Saw video thread

[bikemike]

Beer drinkin weather here

You might have the nice weather but we have cheeper prices on saw parts lol

 

[jmssaws]

Beer drinkin weather here

Back when I drank,any weather was beer drinking weather

 

[jk14]

A chainsaw is balanced regardless of piston weight.

Have you ever heard of "blueprinting" or "balancing" a four-stroke racing engine? I have done it, and it involves weighing the pistons and making the counterweights on the crank match the weight of the pistons, as measured by the balancing machine.
The amount by which we change a saw piston is almost inconsequential at the speed which it runs; try it on saw with no anti-vibe though, and you will have a different view.

I have balanced hundreds of 4,6,&8 cylinder engines. On "V"engines we always used "bobweights" in the crank journals to simulate the weight of rod/piston/rings/bearing. The bobweight was calculated by first weight matching all components then adding the weight of all rotating components(rod bearing & big end of rod) to 50% of the reciprocating components (small end of rod, piston,pin,rings,and a few grams for oil). That number is what you make the "bobweight" .
On inline engines, parts are weight matched and the crank is balanced without "Bobweights" because every journal has a "companion" journal at 180 degrees which balance each other out. That being said I've never done a single cylinder or any crank with an odd # of cylinders.
Not sure how it would apply to a single cylinder 2 cycle engine, but I would definitely think piston weight would play a part in balance.

 

[awol]

Excellent, thank you!

I have been in a few engines that had odd number of cylinders, and they seemed to always vibrate more than those with even number of cylinders. I ran a five cylinder Deutz in my pickup for several years; it would almost shake the doors off.
Deere's three cylinder and five cylinder engines have balance shafts alongside the crank.

 

[X 66 stang347 X]

I'll throw a boxer or a opposed motor in the mix. The opposing piston balances each other.

 

[MustangMike]

Odd # of cylinders, and even V-6s are very hard to balance, that is why the V-6s generally have an addl counter balance shaft to reduce vibs.

A straight slant 6 is one of the most efficient designs. Most passenger car engines have the piston pins slightly offset to enable them to idle smoothly, but for high RPM you want the pin centered. On a slant 6, they don't need as much piston pin offset due to the slant (gravity helps), so it is a very efficient design. 6 also balances much better than 4.

V-6s are only popular because they save space and are easier to package in the car.

 

[MustangMike]

I'll throw a boxer or a opposed motor in the mix. The opposing piston balances each other.

Yes, and that is an advantage. The disadvantage is keeping the pistons out of the oil (unless it is a dry sump system). Also, it takes up more horizontal space than a V engine. There are always trade offs.

The new flat plane V-8 in the GT-350 Mustang revs to 8,250 and has 525 HP (naturally aspirated). But it is not as smooth as a traditional V-8, and has less low end torque. The advantage of a flat plane is that is never fires twice in a row on the same side of the engine, so air/fuel delivery is more efficient.

 

[jmssaws]

If piston weight changes balance then a 066 with a much heavier 288 piston and bearing and wrist pin and shims would certainly shake it's self apart or a 044/046
OR a 064/066 and stihl done that one themselves.

In a multiple cylinder motor piston weight does affect balance but not in a single cylinder.
Maybe that's why nobody has ever balanced one?
All it can do is change the load that the crank is moving and that cant possibly affect balance or revving the saw or a light load or heavy load would throw balance off.

Chuck a crank up and hold the rod tight with a bungee strap and spin it.

 

[jmssaws]

Lot of cams for race cars switch firing order.

 

[X 66 stang347 X]

Yep. Like the original cam that was in my 68' 302. Swap to a newer cam and it changed. Supposedly it's easier on the bearings

 

[94BULLITT]

Yep. Like the original cam that was in my 68' 302. Swap to a newer cam and it changed. Supposedly it's easier on the bearings

The cams for the 302 change to the 351W firing order. The 5.0 HO also has the 351W firing order.

The coyote has the old flathead firing order. It is funny after all these years they went back to that because it is the best.

Sent from my SPH-L710 using Tapatalk

 

[dall]

ive tried staying out of this argument but heres my opinion the crank is sized for the weight range of the piston it will be pushing think what would happen if you had a piston as light as a 026 piston hooked on a 066 crank the crank will throw it easier and faster because of less mass im sure you can go a little heavier or lighter than originally came with but too light or too heavy and it will break at the weakest point

 

[MustangMike]

Lot of cams for race cars switch firing order.

Yes, that is true, but unless you have a flat plane crank, your V-8, you will always have two consecutive firings on the same side during the firing cycle.

 

[X 66 stang347 X]

The cams for the 302 change to the 351W firing order. The 5.0 HO also has the 351W firing order.

The coyote has the old flathead firing order. It is funny after all these years they went back to that because it is the best.

Sent from my SPH-L710 using Tapatalk

I use to have a short bed single cab ranger with a H.O and and t-5 with a explorer rearend with lockers. Fun truck

 

[94BULLITT]

I use to have a short bed single cab ranger with a H.O and and t-5 with a explorer rearend with lockers. Fun truck

Too bad Ford never made one like that.

Sent from my SPH-L710 using Tapatalk

 

[X 66 stang347 X]

I did have a guy ask me if I ordered it that way. At first it had a 289 in it but I scattered it all over the road racing my buddies z28. It Sounded good with shorty headers with a single 3". And E303 cam. Good ole days. Better than the 4 banger it had.

 

[MustangMike]

I used to have a 1980 Pinto Station Wagon with the 2.3 ltr 4 speed. Always wanted to replace it with a 2.3 ltr turbo coupe motor & 5 speed, would have been one heck of a sleeper! Also had the Ranger with 2.3 ltr & 4 speed (first year they made them 83???). Was a good little truck.

The next two cars (I started making more money) were a 1985 T-Bird Turbo Coupe (Silver over Grey) and a 1985 Mustang GT (Dark Grey). Both with 5 speeds, and both major improvements in power! I averaged 26 MPG with the Turbo Coupe, which for how I drive was damn good! In fact, they best I have ever done. 80 MPH on the Hwy usually kills the mileage of most cars.

 

[awol]

If piston weight changes balance then a 066 with a much heavier 288 piston and bearing and wrist pin and shims would certainly shake it's self apart or a 044/046
OR a 064/066 and stihl done that one themselves.

In a multiple cylinder motor piston weight does affect balance but not in a single cylinder.
Maybe that's why nobody has ever balanced one?
All it can do is change the load that the crank is moving and that cant possibly affect balance or revving the saw or a light load or heavy load would throw balance off.

Chuck a crank up and hold the rod tight with a bungee strap and spin it.

Google "Newton's 3 laws of motion" for a very interesting and informative read.

 

[bikemike]

This is the fastest saw on this page

 

[jmssaws]

The piston in a single cylinder engine has no bearing on balance of the rotating Assembly.
The piston is not part of it.
It goes back and forth so please explain how that has anything to do with it?

Does a saw vibrate more or less with a very heavy meteor?
I've built a few 99cc 064s, did they vibrate more or less?

The Crank is balanced regardless of the load applied to it and all the piston is
Is a load that the crank is pushing.