Yes,

We are working with DPR and a company that they have been using for their pistons for a long time. This is a joint venture between the 3 companies do design the pistons and cylinder head to work well together. There are some small diffrences, but the general idea is similar, and that covers the concepts rather well

JLM,
The stock compression if 8.3:1, not 8:1, and we did increase it by .2 to 8.5:1 but with the reworked cylinder head, and the tighter quench design, we are avioding Detonation from this increase. I will post all the information once we are finished compiling it. We will post the piston pictures when they are completed.

 

Dan,

Any thoughts on changing the rods too? I assume this $650 figure doesn't include them...

Are the stock rods an issue too or just the pistons?

Thanks!

 

We do have the ability to create forged rods, and that will be something that we can do custom to your requirements.

 

What type of piston is the stock piston? cast, Hypeurtectic, forged? Forged pistons usually require a little more clearance and can be a little noisier. What about the weight of the new piston, pin, and rings? I don't think I would do this without rebalancing the engine. Maybe you could carfully balance each new assembly to exactly the each old assembly being removed?

 

I thought that the MCS rods are forged.

Alex

 

I am sure they are but I was refering to the pistons.

 

I was refering to Dan's post.

Alex

 

I believe the MCS uses Mahle 142 eutectic aluminum/silicon alloy pistons (same material as a GM LT1 engine).

 

Has anyone bored out a MINI engine yet? I guess it'd be the next step, with over sized pistons, etc. I know the SB Chevy guys do it all the time...


There's no replacement for displacement


Mike

Side note... My service manager measured a MINI engine bay with the motor removed, and he feels you could fit a SB Chevy engine in there, with some sick custom fab work to count for the extra weight, diffrent tranny, and the RWD setup

 

I recall a thread over on MINI2 (Racing forum) that echoes Andy's beliefs. It's been a while, but I think it's in here also...

http://idisk.mac.com/thezachs/Public/MCS_Powertrain.pdf

 

I am having some custom pistons made by Arias..... should have them in 3 weeks or so.... going to be deeper dished , rings moved lower , 8:1 compression and forged of course

 

I do not have the final wights of the parts, but will when I have every thing in my hand.

Forged can make more noise, but we use a higher silicon content which is harder to make, but allows for quiet operation, and longeveity.

 

isn't that just when everything is cold?

 

That is correct, but we want every thing to run as smooth as stock to the user. Well, of course with much more power!

 

It's not generally recommended to fit new rings without a cylinder honing or you can expect a smoker; what are you suggesting about that?

Most people would fit new rod bolts; you might consider supplying those.
what about ring end gap?
Custom engine builders have the option of setting the piston-bore tolerance by the boring operation. What about stock variation or worn-in bore variations matching your piston size?

 

JLM,

As with any install, the install should be done by a qualified mechanic. If you are unsure of the process, I'd let some one else do it for you. When we are finished, we will have all the clearences and such provided with the purchase of the piston.

 

Just got off the phone with the Piston Builder, and we talked about alot of the concerns that people had.

First was noise. The noise is a issue that used to happen with the older forged pistons. There are new designs, as well as new alloys that make this a non issue. These will run just as quiet as the stockers.

We also discussed the ring gaps, and they will be set up for our high boost applications, and given out to those who purchase the pistons.

Detonation ,and The 20 Lbs Boost with Turbo. These pistons are made to be able to run high boost, and are designed to be more efficient then the stockers. This causes a lower comustions chamber temperature, from being able to more efficiently move the comusted gasses out of the chamber. This will deter detonation, as well as the tighter quench. Our final Marketing is being worked up tonight, and will be available very soon.

 

I am very interested in these pistons. This will be something I will be getting for my car. Luckily I'll have my car back in about three days. My concern with this car has always been about stengthening the bottom end, so this is a good beginning to this. Danny

 

I am worried about 8.5:1 compression with 20lbs of boost OR more
after talking to people who have turbo'd many many cars . Also moving the rings lower would probably help

 

As we get closer to the first prototpes finishing wih production, Here is the full info on the pistons

MINI PISTON advantages

Design: Our MINI PISTON is the end result of a collaboration of work with premier piston firms; producing the most technologically advanced, application specific forged piston available. Forged pistons have superior properties compared to OEM stock “cast” pistons, allowing thinner cross-sectional areas for high strength and light weight. If you’re running forced-induction and/or nitrous oxide then forged pistons are just about mandatory!

