs or 220ish for full open like we run. YOU WILL CRANK IT UP...that is the fallacy with the aerocharger...boost is a bleed hose block away. Faster is always funner!
Do it right from the get go...save yourself large amounts of time and money. Email me at rob@f-bombracing and I will regergitate my notes of the complete setup. It's been years since I've even looked or thought about this stuff. The dragster is sitting in the shop under cover and has been for a long time.
What I did learn over the thousands and thousands of dollars that we threw into this process was to do it correctly right from the start. Little bits here and there are expensive lessons waiting to happen with a turbo. Number one you have to acknowledge that turbo is expensive and demanding...so be prepared. Otherwise the best advice you will ever receive in sledding is to bag that concept!
Here are the keys:
You must have low cranking compression
retarded timing (you can only get this with pre 98 fly componants) The HO system only retards to a degree which is not adequate)
exhaust (guys have tinkered with stock expansion with side dump but the facts are that no exhaust has been as consistant and reliable as the fat boy end dump single for this setup.
Internal engine: water craft seal keeps you from coking (burning, foaming, and reintroducing it to your system for a quick failure) your oil.
pto seal ...that seal is designed for 120hp not 180 and up. The pto seals will not stay in place long.
pistons...the old style pistons were all that would consistantly live...domed versus non domed so the heat sig is distributed correctly otherwise even at lower boost with a long duration run you burden direct areas and have failures.
head design..once again you have to have a correct squish and compression setup going against the timing spark to have this entire thing work. It's then got to be sucked out of the system correctly and in perfect time or things go CLANK. Understanding the basics of the 2 stroke as an air pump makes it easier to see why it's a complete system from start to finish that works. It really isn't as much I'll run it at low boost and it will be ok...even making small boost you can have incredible heat and stress and that equals hassle, frustration, and MONEY! Think in terms that you are simply asking your pump to work faster (therefore HP) ....while it works faster it all has to go in and out at the exact correct time or it's bad. You are also introducing a much wider variation of the pump requirement...before you pump has to work from low HP to 120ish. Now it has to work at low HP to 180 for 8lbs or 220ish for full open like we run. YOU WILL CRANK IT UP...that is the fallacy with the aerocharger...boost is a bleed hose block away. Faster is always funner!
Do it right from the get go...save yourself large amounts of time and money. Email me at rob@f-bombracing and I will regergitate my notes of the complete setup. It's been years since I've even looked or thought about this stuff. The dragster is sitting in the shop under cover and has been for a long time.
What I did learn over the thousands and thousands of dollars that we threw into this process was to do it correctly right from the start. Little bits here and there are expensive lessons waiting to happen with a turbo. Number one you have to acknowledge that turbo is expensive and demanding...so be prepared. Otherwise the best advice you will ever receive in sledding is to bag that concept!
S
Don't want to derail the topic here but I thought you were always a Polaris guy....have to agree though, my 670 ran and ran and ran....over 8000 miles (mtn miles) without doing any thing to the motor but putting gas and oil in it. I loved that motor!!!
you guys are the ****
thanks i need to read these threads somemore when i got longer-ill be back on sw hopefully later-this is great.
thanks i need to read these threads somemore when i got longer-ill be back on sw hopefully later-this is great.
snengineer...I'm not a brand guy at all what so ever. I'm a guy who used to like to win a lot of races and that happened to be the tool in our box. THAT ONE DID SO! We could make incredible HP and stay in a small cc open class and had a HUGE HP ADVANTAGE! Get all other things in correct order and it wasn't much of a game. Gonna guess I wasted in the neighborhood of 20 grand getting it right!
Now I'm a guy who likes to free ride sleds so I get which ever one is the best. Pretty simple deal!
Setup as a mountain sled we used to be able to set these things on 10 lbs boost and hold it wide open for miles on Brundage Res in MCCALL ID about 6500ft. BAck then the thing was really only good for going straight up and staying at one throttle position ON. Anytime you were in and out or hitting huge woops in a climb it became unridable. The part when you made 110 hp to the part where you were making a real 200hp was too violant to control! We then got into grass drag racing and had a lot of success whipping rump all across the west with it.
Now I'm a guy who likes to free ride sleds so I get which ever one is the best. Pretty simple deal!
Setup as a mountain sled we used to be able to set these things on 10 lbs boost and hold it wide open for miles on Brundage Res in MCCALL ID about 6500ft. BAck then the thing was really only good for going straight up and staying at one throttle position ON. Anytime you were in and out or hitting huge woops in a climb it became unridable. The part when you made 110 hp to the part where you were making a real 200hp was too violant to control! We then got into grass drag racing and had a lot of success whipping rump all across the west with it.
nice sounds like it might not be to trail freindly,F-BOMB did you get the pics
C
670 turbo
that motor is a geat turbo motor . wish i still ran one.i am curently running a 66 series on a 600ho polaris . i would look at running the 66 instead of smaller 53 . then do every thing else fbomb said to do on fuel system and heads if running over 12psi . make sure and split cases and put clip in to keep rotary valves seals in place . really sucks if you have a backfire and blow rotary oil into cylinder. good luck
that motor is a geat turbo motor . wish i still ran one.i am curently running a 66 series on a 600ho polaris . i would look at running the 66 instead of smaller 53 . then do every thing else fbomb said to do on fuel system and heads if running over 12psi . make sure and split cases and put clip in to keep rotary valves seals in place . really sucks if you have a backfire and blow rotary oil into cylinder. good luck
