Feedback on hyway 066 56mm kit

[Stevetheboatguy]

Anybody know first hand how a hyway 56mm top end would compare to either a oem 066 54mm or a oem 52mm 064?

I'm thinking of putting one on a 064 possibly.


Steven

 

[cus_deluxe]

I think @drf256 did one of these on a china 660?

 

[Larry B]

Anybody know first hand how a hyway 56mm top end would compare to either a oem 066 54mm or a oem 52mm 064?

I'm thinking of putting one on a 064 possibly.


Steven

Got one on a china 660. Has 178psi compression and .023 squish using a base gasket. Runnin a .020 filed key for timing advance and a hyway dual port muffler. Whips the pants off of a stock 440. I smoothed the ports too.

 

[Stihlmar]

Had one with stuck rings given to me to play with. Literally dug the rings out of the piston. Cylinder and piston looked new. Had almost no run time by the looks of it. Cut the base and made a pop-up just for fun and ended up with .040 of Freeporting. Oops. Found that. Haven’t watched it thought.

 

[drf256]

I did two. @Onan18 has one. Runs fine with supplied piston.

The other I did was with a 395 piston. It’s meh...

 

[Deets066]

I just don't care for the quality of AM jugs yet. But, with that said a little beveling and cleanin up of ports, should be fine

 

[Stevetheboatguy]

Well. Not as much feedback as I was expecting. But I think I'm going to go with the oem 54mm p&c on the 064 case.




Steven

 

[Flying_Dutchman]

I had one on an 066 for a while... eventually it caught a ring in the exhaust port. Probably avoidable if you clean up the bevels in the ports.
The stock 066 had slightly more power, not noticeable unless you ran them side by side.

 

[Mastermind]

I've yet to see a BB kit that was worth messing with.

 

[mgr1]

What is a good am 56mm piston from these bb kits?

 

[Mastermind]

What is a good am 56mm piston from these bb kits?

I can't answer that. I gave up on BB kits several years ago.

 

[MustangMike]

I can't speak to an 064, but the Cross P&C for the 066/660 generally runs stronger than stock. Just make sure you check the port bevels, and they generally have about .020 squish w/o the base gasket. Often you need to file the Cross name off the side for flywheel clearance.

The ports are noticeably larger than OEM, so that is what I would go with if you are not porting the cylinder (these are based on a ported cylinder Randy did).

If you go to HL Supply, youtube, Cross vs OEM you will see my video with one on an 066.

 

[T.Roller]

Make sure to check squish because they are all over the place with AM.

 

[Larry B]

I've yet to see a BB kit that was worth messing with.

Since my china saw is an experiment does anybody know how a stock hyway BB kit bs. Say a stock Cross MMWS top end would compare for power? Longevity? I can smooth and bevel ports but dont have the chops for real porting.
The BB kit i have now seems to make good power. Has 178 PSI compression. I like tinkering with the toys so my swap top ends to see a difference

 

[T.Roller]

I'd say a cross mmws cylinder would eat a stock BB lunch.

 

[MustangMike]

I've built 4 saws with the Cross P&C, so I don't have enough time on any one of them to comment on longevity, but as long as you use an OEM piston pin bearing and OEM clips, I think you will be good for a while.

I've milled Red Oak and Hickory with one, using a 36" bar, w/o issue (other than an AM piston bearing).

 

[huskihl]

Squish on mine with the MMWS Cross cylinder is .013" without a gasket. And the exhaust roof is a little flat for my liking. I'd think a heavy bevel in the roof center would alleviate the issue of catching a ring, if a guy didn't want to crown the roof more.

They are pretty good runners, though

 

[MustangMike]

The exhaust roof is often very flat, but the exhaust floor is what is often lacking a bevel, so be real careful with that.

 

[huskihl]

The exhaust roof is often very flat, but the exhaust floor is what is often lacking a bevel, so be real careful with that.

Mine was only assembled and run for comparison purposes. It sits on the shelf awaiting the knife.

 

[MustangMike]

Milled a good amount of Oak and Hickory with mine.