Materials: We utilize extruded, not cast, billet bar-stock 4032 aluminum alloy because of its strength, ductility, and fatigue resistance. With 13.5% silicon content, 4032 pistons offer excellent wear resistance on critical surfaces such as ring grooves, pin bores and skirts. The higher silicon alloy can also be installed with minimum cylinder wall clearances.

Cylinder Wall Clearance: Our pistons feature diamond-turned ellipsoidal skirt profiles, machined on precision multi-axis machining centers. Pistons with contoured skirt faces can be installed and run with super-tight piston-to-wall clearance - resulting in ring squareness to bore, proper heat transfer & quiet operation.

Quench: We designed our pistons with a tighter quench clearance than the OEM stock piston, which sits at an enormous .146" away from the deck. Quench lowers the temperature of end gasses trapped between the piston dome and head thru radiation and conduction, preventing a second flame-front from prematurely igniting the mix (due to thermal shock, etc.). Combined with a combustion chamber-matching “inverted dome” piston crown, the result is reduced chances for detonation - allowing for us to run a higher compression ratio with a greater area of safety.

 

These would be from Atomic, no?

QUOTE:

ATOMIC PISTONS brings you over twenty-five years of practical piston knowledge. ATOMIC’s Nick Arias 3rd has forged a name as one of today’s most innovative piston designers, and that experience is passed on through every ATOMIC piston.
Custom pistons offer the ultimate in flexibility, allowing the engine builder to design a reciprocating assembly that is not bound by off-the-shelf** piston kits. In collaboration with ATOMIC, your crucial data is extracted and transferred to a blueprint. This “jobcard” is then forwarded to a premier piston machine shop for precision manufacture. Normal process time is four weeks (20 working days). Expedited turnaround is available.
Once in ATOMIC’s hands, the pistons are inspected against the jobcard and Arias 3’s intended concept, then shipped to you. All jobcards are kept on file as PROPRIETARY customer information. If you have a top-secret design, and want it to stay that way, you can put your trust in ATOMIC. **Please check ATOMIC’s vast listing of shelf piston applications before ordering custom pistons.


ATOMIC PISTONS advantages:

Forgings: ATOMIC works with premier piston firms; producing the most technologically advanced, application specific forgings available. Configurations include hollow dome, inverted dome, pentroof and right/left dome designs. Custom pistons can be produced for any practical bore size between 2.125” (54mm) and 5.750” (146mm). Note: Piston bore size is usually determined by ring size availability.

Materials: ATOMIC utilizes extruded, not cast, billet bar-stock 2618 aluminum alloy because of it's strength, ductility, and high-temperature fatigue resistance. Forged pistons have thinner cross-sections than cast “Hypereutectic” or “Powerforged” pieces, resulting in lighter weight. If you’re running forced-induction and/or nitrous oxide then forged pistons are just about mandatory! Hi-Silicon 4032 alloy forgings are also available for certain applications.

Ring Grooves: Custom pistons can be ordered with just about any ring groove width from .8mm up to ¼”. Radial depths vary from ultra-narrow back-cuts to traditional SAE “D” and “K” walls. In addition, these grooves feature the flattest run out and smoothest finish in the industry.

Cylinder Wall Clearance: Our pistons feature CNC diamond-turned ellipsoidal skirt profiles. Pistons with multi-contoured skirt faces can be installed and run with super-tight piston-to-wall clearance - resulting in ring squareness to bore, proper heat transfer & quiet operation.

 

That is correct. Atomic designed the pistons to the specifications that we have. We will be the retailer of these pistons, as they are our design specs.

Listed above though are the specifics to the mini piston.

If you want more info on their site, you can link to it through www.atomicspeedware.com

 

these pistons sound interesting, but anyone considering using them should certainly consider removing the block to do the following:

the proper way to fit a piston is to bore the block and finish hone to size (to hold the .0015", or as recommended, piston-to-bore fit) with the final hone a special finish to promote ring seal. Bore taper and out of round, bore perpendicularity to the crank, diameter swelling due to head bolt stress, etc. are dealt with by using torque plates and very expensive and accurate, boring and honing machines. Then you clean out all the abrasive materials very, very thoroughly and put the sucker together. Typically, if you bring your block and your pistons to a engine machining specialist, this process would cost around $6-800.
If you are going to all this trouble, consider replacing the rods as well, but then you are into crank rod throw bearing fitting, wrist pin honing, etc.

When done, your rings will seat well, your rig will hold boosted compression and be a rocket.

 

Ah, so they're Arias pistons?

 

They were designed by Nick Arias III.