6m6 cylinders on X cases?

[jetskiking]

I have an 6m6 that was done up by protec with porting and the 701 bigbore. I read somewhere that the cylinder was basically like a 61x with a little lower port timing. I had origanally planned using the guts and head to build a 61x. So knowing that for freestyle the port work is usually done so the port timing dosnt get raised I got to thinking about trying the big bore 6m6 cylinders on x cases. Has anybody tried this? Also can the outside of the exhaust port meating the manifold be opened up large enough to match a 701 manifold? Its opened up on the inside against the piston but tapers for the smaller 650 exhaust. What does everyone think? This is just me being crazy and wanting to try something strange with some parts I have. I'm just curious how well it would work.

 

[cookerq62]

douglee has a bigbored 6m6 he bought from Paul that was ported by Tim Judge. Its got plenty of balls. Try and get ahold of paul for more info on the porting. The exhaust ports looked a little more square than ported 701 cylinders probably because they couldn't be widened as much. I want to say th manifold matched up fine but you would have to talk to doug.

 

[Freestyleriverrat]

Also can the outside of the exhaust port meating the manifold be opened up large enough to match a 701 manifold? Its opened up on the inside against the piston but tapers for the smaller 650 exhaust.

I would think it is better to do a 701 then BB that to a 760. I had a ported 6m6 w/ dual 38's, protec exhaust and high compression head. I thought it was great but noticed that a stock 701 have more torque than mine which is better for freestyle.
paying to BB a 6m6 is not worth the effort or $$ IMO. It may perform the same as a 701 but you could probably pick a 61x cylinder up for the price of a new piston. If you sold your ported cylinder that may cover the cost of the switch minus the freestyle porting.

 

[Mouthfulloflake]

you cant open the ports quite as much on the 650 cylinder, there isnt enough meat around them, they get thin when they get nearly as wide as 701 exh ports.

 

[jetskiking]

I would think it is better to do a 701 then BB that to a 760. I had a ported 6m6 w/ dual 38's, protec exhaust and high compression head. I thought it was great but noticed that a stock 701 have more torque than mine which is better for freestyle.
paying to BB a 6m6 is not worth the effort or $$ IMO. It may perform the same as a 701 but you could probably pick a 61x cylinder up for the price of a new piston. If you sold your ported cylinder that may cover the cost of the switch minus the freestyle porting.

I wouldnt be paying to bigbore because its already done. I'm just thinking here. Because I already have the cylinder, crank, head, pistons and rings I could just buy some x cases for cheap and I think I have an x manifold laying around. Believe me I wouldnt even be thinking about it if I didnt have the parts. If I buy an x cylinder to go with it its probably going to cost alot more considering I would probably have to get bored and buy pistons since mine are 81mm (Stock bore on 701). Like I was saying these are extra parts laying around I'm just curious how it would work since everyone says the downfall of the 6m6 is the intake area on the cases.

 

[jetskiking]

you cant open the ports quite as much on the 650 cylinder, there isnt enough meat around them, they get thin when they get nearly as wide as 701 exh ports.

Yeah I was thinking that. I might would open it up as much as I could then port match a 650 manifold.

 

[romack991]

post some pics of the protec port job, i'd like to see em. like mouth said, the 650 is limited by the coolant passages. I've just started porting a 650 myself, everything is still rough.

 

[Mouthfulloflake]

post some pics of the protec port job, i'd like to see em. like mouth said, the 650 is limited by the coolant passages. I've just started porting a 650 myself, everything is still rough.

page 5 or 6 of this thread.

http://www.pwctoday.com/showthread.php?t=46632&page=5&highlight=sportport

Octane did a set that looked great, dont know ifhe ever ran them though.

 

[jetskiking]

I think there are some pics in my build thread.

 

[douglee25]

I could ask Paul but maybe someone knows the quick answer.... I bought a cylinder off of him that was ported by Tim Judge. the port job of his was insane. I assembled the motor with 81mm pistons and noticed the cases read 6m6 on the side. How could a 6m6 cylinder have enough to bore all the way up to 83mm? There was plenty of sleeve left to achieve that if need be.

Doug

 

[Idok]

I could ask Paul but maybe someone knows the quick answer.... I bought a cylinder off of him that was ported by Tim Judge. the port job of his was insane. I assembled the motor with 81mm pistons and noticed the cases read 6m6 on the side. How could a 6m6 cylinder have enough to bore all the way up to 83mm? There was plenty of sleeve left to achieve that if need be.

Doug

on the cases, or cyl?

lots of cases have 6m6 bottoms.........

 

[douglee25]

on the cases, or cyl?

lots of cases have 6m6 bottoms.........

Apologize. I meant cylinders. Any idea why or how?

Doug

 

[cookerq62]

I assembled the motor with 81mm pistons and noticed the cases read 6m6 on the side. How could a 6m6 cylinder have enough to bore all the way up to 83mm? There was plenty of sleeve left to achieve that if need be.

Doug

I think those jugs were resleaved. How much does it usualy cost to bore out a set of cylinders to be resleaved to the next size????

 

[romack991]

I think those jugs were resleaved. How much does it usualy cost to bore out a set of cylinders to be resleaved to the next size????

they'd still be constrained by the coolant passage though :worried: can't imagine they could be anything like a 61x. but then again i didnt really pay close attention to how close the coolant passage was when i did my 61x cylinder.

 

[douglee25]

Here's pics before I installed the cylinder.

Any clue? Maybe Paul will chime in.

Doug

 

[romack991]

Here's pics before I installed the cylinder.

Doug

wow, that exhaust is pretty, intake corners are sharp though. i did the same on my intake but with large radius on the corners.

 

[Jr.]

When TJ designed & ported those cyls, it was back in the MOD Sport class racing days. One of the big tricks then was to BB sleeve a 650 jug. & use it on a 61x case.

The B1 race porting will work very well as a freeride port, the ex port isn't raised quite as high as full race porting. The actual shape of the port is very similar to the FS porting I'm currently doing.

If you were to take that Cyl & install it on a set of T cases, you results will be noteworthy with duel 38's, even better with duel 44's

ski ya, Paul

 

[douglee25]

When TJ designed & ported those cyls, it was back in the MOD Sport class racing days. One of the big tricks then was to BB sleeve a 650 jug. & use it on a 61x case.

The B1 race porting will work very well as a freeride port, the ex port isn't raised quite as high as full race porting. The actual shape of the port is very similar to the FS porting I'm currently doing.

If you were to take that Cyl & install it on a set of T cases, you results will be noteworthy with duel 38's, even better with duel 44's

ski ya, Paul

That explains it well! Thanks Paul! :biggthumpup:

Doug

 

[jetskiking]

. It looks like my jug has been resleived also but the porting is slightly different. Its an 81 mm bore and looks like it could go over a few more times. So the T cases isnt something I have thought of doing but that opens up a new world.