Anyone tried MAP pistons?

These look nice:

http://www.mapcycle.com/categories/engi ... -kits.html

I assume they're JE ?

Anyone tried them ?

I once used BSA DB32 pistons in a 650 Triumph. I marked where the protruded from the top of the bore and using a template turned the crown of the piston to be a close fit in the head - in effect a squish band. The pistons ended up lighter than the standard 8.5 to 1 Triumph pistons. I don't know where the comp. ratio ended up, but they gave the bike wings.

Interesting advertising. They are made from billet, i.e. turned and machined from solid bar stock, not a forged piston blank. I don't think they are by JE. All the pistons I've ever had JE make started as forgings, not billets. And I can't find any mention of making custom pistons from billets in any of their literature or web sites. They certainly sound trick, however, and do seem like a modern design. It would be interesting to find out who makes them. I've sent them an email asking if they are made in house, and if not, who makes them. If I get an answer, I'll post it.

Ken

These were rather nifty!



M.A.P. pistons with teflon coated skirts and ceramic coated crowns.

Slick. Literally.

grandpaul said:

These were rather nifty!

M.A.P. pistons with teflon coated skirts and ceramic coated crowns.

Slick. Literally.

Click to expand...

They look sexy GP, can you tell us more, did you run them, if so in what, did you rate them, etc?

lcrken said:

Interesting advertising. They are made from billet, i.e. turned and machined from solid bar stock, not a forged piston blank. I don't think they are by JE. All the pistons I've ever had JE make started as forgings, not billets. And I can't find any mention of making custom pistons from billets in any of their literature or web sites. They certainly sound trick, however, and do seem like a modern design. It would be interesting to find out who makes them. I've sent them an email asking if they are made in house, and if not, who makes them. If I get an answer, I'll post it.

Ken

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I didn't notice they claimed they were billet Ken, I assumed they were forged!

Fast Eddie said:

lcrken said:

Interesting advertising. They are made from billet, i.e. turned and machined from solid bar stock, not a forged piston blank. I don't think they are by JE. All the pistons I've ever had JE make started as forgings, not billets. And I can't find any mention of making custom pistons from billets in any of their literature or web sites. They certainly sound trick, however, and do seem like a modern design. It would be interesting to find out who makes them. I've sent them an email asking if they are made in house, and if not, who makes them. If I get an answer, I'll post it.

Ken

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I didn't notice they claimed they were billet Ken, I assumed they were forged!

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Nope, billet. I wondered when I first read their ad if they had just misused the term, but they have some pictures on the site that show the fully machined underside, which has a different appearance from a forged piston, even one that has been extensively lightened with CNC equipment.

Making one-offs from billets for uncommon applications has been around for a long time, but this is the first time I've seen them advertised as a production item. Not all that surprising now that solid modeling software and CNC machines are readily available, and becoming much more common in even the smaller shops. I've got a couple books ( the classic "Tuning for Speed" for one) that discuss the process using old school conventional machine shop equipment, but I've never had the need (or the confidence, perhaps) to try it. Besides, getting the right sort of surface finish on the ring grooves requires more elaborate equipment than I can manage. Here in Socal, firms like JE, Ross, Venolia, Arias, CP-Carrillo, etc., will make pretty much any sort of piston you could desire, with very high quality, and at reasonable prices. On your side of the pond the main choice seems to be Cosworth, but I've been told that they now require a fairly large order to do anything custom.

Just browsing around, I found that CP-Carrillo does billet pistons. More info here

https://www.cp-carrillo.com/pt-3507-pistons.html

Ken

Well, I'm convinced enough to try them!

I've bought a Morgo barrel kit minus pistons and ordered a pair of 9:1 76mm MAP pistons. I looked at the MAP alloy barrel kit but it's too much $$ for me.

No sure when I'll get the pistons or get around to fitting it all though...!

Another update. JE does do billet pistons, and they generally use the same 4032 alloy that MAP's ads mention. So I guess that the MAP pistons could be from JE, as well as from CP-Carrillo, or Diamond, or ??? The designer at JE mentioned that billet pistons are becoming more common, particularly for prototypes, but also for quick production of pistons for which they don't already have a suitable forging. Technology marches on. No more casting pistons in a hole dug in the ground.

