034 Super Build

[Mastermind]

This is a great thread! Never knew about the differences in the 034 vs 036 cranks. Want to see what you do with the ports and muffler.....

Those transfers are much rougher than the 036 cylinders I've worked on. I've got an 036 spare that is not on a saw, I'll check that.

This is one I cleaned up that was straight gassed. Piston was ugly.

View attachment 445706

Don't have better pic of transfer ports, this after aluminum transfer removed.

View attachment 445703

On ex ports I'm a fan of polishing them.

Before polish, don't have one of muff side

View attachment 445704

After polish

View attachment 445705

Nice work on cleaning that up.

 

[Mad Professor]

I’m here now… Thanks for the build thread Doc! What is the displacement dif between the 034 & 034S?

46mm vs 48mm pistons, ~4.5cc, 57cc vs 61.5cc.

This is a NOS 46mm 034 jug, it has the "tonsil" on the intake like the 038.

@drf256 what are your thoughts on the "tonsils"? For ring support, to direct flow/turbulence, or both?

 

[Duane(Pa)]

Cool thread. I have seen some intake boots with texture molded into the rubber. I think it is for enhanced mixing or atomization?

 

[Loony661]

Cool thread. I have seen some intake boots with texture molded into the rubber. I think it is for enhanced mixing or atomization?

Exactly. Keep the fuel mix in suspension by inducing some turbulence.

 

[Mad Professor]

Nice work on cleaning that up.

How you doing Randy? Happy New Year!

Thanks. I forgot to take pictures of the ugly mess inside the jug before I cleaned it. That was using acid and a "finger hone" with wet/dry.

 

[Mastermind]

How you doing Randy? Happy New Year!

Thanks. I forgot to take pictures of the ugly mess inside the jug before I cleaned it. That was using acid and a "finger hone" with wet/dry.

I'm good. Ready for spring !!!

 

[EFSM]

You aint wrong…never understood the love for those things.

There are cheaper boat anchors and tire chocks.

 

[SCHallenger]

Stayner, hope u are well. Hope my spelling ok.

Your spelling is right on Dr. Al. I'm doing reasonably well for an antique. A recent prostate biopsy confirmed the presence of cancer, but the detailed scores a la Gleason ( I think that is correct) were like two ones & a two & one six & a couple of sevens. My Urologist, prior to the biopsy expected radiation to be necessary. Post biopsy he said no treatment is necessary. He expects me to outlive the lesion. Good news as far as i was concerned. The biopsy was no fun. Post surgery it felt like someone had grabbed my hemorrhoids with a pair of pliers & ripped them out!!*$#%!?# I hope our paths cross again sometime at another GTG!

 

[drf256]

Your spelling is right on Dr. Al. I'm doing reasonably well for an antique. A recent prostate biopsy confirmed the presence of cancer, but the detailed scores a la Gleason ( I think that is correct) were like two ones & a two & one six & a couple of sevens. My Urologist, prior to the biopsy expected radiation to be necessary. Post biopsy he said no treatment is necessary. He expects me to outlive the lesion. Good news as far as i was concerned. The biopsy was no fun. Post surgery it felt like someone had grabbed my hemorrhoids with a pair of pliers & ripped them out!!*$#%!?# I hope our paths cross again sometime at another GTG!

Good to hear you’re well. I’m not certain on just how old you are, but lower grade prostate Ca is almost considered to be normal aging. I learned that 100% of men that make it to be 100 years old have prostate Ca on autopsy. The same is supposedly true of 80 and 90 year olds in terms of percentages (ie 90% of 90 yo have it). There are varying grades of it. You are probably Stage 1a and not Gleason. Gleason is histological grading. I THINK there is Gleason 2 as lowest and 5 as highest, but it’s a scoring system and not a grade. A 3+4 is better than a 4+3, regardless of the fact that the numerical sum is the same. Capsular and lymphovascular invasion are figured into the grading system. The urologic community has created the moniker “active surveillance” to be the appropriate medico legal term for just watching it. Actively surveillance sounds a lot better than “You’re old and we are just gonna watch you”.

I generally tell people that you’ll die with it, not from it. Only had 4 patients die of it in 28 years of practice, even though I get the diagnosis once or twice weekly. One guy presented with aches and hadn’t seen a doc in years. I did a PSA and it was 1400+. He lit up like a Christmas tree on bone scan. He died 3 months later from C. Diff, not the prostate. In addition, if you live another 10 years (please lay off the horse riding), there will likely be 10 more treatments out that are effective. That should give you another decade till they’ve found 10 more.

 

[drf256]

46mm vs 48mm pistons, ~4.5cc, 57cc vs 61.5cc.

This is a NOS 46mm 034 jug, it has the "tonsil" on the intake like the 038.

