Ready to buy another set of piston for my cobra how does the M2500R piston stand up to a Diamond piston as far as quality, longevity and endurance ?
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MMR M2500R Racing Pistons
- Thread starter BigWill90
- Start date
Is anyone using M2500R pistons ?
Hey, ya i'm using them in my 03 turbo cobra. I'm still putting it all together well the motors done everything just have to go into the car. mine were built to .20 and 9.5-1 compression there a full custom piston so i'm hoping for good things, i'm shooting for 7-750 rwhp on 94+meth.
Doesnt look like many are running these pistons on SVTP. I too would like to know if the MMR M2500R is a better piston.
I email a MMR Rep hopefully I'll hear from him soon.
Technically there only good for 1500 unless u upgrade the pins. I just got them because I would rather over build than under build my car. And they are around the same price as the others.
Here is the response from MMR.
Hi, the M2500R is the top shelf piston by comparison, MMR offers both Manley and Diamond but the MMR/Manley design is far superior. When you purchase the M2500R pistons you get the same exact piston that is in our 3000HP Pro Mod -super strong- super reliable for street and full race use, - the Diamond on the other hand we would call a good sportsman piston. Please let us know how we can help!
Hi, the M2500R is the top shelf piston by comparison, MMR offers both Manley and Diamond but the MMR/Manley design is far superior. When you purchase the M2500R pistons you get the same exact piston that is in our 3000HP Pro Mod -super strong- super reliable for street and full race use, - the Diamond on the other hand we would call a good sportsman piston. Please let us know how we can help!
I'd get some JE pistons with the biggest pin they have. But why are you buying pistons? Did you burn one up? Are you building a new motor? What block and bore size?
All good questions, and here's another...do you expect to be using the car for road racing with long periods of time between 1/2 to full throttle? For a DD, even one that makes 700 RWHP, the stock cast pistons are still a good bet. You can fit them very tight to the cylinder wall on an iron block and this will give you long and happy ring life. My 93000 mile old motor still holds up to frequent full boost blasts from a 2.3 Whipple, has perfect compression on all cylinders and doesn't use ANY oil, and i mean not a drop! I actually went 8,000 miles between oil changes :dw: last time and the oil level on the dipstick never moved. Yes, I know that was stupid and careless of me; won't happen again.
Piston weight should also be considered. Heavy pistons/wrist pins will load the bearings more and are harder on the bottom end at high RPM's (6500 rpm's = 108 cycles per second). A thick walled Mod Max slug weighs 455 grams. My CP's which are not the lightest weigh 399 grams. That's a pretty good leap. Thicker walls are good for strength and heat transfer so there is a trade-off to be made here.
Avoid coatings of any kind. They can do bad things as well as good and sometimes both. That red coating on some pistons appears to be nothing more than an anodize which is good for wear on the skirts but bad for heat transfer and they are coated 100% of the piston surface. Thermal coating the crowns will reduce the cooling effect of the incoming charge will have on the piston and raise compression temperatures which will be less tolerant of ignition advance (I have first hand experience with this :nonono
. Teflon coating the skirts are generally used to reduce scuffing on tight piston to wall clearances and not needed or desirable in an engine will loose(r) fitting pistons. You won't do much better than bare aluminum to transfer heat. This won't apply as much with an engine running E85 due to the super cooling effect of methanol but most people don't realize how much heat plays a role in the demise of a high output engine.
Our pistons are usually the fist things to go!
Avoid coatings of any kind. They can do bad things as well as good and sometimes both. That red coating on some pistons appears to be nothing more than an anodize which is good for wear on the skirts but bad for heat transfer and they are coated 100% of the piston surface. Thermal coating the crowns will reduce the cooling effect of the incoming charge will have on the piston and raise compression temperatures which will be less tolerant of ignition advance (I have first hand experience with this :nonono
. Teflon coating the skirts are generally used to reduce scuffing on tight piston to wall clearances and not needed or desirable in an engine will loose(r) fitting pistons. You won't do much better than bare aluminum to transfer heat. This won't apply as much with an engine running E85 due to the super cooling effect of methanol but most people don't realize how much heat plays a role in the demise of a high output engine.Our pistons are usually the fist things to go!
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The 2500r piston coating is a bit different now they only coat the top of the piston and ring landings, not the sides anymore, for cooling reasons. I'm also running a meth kit on my car so I'm not to worried about heat.
One issue I did have with these pistons tho when my engine builder was balancing them which I'm guessing is do to the coating, took them awhile but it got done.
One issue I did have with these pistons tho when my engine builder was balancing them which I'm guessing is do to the coating, took them awhile but it got done.
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I don't see how anyone can answer this without building two identical engines except one has MMR pistons and the other Diamond and then subject them to the same endurance testing. Over the years I've seen so many which pistons are better threads and you'll see everything from CP, JE, Diamond, MMR, you name it but no real data as to why. It's all opinion and why one is liked over the other. I never see threads however saying X brand piston failed me so need to get something better (other than stock pistons) so I'm not sure you can go wrong with any reputable brand.
I ran into this a few years ago myself when looking for pistons on my engine rebuild. No one could point me to any one piston over another other than opinions or preferences based on things like ring landing depth, weight etc. Which are all great pointers but at the end of the day none of the other brands fail you either.
That may very well be true but I wouldn't have expected anything else. Any manufacture/reseller will tell you their product is superior and you should get theirs. I bet if you called Diamond, JE, CP or any other name brand they'll all tell you why their designs are superior and why you should buy their product.
The only real differences I see is when you start comparing the 4032 alloy pistons to the 2618 alloy. Most manufactures usually offer both though. Do some googling on it and learn the differences. In summary the 4032 has a higher silicone content which allows for less piston expansion giving you tighter piston to wall clearances for a quieter engine. They are also rated as the lesser of the two alloys in terms of strength. Again google it as opinions on just how much HP the 4032 can handle varies greatly. The 4032 is also said to be less ductle and less forgiving to detonation which is compounded in a boosted motor like ours. The 2618 needs a greater piston to wall clearance and could potentially have a piston slap noise on cold start up but it's a stronger piston. If nothing else read up on all the differences because it's quite interesting.
Ya, Malcolm I was just about to say pistons are like a**holes everybodies got one. It pretty much comes to picking one you like. Everybody is going to say use the one they have in there car because they had good results.
And before someone jumps on me for saying all pistons are the same comment, I'm talking once u get into the high end custom stuff, they are all pretty similar.
And before someone jumps on me for saying all pistons are the same comment, I'm talking once u get into the high end custom stuff, they are all pretty similar.
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