Super Jet 701 Superjet with 84mm Pistons...Big bore sleeve? Or last bore 61x...

nightrider05

nightrider05

Location
St.Louis Missouri
I have a bit of a mystery motor that I bought off a forum member last year...discovered something else about it tonight..

It is a 62t case, with 61x cylinder. Cases and cylinder are ported.

Out of curiosity I typed the piston number( 790M08400 ) in google to find out what exactly it was...The number comes up as a 84mm Wiseco part number...I then dug the mic out and sure enough it is a 84mm bore. I had never checked this because it was sold to me as a 701cc motor, and these pistons don't show the oversize on them like regular pistons do.

Now here is my question..If its a stock 61x sleeve, I know its on its last bore. However, the sleeve measures at 5mm thick(just the sleeve, not measuring casting outside of sleeve)...So how thick would a bored out 61x sleeve be, and how thick would a big bore sleeve be?

I am hoping its a big bore 760 sleeve on STD size.

Thanks for the help! Would be a HUGE plus if this is a big bore sleeve..I just don't have a stock cylinder around to compare to.
 
nightrider05

nightrider05

Location
St.Louis Missouri
BoostedBseries said:
Are you measuring the top or bottom/ skirt of the sleeve? Im running a 84mm piston in a stock 61x sleeve as well as a few other guys i know.
Click to expand...


Hey,

I was measuring the top as the motor is fully assembled still. However another member schooled me a bit about the sleeves and how to properly measure them (Thanks 3rid!) and the final conclusion is that its most likely a 61x sleeve bored out.

How do you like yours?
 
Mark44

Mark44

Katie's Boss
Location
100% one place
nightrider05 said:
Hey,

I was measuring the top as the motor is fully assembled still. However another member schooled me a bit about the sleeves and how to properly measure them (Thanks 3rid!) and the final conclusion is that its most likely a 61x sleeve bored out.


How do you like yours?
Click to expand...

You lucky dog!
 
JetManiac

JetManiac

Stoked
Site Supporter
Vendor Account
Location
orlando
The pistons dont show an oversize mark because they are standard bore 760 pistons.

I have a buddy running 84.5mm prox pistons in my old team scream blaster ported motor with 61x cylinder. The motor has been ripping with this bore for several years now.
 
Freakrider

Freakrider

X247
Location
Tampa Bay area
nightrider05 said:
Hey,

I was measuring the top as the motor is fully assembled still. However another member schooled me a bit about the sleeves and how to properly measure them (Thanks 3rid!) and the final conclusion is that its most likely a 61x sleeve bored out.

How do you like yours?
Click to expand...

Why do you think it is a 61x sleeve when it measures 93mm outside diameter ? it should measure close to 88.13mm ?
 
nightrider05

nightrider05

Location
St.Louis Missouri
jetmaniac said:
The pistons dont show an oversize mark because they are standard bore 760 pistons.

I have a buddy running 84.5mm prox pistons in my old team scream blaster ported motor with 61x cylinder. The motor has been ripping with this bore for several years now.
Click to expand...

That is good to know...so if I need to freshen the motor up I can go to a half size. Thanks

Jump On It said:
Why do you think it is a 61x sleeve when it measures 93mm outside diameter ? it should measure close to 88.13mm ?
Click to expand...

Matt_E said:
He measured the lip at the top of the sleeve.
Click to expand...

Correct. The only accurate way to measure the sleeve is to remove the cylinder and measure at the bottom. The top of the cylinder sleeve has a lip to allow it to only go so low in the cylinder casting.
 
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