New Baileys BB kit not a very pretty sight

[volks-man]

Howdy,
Unless there is a problem that precludes them from being functional we sell them. We did have an issue recently on the BBN 066's where the piston was hitting on a high spot that was created by decreasing the combustion chamber volume. I ended up throwing about 225 cylinders in the trash.Regards
Gregg

i like to see a commitment to quality.
though if that happens again, send a few my way rather than throw them away!

 

[SkippyKtm]

As you probably already know those weren't my pictures. I had my camera out and was unable to get any detail of inside the cyl. My camera is a decent new Canon but only a 6x zoom. Evidently a higher zoom is required.
Possibly different lighting techniques. What are the guys using that get nice up close detailed shots?

I use the "macro" setting on my old Minolta dimage G400 -its not a high end camera or anything, Its only a 4 megapixel camera. If the flash can't reach the areas it needs to, I use a very bright LED Flash light (It can be focused it down to a narrow spot) as fill lighting.

 

[mtngun]

Howdy,
I ended up throwing about 225 cylinders in the trash.

Ouch, I feel your pain.

We at AS are tough customers, but we also know you are taking steps to improve the quality and it has shown in the recent reviews. This thread is picking nits compared to where the BB kits were a year ago.

8 weeks for the revised 066BB, eh ? Hmmmmm........ maybe I'll try a pop up piston while I'm waiting.

 

[Grande Dog]

Howdy,
I hated canning all those cylinders. I had got some quotes to to machine them. The manufacturer decided he would rather replace than repair. We pulled the components and the manufacturer is sending just cylinders.
Regards
Gregg

 

[bayshorecs]

Howdy,
One thing to remember when it comes to squish is that it's relative to the displacement of the combustion chamber. So, if you have a squish of .025" with 2cc's of combustion chamber, i'ts going to have much more compression than a saw with 3cc's of combustion chamber with the same squish. In the past it was all relative because you only had OEM's building cylinders to spec. We're beginning to cloud the water a little because we're starting to modify size and shape of combustion chambers. The compression reading is going to be more useful in the future.
Regards
Gregg

Hmmm...

Being getting ready to install this 84cc kit on my 6401, what kind of squish should I shoot for? Have you already started to alter the combustion chambers?

Maybe I should just install the .019 gasket and forget about seeing what gasket-less squish would be?

What is a good compression number to shoot for? I know generally higher is better, but what should I consider as "good enough"? 160-170?

 

[blsnelling]

Hmmm...

Being getting ready to install this 84cc kit on my 6401, what kind of squish should I shoot for? Have you already started to alter the combustion chambers?

Maybe I should just install the .019 gasket and forget about seeing what gasket-less squish would be?

What is a good compression number to shoot for? I know generally higher is better, but what should I consider as "good enough"? 160-170?

Put it together without the rings or gasket the first time and measure the squish. .018"-.022" would be a good squish. You get what you get with compression. Hopefully you'll have 150+.

 

[atlarge54]

Hmmm...

Being getting ready to install this 84cc kit on my 6401, what kind of squish should I shoot for? Have you already started to alter the combustion chambers?

Maybe I should just install the .019 gasket and forget about seeing what gasket-less squish would be?

What is a good compression number to shoot for? I know generally higher is better, but what should I consider as "good enough"? 160-170?

Bayshorecs what do your transfers look like? Should they be approx. the same size and shape? On mine one transfer is probably 25-30% smaller than the other.

Where the brass impulse line is exposed in the transfer about a 1/4" would it be a good idea to grind it off to improve flow?

I thought the answer to my squish question was a bit evasive. If going by compression what is the recommended value? Good question.

Someone suggested maybe we're being nitpicks on this issue. I don't really think beink able to see a nick in the cyl in natural lighting without glasses when normally I wear reading glasses is nitpicking. This nick is probably .150" long by .030" wide and easy to feel with a fingernail. When I put my glasses on and get out a flashlight several other smaller nicks are visible.

I'm no expert on these issues but I'd venture to guess that with the transfers on this cyl. it might make less power than a stock 79cc cyl.

If the replacement Bailey sends me has a smooth bore I'll be happy to install it and even if it blows up maybe I'll ask for a replacement maybe I won't. More than likely I'll do some smoothing up the flow but only slightly.

 

[blsnelling]

Bayshorecs what do your transfers look like? Should they be approx. the same size and shape? On mine one transfer is probably 25-30% smaller than the other.

Where the brass impulse line is exposed in the transfer about a 1/4" would it be a good idea to grind it off to improve flow?

I thought the answer to my squish question was a bit evasive. If going by compression what is the recommended value? Good question.

Someone suggested maybe we're being nitpicks on this issue. I don't really think beink able to see a nick in the cyl in natural lighting without glasses when normally I wear reading glasses is nitpicking. This nick is probably .150" long by .030" wide and easy to feel with a fingernail. When I put my glasses on and get out a flashlight several other smaller nicks are visible.

I'm no expert on these issues but I'd venture to guess that with the transfers on this cyl. it might make less power than a stock 79cc cyl.

