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Re: A65L head's'
maxx77 #481193 03/14/13 12:46 am
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If you want to confuse yourself a bit more, check Johnson Cams site and/ or talk to Keith Johnson. Get the straight story from him. Megacycle not too helpful. GP's are cool if cranky at idle if you have them. If not. $$ I bought a pair on eBay for about 750. Did the job and when I'm done racing will probably resell. Have fun!! PRT

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Re: A65L head's'
MAXX #481215 03/14/13 3:09 am
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Before you go making aluminum dust it would be worthwhile to make a mold of the port and chamber, cast a resin head to put on a flow bench then do a lot of testing. A lot easier to refill resin than aluminum and if you screw up you have not lost much.

Re: A65L head's'
MAXX #481378 03/15/13 8:03 am
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I think there are two roads you can go to get better flow and power, with a cam or with a head. My preference is with a modified head, its not radical and the motor will run sweet, no heavy valve springs and less of a hard time for the valve gear. On a std stroke big bore 750 the std cam is good, and with head mods and good pipes you can have power up to around 9,000RPM. This has 79.5mm bore Devimead cyl, std stroke crank changed to 90deg, 38mm VM Mikunies, big valves(44.5mm and 39mm) big ports and bigger dia pipes using an 'X' connector. Changing pipes changes power characteristics. This also has V/tall gearing 20T-40T final drive.
http://www.youtube.com/watch?v=oBD2g_bBog4


mark
Re: A65L head's'
MAXX #481386 03/15/13 10:43 am
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Now I know your steed is not qute the standard BSA but curious minds would like to know how you keep the rockers & pushrods from parting company at 9000rpm ?


Bike Beesa
Trevor
Re: A65L head's'
MAXX #481399 03/15/13 1:29 pm
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Don't know how fast it would go Allan but I think it would wind out a bit. With that gearing it should do 103 in second at 8,500.
Its one of my heads on my son's motor in my brother's bike with his cyls smile Trevor it has good standardish valve springs that give about 170-180lb at full lift. I haven't had the data logger on it so don't know exactly where its power peak is but it feels like it'd be somewhere over 8 with those pipes. I think that bore and stroke is a good capacity for it. The 74mm stroke lets it rev.


mark
Re: A65L head's'
maxx77 #481551 03/16/13 5:00 am
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In Remembrance
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Originally Posted by maxx77
I'm now not really sure how the SRM750 is going to respond to, or what the 750 is going to want in regards to a cam; in regard to the Mega x3 cam, my best thinking tells me its going to like it.

A 750 would want pretty much the same as a 650,but just a little more (15.4%) valve curtain.With 1-3/4" intake valves,you've got about 9.5% already.

The X-3 cam seems sensible for a street bike.What it loses in duration,compared to a standard cam,it more than makes up for in extra lift.You'd be about 4% in front,but have better low rpm response.It should be pretty strong at mid-range.

The X-8 cam has a ridiculous amount of duration.If you wanted a 650 to make good torque at 7000 and max power at 8500rpm,it could be OK.

Re: A65L head's'
Pete R - R.I.P. #482989 03/25/13 8:10 pm
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talked to E&V last week; what a great guy. answered all my questions and didn't call me a dumba$## not once.. guess who's name came up???yep; pushrod tom. ok here's the question; how much weight should I remove form the flywheel on a 40 over set of a65 cylinders, running R&R rods, E&V pistons and a x3 cam,for steet work.?? and no I have not started on the 750; wanna get another motor together while I wait on the crank for the 750. soon as I get a photo bucket account set up, I will start posting pix. AND, guess what followed me home all the way from Michigan??? yep. a cherry 1972 Thunderbolt, box stock,5400 miles... woooo hoooo.
thanks in advance for response to the question in regard to the crank.

Re: A65L head's'
maxx77 #483013 03/25/13 9:30 pm
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I'm thinkin 0 grams. PRT

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Moderated by  Allan G, Jon W. Whitley 

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