295/S & 340/S pistons

Post by **ICCSF 108** » Mon Mar 09, 2009 10:43 am

Just keep an eye on this post as this will give you all the info you'll need to order once things are finalized..

Kenny

pj sportfire · Post by **pj sportfire** » Tue Mar 10, 2009 5:12 pm

Update: 3/10/09

I spoke to Wiseco Engineering today and received some good news and some bad news....

JD 295/s Piston Kit
Bad News~
Due to the unique and odd-ball specifications of the 295/s piston design and since there hasn't been a piston type like this produced since the 70's, using JD's standards from wayyyy back then; Wiseco is unable to place this design on any of their existing forge tooling. Out of the seven(7) forgings they had available that was even remotely close, they all fell short in existing design, due to the piston material thickness and pin boss length for the 18mm pin diameter. Addtionally, the transfer skirt and ring indexing pin hump on the interior of the forging was also a key reason the original design was of poor placement.

Good News~
The pistons can still be produced with new tooling...BUT, the cost is going to be much higher per kit, since this tooling is special for this odd-ball design. This would require the design / construction of a new forge punch that Wiseco can use with their existing dies to reduce overall cost, as compared to having to add the punch dies also. Due to the unique design parameters of this piston design, Wiseco is offering to engineer a forge punch at their cost of $4,047.00, with the commitment of a 100 unit production run in the foundry. This cost doesn't include the other periphreal parts that would be included in the kit, so I'd guess each piston kit in this format would probably come in under $200 when it was all said and done. Of course, Wiseco would firm up the costs much more accurately if you folks decide to move forward.

JD 340/s Piston Kit
Bad News~
Another issue with the wierd piston designs from JD... This design can **possibly** be placed on their existing forge tooling pending the boards input. The part would not meet the OEM design parameters due to the ring index pinning and transfer skirt area changes from stock. Their current tooling would produce a forging that would have a loss of material in transfer skirt area and the lower ring indexing pin would break through the interior of the forging. It's critical to have 85% capture of the ring indexing pin for ring support in this area; therefore, their current tooling could only produce a single ring piston to fit this application, unless new, expensive tooling was created for this piston also....

Good News~
What they could offer to do as a second option is build a "Pro-Lite" piston version that would be of a single ring design, once they verify its compatibility to the transfer ports of the actual cylinder. If you guys can supply a standard 340/s cylinder for them to look at and approve a single ring piston design, they may be able to make all of this work very well with their current, existing tooling; which would not only speed up the completion process, but also be *MUCH* cheaper per piston kit. They would need a cylinder to double-check a few specs before they would be able to approve the new design from a manufacturing QC standpoint.

There you go...right from the preverbial horses mouth. Feel free to discuss and I'll relay to Wiseco whatever decision you guys' come up with in verbatim. They have put the project on hold until you folks' can decide for sure which way you want to go for both piston designs.

Cheers!
PJ

400brian · Post by **400brian** » Tue Mar 10, 2009 7:49 pm

I've never held a 295S piston in my hand, so I'm a bit confused.

I didn't realize these two pistons were that much different.

What are the pros and cons of running a single ring in this app?

pj sportfire · Post by **pj sportfire** » Tue Mar 10, 2009 8:20 pm

There's more to a piston design than just a cylindrical object- especially for a piston ported engine and I'd trust Wiseco's expertise in the matter regarding 2-stroke applications before many other companies.

Oversimplified~
Pro's: Less drag, less friction, lighter weight, cooler operation= More power.
Con's: Less time between ring changes and more of them overall= More maintenance.

Post by **WinnipegStPaul9** » Tue Mar 10, 2009 9:08 pm

PJ, I can get you a jug for the 340/S provided it doesn't have to be new. I'll be home in a couple of days. DA

Post by **ICCSF 108** » Tue Mar 10, 2009 10:08 pm

PJ, I guess I'm a little confused as to why they want to go with single rings?? Also on the 340/S pistons do they not still have the Mold or whatever it's called that they built there Wiseco CW-340-S pistons on??
Now to the 295/S piston Kits is that $200.00 est for a piston kit.. meaning 1 piston, rings, pin & bearing???

Kenny

pj sportfire · Post by **pj sportfire** » Tue Mar 10, 2009 10:51 pm

WinnipegStPaul9 wrote:PJ, I can get you a jug for the 340/S provided it doesn't have to be new. I'll be home in a couple of days. DA

A used cylinder should be fine.

pj sportfire · Post by **pj sportfire** » Tue Mar 10, 2009 11:07 pm

ICCSF 108 wrote:PJ, I guess I'm a little confused as to why they want to go with single rings?? Also on the 340/S pistons do they not still have the Mold or whatever it's called that they built there Wiseco CW-340-S pistons on??
Now to the 295/S piston Kits is that $200.00 est for a piston kit.. meaning 1 piston, rings, pin & bearing???