If the replacement Bailey sends me has a smooth bore I'll be happy to install it and even if it blows up maybe I'll ask for a replacement maybe I won't. More than likely I'll do some smoothing up the flow but only slightly.

The front and rear transfers are different sizes. They are on most saws. Can you describe this "nick" a little better?

 

[bayshorecs]

I don't have it with me at work, but based on the pics I posted, it does look like the transfers are slightly different. That may be camera angle.

I will try to get a measurement tonight of the 4 holes.

I don't think (or know) about the nipple. I would think it is ok. I didn't think it was impeding flow when I looked at it.

Overall, I did not see anything to my untrained eye that looked bad. I didn't see any nicks like what you are describing and I stare at it every night, waitint to install it. I want to get a timed run on the stock first before I change it out.

In one of my pics, there is a smudge/drag line where I slid the piston and ring down the jug playing around. Not a scratch, just a rub mark.

 

[blsnelling]

Don't worry about that nipple unless you're porting the saw anyway.

 

[atlarge54]

The front and rear transfers are different sizes. They are on most saws. Can you describe this "nick" a little better?

It's one straight side and one radius side. If you took a circle slightly smaller than a dime and clipped a .030 wide piece off it that would be about the shape. In the cyl it's about 1/2" below the top of the cyl and the long side is in the direction of piston travel.

All I'm asking for is a smooth cyl. This isn't a race saw or even a full time work saw.

Should 150 psi be my goal? I was thinking of making a base gasket out of brass shim stock since it's easy to work with and I already have plenty of it. Would brass be a bad idea because of electrolytic action of different metals?

Thanks

 

[gink595]

This nick is probably .150" long by .030" wide and easy to feel with a fingernail. When I put my glasses on and get out a flashlight several other smaller nicks are visible.

Can you describe this "nick" a little better?

:monkey: LOL, I thought it was a good description. As I said earlier when I looked at it, it looked like some type of careless tooling marks.

 

[blsnelling]

:monkey: LOL, I thought it was a good description. As I said earlier when I looked at it, it looked like some type of careless tooling marks.

Then let me clarify. Where in the bore is the mark? Above or below the exhaust port? Is it a gouge through the NiSi, or just a "mark"? Is it raised at all?

 

[gink595]

As I was looking at it last night, the ring locater pin is center of the bore perpendicular to the wrist pin, I don't remember which way the arrow was facing now but I believe it was correct the pin was towards the intake side, after thinking about that later on I don't believe the piston ring would ever enter the intake area anyhow so that might be okay on how it is, I just have never seen a piston that located it's rings there in the center??

Also the Nikasil coating was thin near the decomp hole along with it looked to me like tooling marks in the upper part of the cylinder that penetrated teh nikisal coating, I could catch my finger nail in it and there was 2-3 of those. Another horrible looking thing I noticed was the upper transfer they were not aligned and not symeterical at all, the one transfer was only about 3/4 open blocked off with cast compared to the other side. All around this was not a very nice cylinder and I agree'd with Atlarge that he should either try another one or go with OEM.


I forgot to mention this also, but the Nikisal stop short of the squish band by about a good .125, someone else pointed this out to me on a 372 BB kit and it is the same with this kit. I don't think this would affect 99% of people but for the guys milling the base of the cylinder to do pop ups and such might get a ring snatched up in there.

I snatched this photo from Skippyktm in a thread he had, I noticed his had this also, you can see teh darker ring near the squish area, that is what I'm talking about, and you can put your fingernail in it and feel the thickness difference.

From a earlier post, the location is if I remember right above the upper transfer about half way to the squish band.

 

[blsnelling]

From a earlier post, the location is if I remember right above the upper transfer about half way to the squish band.

Thanks for the clarification. I took a quick look back through the thread and missed that.

 

[Tzed250]

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Imagine what this thread would look like if the subject was an OEM Stihl cylinder.


.

 

[Grande Dog]

Howdy,
I've been trying to find my notes when I tested it. I remember that the compression on the Solo was 195 and I think the Makita 6401 had 155. These were cold dry numbers using the gaskets that come with the kit. I think if you get around 150 with no mods, it should perform as advertised. This is the first generation of BBN 7900 and I believe the combustion chamber is a replica of stock.
Regards
Gregg

 

[TRI955]

.


Imagine what this thread would look like if the subject was an OEM Stihl cylinder.


.

Wouldn't be much to it, both would be made in China then.....oke:

Mike

 

[THALL10326]

Wouldn't be much to it, both would be made in China then.....oke:

Mike

Forgot Mahle, China too,hehe

 

[bayshorecs]

Howdy,
I've been trying to find my notes when I tested it. I remember that the compression on the Solo was 195 and I think the Makita 6401 had 155. These were cold dry numbers using the gaskets that come with the kit. I think if you get around 150 with no mods, it should perform as advertised. This is the first generation of BBN 7900 and I believe the combustion chamber is a replica of stock.
Regards
Gregg

Thanks.

So that means a squish of .020ish should still be safe as well as a squish of .050ish squish using supplied gasket (as others report).

I am taking away that either setup is fine depending on your comfort of running without gasket.

Just a noobie to switching jugs trying to get my head around things.