I've been watching the different options JE offers for their pistons for a long time now, and I've considered adding some of the cool features to the Norton pistons I get from them, but the only one I've used is an extra lightening cut on the underside of the dome, and only on some pistons. I don't think most of the trick options really add anything to the typical Commando engine build, but some of them can be very helpful to the really high rpm, high horsepower builds. But they all add to the price, and at some point I'd be trying to market the world's most expensive Norton pistons. That would be fun, but probably a real financial loser. I have to admit, though, that all the cool coatings, extra pin oiling, trick rings and ring groove treatments, extra lightening cuts, and so on, are awfully seductive to any gearhead. Jim Schmidt offers some of those options on the pistons JE makes for him, as part of his light weight piston/long rod kits, so there is at least one retail source for Norton guys who desire them.

I asked JE a while back if they had considered using metal matrix alloys (MMC) for pistons, and they said they had experimented with them, but because of the machining difficulties, they would be very expensive. They weren't planning to produce them at that time, and I think that's still the case. JE experiments with a lot of high tech stuff, just trying to be competitive, but only a little of it shows up in production.

So what's next? 3D sintered beryllium pistons, maybe?

Ken

This is the response I got from MAP this morning.

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Ken,

Our pistons are manufactured to spec by one of the top performance piston manufacturers in the country. Our Triumph pistons are based on a design we’ve worked on for years using our racing bikes as testing platforms (we’ve won 5 national championships so we must be doing something right). Although we sell a lot of JE piston, it is not JE who makes our pistons. Similarly, our rings are made to spec by one of the top manufacturer of racing piston rings in the country.

The Norton has a different head chamber shape than the Triumph, so it can’t utilize the same design. However, we are now manufacturing a new piston for Norton using the same advanced materials (as our Triumph pistons) and manufacturing methods.

By far, the best way to go for the Norton is the long rod conversion. This conversion utilizes our amazing H-beam rod and the new lighter, shorter-skirted piston. A lighter piston means more engine RPMs and better performance. We carry these in several compression ratios:

For the 750cc bikes

· MAP90932A @ 8.5:1 (or 9.0:1 in a combat head)

· MAP9033A @ 10.0:1 (Combat head requires mods)

For the 850cc bikes:

· MAP9037A @ 8.21:1 (increase to (9.0:1 with .040 decked head)

· MAP9038A @ 9.5:1 (increase to 10.5:1 with .040 decked heads)

· MAP9039A @ 10.5:1 (required head modifications)

These pistons are already in stock but they need to be mated to long rods (which are also used as stroker rods on a Triumph). Here is a link to those rods: http://www.mapcycle.com/categories/engi ... steel.html

We also are manufacturing new “stock style” pistons for the Norton. They use the same high-tech alloys and manufacturing methods but retain the stock design. These will be offered in 8.5:1, 10.0:1 in both 750 and 850cc. These pistons should be in within a week or so.

Rick

Great info Ken.

There has never been a better time to be into these bikes has there? The range of quality kit on offer is just amazing. And a lot of it from you boys 'over there' too.

Long may it continue...!

Fast Eddie said:

They look sexy GP, can you tell us more, did you run them, if so in what, did you rate them, etc?

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Sorry, I just know what they WERE, nothing else. They belonged my late friend and vintage roadracing mentor, Malcolm "BritBodger" Dixon. I passed them on to a mutual friend who was thinking of using them in a rat rod Triumph that he has, but never received any update on the subject.

Not to worry GP, Kens research already convinced my to pull the trigger on these!

Will let y'all know how they work out.

If it blows up, it's Kens fault...

Received these today. Wow. Simply stunning. Almost a shame to hide them away inside the engine. Almost!
Oh how I wish I had access to these when I was racing Triumphs and chasing my arse with seizures etc!
Not tried them yet though, they'll be staying on the shelf for a bit yet however as I have the small matter of a Norton engine to nail together and fiddle around with first...

grandpaul said:

These were rather nifty!

M.A.P. pistons with teflon coated skirts and ceramic coated crowns.

Slick. Literally.

Click to expand...

They don't look forged to me, the skirts are too thick. Have a look at a Mahle Piston out of a two valve JAWA speedway engine - the skirts are paper-thin. I saw one which had been run so loose that the end of the skirt had curled under, it still did not crack. Changing to lower piston weight in most motors, gives a performance boost, you can feel. The pistons reverse direction two times on every rev of the crank. The inertia effect is immense. Cutting the piston weight allows the motor to spin up quicker. When you go high comp. you usually add weight to the piston crown. That is why motors with low comp. are sometimes as quick as those with high comp. when using methanol fuel.

acotrel said:

They don't look forged to me

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They aren’t Al, they’re billet, as discussed earlier in the thread...

MAP pistons are machined from a forged aluminum slug which is typical of aftermarket auto and bike pistons...They weigh just a few grams more than a stock cast Hepolite piston..The lower dome along with a tight quench gives a fast combustion burn, less chance for detonation ....I run them in several race Triumphs