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Well, I've been planning on building a stroker, and just about decided on a 82mm crank.

Why?

Price. You can get a forged 82mm crank for about 450 from Cb performance or aircooled.net.

Engine width. I want to keep it narrow as possible.

Better support for the piston. The shorter stroke keeps more of the piston in the cylinder at BDC, where as the larger strokes will start to pull it further. I think the motor should last longer, especially when compared to a 86mm stroke.

The cheapest forged 84mm or larger crank is 650 or more. So your going to pay 200 bucks more, for 2mm more stroke. It only adds about 60cc. Although I would go for 84mm if I could get at the same price. I doubt I would try to build a 86mm motor. Just to wide, and the piston is pulled pretty far out of the cylinder at BDC.

So, here the final plans-
82mm forged crank
Scat or eagle rods( still undecided)5.5 inch
94mm P/C
Stage 7 Pef Tech heads or = 044s
web cam 86c
pauter roller rockers
stock flywheel 8 dowelled
dual 45 dells with 40mm vents.

I'm hoping for 170-180 hp.
Which in a 1700lb bug, with close ratio 4 speed and 165r/15 tires should get me in the mid 13s-hopefully.

Any comments, tips , help? Naysayers?

James, that is some nice tips that i need.....have some questions......
1) what is the biggest stroke i can go before i start cutting metal?
2) what is the biggest stroke i can go and will still bolt on the engine tin..doghouse shroud etc.
3)what is the biggest i can go and still use the factory 8mm studs?
thanx
wallace

I'm a 78 stroke man, after you build the 2275, you will see why...

82 stroke is ok, but it tends to kill the snappy power that I like to make...The CB cranks are good, but if you use a cam with more than .435 lift you will have crank interferance.....I just had a big clearancing issue with a 2275 last week, running a 122/125 web grind..

2275 is a good engine, but bigger is not always better for the street, the 78 stroke, 94 bore engines are my favorite big engine, snappy, and pull hard with better top end and crisp throttle response..We do alot of 2165 engines for Spyders, and they are true rockets..

The 78 stroke can use a shorter rod to keep a good ratio, meaning less deck shim, and more cylinder in the spigot, for better support and less chance for leakage.....It is all up to you, either way it will be a powerhouse.

Jake that is some great practical info. Thanks!! BTW what's the 122/125 2275 going into? A daily driver perhaps?

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Matt Harris
78 x 90.5
2007cc
1971 Super

You will laugh when you see how little of the piston is still in the cylinder at BDC! With CB82, and Scat 5.394" rods you just keep waiting for that ring package to pop out the bottom of the Cimas That is w/ .040" copper head shims, so most of the barrel is in the case.

Go for the CB 84 w/ Chevy journals, it is also $450!!!!!!!!!

Yep, the 82 with a 5.394 rod is a little too high on the ratio scale too..

The 78 with the 5.4 rod is a great combo.

BTW that 2275 engine went into a SHRINERS wheelie popping parade buggy, it is a serious ride..

What's a SHRINERS? Is it the buggy? Either way, I'm suprised that thing doesn't just pop wheelies, but flip all the way over onto its back

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Matt Harris
78 x 90.5
2007cc
1971 Super

Jake, do you use "A" or "B" pistons when using the 78mm crank? Thanks.

Gotta be B pistons unless you want mondo barrels spacers. I've built a 78 w/ A pistons and I will never do it again. Lots of work to fit the engine tin!!!

Anything more than 74 stroke is an absolute must to have B pistons..

The SHRINER"S buggy is used for parades, he rides wheelies for the crowd, it is a true beast in a MANX...it never gets out of second gear..

Man that buggy has gotta be so friggin wicked it's unreal. That beast of a cam in a 2275 in a light car.......good grief Charlie Brown. Must be nice.

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Matt Harris
78 x 90.5
2007cc
1971 Super

Matt, Shriners are a group of people, like Masons kind of, or Elks Lodge, or the Loyal Order of Waterbuffalo....

OOOOOOHHHHHHH I see. Now I get it.

Thanks Tate.

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Matt Harris
78 x 90.5
2007cc
1971 Super

Actually, the Shriners ARE Masons. There are various sub-branches to Freemasonry and the Shriners are one of those. In fact they are probably the most visible of the order due to the Shrine Hospitals which help children(aside from their little red hats). The hospitals are funded in part by the Shrine Circus, Shrine Football games, etc...

Steve
A Mason (but not Shriner) and VW owner x2

HELP ME!

I bought a set of 90.5 Mahle P&C's last year with intentions of building a 2110 motor. After reading these posts I'm not sure if I want the 82mm stroke anymore... I understand there is A and B model pistons but when I bought them I didn't know this I thought they were clearanced for Individual strokes, anyway the Model number is:K70441
Are these B pistons, or did they sell me some junk?

I really appreciate the help, I paid too much for these and it would be really bad if they aren't what I need! Thanks!
-Bobby