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 Post subject: Re: P grind cam wanted for test
PostPosted: Sat Oct 14, 2017 8:22 pm 
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Joined: Fri Jun 24, 2016 2:38 am
Posts: 46
Location: New Zealand
Really great to see Brad.
Anecdotally, and with the graph work now, how would you differentiate the engine characteristics between HT and 8J?

I.e. it's been suggested somewhere that the HT profile is designed for carbs + long inlets, i.e. high inlet inertia, where maybe the 900ie is less well behaved on carbs in lower RPM band.

Does my question make any sense?

Top work!
Nick.


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 Post subject: Re: P grind cam wanted for test
PostPosted: Sun Oct 15, 2017 12:01 am 
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Joined: Tue Mar 18, 2014 10:03 am
Posts: 188
Hi Brad...
I notice the point of intersection for the P grind is almost twice as high as most of the other cams. Is this the reason why the 900 cams are an easier swap, assuming that the valve sizes remain the same?
Best Regards...
Flattop


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 Post subject: Re: P grind cam wanted for test
PostPosted: Tue Oct 17, 2017 4:57 am 
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Joined: Mon Jan 21, 2013 4:36 pm
Posts: 185
thanks to boucher and peter nuss for the cams for testing.

the ie (8j) cams are longer and work at a bit higher rpm. both it and the st2 have a lot more exhaust duration. doesn't neccesarily mean the 8j will have less midrange than the ht depending on where you set them. more that the engines were undervalved and they were trying to make the 900ssie make more top end power i'd say.

bruce meyers said this about fitting different cams to 800 engines, easiest just to post this:

If you have invested or plan to invest in ported heads there are a couple options,
--900SS Carby cams: give a nice increase from 4000 rpm up with avg +4 rwhp over stock cam.
--ST2 cams: Net a bit more on top end rwhp with no loss of midrange.
--900SSie cams: Net alot more on top, maybe 2-4 more rwhp than carby cams but a slight loss at 4500 rpm. I think that dip could be tuned out with a good pipe.
--V2 212 cams: Exactly the same as 900SSie cam results
--V2 210 cams: Exactly the same as ST2 cam results


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 Post subject: Re: P grind cam wanted for test
PostPosted: Tue Oct 17, 2017 5:00 am 
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Joined: Mon Jan 21, 2013 4:36 pm
Posts: 185
the p will require deep valve cutouts for the additional lift at overlap. the 900 cams require machining for the later 750 engines, but the f1 had deeper cutouts than the later ones so it may take ht cams without machining.


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 Post subject: Re: P grind cam wanted for test
PostPosted: Thu Oct 19, 2017 6:24 am 
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Joined: Wed Sep 11, 2013 7:13 am
Posts: 173
Yesterday returned from a mostrascambio-trip in Italia.
In an old shop I "found" a NOS set of GioCaMoto cams for reversed vertical head, marked GM P (O and V)
I can measure the lift (at the cam) tonight at work :-)
Or did You get the chance to measure a GM cam ?

ciao
ducadini

sps : the 500 Pantah (grey) 20K for a VERY reasonable price was sold two weeks before :cry: :cry:

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 Post subject: Re: P grind cam wanted for test
PostPosted: Mon Oct 23, 2017 11:20 am 
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Joined: Tue Mar 18, 2014 10:03 am
Posts: 188
Hi Brad...
Any plans for charting the NCR7 cam or the GM F1?
Great work on the graphs. Thank you for sharing.
Best Regards....
Flattop


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 Post subject: Re: P grind cam wanted for test
PostPosted: Sun Oct 29, 2017 4:33 am 
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Joined: Mon Jan 21, 2013 4:36 pm
Posts: 185
i don't have any of those cams to test.


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