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1  General / Coffee Shop / Re: jetting on: May 23, 2015, 05:45:35 PM
A jet is an orifice, which is calculated in square inches , so if you multiply your diameter by 6% you will gain 12% area (square inches) which is what your looking for.
Multiplying jet diameter by 12% will net you 24% larger square inches more  than what you started with
2  Mower Building / Setup Help / Driveline / Re: Mod XR / GP Gearing on: May 20, 2015, 01:51:36 PM
Do you think that's too high? Or should that work out for a 1/10th mile track like BBR?

That track carries a lot of speed thru the corners, plus you don't weigh much,i would stop trying to overthink this and try what you have!
3  For Sale / Want To Buy / Who Has It? / Re: 1 inch axle rea hubs. 4 on 4 on: May 20, 2015, 11:21:39 AM
Making a jp for the boy. Need  1 inch rear axle hubs for a 4 in 4 bolt pattern.  He wants the shinny wheels. lol.   Let me know. Thx.  651-328-1352

I may have a couple used ones! Let me look tonight.
4  Mower Building / Setup Help / Driveline / Re: Mod XR / GP Gearing on: May 20, 2015, 11:19:59 AM
Final ratio =4.7999999 -------in short 4.80
5  General / Coffee Shop / Re: help with sprockets on: May 20, 2015, 05:29:30 AM
Are you running a governed motor?
6  Engine Help / Briggs OHV & Vanguard / Re: Intek vtwin EC billet cam specs on: May 12, 2015, 05:13:30 AM
Didn'tget a chance to look yet George.



7  Engine Help / Briggs OHV & Vanguard / Re: Fuel Usage on: May 11, 2015, 08:29:16 PM
Better efficiency now!
8  Mower Building / Setup Help / Driveline / Re: Mod XR / GP Gearing on: May 11, 2015, 08:23:40 PM
mostly on the straight aways is when I get beat, so I just invested in a larger trans. sprocket (12T) from an 8T so that should help, and still give me some good pull out of the corners. Now with the 12T it should do 32 MPH, it used to only go around 27-28 MPH in 3rd

Where did you race?
9  Mower Building / Setup Help / Driveline / Re: Speed calculator for peerless 400 on: May 11, 2015, 07:41:27 AM
I ran the numbers through and here's what I get.

I got 0.625:1 pulley ratio.
input shaft to bevel gear is 2.538:1
1.692:1 output to axle ratio.

Total reduction ratio not including the shifted gears is 2.683935:1

1st gear is 2.4375:1
2nd gear is 1.619:1
3rd gear is 1.2:1

Total drive ratios in each gear will be:
1st is 6.542:1
2nd is 4.345:1
3rd is 3.221:1

The ratios sound right. But plugging them in to get MPH using what stvn_VA posted, I still get some seemingly odd/large numbers.
41.544mph 1st gear.
62.55mph 2nd gear.
84.378mph 3rd gear.

As a machinist and CNC Programmer, I have brainwashed myself into enjoying doing math stuff like this. Probably because of what it's getting used for....  smile
Your numbers are right!!!!!
I think 32.48 MPH is kinda fast for a 10:1 ratio as in the example.  Check your numbers again on the tranny to axle ratio, should be around 1.7


For the example given the 32.48mph is right!
10  Engine Help / Briggs OHV & Vanguard / Re: Intek vtwin EC billet cam specs on: May 11, 2015, 05:40:23 AM
should be in the catalog paul down load it and check. I will look at work today!

Thanks George.
11  Engine Help / Briggs OHV & Vanguard / Intek vtwin EC billet cam specs on: May 10, 2015, 08:03:18 PM
Anyone know cam specs of the new EC billet cam for the Intek vtwin?
12  Mower Building / Setup Help / Driveline / Re: Speed calculator for peerless 400 on: May 10, 2015, 09:54:22 AM
Thanks.   So the 5 you used is is 60 minutes in a hour divided by the 12" in a foot.   And who sat in class and said we wouldn't use math in "real" life.

You got the Gold Star today!
13  Mower Building / Setup Help / Driveline / Re: Speed calculator for peerless 400 on: May 10, 2015, 07:11:22 AM
I have to do the old school way and work the MPH the long way because I don't know any easy equation.  So here goes.   

Using 7,000 RPM per your original post.  RPM = Revolutions Per Minute.  That gives us the time to build our hour from.  That wasn't for you Owen but for others who may read later.   

Tire roll out of 49".   I literally wrap a tape measure around my tire. 

Final overall ratio, from previous post- 10:1   (I'm just throwing this out there, so don't freak out people, 10 is easier to divide with)

7000/10 = 700 tire rotations in 1 minute

700 x 49" = 34,300" traveled in one minute

34,300" / 12" = 2858.33 feet travelled per minute.   Remember 12" in a foot.

2858.33 x 60 (minutes in an hour) = 171,500 feet traveled in an hour

171,500 / 5,280 (feet in a mile) = 32.48 MPH

I hope I did that right.

Yes you did it right!
Here is a shorter version :7000/10=700
700x 49=34300x5=171,500/5280=32.48
14  Engine Help / Briggs Flathead / Re: oppy starter? on: May 07, 2015, 11:43:12 AM
Briggs makes 2 starters for these 3 5/8" long housing and 4 1/2"housing which is briggs pt#498148.
the 4 1/2" starter works very well.
15  Engine Help / Briggs Flathead / Re: oppy porting and can? on: May 07, 2015, 11:39:28 AM
But would I be hurting myself in the long run if I leave it splash lube



Iv'e never had a problem with splash lube,if done right,turn mine 6500-6800 rpm all the time!
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