All Things 288XP

[XP_Slinger]

I've heard of it being done. I think you have to loose the cylinder extension into the case and let the piston come out of the bore at BDC, there isn't enough room on the gasket surface of the case to bore it for the extension.

Sounds like the makings for a broken skirt. Still though I’m intrigued at the thought of a 56mm top end on the smaller volume case. Kinda like Jim’s 064 with the 395 P&C on it. Seems that boring and replating would be simpler though not the most economical route.

 

[srcarr52]

Sounds like the makings for a broken skirt. Still though I’m intrigued at the thought of a 56mm top end on the smaller volume case. Kinda like Jim’s 064 with the 395 P&C on it. Seems that boring and replating would be simpler though not the most economical route.

Not much side load at BDC so there isn't much risk of breaking a skirt. Just make sure it has a nice chamfer. You'd be surprised how many engines hang the piston out of the bottom. Our 900hp 14:1 compression SBC based dirt late model engines hang out probably 1/2".

You can't bore a 288 cylinder out to 56mm, the cylinder extension would be paper thin.

 

[XP_Slinger]

Not much side load at BDC so there isn't much risk of breaking a skirt. Just make sure it has a nice chamfer. You'd be surprised how many engines hang the piston out of the bottom. Our 900hp 14:1 compression SBC based dirt late model engines hang out probably 1/2".

You can't bore a 288 cylinder out to 56mm, the cylinder extension would be paper thin.

What if you removed the extension as you suggested for the 394 cylinder? Now I wonder if the cylinder itself would be getting too thin

 

[srcarr52]

What if you removed the extension as you suggested for the 394 cylinder? Now I wonder if the cylinder itself would be getting too thin

It would probably be close. In my opinion the transfers get to shallow and the transfer bridge is too small when over boring.

 

[RIDE-RED 350r]

OK, this brings up another question/debate between XP_Slinger and myself... case capacity between the 288 and 394... Being that they share the same crank, I don't really see how or why a 394 case would have more capacity...the case itself..I mean, I don't recall there being any more clearance between the crank lobes and the bottom of the case housing on the 394s I have had apart than any other saw I've had apart. Where and how would there be more capacity in the case itself when the same crank is housed in both?? I know that there would be more capacity under the piston in the bore added by the larger bore though.

Thoughts?

 

[XP_Slinger]

I think the crankcase is taller on the 394.

 

[RIDE-RED 350r]

That may be possible. But how much taller could it possibly be??? It's the same stroke and from what we've learned firsthand, the squish clearance on both is pretty much the same on stock config. Did we ever compare piston height between the 288 and 394?? Being the same stoke and squish, I would have to think that pin-crown height is the same. Why then would the case deck height need to be taller if it is?? Longer skirt on the 394 piston? I'm starting to get confused the more I think about if the 394 case deck is taller and why it would need to be.... Remember, same crank, which also means same rod, which means the distance from the crank centerline to wristpin centerline is the same, which should mean that with the same squish on the same crank, pin-crown height would be the same. Yep, still not seeing the how and why a 394 deck would be taller.....

 

[srcarr52]

OK, this brings up another question/debate between XP_Slinger and myself... case capacity between the 288 and 394... Being that they share the same crank, I don't really see how or why a 394 case would have more capacity...the case itself..I mean, I don't recall there being any more clearance between the crank lobes and the bottom of the case housing on the 394s I have had apart than any other saw I've had apart. Where and how would there be more capacity in the case itself when the same crank is housed in both?? I know that there would be more capacity under the piston in the bore added by the larger bore though.

Thoughts?

You're right, the case volume difference is pretty small, mostly from the unfilled space where the cylinder extension goes into the case. The 394/5 case opening is larger.
I think the swap is mostly for big cc on small chassis.

 

[RIDE-RED 350r]

And now I'm itching for a 288...these things are as bad as firearms!

 

[XP_Slinger]

And now I'm itching for a 288...these things are as bad as firearms!

Don’t fight it big bro, a 288 would be a noteworthy addition to your collection. If I wasn’t wanting to build a 281 you’d have a set of cases and lots of other parts to get you going.

 

[RIDE-RED 350r]

It's all good... I'll get to it sooner or later


(You need to edit your sig line )

 

[XP_Slinger]

It's all good... I'll get to it sooner or later


(You need to edit your sig line )

I do! Dot dot dot

That better? Lol

 

[RIDE-RED 350r]

Yes, that's better

 

[XP_Slinger]

Yes, that's better

Now it feels official...the 254 has risen from the ashes

 

[XP_Slinger]

Finally ordered a 28” Tsumura lite bar from Nate for my 288 this morning. Been talking about it since I got my saw done. It may have been an impulsive purchase that creates a little friction.. oh well, just more heat to keep the house warm...lol!

 

[rattler]

Speaking of heat in my shop at 9:00

 

[RIDE-RED 350r]

Finally ordered a 28” Tsumura lite bar from Nate for my 288 this morning. Been talking about it since I got my saw done. It may have been an impulsive purchase that creates a little friction.. oh well, just more heat to keep the house warm...lol!

Bass-turd

What happened to a bar and decal set for the too-fiddy-fo?

Had -4 when I got called to work at 0300 this morning

Good day to cuddle with the woodstove...even though I got a couple odds-n-ends parts in the mail for the Yahoo 242... Too fricken cold!

 

[XP_Slinger]

Bass-turd

What happened to a bar and decal set for the too-fiddy-fo?

Had -4 when I got called to work at 0300 this morning

Good day to cuddle with the woodstove...even though I got a couple odds-n-ends parts in the mail for the Yahoo 242... Too fricken cold!

I’ll get the decal kit on the 15th. Not in a huge hurry for them because I’ve got some plastic work to do, thought about that last night after I talked to you.

 

[XP_Slinger]

Speaking of heat in my shop at 9:00View attachment 105366

Can’t like that, same here. Not looking forward to starting muh diesel truck Monday morning lol. Rattle rattle rattle

 

[RIDE-RED 350r]

It's supposed to be much warmer by Monday... Take her for a ride tomorrow and you'll be good to go.