Stroker? Big Bore? Looking for power starting from scratch.

kawirydr44

kawirydr44

Location
Danville, CA
So recently i blew up my 701 real bad. took out everything but the head. so im looking to built up a motor. im wondering about stroker cranks tho. ive been thinkin about a 4 or 5 mm stroker with 83mm ported 61x cylinder. Would something like this work?

would it be better to run big bore? itll be stricky flatwater. who should i contact about strokers?

thanks
 
wsuwrhr

wsuwrhr

Purveyor of the Biggest Brapp
Location
Alta Loma, working in Upland
kawirydr44 said:
also what is needed to run a stroker setup? is it required to buy stroker cylinders?
Click to expand...

For a stroker cases will need to be clearanced for the offset of the rods, or trenched as most people call it.

Cylinders certainly need to be designed around the crank to get the port timing correct.

Stroker cranks can be added to stock cylinders but the port timing is always a compromise.

I would be happy to price out a complete motor, or parts, if you want to do it yourself.

Brian
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
If you're considering stroker cranks, I bet the 865 from xscream isn't too far out of your reach. I assume you've got 62t cases already and you'd just need another stock crank. I've never ridden one but a lot of people are saying they hit harder than stroker motors.
 
masterblaster

masterblaster

X-H2
cc for cc strokers make more torque.You can use a stock cylinder with a recessed head and have minimal sacrificing of port timing with a 4 or 5 mill crank,make alot of power for way less than a billet 865,just less bling.depends if you have to buy the crank new or not. BB sleeves installed in a stock cylinder and ported right,cost much more than custom machining a set of domes to work with a 5 mill crank.you can clearance the cases your self very easy for a small stroker.
 
W

waxhead

wannabe backflipper
Location
gold coast
I would look at a 3mm stroker.
the cases will not need to be clearanced and then bore it to 83mm on the stock cylinder
That way you can use the stock sleeves and not put in bigger sleeves and break into the valuable transfer port volume that these engines suffer from a lack of.
The 3mm crank with a recessed head on a stock ported engine puts the transfers very close to where you would want them , you still need to adjust exhaust port height
 
2

2XLR8

X-
You still have to pay to port the cylinder even if you don't go big bore sleeves. If your crank is shot and you want a stroker that has to be close to a grand plus pistons, case, cylinder, domes, reed cages? It can add up very quickly.
 
W

waxhead

wannabe backflipper
Location
gold coast
Of course you still have to port it, but big-bore sleeves require a bigger outside diameter on the sleeve.
The 61x already is lacking in transfer port flow and this just hinders it more.
The good thing about a 3mm stroker is it effectively increases the transfer port height to just about right, this means you can get a nice shape on the transfer tunnel and not have to worry about breaking through in to the water jacket.
 
masterblaster

masterblaster

X-H2
good luck finding a used 3 mm crank though,5 mills are all over in good shape used. You bring a interesting ques up though,staying with 83 mill bore to have increased transfer flow? Wouldnt the extra cc of the bb sleeve being at 85.5 and up more than make up for that lost flow area?
But in this case trying to do it for less $ I can see it still making great power at 83. Most people already have ported cylinders or one can be bought cheap used.Its not hard to clearance the cases for a 5 mill with hand tools either.
 
W

waxhead

wannabe backflipper
Location
gold coast
there is a guy over here in aussie making 3mm stroker cranks so we can buy them

No the big bore cant make up for the decreased transfer port flow.
This is one of the reason people are making aftermarket cylinders
 
kawirydr44

kawirydr44

Location
Danville, CA
I'm lookin at 85mm big bore with a 5mm lighten And stroked crank with port work done by dasa runnin a wammer head Around 200psi. Am i not gunna be happy with it? I am also lookin at a Ada billet cylinder motor 83mm running 5mm stroker but not sure on the port work or time on crank.

I'm confused to how 83mm would hit harder then a 85mm if there both stroked.... I realize it's becuase of transfer ports but it just don't make sense. The first motor I'm looking At looks real good and people have said it makes good power...
 
Matt_E

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Size isn't everything that determines how a motor hits.
Expertise of the builder has a lot more to do with it.
Stock stroke motors by one builder may hit a lot harder than big strokers by other builders.

For your budget, either motor sounds like something that you "should" be happy with (because you're not going to get much more motor for that budget)
 
kawirydr44

kawirydr44

Location
Danville, CA
Thanks matt e that's what I was thinking. I've heard of people sayin an 83mm motor ported by lamey will hit just bout as hard as any bigbore setup.

But being I am stuck at spending around 2000 I wish soo bad I could get the 865 just not enough funding. These strockers are more
within my price range.

How's the realiablitly of a stroker like a 5mm I will be going through my motor each season but strokers don't make extremely unreliable correct?
 
Matt_E

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Depends on who built it, how old it is, and how it's been taken care of so far.
 
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