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Author Topic: Sports engine build  (Read 2830 times)

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Offline voxonda

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Sports engine build
« on: January 14, 2012, 10:35:07 AM »
Am in the process of building, yet again, another engine mostly for track use. Decided not to go big-bore but stay 750.
Planning to use F2 pistons in K barrel and head. Have the specs for machining them, tho not sure about the diametre of the valve pockets. Exh oem and intake +1 m/m. Anyone can help?

Thanks Rob.
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Offline MRieck

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Re: Sports engine build
« Reply #1 on: January 14, 2012, 11:21:55 AM »
Rob
 Can you mark the valve center on the piston and add .060" to the OD of the valve? I use an old valve with the head cut off and the end sharpened to a point. Makes it easy to index off.
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Offline voxonda

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Re: Sports engine build
« Reply #2 on: January 14, 2012, 11:25:35 AM »
Thanks Mike, as always you're a great source.

Cheers, Rob
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Offline Sam Green Racing

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Re: Sports engine build
« Reply #3 on: January 15, 2012, 04:09:43 AM »
That's why they call him the HEADMASTER.  ;D ;D ;D ;D ;D ;D ;D
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Offline turboguzzi

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Re: Sports engine build
« Reply #4 on: January 15, 2012, 06:24:14 AM »
Quote from: MRieck on January 14, 2012, 11:21:55 AM
Rob
 Can you mark the valve center on the piston and add .060" to the OD of the valve? I use an old valve with the head cut off and the end sharpened to a point. Makes it easy to index off.

yep, good tip mike, but do you this at TDC or at some angle before/after?
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Offline MRieck

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Re: Sports engine build
« Reply #5 on: January 15, 2012, 07:26:52 AM »
Good point. At overlap TG when the intake and exhaust are open the same amount.
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Offline Doctor_D

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Re: Sports engine build
« Reply #6 on: January 15, 2012, 07:48:17 AM »
For you AHRMA-ites stateside, is it 2nd or 3rd overbore that gets you to the F750 class limit?  2nd is around 748cc and 3rd is 753.

(I guess I could just go to the AHRMA site and read the rulebook too.  ::) )
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Offline voxonda

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Re: Sports engine build
« Reply #7 on: January 30, 2012, 11:40:42 AM »
Well bike is (almost) ready for another season. Just waiting for the snow and cold to disappear again.

Got my Titanium bolts in today to gain that little extra, and yes I am trying to loose some too!
Side stand is coming off too, but is handy for when moving the bike around.
« Last Edit: January 30, 2012, 11:43:53 AM by voxonda »
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Offline bwaller

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Re: Sports engine build
« Reply #8 on: January 31, 2012, 10:14:16 AM »
Good looking race bike Rob. Did you use F2 pistons afterall and have you any pics of the finished products?
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Offline voxonda

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Re: Sports engine build
« Reply #9 on: January 31, 2012, 12:46:28 PM »
Thanks Brent,

This is actually a, very healthy, F2 engine with minor porting, 41a cam, PD carbs with choke parts removed and tuned.
The (F1)engine I am building is waiting for me what to do with the pistons. Have a few options, F2 pistons not done yet, 822 kit with 900DOHC pistons
but not much room for deeper pockets for the 63b cam.
Still looking what to do.

Chers, Rob
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Offline Sam Green Racing

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Re: Sports engine build
« Reply #10 on: February 01, 2012, 05:10:22 AM »
Hey Robbie, you'd better not finish last with THAT sticker on the tank, ::) ::) ::).......................




























































..................Castrol won't be to pleased. ;D ;D ;D ;D ;D ;D ;D ;D

Looking good mate, ride safe. 8) 8) 8) 8)

Sam. ;)
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C95 sprint bike.
CB95 hybrid race bike
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CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline voxonda

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Re: Sports engine build
« Reply #11 on: February 01, 2012, 06:56:16 AM »
No, you're right Sam. Castrol........ehm Jay would not be pleased ;D
Can always build something like this, bigger is not always better:
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Offline Sam Green Racing

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Re: Sports engine build
« Reply #12 on: February 01, 2012, 08:36:30 AM »
That's cute Rob, I love the smaller ones. 8) 8) 8) 8)

Sam. ;)
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C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline NickO

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Re: Sports engine build
« Reply #13 on: February 01, 2012, 04:00:28 PM »
Quote from: SamCR750A on February 01, 2012, 08:36:30 AM
That's cute Rob, I love the smaller ones. 8) 8) 8) 8)

Sam. ;)


Strange you say that Sam, your girlfriend says exactly the same thing!  ;D
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