@drf256 what are your thoughts on the "tonsils"? For ring support, to direct flow/turbulence, or both?View attachment 445707View attachment 445708View attachment 445709View attachment 445710View attachment 445711

I believe it’s for ring retention and was phased out when they figured out it wasn’t needed. Most intake flow is on the floor anyway. I would love if they added a center exhaust column to the ex port. I believe McColloch models had a split exhaust ort at one time. I haven’t found any applications for the uvula-the actual term for the punching bag that hangs down off your soft palate. If 066 had them, I’d love it to retain the 288 piston ring. Iron pony made his own on some intake ports, but he raised the sides above the piston skirt at TDC. So he just created lower port speed, less inertia, and likely less flow with more turbulence. In addition, the intake port is on the thrust side of the cylinder. In general, the bigger and squarer the intake, the more wear on the piston skirt.

The intake port is akin to an intake valve in a car engine. It’s why a Stage 1 Buick Gransport would often beat a 454 LS6 Chevelle on the street. The 2.19” (or larger) 454 intake valve was too big for the rpm range hit on the street. Many guys went to the smaller oval port 454 heads for street dominance.

A bigger intake port on a saw would flow more air at higher rpm. When you lay the saw into wood and there is a sudden loss in rpm, the slower port flow continues and results in a saw that’s a dog and is only stronger within a narrow high rpm range.

 

[drf256]

The ideal intake and upper transfer would have a small enough area to maintain speed, and a big enough area to supply the upper rpm range during use.

I have gone smaller w my ports. I built an 026 with a huge intake port that would 4 stroke at 16,000 comfortably. Was great for small limbing. Once laid into bigger wood, it was an absolute dog.

I’d rather have a saw that 4 stroked at 13,500 and held 12k in-the-cut than one that 4 stroked at 17,000 and could on;y hold 10 in wood.

It all has to work together and be designed for its intended use.

I build the 112t series of saw to (DRUMROLL) cut firewood. Lots of torque and power from 9500-12000 rpm.

 

[drf256]

This one was a high wonder with no air filter. I would slow it down a bit for more area under the curve.

 

[Loony661]

You definitely understand what needs to happen for an engine to be strong. In the high performance V8 world, we would consistently be trying to get the volumetric efficiency past 100% for the application. Intake port volume is a big deal. So is carburetor size matched to engine size and target rpm. The only thing a carburetor will limit, is rpm. The bigger the engine displacement, the sooner it will hit the rpm threshold, and start losing power. And of course, the smaller the displacement, the more rpm it can achieve. We always ran the smallest carburetor we could, without losing power before our application rpm limit. Any larger carburetor, would make the engine less efficient at all rpms.

I think the same principles apply to saws. A stock sized carburetor should be more than enough for the saw that it’s on - even ported. (Exceptions of course for race saws trying to achieve MAX rpm levels). And intake size is also important. In fact, I would be willing to bet if you didn’t touch another intake port, the saws would still run strong. At some point in the RPM, the volumetric efficiency should be near, or above 100%, packing the most charged air into the crankcase as possible. My opinion is that the gains are made in the transfers and exhaust ports.

If the intake port and/or carb is too large, the engine power curve will be very “peaky” and fall off quickly with any change in rpm, as you’ve experienced.

 

[Mastermind]

And intake size is also important. In fact, I would be willing to bet if you didn’t touch another intake port, the saws would still run strong.

I'd agree with this statement......but.

LOL

In a two stroke the port width can relate to intake valve size, but not necessarily port runner volume. In other words, its possible to widen the intake at the plating end without opening the entire port. Squaring up the bottom corners is also a possibility. I'm not thinking about this particular series of saws here....but making an "in general" statement. The first few degrees of port opening is where most movement happens....so just paying attention to the bottom of that port can net some gain. Like anything though....too much is not a good thing.

 

[Loony661]

I'd agree with this statement......but.

LOL

In a two stroke the port width can relate to intake valve size, but not necessarily port runner volume. In other words, its possible to widen the intake at the plating end without opening the entire port. Squaring up the bottom corners is also a possibility. I'm not thinking about this particular series of saws here....but making an "in general" statement. The first few degrees of port opening is where most movement happens....so just paying attention to the bottom of that port can net some gain. Like anything though....too much is not a good thing.

Makes sense. I understand.

We had a formula for finding “correct” intake valve size in relation to cylinder volume. Most often than not, power was gained by machining for a larger intake valve. However, as stated, too much and it would hurt flow.

 

[Mad Professor]

View attachment 445830

This one was a high wonder with no air filter. I would slow it down a bit for more area under the curve.

Impressive for a 60cc saw! More HP than an 066.

Claimed HP on a stock 036 is 4.5 (Acres site), so that's nearly double.