tree monkeys 2153 deluxe

[Stihl Livin]

You two need to get a room.

 

[lmbrman]

sorry I am used to a longer bar

 

[tree monkey]

I'm definitely not Scott, but it escapes from the last place it can, right out of the exhaust port.

Trapped CR is when the piston just closes the exhaust port top edge on its way up & thus traps the charge down for "doing its business".

The other number is using the volume from the bottom dead to top dead centers piston travel positions for his calcs.

Great runner there Scott!

you are correct sir
and we don't have to worry about detonation until we get over 9-1 trapped

 

[Deets066]

you are correct sir
and we don't have to worry about detonation until we get over 9-1 trapped

About how much psi would that be on this saw?

 

[tree monkey]

it would appear that my jonsered has bigger nuts then daves husky, just saying

 

[tree monkey]

About how much psi would that be on this saw?

9-1 would be far more then the crank could handle.
I built a 440 head saw that had over 350lbs comp, killed the crank in just a few minutes

 

[Deets066]

Head saw, as in removable head, that's awesome

 

[Deets066]

9-1 would be far more then the crank could handle.
I built a 440 head saw that had over 350lbs comp, killed the crank in just a few minutes

Have you tried removable inserts in the head,
Different compression, just pop the head off and put in desired insert.

I have a custom set like this on my sled, works great.

 

[tree monkey]

Head saw, as in removable head, that's awesome

yes

 

[tree monkey]

 

[tree monkey]

the 371xp was introduced in 1996, I did this one in 96-97, I learned a lot from this cylinder.

 

[Deets066]

If Rollform racing was still around my 066 would probably look like that, very interesting stuff thanks for sharing

 

[lmbrman]

View attachment 399775

those look like nuts of stihl

 

[wigglesworth]

View attachment 399784

the 371xp was introduced in 1996, I did this one in 96-97, I learned a lot from this cylinder.

Still putting fingers in them quad ports Scott?

 

[Hedgerow]

Still putting fingers in them quad ports Scott?

Fingers...
Doubtful...
Factory done put the boost ports in there for us...

 

[Moparmyway]

View attachment 399784

the 371xp was introduced in 1996, I did this one in 96-97, I learned a lot from this cylinder.

It doesn't look like any squish work was done ........... quads with fingers .......... HUGE transfers

My head is spinning, I am trying to get what you are giving, but this reminds me of an episode of the twilight zone.................. unless it didn't work...... when you say you learned a lot, was it from this thing running like a champ, or a turd ?

Throw me some more scraps off your table please !!!!

 

[tree monkey]

Still putting fingers in them quad ports Scott?

one of the 346's that i'm testing has them

 

[tree monkey]

It doesn't look like any squish work was done ........... quads with fingers .......... HUGE transfers

My head is spinning, I am trying to get what you are giving, but this reminds me of an episode of the twilight zone.................. unless it didn't work...... when you say you learned a lot, was it from this thing running like a champ, or a turd ?

Throw me some more scraps off your table please !!!!

this was a r&d cylinder before I figured out how to cut squish. it was fast, but no torque.
I would not call it a fail, it was a learning tool.

 

[EvilRoySlade]

On a 357xp, I've heard people say with the high crankcase compression they are high RPM power but lack torque.
Could this be a good thing when hogging out transfers? If the pressure is there, why not get more volume through. When you're done maybe the velocity would end up near 346/2153 transfer velocity. This is why you stuff a crank in the first place, right?
Correct me if I'm wrong, just thoughts leaking out.

 

[redfin]

Great reading here. Thanks to all.