Question??…..How would SAAB make a piston today??
…Here is HOW!
NEW SAAB High Performance Pistons made with…
4032 Forged Aluminum alloy which is designed SPECIFICALLY for Two-Stroke engines!
WHY 4032 alloy??
Saab OEM pistons (and many made today) were/are only made from poured mold cast aluminum. These are the weakest design made. OEM Saab pistons got away with this by using quality Swedish tooling and aluminium. Not all steels and aluminum are made the same today!. Simply put, Saab made the best they could given the days technology.
Now with today’s modern metallurgy come forged pistons. Where the aluminum is squeezed under extreme pressure to compress the molecules into a superior aluminum forged alloy for a more durable piston with higher heat tolerances (it cost more too which is why some companies still offer only cast pistons).
NOTE: Myself and others have used Venolia forged pistons for years. Venolia uses a 2618 alloy which is designed specifically for FOUR STROKE ENGINES. 2618 alloy is still superior to cast pistons but are not as ideal as 4032 alloy forging are for two stroke engines. Dyno & real life experience show 2618 to be not as good for two stroke wrist pin boss, allowing wear in some cases. Also when 2618 experiences a heat event they just have no room for error. Enter the Wiseco 4032 alloy has a higher silicon content which is stronger and more resilient to heat.
Fitted with two .060″ tapered piston rings in “Semi-Keystone” design.
Why 2 thin Semi-keystone rings??
Saab OEM pistons use the old school THREE ring setup. These rings are usually .0997″ thick and are very heavy. These heavy rings can “flutter” (Flutter is when the ring floats in the ring land and loses it’s seal on the cylinder wall) on the ring lands under higher RPM’s (over 5,000 RPM’S) which allow hot exhaust gas to blow by the ring’s sidewall seal with the cylinder, which melts the thin layer of oil, which will destroy/melt a piston rapidly. In many of these cases you will read or think of the “melt down” as “detonation” but really it is most commonly caused by ring flutter. If you have ever seen an Original Saab 74mm piston you will notice it only uses 2 rings and they are thinner than stock at .0775″ thick. Saab knew even back then that High Performance and High RPM’s pistons had different ring needs!
The Semi-Key Stone design means the rings are tapered on the top. This tapper lets the ring seal better because of the angle it is cut which allows the compression gases to push the ring outward in the cylinder wall and downward into the piston land…all in a more natural fashion. It also gives the ring more movement within the ring land, which aids in reducing carbon build-up on the lands. Remember “back in the day” you had to “de-carbon” an engine every now and then? This Semi-Keystone Tapered ring is the two stroke answer!
NOTE:Currently not stocking but we can special order a flat 1 mm* or .039″ super thin racing ring*. This type of ring utilizes an internally notched piston ring locating pin. This style of ring is best used for all out competition. Because of its thinness (shorter life and poorer heat dissipation) it is normally not considered a good choice for highway applications where longevity is a concern. These rings are good for applications that exceed 8,000 RPM’s. *These are only available special ordered in quantities of 12 or more (two different bores sizes are ok) for your specific applications and 3 month lead time. Cost is $75 PER piston higher (lower for quantity orders, example quantity of 60 or more are normal $199 price)
These pistons have ArmorGlide™ Coating on the Skirts.
Why coat the skirts??
Coatings have become a real “thing” in engine rebuilding. Even transmission and rear end gears get coated today. It reduces friction. The “ArmorGlide” used by Wiseco is a Moly based coating and it will protect the piston through its life. I feel the extra money spent to have a skirt coated is well worth it. (I currently pay $20 per piston for coatings for my Bonneville project)
(Some companies use a Teflon skirt coatings but they are more to aid break-in only and disappear with in a few hundred miles)
They also have an Electra-Coating on the ring Grooves and wrist pin boss areas for added durability.
Why do an Electra-Coating??
This is an added process during the production of the piston that adds real reliability and durability to the ring grooves and wrist pin areas. Again it does costs more but why not build the best piston possible! (Most piston companies can’t even do this process!)
The pictures below show what I believe to be the finest pistons ever produced for a Saab two stroke…ANY WHERE in the world!!
…Demand the best for your rebuild!
check out Wiseco’s website to learn more at http://www.wiseco.com/Automotive/Pistons.aspx
Sizes from 70.0mm thru 74.5mm in .5mm increments!
70mm, (New size 70.25mm), 70.5mm, 71mm, 71.5mm, 72mm, 72.5mm, 73mm, 73.5mm, 74mm, and 74.5mm (75mm special order only)
We sell directly to you, the Saab owners (and or repair shops)*
*NOTE: XP Extreme Power in Sweden is offering their own Specially Designed Flat Top Wiseco Racing Pistons with two .039″ internally pegged rings for their customers. (These Wiseco Pistons are supplied to XP by Tom Donney Motors.)
(Saab Clubs are welcome to contact us to become a stocking dealer)
Piston retail price is $199 each or $597 per set.
Replacement Keystone Rings retail price is $23 per set.
Replacement 1mm Rings retail price is $26 per set.