30 and 40 series max rpm question

gran_pann

gran_pann

Member
#1
#1
Provided your engine can dish out the RPMS, what is the 'max' rpms any of you all have been able to pull on your torque converters? Failures? Safeguards? I'm not talking about the guy that forgets to put lock-tite on his drive unit crank bolt and throws it at 3600 rpms.

Lets hear what you all have to say.
 
SAS289

SAS289

Well-Known Member
#2
#2
I always thought it was odd that they only give a HP rating and not a max RPM rating.

And from what I have seen from this site and others is that it's not how many RPM's your engine can dish out, it's how you are geared to allow the available RPM's that the engine can reach under the given load.
 
Sixpac440

Sixpac440

#3
#3
I have never used Loc-Tite, just a swift hit with a brass hammer to the edge of a box wrench. Never had one come loose.

Comet and Clone 40 series call out 5000 RPM max but I suspect you can exceed that on occasion but not continuously.

30 series engagement is 3100 max so max RPM must be above that, maybe 5000 RPM like its larger stable mate.
http://www.bmikarts.com/pdf/comet_30series.pdf
 
ole4

ole4

#4
#4
Best bet for hi rpm and drag race use are the 330 salsbury and its twin comet 340. They have stamped on driver max 8500 rpm.
 
super nate

super nate

Member
#5
#5
I turn my 30 series at 8125 rpms and turn my 40 series at 7800 ---both are modified to launch at 5000 rpms but had to roll back the 30 series to 4000 because the silver/blue garter springs keep breaking but the whites don't,, think bmi has a problem with the springs been working with then about it. the 40 series can stretch the three roller springs inside at high rpms so ive been designing a bushing to limit the amount of engagement the sheave can move to stop the stretching.
 
David wulf

David wulf

#6
#6
I have a comet 20 setup and have turned it 8,250 so far . I have one blue/ white spring in the driver and a sleeve to limit that closing . The driven is almost locked up with a sleeve, the belt drops maybe 1/4 inch down . I will go with a bigger sleeve to stop it .
 
FirePowerMinis

FirePowerMinis

Active Member
#7
#7
David wulf said:
I have a comet 20 setup and have turned it 8,250 so far . I have one blue/ white spring in the driver and a sleeve to limit that closing . The driven is almost locked up with a sleeve, the belt drops maybe 1/4 inch down . I will go with a bigger sleeve to stop it .
Click to expand...
To intentionally limit the ratio change?
 
S

SoFloMiniBikez

Member
#10
#10
super nate said:
I turn my 30 series at 8125 rpms and turn my 40 series at 7800 ---both are modified to launch at 5000 rpms but had to roll back the 30 series to 4000 because the silver/blue garter springs keep breaking but the whites don't,, think bmi has a problem with the springs been working with then about it. the 40 series can stretch the three roller springs inside at high rpms so ive been designing a bushing to limit the amount of engagement the sheave can move to stop the stretching.
Click to expand...
What color spring you have on your secondary ?
 
K

Kleyny

New Member
#11
#11
David wulf said:
I have a comet 20 setup and have turned it 8,250 so far . I have one blue/ white spring in the driver and a sleeve to limit that closing . The driven is almost locked up with a sleeve, the belt drops maybe 1/4 inch down . I will go with a bigger sleeve to stop it .
Click to expand...
Can you please post a few photos of the driven sleeve in place? I have put a sleeve on the driver I'm wondering if your idea to put one on the driven might be better.
Thanks
 
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