295/S & 340/S pistons

Topics related to the 295/S, 340/S, Liquidator, and Cross Country
Post Reply
User avatar
400brian
Posts: 5620
Joined: Wed Jul 20, 2005 12:00 am
Real Name: James T. Kirk
Location: South Central Wisconsin

295/S & 340/S pistons

Post by 400brian »

Plus, the 340/s piston has a raised pin height over the other pistons "like" it, allowing for an assumed longer rod that improves rod angle ratio for greater high RPM durability and power output from reduced piston skirt side loading, reduced frictional losses, reduced mean piston speed and increased piston TDC dwell time in the combustion cycle.
i'm not trying to muddy the waters here, But...

The 340S piston and the production piston are very similar. As far as I can tell, the pin location is the same. The rings are higher on the piston on the 340S, and the lower ring is indexed to the opposite side of the port.

Attachments:

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
User avatar
WinnipegStPaul9
Posts: 5577
Joined: Sat Jul 23, 2005 12:00 am
Real Name: Don Amber
Location: Churubusco, IN

295/S & 340/S pistons

Post by WinnipegStPaul9 »

Brian, that goes against what I've been told. I've always been told that the pin of a RS/2 is higher in the piston than other CCW 340cc engines. I'm pretty certain we even have a comparison picture somewhere on this board. Couple of other comments I have are that 100 pieces doesn't seem out of the question since I for one would like four and I just want a piston that will be a replacement for any 340/S piston that I may "burn down". Right now no such piston exists. What's wrong with a piston that Wiseco builds for us. None of us are going to race these sleds anyway are we?? DA
Feel free to check out our website www.buscobullet.com for restorations or parts.
User avatar
400brian
Posts: 5620
Joined: Wed Jul 20, 2005 12:00 am
Real Name: James T. Kirk
Location: South Central Wisconsin

295/S & 340/S pistons

Post by 400brian »

As far as I know Don, the comparison photo on the site, is the one that I took.

In the previous photo, both pistons are sitting flat on the table, and the pin fits snugly and squarely in both. Production piston port, and 340S.

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
pj sportfire
Posts: 221
Joined: Sun Jan 18, 2009 1:00 am
Location: Fort Wayne, Indiana

295/S & 340/S pistons

Post by pj sportfire »

My head hurts.... I'm letting W. figure it out. :)


pj
ICCSF 108
Posts: 4369
Joined: Sun Jul 17, 2005 12:00 am
Real Name: Kenny Heins, AKA Grumpy
Location: Blue Springs Mo.
Contact:

295/S & 340/S pistons

Post by ICCSF 108 »

One thing I think that is confusing is that the first CCW replacement Wiseco pistons were CW-340-S for CCW std 340 motors which I'm sure stood for CCW - 340 cc - Std bore. I don't believe they ever produced a RS/2 340/S replacement although I have been told that the CW-340-S pistons will work in the 340/S motors.
I hope this clarifies some of the confusion

Kenny
AKA: Kenny, Grumpy, Mr. Richard Head
"I Hunt For it, Purchase it, Haul it, Sometimes Repair it, Sometimes Break it, Then Fix it Again, Label it, Warehouse it, Talk About it, So NOW, HOW Can I Take Any Less $$ For It?"
"God I love the smell of KLOTZ in the morning, That smell, you know that Gasoline/Oil Smell, MAKES the whole place SMELL like.. LIKE VICTORY. You know someday the 2 strokers are gonna end..."
Do Anti-War Protesters have reunions? If so what do they TALK about?
User avatar
400brian
Posts: 5620
Joined: Wed Jul 20, 2005 12:00 am
Real Name: James T. Kirk
Location: South Central Wisconsin

295/S & 340/S pistons

Post by 400brian »

I'll post some more photos later.

I just threw this in because the Wiseco guys are telling PJ this stuff is weird.

Generally you hear that kind of talk when you are looking at 35 year old parts, and talking to a 30 year old engineer. :doh:

Like I said, the 340S pistons are not that much different from the production versions.

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
pj sportfire
Posts: 221
Joined: Sun Jan 18, 2009 1:00 am
Location: Fort Wayne, Indiana

295/S & 340/S pistons

Post by pj sportfire »

37 here, but body feels like 87.... LOL
User avatar
400brian
Posts: 5620
Joined: Wed Jul 20, 2005 12:00 am
Real Name: James T. Kirk
Location: South Central Wisconsin

295/S & 340/S pistons

Post by 400brian »

OK, here are some photos.

