M.A.P. Cycle Billet Piston Kits for OEM T140/TR7 cylinders. Not for T120/TR6 big bore cylinders.
- Hi-Silicone, low expansion, Hi-Strength 4032 aluminum alloy. The ultimate for severe use in air cooled engines.
- 100% CNC Machined, utilizing the latest “Solid Works” CAD design. This allows for consistent cross-section providing the most even heat distribution with the highest weight reduction (lightest commercially available piston kits for less vibration).
- Lo-Dome "Tight Quench" design for efficient flame travel and combustion (9.5:1 compression ratio and higher)
- Zero Deck design for max power while minimizing octane requirements (9.5:1 compression ratio and higher)
- 2nd Ring-Land "Accumulator" groove to prevent unloading of the top ring from trapped blow-by.
- Tapered wrist pin (I.D.) for rigidity and weight reduction
- “Micro Groove" piston skirt for high scuff resistance.
- Race Type "SpiroLoc" clips for reliability - Won't come out
- Latest piston cam design reduces noise, and increases life better than any other commercially available vintage Brit Bike piston kit.
- 4 location pressure fed wrist pin oilers
- Increases oil volume to pin
- Dual clocked pin bore grooving holds and disperses the oil around the wrist pin
- Minimizes heat buildup to prevent galling between the small end of the rod and the wrist pin
- Perfectly round making these the best sealing, quickest seating rings available.
- Modern sizing for the least amount of friction with the most amount of heat transfer for cooler running pistons.
- 1.0mm Nitrided Stainless Steel Barrel-Face Top Ring
- 1.2mm Ferrox Cast-Iron Napier 2nd
- 2.8mm Nitrided Stainless Steel Rails with expander (3 piece design)
Updated wrist pin oiling:
Race proven ring pack features:
Note: Stated compression ratios are an approximation, and are dependent on several variables such as base and head gasket thickness, and any modifications that changes combustion chamber volume such as valve recession, valve sizing, and head surface milling.
Designed by, and exclusively manufactured for M.A.P. Cycle thru sources in the U.S.A.
SKU MAP9012-9014-BILLET Piston Material Billet - 4032
- Additional Information
SKU MAP9012-9014-BILLET Piston Material Billet - 4032
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- Product Question
Product QuestionsQuestion by: christianson on Feb 9, 2018 9:49:00 PMThe clearance for these pistons is 10.5:1 is .004-.0055" generally speaking based on usage, break-in oil, outside temps etc. You could run the piston a bit tighter with iron lined alloy jugs (.0005"). For racing, add .0005-.001 to these dimensions.
Keep in mind that Nikasil lined alloy jugs take special pistonsAnswer by: rick c (Admin) on Feb 13, 2018 4:20:00 PMHello and Good Day !
currently on my T140V '77 engine I have .080 oversize piston's . What size pistons would I need to have for the "Triumph T140 Billet Piston Set" considering having to hone the cylinders ?
Thanks a lot,
Question by: Holger Schaefer on Feb 21, 2017 6:42:00 AMMr. Schaefer,
Triumph originally recommended nothing larger +.060 over for the 650cc bikes. I can't imagine they would have approved of anything larger than that for the 750cc bikes (T140). We do carry +.080 cast pistons by EMGO . Here is a link to our website and those pistons: http://www.mapcycle.com/categories/engine/pistons-related/triumph-pistons-rings/triumph-pistons/19255-e-grp-triumph-750-twin-piston-set.html.
If your cylinder isn't in good shape, I'm afraid you'll have to replace both the cylinder and the pistons.
RickAnswer by: rick c (Admin) on Feb 21, 2017 10:56:00 AMI had a bit of a glitch on my race bike and holed a piston
I need the rings replaced for both cylinders but just one piston
Is this possible?
The underside of the piston has this on it
serial# 638951Question by: Ken Cook on Sep 17, 2018 10:10:00 AMHi,
could you tell me the distance from the rist pin hole to the top edge or deck location of the piston and the pin dia.?Hi...do you have direct experience with running these pistons on T140 street bike/mild cams in 100F + weather and our lovely CALFONIA "91" pump gas?
will 10.5 c.r. work- without excessively retarding ignition timing? or even the 9.0 c.r. ?
thanks for any helps
PetermanQuestion by: Peterman/ Motorworks on Feb 1, 2018 11:18:00 PMWe've sold a lot of these piston sets in both the early style forged and the latest 4032 versions. And yes, many were sold in the great state of California. We've found our "Quench" design allows those customers using 9:1 pistons to run without any problems on high octane pump gasoline. That being said, every part of the country is a bit different in their formulations and I’m sure California is no exception. The best practice is to use the highest grade you can readily find and plan for that. If you feel that only lower octane grades are available than mentioned it may behoove you to get lower compression pistons (we make 8:1). Of course, the 9:1 pistons really liven up the engine, especially if you change out the cams, but a free-flowing exhaust also provides a big boost in performance.Answer by: rick c (Admin) on Feb 2, 2018 3:23:00 PMhi, what are the weight compared to the originals? also, do you make pistons for other brit bikes than triumph .I am moving back into m/cycle restoration and want to provide customers with quality parts. always liked hepolite in the past, but now seem doubtful they are the same quality as the good ol days, when brit bikes where thouroughly thrashed like the owners hated them,haha,well,loved thrashing them.Question by: gabejarvis on Feb 19, 2018 11:59:00 PMNo answers yet. Be the first to answer the question!
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