Another chainsaw dyno...

[huskihl]

I didn't see a ported 572 graph in the graph only thread, is there a graph for one?

Shaun did one a couple months ago. I was sposed to have one for it also but the dyno broke and the owner was ready to start using the saw.

 

[redline4]

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choices

Central waters is made right in my hood.

 

[deye223]

Dont do it.
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[cuinrearview]

Central waters is made right in my hood.

My friend has family in Madison and Milwaukee. He always brings back some of their big barrel aged stuff to share. Tasty!

 

[MERR6267]

Just a little too much nitrous. I read that they made 2920hp at the wheels on the previous run and were trying for 3k . . .

In the video you can hear the crank and rods still clattering around after the top of the block lifted off.

 

[markds2]

Just a little too much nitrous. I read that they made 2920hp at the wheels on the previous run and were trying for 3k . . .

In the video you can hear the crank and rods still clattering around after the top of the block lifted off.

Can you post the video here for the benefit of all?

 

[RI Chevy]

I think he can rebuild it...lol

 

[MERR6267]

Ask, and you shall receive.

This is not my video, I wasn't there, I don't know anyone there, I just saw a shorter clip on Sunday.

You can skip to about 3:10 to get to the meat of it.

Editorial on my "crank and rods." comment above. You can clearly see the balancer is stationary after the explosion, but I bed that some bit of crankshaft is flopping there with the dyno rollers still coasting down.

What a mess. I read that this unit was a full billet with no cooling. You can see the fire go out a few times as he's spooling it. I've experienced this a few times in my smoky truck (maybe 700hp on a good day) If you add waaaay too much fuel when the air isn't there you can get that white smoke, super, extra rich, no-fire phenomenon like you see here. As soon as he lets off the fire comes back. The turbo spools a little more and then he's able to hit the nitrous and clean up the soot. That's when the revs come up, the turbos spool harder and then ultimately the block lifts up.

 

[RI Chevy]

He must have had some propane in there too, no?

 

[cuinrearview]

Serious sads now. All I saw at the real saw dyno was real saws and real info.

 

[RI Chevy]

You see the saws in real wood too?

 

[Nutball]

With real variables?

 

[RI Chevy]

Here we go. . Ding ding

 

[Nutball]

It's hard to tell, but I thought I saw a belt or something flying apart in camera angle 2 shortly before it blew, so maybe some timing changed or something. I saw it in the third angle too: a shred of rubber fly out, then the cloud of oil appears.

 

[NightRogue]

That’s what I call it also, the cranks are made up of a number of two different forgings, a “semi built” crankshaft, basically they are made of multiples of the same two parts, crank web and pin as one piece, and main crankpin as the other, they just add more to make the appropriate cylinder count, 4 through 14 cylinders.

The crank webs machine bored main journal holes are interference fit over the main crankpins with no positive locking mechanism to avoid stress raisers.

Here is photo from online of a marine slow speed two stroke crank.

Note no bob/counterweights, and the toothed gearwheel at the far end of the picture, that is the flywheel, relativity speaking they are tiny.

Same online photo source showing flywheel, again relatively small compared to smaller engines, it's main purposes is simply being a gearwheel to allow turning of the engine for maintenance and checking for unwanted fluid ingress into the cylinders before starting, it does not play much part storing energy or stabilising rpm, not used for starting either, that is achieved by timed 'start air' direct into the cylinders.

Link to photo source http://www.marinediesels.info/2_stroke_engine_parts/Other_info/semi_built_crankshaft.htm


I spent four years operating, maintaining and fault finding Man B&W 6S70-MC engines, around 23000HP @ 91rpm, 700mm piston, 2680mm stroke, don't have many photo's at hand, but here are some of prepping a spare piston before a change out.


Lowering into maintenance position.

View attachment 259496

View attachment 259501


Prepping for new piston crown.
View attachment 259489


New crown and ring pack fitted, yours truly in place for scale.

View attachment 259479

If something isn't adding up, these are a crosshead engine.

Far out Bro!
I'll ask him what he actually meant, good to know they're people from all walks of life in here

Sent from my INE-LX2r using Tapatalk

 

[SpaceBus]

It's hard to tell, but I thought I saw a belt or something flying apart in camera angle 2 shortly before it blew, so maybe some timing changed or something. I saw it in the third angle too: a shred of rubber fly out, then the cloud of oil appears.

It's a Cummins 6 cylinder so there are no timing belts. The only rubber would be the serpentine belt, but I'm guessing this setup doesn't use one. Not doubting that it could have been something important though. Maybe a piece of of the block, exhaust manifold, etc. My friend's 2013 BMW 335i with all the BMW dealer installed performance bits ejected a piece of the block while on an autocross course. A few seconds before the new window was created you could hear the rod knocking on the block, letting us know he was coming out. Usually there are signs right before catastrophic failure, but it's usually far too late.

 

[Sawrain]

Far out Bro!
I'll ask him what he actually meant, good to know they're people from all walks of life in here

Sent from my INE-LX2r using Tapatalk

It was the agreement on your bob weight idea to I was referring to, for clarity.

For sure there are all types here, great to know OPE attracts people from many different backgrounds.

Just a little too much nitrous. I read that they made 2920hp at the wheels on the previous run and were trying for 3k . . .

In the video you can hear the crank and rods still clattering around after the top of the block lifted off.

What kind of rpm are they turning at that power? Must be huge torque for the crankshaft/gearbox to take.

 

[Dub11]

Ask, and you shall receive.

This is not my video, I wasn't there, I don't know anyone there, I just saw a shorter clip on Sunday.

You can skip to about 3:10 to get to the meat of it.

Editorial on my "crank and rods." comment above. You can clearly see the balancer is stationary after the explosion, but I bed that some bit of crankshaft is flopping there with the dyno rollers still coasting down.

What a mess. I read that this unit was a full billet with no cooling. You can see the fire go out a few times as he's spooling it. I've experienced this a few times in my smoky truck (maybe 700hp on a good day) If you add waaaay too much fuel when the air isn't there you can get that white smoke, super, extra rich, no-fire phenomenon like you see here. As soon as he lets off the fire comes back. The turbo spools a little more and then he's able to hit the nitrous and clean up the soot. That's when the revs come up, the turbos spool harder and then ultimately the block lifts up.

Plot twist it wasn't the Dodge trans that ended its run that day.

 

[rogue60]

Some dyno action the Aussie made 4-litre Barra engine is gaining a reputation for making big hp guy's are starting to import em into the US
Seen a vid on YouTube with a Barra powered Mustang in the US good stuff.

 

[NightRogue]

What you agreed with my idea? Now that makes us both boring lol

Anyway I'd guess due to the massive stroke, the weight being swung around on this area will make the majority of the power/counter balance. Refer picture