Production piston AM52370 on the left throughout. This piston was used on all production piston ported 340 engines, with PN subs. 340S piston AM53541 on the right.

You can see the the similarities and some differences. Slightly different cut outs in the skirts, ring placement is higher in the 340S, wrist pin location and size seems the same.

Attachments:

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
User avatar
400brian
Posts: 5620
Joined: Wed Jul 20, 2005 12:00 am
Real Name: James T. Kirk
Location: South Central Wisconsin

295/S & 340/S pistons

Post by 400brian »

Top view shows how the ring locator pins are differently located.

View of jug has lines drawn down so you can see the path of the ring gap.

On the 340S piston, I measure the lower ring pin at 50 degrees from the top pin.

One piston puts the gap to the left of the exhaust port, the other the right.
Anybody know why?

Attachments:

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
User avatar
400brian
Posts: 5620
Joined: Wed Jul 20, 2005 12:00 am
Real Name: James T. Kirk
Location: South Central Wisconsin

295/S & 340/S pistons

Post by 400brian »

A look inside. There are some differences here. The 340S piston seems a bit thicker in places, and the wrist pin bores have two oil holes rather than one.

Attachments:

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
User avatar
WinnipegStPaul9
Posts: 5577
Joined: Sat Jul 23, 2005 12:00 am
Real Name: Don Amber
Location: Churubusco, IN

295/S & 340/S pistons

Post by WinnipegStPaul9 »

Great pictures and explanation Brian. Perhaps I was thinking about the rings when I said the pin was closer to the top of the piston. Just proves why I'm not a mechanic. DA
Feel free to check out our website www.buscobullet.com for restorations or parts.
mikestrat
Posts: 4
Joined: Sat Feb 28, 2009 1:00 am
Location: Southey, Sask.

295/S & 340/S pistons

Post by mikestrat »

I am just trying to get up to speed here, but to my understanding, Wiseco is having trouble building something that they used to build at one time? Very strange. I will take 4 .020 over for the 295/s, 2 standard, and 4 .020 over for the 340/s. Somebody please get ahold of me with who I should send a deposit to. P.S. I am planning to drag race my machine!!!
pj sportfire
Posts: 221
Joined: Sun Jan 18, 2009 1:00 am
Location: Fort Wayne, Indiana

295/S & 340/S pistons

Post by pj sportfire »

TakeItToTheLimit wrote:As I stated earlier...I do not see any concern with a build of 100 for each model. One question...how does the oversize fit into the tooling...is it an issue or does that come when they machine it (forged oversize & machine it down to standard)?
(forged oversize & machine it down to standard)?
Correct.
pj sportfire
Posts: 221
Joined: Sun Jan 18, 2009 1:00 am
Location: Fort Wayne, Indiana

295/S & 340/S pistons

Post by pj sportfire »

mikestrat wrote:I am just trying to get up to speed here, but to my understanding, Wiseco is having trouble building something that they used to build at one time? Very strange. I will take 4 .020 over for the 295/s, 2 standard, and 4 .020 over for the 340/s. Somebody please get ahold of me with who I should send a deposit to. P.S. I am planning to drag race my machine!!!
Nope, you've miss-understood the text presented, as Wiseco isn't having "troubles" with anything. At the end of the day, it all boils down to money and quantities, which is what everyone is trying to work out here. When that info is gathered in its entirety and presented here, you guys' can then make the final decison to "Go" or No Go" on the project. I have no dog in the hunt, nor am I making one single red cent from any of this effort, so it matters not to me which way you folks' choose to go, as I've done my part either way.

That's it, easy-peasy..

pj
User avatar
400brian
Posts: 5620
Joined: Wed Jul 20, 2005 12:00 am
Real Name: James T. Kirk
Location: South Central Wisconsin

295/S & 340/S pistons

Post by 400brian »

And we very much appreciate the effort you are expending on our behalf PJ!

As a dumb farmer, I must say, I really do not understand the mentality of scrapping or getting rid of tooling that was engineered, bought, and paid for. You just never know when someone is going to want a run of 1937 Studebaker pistons! :wall:

'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
Post Reply