Kenny

1. The single ring design was only for the 340/s piston, not the 295/s version and as stated in what I posted eralier, they would be forced to a single ring design using their current forging die they have now that is "close" to the odd-ball specs of the JD piston. Otherwise, if you want the two ring piston, brand new die and forging punch tooling needs to be developed to produce the 340/s piston in it's original design.

2. These pistons aren't "molded" like cheaper cast parts are, they are forged in a press that uses a die and a punch which pressure formes an aluminum blank into the size/shape of the piston to be finished machined.

3. I was told that just recently, Wiseco management pulled all one-off or very low production tooling out of service if those tools didn't produce *at least* 100 pcs. per year or more for the given application. Obviously, the vintage JD piston of yester-year didn't make the cut... Therefore, in order for those tools to even be considered to put back into service, (**IF** they even still have them) a large order must still be made to make it worth it to Wiseco, since the likelihood of those tools ever being used again is slim-to-none.

4. As I stated earlier, I'm speculating on the costs of under $200 for the kit, based on the math where-by dividing $4000 by 100 pcs. and that's why I said right after that statement, that Wiseco will likely firm up the final costs more accurately than I could, *IF* you guys' decide to move forward with the project.

I'd guess it's like anything else in manufacturing business... If the tooling doesn't make the company the money it needs to keep it around, they either moth-ball the tool or send them to scrap in favor of tools that do make them profit and are more popular with the going trend.

From what they're seeing, this vintage stuff is going to be harder and more expensive to re-produce overall, due to some of the design engineering oddities of the early 60's-70's for the 2-stroke engines of that time. Technology has moved wayyyyy beyond those days now and those odd-ball designs aren't used today, but are expensive to retro-replicate.

PJ

pj sportfire · Post by **pj sportfire** » Wed Mar 11, 2009 10:33 am

I spoke to Wiseco Powersports Engineering again and requested a firm price quote for each piston kit design utilizing the new tooling for the 295/s model @ 100 pcs. they described and the 340/s model @ 50 pcs. utilizing their current tooling to produce the one-ring design they suggested. (The 340/s single-ring design approval is contingent on verification of it's proper fit with a test cylinder provided by DA.) This should give you guys' the final cost per kit, so you have a better understanding on what each complete "kit" would cost that contains the piston, ring(s), pin, circlips, upper end bearing and instructions. Hopefully I'll hear back from them within the next 2 days or sooner.

EDIT: Hey Don, I spoke to Kenny and he's sending a 295/s and a 340/s cylinder sample in here for Wiseco to look at, so no need for yours after all. Thanks for the offer though!

PJ

Post by **Wildfire II** » Wed Mar 11, 2009 10:43 am

Call Anthony Hopkins that was in the movie The Worlds Fastes Indian. He might make us some pistons!!!!!!!

JDT · Post by **JDT** » Wed Mar 11, 2009 10:02 pm

Great film !! I went out and bought a lemon tree.

S_Kyle · Post by **S_Kyle** » Wed Mar 11, 2009 11:47 pm

It might be hard to find 39 pistons to melt for ours. What was it 2 parts ford to a part chev?

Dator76 · Post by **Dator76** » Thu Mar 12, 2009 2:55 am

pj look at this it might jog wisecos memory if its the right piston. give them part number CW-340-S.
ebay
260273223536 CW-340-S
180292256403 C?-340-S
180292264634 2012PS claims to be 340-S this is top L ring.

again if its right piston they should have all the tooling and might cut your cost way down.
the blue box and red box in ebay auctions indicate wiseco has run this piston at least 2 times before

i have never seen any 340-s pistons anywhere before now but have been told wiseco made them more than once.

I asked them about making dator pistons just for fun and they told me something like they told you, when i gave them the wiseco part number suddenly the price came way down and they had all the specs, (im not making any).
wiseco dator part number 9931M06100 2402CD - 61.00MM
010840O/563 CW19/S615 (this is big oversize like .040" some of those numbers will not apply as pin brng and circlip are 19mm)

i would think they could make the 340/S pison from the same forging as the dator forging and they use the same rings, so you can have a 2 ring piston if you want.

pj sportfire · Post by **pj sportfire** » Thu Mar 12, 2009 9:56 am

pj look at this it might jog wisecos memory if its the right piston. give them part number CW-340-S. ebay 260273223536 CW-340-S / 180292256403 C?-340-S / 180292264634 2012PS claims to be 340-S this is top L ring. again if its right piston they should have all the tooling and might cut your cost way down. the blue box and red box in ebay auctions indicate wiseco has run this piston at least 2 times before. i have never seen any 340-s pistons anywhere before now but have been told wiseco made them more than once.

