Simonizer
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I just dynoed one at 8.2HP@14160. No expansion chamber. Stock is 5.4. Doug Herman raced it against a modded 390 and won marginally in a 50" spruce, bucking, 34" 75ga. Fun. Cheers, Simon.
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Still 71 cc's, but vented-skirt piston and pretty aggressive porting. I have built about 80 this year, had a half-dozen connecting rod failures, big-end. 3 or so were due to poor quality oil. Doug is a pro-faller and has two of mine both over a year old, both still strong other than usual wear, clutches etc. Is is sad that production on this excellent little machine will stop in 2008. Last year the swedish engineers told me they would be available through 2011, but I guess the emissions criteria folks are really pushing these 575's, (which are a piece of S**t).Thats insane
good work !!!!
Still 71 cc's, but vented-skirt piston and pretty aggressive porting. I have built about 80 this year, had a half-dozen connecting rod failures, big-end. 3 or so were due to poor quality oil. Doug is a pro-faller and has two of mine both over a year old, both still strong other than usual wear, clutches etc. Is is sad that production on this excellent little machine will stop in 2008. Last year the swedish engineers told me they would be available through 2011, but I guess the emissions criteria folks are really pushing these 575's, (which are a piece of S**t).
I just dynoed one at 8.2HP@14160. No expansion chamber. Stock is 5.4. Doug Herman raced it against a modded 390 and won marginally in a 50" spruce, bucking, 34" 75ga. Fun. Cheers, Simon.
Also what type/brand is the dyno?
I bet people would love to see some pics of your test set up
Probably Inertia or Hydraulic.Also what type/brand is the dyno?
Water brake?
Electrodynamic?
Mechanical brake?
Actually torsion-bar set-up. A driven shaft is forced against a load, (tiny disc-brake), the shaft deflection is measured at several different rpm's. Horsepower is derived from 2*Pi*rpm*torque/33000. This gives a very accurate reading as there are no frictional losses to calculate as with a hydraulic or electric dynos. Yes, the stock 372 does deliver 5.35 hp +/- 0.30 hp. Any saw builder will agree with me that there are casting differences and port-height differences as Mahle probably has 25-30 different dies. Cheers, Simon.Probably Inertia or Hydraulic.
Doug Herman raced it against a modded 390 and won marginally in a 50" spruce, bucking, 34" 75ga. Fun. Cheers, Simon.
Actually torsion-bar set-up. A driven shaft is forced against a load, (tiny disc-brake), the shaft deflection is measured at several different rpm's. Horsepower is derived from 2*Pi*rpm*torque/33000. This gives a very accurate reading as there are no frictional losses to calculate as with a hydraulic or electric dynos. Yes, the stock 372 does deliver 5.35 hp +/- 0.30 hp. Any saw builder will agree with me that there are casting differences and port-height differences as Mahle probably has 25-30 different dies. Cheers, Simon.
Actually torsion-bar set-up. A driven shaft is forced against a load, (tiny disc-brake), the shaft deflection is measured at several different rpm's. Horsepower is derived from 2*Pi*rpm*torque/33000. This gives a very accurate reading as there are no frictional losses to calculate as with a hydraulic or electric dynos. Yes, the stock 372 does deliver 5.35 hp +/- 0.30 hp. Any saw builder will agree with me that there are casting differences and port-height differences as Mahle probably has 25-30 different dies. Cheers, Simon.
so i have to ask...what could u get out of a 395 or a 660???
How much money do you have????? LOL!!!!!
The resistive load is 100%friction, but the torque measured before this gives the accuracy that beats a hydraulic or electrical dyno.A straight mechanical brake dyno
With no friction losses
Now I GOTS to see a picture
Simon
It appears you are reluctant to post a pic of your set up.
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