Posted by Big Ben on July 15, 2010, 10:44 pm
ever wonder what the linear speed of your pistons at a given rpm is? I
did, because sometimes I wonder about shit like that...
to find for linear piston speed at 1000rpm, simply multiply length of
stroke by 2.8, result for piston speed is in feet per second @ 1000
rpm. To find for other rpm values, multiply previous result by rpm in
multiples of 1000, eg, 1500rpm = 1.5
example: for 80" Evo or Shovel engine with 4.25" stroke, 4.25*2.8 =
11.9 fps @1000 rpm
= 23.8 fps @2000rpm
= 35.7 fps @3000rpm
= 47.6 fps @4000rpm
= 59.5 fps @5000rpm
piston speed at 1000 rpm can be calculated in mph by multiplying
length of stroke by 1.894
to answer your other questions, yes, I wonder about weird shit
sometimes, and yes, I do have too much spare time on my hands....at
least I aint trolling or spamming, <sfsf>
--
Big Ben
BS266
the "at least the hands won't be idle tomorrow" Slug
Posted by Jinks on July 16, 2010, 7:12 am
On Thu, 15 Jul 2010 19:44:08 -0700 (PDT), Big Ben
>ever wonder what the linear speed of your pistons at a given rpm is? I
>did, because sometimes I wonder about shit like that...
>to find for linear piston speed at 1000rpm, simply multiply length of
>stroke by 2.8, result for piston speed is in feet per second @ 1000
>rpm. To find for other rpm values, multiply previous result by rpm in
>multiples of 1000, eg, 1500rpm = 1.5
>example: for 80" Evo or Shovel engine with 4.25" stroke, 4.25*2.8 =
>11.9 fps @1000 rpm
>
>= 23.8 fps @2000rpm
>
>= 35.7 fps @3000rpm
>
>= 47.6 fps @4000rpm
>
>= 59.5 fps @5000rpm
>piston speed at 1000 rpm can be calculated in mph by multiplying
>length of stroke by 1.894
>to answer your other questions, yes, I wonder about weird shit
>sometimes, and yes, I do have too much spare time on my hands....at
>least I aint trolling or spamming, <sfsf>
Even though it may seem pointless to some, that's important
information. Knowing the linear speed of your pistons is useful in
setting a "red line" or "rev limiter". I used that information to
determine a safe rev limit when I had the FXR stroked. D. William
Denish covered it in detail in his "Big Twin High Performance Guide".
Jinks ('86FXRS, '07FLTR)
#64
Remember, "No good deed goes unpunished"
Posted by Old Crow on July 17, 2010, 6:50 am
> On Thu, 15 Jul 2010 19:44:08 -0700 (PDT), Big Ben
>>ever wonder what the linear speed of your pistons at a given rpm is? I
>>did, because sometimes I wonder about shit like that...
>>
>>to find for linear piston speed at 1000rpm, simply multiply length of
>>stroke by 2.8, result for piston speed is in feet per second @ 1000
>>rpm. To find for other rpm values, multiply previous result by rpm in
>>multiples of 1000, eg, 1500rpm = 1.5
>>
>>example: for 80" Evo or Shovel engine with 4.25" stroke, 4.25*2.8 =
>>11.9 fps @1000 rpm
>>
>>= 23.8 fps @2000rpm
>>
>>= 35.7 fps @3000rpm
>>
>>= 47.6 fps @4000rpm
>>
>>= 59.5 fps @5000rpm
>>
>>piston speed at 1000 rpm can be calculated in mph by multiplying
>>length of stroke by 1.894
>>
>>
>>to answer your other questions, yes, I wonder about weird shit
>>sometimes, and yes, I do have too much spare time on my hands....at
>>least I aint trolling or spamming, <sfsf>
> Even though it may seem pointless to some, that's important
> information. Knowing the linear speed of your pistons is useful in
> setting a "red line" or "rev limiter". I used that information to
> determine a safe rev limit when I had the FXR stroked. D. William
> Denish covered it in detail in his "Big Twin High Performance Guide".
> Jinks ('86FXRS, '07FLTR)
> #64
> Remember, "No good deed goes unpunished"
Fuck, I just scared myself. I ain't turning that stroker shovel at 7 grand
ever again...no matter how good it sounds. 92 fps...HOLY SHIT!!!
--
Old Crow
'82 FLTC(P) 92"
'87 FLTC
'61 F-100 302/C-6
BS#133, SENS, TOMKAT, SLOB#13, MAMBM
Posted by me on July 17, 2010, 9:04 am
>Fuck, I just scared myself. I ain't turning that stroker shovel at 7 grand
>ever again...no matter how good it sounds. 92 fps...HOLY SHIT!!!
It'll be fine! ran em a long time like that
Posted by Old Crow on July 18, 2010, 5:56 am
> wrote:
>>Fuck, I just scared myself. I ain't turning that stroker shovel at 7
>>grand
>>ever again...no matter how good it sounds. 92 fps...HOLY SHIT!!!
> It'll be fine! ran em a long time like that
I don't spin it that fast anymore since I got rid of the S&S 514 that was in
it and went with an A grind. That 514 wouldn't really start to pull untill
you were over 3 grand and never stopped pulling even at 7. Woulda been a
*really* fun motor on a smaller bike.
I've got a J grind sitting on the shelf now that I'm gonna install this
winter, maybe get the torque down under 2 grand for when I'm pulling the
trailer.
--
Old Crow
'82 FLTC(P) 92"
'87 FLTC
'61 F-100 302/C-6
BS#133, SENS, TOMKAT, SLOB#13, MAMBM
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>did, because sometimes I wonder about shit like that...
>to find for linear piston speed at 1000rpm, simply multiply length of
>stroke by 2.8, result for piston speed is in feet per second @ 1000
>rpm. To find for other rpm values, multiply previous result by rpm in
>multiples of 1000, eg, 1500rpm = 1.5
>example: for 80" Evo or Shovel engine with 4.25" stroke, 4.25*2.8 =
>11.9 fps @1000 rpm
>
>= 23.8 fps @2000rpm
>
>= 35.7 fps @3000rpm
>
>= 47.6 fps @4000rpm
>
>= 59.5 fps @5000rpm
>piston speed at 1000 rpm can be calculated in mph by multiplying
>length of stroke by 1.894
>to answer your other questions, yes, I wonder about weird shit
>sometimes, and yes, I do have too much spare time on my hands....at
>least I aint trolling or spamming, <sfsf>