Kenny has already sent me that former Wiseco piston number information earlier and they already know about that. That's not the problem with the 340/s piston production this time though... As I stated earlier in this thread; Wiseco management pulls all product tooling that doesn't produce **AT LEAST** 100 pcs./year or more and either scraps the tooling completely if it's not viable any longer or moth-balls it away somewhere out of regular lines of aquisition.

Obviously, the 340/s piston tooling didn't make this cut due to probable very low production numbers... Therefore the tooling either got scrapped entirely or put away- hopefully the latter. In either case, the *only* way they are going to pull this tooling out of storage (if they even have it anymore) or produce new tooling if needed, is for a *minimum* order of 100+ pcs. to be attached to it, which obviously drives the cost up. That is why they suggested the single-ring piston design instead, because they could produce those relatively easily using current tooling that is in production circulation right now, which saves everyone time -AND- money. Plus, they can offer lower minimums because of that.

It doesn't matter to me which way you guys' choose to go, as I don't have a sled that these pistons fit anyway, I'm just giving of my time to try and help you guys figure this out with the contacts I have in the field, for those that do. Ultimately, it's the jdsleds.com board's call...

would think they could make the 340/S pison from the same forging as the dator forging and they use the same rings, so you can have a 2 ring piston if you want.

One would *think* it was that easy, but from what I've been learning about the complex/expensive piston forging manufacturing process...it isn't and that's probably why you don't see Wiseco even messing with any offerings for the 340/s in their catalogs. Simply NOT enough numbers to make the investment viable for them, unless a custom order comes through for a lot of product all at once.

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.

As an example of this~ We *always* install the absolute longest rod we possibly can in our automotive LS-Series racing engines to improve what I described above, even if it means the pin hole encroaching into the lower oil control ring land; for which we then correct for with a lower oil control ring support rail. Then, we can spin these long stroke, big inch, big bore engines to 6500-7500+ RPM all day long without fear of the thing spinning itself apart...

As long as the physics of the engines are kept in check, any engine will live a very long time and take a lot of abuse, so I suspect that is what JD was trying to do with their high RPM race sleds that were destined to be beat to death on the endurance race circuits back in the day.

I'm supposed to talk with them again today, so I'll let everyone know what was discussed.

PJ

pj sportfire · Post by **pj sportfire** » Thu Mar 12, 2009 11:01 am

Update: 3/11/09
I just spoke to Wiseco Engineering again this morning and after presenting them with some of the info that Dator76 posted, we may be able to pull something off for the 340/s piston design, by altering the dator forging slightly to fit.

Here is some tooling history of the 340/s and Dator piston~

A.) The original 340/s tooling was first developed in 1988 that included the double ring design, with the second ring set at 56* offset from the 18mm pin axis to clear the ports and the pin axis itself. Then in 1993, that tooling was changed to remove the 56* second ring index pin material hump from that piston design entirely, which leads to a single-ring only piston design for present day that I spoke of. That tooling number for both designs is #F2212Z, although it was "revised" in 1993 as described.

B.) The original Dator piston tooling was first developed in 2003 that included the double ring design, with the second ring set at 15* offset from the 19mm pin axis to clear the ports and the pin axis itself. Then in 2006, that tooling was again updated for other things not pertaining to the issue we have here. That forge tooling number for that designs is *ALSO* the #F2212Z, although it was updated in 2006 as described.

What does this mean to you 340/s guys?

Well..... It means Wiseco may be able to produce the 340/s piston in a double ring design using the modified Dator piston tooling if they can swing the ring index pin from its current 56* on the 340/s piston now(that won't work for the double-ring design currently) over to the Dator 15* ring index pin location. This should work **IF** that new location agrees with the port configuration of the 340/s cylinder, for which Kenny is sending me a sample of the 295/s and 340/s as I type this. Plus, since the 340/s has a smaller 18mm pin diameter, it should make it easier to move the lower ring index pin around where they want it, with regards to the port configuration of the 340/s cylinder.

What does this mean to you Dator guys?

Well..... It means that you too can have pistons reproduced right now with this 340/s batch if you wish, as the tooling is still in current production circulation and your mins would only be 26 pcs.! You guys' could kill two birds with one stone here....inexpensively!!

This is a *LOT* of very valuable information I was able to obtain from Wiseco Powersports Engineering, so I'd suggest that some of you collector guys that save this kind of stuff for your archives, save it (thread and all) all to a safe place for future reference in case you ever need it again. I'd guess I'll be adding to this too as we move thorugh this, so there's more to likely come.

Maybe jdmatt can pin this thread to the top as a sticky? Just a suggestion...

Anyway, that's what I know today and I'll chime back in later with pricing and additional fitment info once I get those cylinder samples here and off to Wiseco.

Regards,
Phil "PJ" Rickard