The Cross Performance 066 Top End

[RI Chevy]

Nice job Mike! [emoji106]
I'd like to see another video after 6 or 8 tanks and it loosens up a little more. Runs well.

And boy, you always get some big red oak to cut. Whew. Nice.

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[MustangMike]

Details, and other notes:

I rate the piston in this set at 5 stars, as it is almost an exact repro of the original, is a bit lighter, but has wider skirts. Plus, it comes with Caber rings ... can't beat that!

The jug I rate at 4 stars, only because I had to clean up the intake port a bit. I made no attempt to improve the design, just to correct a bit of a defect so that the intended design would be realized. I was also worried about the factory bevel (or lack thereof) on that portion of the intake port.

I assembled it w/o a base gasket, and squish is .020. However, compression seems about the same as the factory cylinder (which had .028 squish), so the combustion chamber may be a bit larger. Someone else posted they got .019 squish w/o the base gasket, so they seem to be very uniform in that regard.

 

[MustangMike]

CUT TIMES:

This is what I recorded, to the best of my ability (I averaged two times for each cut).

Stock Saw 1st cut: 25.66; 2nd cut 27.12; 3rd cut 28.22.

W/O touching the chain, the virgin cut with the Cross was 28.00, and the next cut was 26.74, but the cuts were not straight, and when I inspected the chain I realized it got rocked a bit, which is likely why each of the cuts with the stock saw got slower. I also realized that even with the rocked chain, the Cross really cut faster on the second cut, so it needed some break in.

So I ran a tank of fuel through the saw, then resharpened the chain, and got times (in the last vid posted) of 22.23 and 22.85. I compared these to the first cut time with the stock P&C to determine the approximate 12% improvement.

 

[Gentleman]

JUDGEMENT DAY!!!

The rain finally stopped, and I got to resume my testing.

Best as I can tell, this P&C is running about 12% faster than my stock P&C, and it does fell like you can lean on it harder. Keep in mind, I thought my 066 was a pretty good runner for a stock saw.

IMO, this kit would make sense for anyone with a burned piston, or anyone that wants a little performance boost from their stock 066/660, especially if your stock saw is not a real strong runner.

This video is after one tank of break in, and a resharpened chain.

Thanks Mustang. Nice video.

 

[MustangMike]

Thanks Bruce, and Randy, for letting me test this kit, I am very impressed with it.

I remember discussing with Randy (last year) putting one of these kits on an AM MS660.

Luckily, I then came into an OEM 066, but for those who don't, an AM MS660 with this kit on it may be a real good idea!

 

[MustangMike]

Other Mods ... I know I have posted this stuff previously, but just to make sure everyone on this thread is on board. In addition to the Cross MMWS P&C, installed w/o a base gasket, the timing on this saw has been advanced by .025 off the key, and the muffler has been modded as follows:

A 1/2" hole was drilled straight away through the baffle. Then, toward the back of the muffler cover, 2 - 1/4" holes on the clutch side (above when the exhaust would hit the saw), and 3 - 3/16 holes on the recoil side (a deflector was needed on that side to prevent the holes from heating your hand). I made the deflector by cutting down another muffler cover, and bolting it over the first muffler cover (see pic).

 

[RI Chevy]

Important to note though Mike, is that your saw wasn't completely stock when you started. You had MM, timing advance and base gasket delete. So you started with a semi-modded saw. Only thing left was to port it. So its good that you did see some improvements. It would have been more delineated if your saw was bone stock when you started.
But good improvements nonetheless. [emoji106]

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[MustangMike]

The OEM 066 still had the base gasket. With squish of .028 you could not just delete it.

But yes, it had the muff mod and timing advance. The only difference in performance was from exchanging the P&C (with a base gasket delete).

If I may say so myself, it does spit a nice stream of chips, covered my foot in no time!

Also, did you note in the lower left, that the deer left their calling card from when I noodled some rounds a few days earlier (to break it in).

 

[RI Chevy]

Lol.

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[MustangMike]

I just realized that the HL Supply site is selling the AM 660s (in parts), and that one of the options you can select is this P&C!!! WOW!!!

If I didn't already have one...

 

[bikemike]

Important to note though Mike, is that your saw wasn't completely stock when you started. You had MM, timing advance and base gasket delete. So you started with a semi-modded saw. Only thing left was to port it. So its good that you did see some improvements. It would have been more delineated if your saw was bone stock when you started.
But good improvements nonetheless. [emoji106]

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I'm glad his saw had the mods that improve the performance of a stock jug. He brought out the potential of the saw to begin with so it is responsive peppy

 

[tickbitintn]

I just realized that the HL Supply site is selling the AM 660s (in parts), and that one of the options you can select is this P&C!!! WOW!!!

If I didn't already have one...

One.....
You sound to have some cad immunity... Please share! LOL

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[BuckthornBonnie]

Good info, Mike. Thanks for a thorough thread.

 

[MustangMike]

OK Deets, your up at Bat, I like watching videos!!!

In fact, it would also be great to see vids of the AM 066s, one of each of the 3 different P&Cs being offered, to see how they compare!

 

[Deets066]

OK Deets, your up at Bat, I like watching videos!!!

In fact, it would also be great to see vids of the AM 066s, one of each of the 3 different P&Cs being offered, to see how they compare!

I hear ya mike, Haven't made time yet

 

[MustangMike]

I understand! Best of Luck with it.

 

[Frank bierce]

I just purchased the whole lot with a cross top end....now I get to anxiously wait.

 

[Dub11]

Build thread?

 

[tickbitintn]

Build thread?

Coming soon..... Lots of them...

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[Gentleman]

Thanks @MustangMike
What was the type of oak you we cutting?