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 Post subject: 69 or 76 crank
PostPosted: Mon Jul 12, 2010 7:06 pm 
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Location: Corydon, IN
im thinking about not going with the turbo setup now.
and just do a 76 crank with 90.5 but will i feel more power if i just had a 69 in it?
if i go this way what cam and carb would you guys run? i really dont want to run duals.

thanks

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 Post subject: Re: 69 or 76 crank
PostPosted: Mon Jul 12, 2010 7:35 pm 
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Joined: Tue Dec 25, 2007 12:40 pm
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Location: selmer tn. pickwick tn.
2 different motors for sure,,,,76 stroke crank has alot of lowend torque,a 69 stroke crank with 90.5 is damn near a stock motor,,,put the stoker crank in it and jus go ahead and put a 82 or 84 crank in it there the same price


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 Post subject: Re: 69 or 76 crank
PostPosted: Mon Jul 12, 2010 8:19 pm 
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Joined: Thu Jul 31, 2008 8:26 pm
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Location: Gadsden TN
I ran a 78 stroke crank with 90.5 mofoco 042 heads 110 cam and dual 40 dells for several years and loved it Keep in mind it wasnt a 2275 by no means but was hands down alot more engine than the stock stroke engine it replaced and it revved quickly but people dont build them much because of what Chris said you can build a 82/84 stroke engine for the same money .


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 Post subject: Re: 69 or 76 crank
PostPosted: Mon Jul 12, 2010 9:07 pm 
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Location: Boone County West (BY GOD) Virginia
depends on if your starting new or your building up off of what you have.it does cost more to build bigger.if your buying all new stuff then for what you can build a 69x90.5 you can go to 69x94 for the same money because the block and heads has to be opened up for bigger jugs anyways.not sure but the 74 or 76 crank can be put in a stockblock with clearancing the rod caps i think,but when you stroke the crank then you have to either get long barrells or barrell shims to get the jug further out depending on what compression ratio you plan on running.and longer push rods,so you do have to spend a little more to go bigger but its money well spent.but if you have the block clearanced for a bigger stroke then go 82,84,86x94.these cranks and cylinder kits are the same money but the bigger the motor then you start looking at better heads,rods and carbs and ratio rockers,flywheel, and then a sump,so on and so on,as you can see bigger does cost more but depending on what you have and what you need the price can change.just throwing a few thing out there for you.but if my only two options was a 69 or 76 i'd take the 76.theres no replacement for displacement.in other words,size does matter.lol. chad :mrgreen:

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 Post subject: Re: 69 or 76 crank
PostPosted: Mon Jul 12, 2010 9:44 pm 
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Location: Corydon, IN
ok i think the 76 will be going in with the 90.5 and what pushrod tubes do you guys run?
my list looks like this and all new but i will be using my stock case
1.25 rockers
110 or fk-7 cam not sure looking for input on that
cb044 heads with 42x37
cb sump pump
12.5 flywheel

would a Weber Progressive or a 44 IDF work on this setup

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 Post subject: Re: 69 or 76 crank
PostPosted: Mon Jul 12, 2010 10:07 pm 
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Location: selmer tn. pickwick tn.
stock pushrod tubes and a 44 weber would be good


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 Post subject: Re: 69 or 76 crank
PostPosted: Mon Jul 12, 2010 10:43 pm 
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Joined: Fri Nov 23, 2007 11:27 pm
Posts: 496
Location: Chandler Az
76x90.5 with a VZ 14 or VZ 15 cam. You will have more agressive acceleration than the W110 of FK 7 both which are still fine choices. Ditch the over priced CB heads and get a set of Steve Tims Stage One heads (www.performance-workshop.com) $590 for the pair includes shimming valve springs for your cam and match porting your intakes. x2 on the 44 Weber use an aircooled.net intake with the entire intake preheated, which helps keep you from having to jet rich. Dual 40s would also work but are not as off road friendly. A progressive would be my last choice.
Stock push rod tubes work fine. Since most CB cranks are all the same price you can also step up to a 78 mm crank and CB Unitech rods and not have to clearance the case. I have built 76x90.5 VW engines with a VZ 14 cam and a single Zenith. They pull extremely hard right off idle. no matter which combination you build I doubt you will be dissapointed. :)


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 Post subject: Re: 69 or 76 crank
PostPosted: Tue Jul 13, 2010 12:46 am 
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Location: moulton,al
69 x 90.5 = 1775
69 x 94 = 1915

76 x 90.5 = 1956
76 x 94 = 2110

78 x 90.5 = 2007
78 x 94 = 2165

here is what i would do

1.25 rockers on solid shafts
w - 110 cam
windage pushrod tubes
40 x 35.5 valved heads cnc ported from scat or c b performance or either hand ported heads by steve tims or shadetree performance
12.5 lb. 8 dowel flywheel
chromoly pushrods
dual 40 mm IDF webers or single 44 mm IDF weber
009 distributor
petronix ignitor electronic ignition
bosch blue coil
either full flow the case or use a oil pump with the in and out cover for an external filter and cooler
and as far as crank, rods and jugs go if i was on a budget i would go with

69 x 94 = 1915

and reuse the crank and rods if possible after rebushing the rods and polishing the crank, however if i had a little more money to spend i would go with

78 x 94 = 2165

and use c b performance counterweighted crank and uni-tech rods so there would be no need for clearancing, as gasman said there is no replacement for displacement and machine work to open up the case and heads for 90.5 or 94 jugs cost the same, but what ever you decide on i HIGHLY suggest that you take the entire rotating assembly from the fan pulley to the pressure plate and have it balanced at a reputable engine machine shop, i did this to my 1915 and it was and still is the smoothest engine ( no vibration ) ive ever had by far ( out of 5 )

also dont forget if you go stroker you have to have barrel shims and longer ( cut to length instead of pre-made stock length) pushrods, also if you go the stroker route you might as well go with a 82 x 94 = 2276 unless you just dont want to clearance the case

these are just my suggestions however :|

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 Post subject: Re: 69 or 76 crank
PostPosted: Tue Jul 13, 2010 7:00 pm 
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Location: mooers hill IN
Bluebuggy come & talk to me at the race . check pm


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