[mlomker]

so yours is noisy when cold?

My tuner said he could hear them during the initial start-ups. I can't tell since everything about my car is noisy. I have the Buschur version. The valve reliefs are deep...really couldn't imagine ever having piston contact.

 

[hollywood_X]

Hollywood - do you have ANY issues with phantom knock?

I presume that as long as you stick to the manufactures tolerances they should all be fine...

might check that out now.. see what JE recommend vs Wiseco..

even though they are the same company now lol

No phantom knock from pistons, we did have some spool up tip in knock from compressor surge we needed to tune out.

 

[Golden]

I only just got it as well...

Your fault for not prefixing with 0x

My post couldn't have 0x in it, as my values were in decimal. Hence the joke...

I could have said 0x4, but 0x10 != 0xA

 

[Clipse3GT]

Yes, the HD variants have better alloy mixture. Better design. Overall a better piston designed to handle high HP applications better.

Can't really go wrong with CP or Wiseco's IMHO.

 

[EvoX2NR]

I didn't like the wiseco's I had in my protege... definitely a noisey piston.

The JE's I have in the evo are nice and quiet. No phantom knock either

 

[Sequence]

ive always used Wiseco for built dirtbikes, not saying much for evo but they have never failed me

 

[hotdog]

You might want to verify availability for 90mm, before you choose on a brand. That's a huge size, obviously, and it may well be several months before they'd be readily available.

 

[lallen3]

I didn't like the wiseco's I had in my protege... definitely a noisey piston.

The JE's I have in the evo are nice and quiet. No phantom knock either

Pistons aren't "just noisy." They make noise when there is too much clearance between the piston and the cylinder wall. Can't blame the piston, only the builder for not measuring the tolerances properly.

You might want to verify availability for 90mm, before you choose on a brand. That's a huge size, obviously, and it may well be several months before they'd be readily available.

^ For sure.

 

[hungryhippos]

REVIVE! Just wanted to throw in my information. I'm currently running Manley pistons, 86mm, 9.0 compression. I'm running .003 clearance, if its cold enough, it'll be noisy. the nice part is though there isn't any knock of any kind so +1 for ease of tuning.

Is anyone running 10+ CP on pump? This is what i'm truly curious about.

 

[morricus]

REVIVE! Just wanted to throw in my information. I'm currently running Manley pistons, 86mm, 9.0 compression. I'm running .003 clearance, if its cold enough, it'll be noisy. the nice part is though there isn't any knock of any kind so +1 for ease of tuning.

Is anyone running 10+ CP on pump? This is what i'm truly curious about.

Excellent, sub'd. I've been researching this lately, along with rods.

 

[Englando]

ERL had JE make me a custom piston for my build, once she is up and running I'll let you know how they perform.

Here is a few pics of one of them...

Sent from AutoGuide.com App

 

[hungryhippos]

ERL had JE make me a custom piston for my build, once she is up and running I'll let you know how they perform.

Looks great, what specifically did they modify to fit your build?

 

[Englando]

Looks great, what specifically did they modify to fit your build?

Their a 90mm piston, have deeper reliefs, coated skirts, and setup for use with Manley 94mm crank, Manley TT rods and 10:1 compression.


Sent from AutoGuide.com App

 

[KickAss]

REVIVE! Just wanted to throw in my information. I'm currently running Manley pistons, 86mm, 9.0 compression. I'm running .003 clearance, if its cold enough, it'll be noisy. the nice part is though there isn't any knock of any kind so +1 for ease of tuning.

Is anyone running 10+ CP on pump? This is what i'm truly curious about.

I have custom CP pistons but the CR is somewhat lesser than 9.5. Dino knows the exact details. My car is noisy as hell though, always been that way. I did not notice any difference from when I was running on the stock motor. Not sure if it helps you in anyway. I am also running kelford-b with their springs and ferrea
Valves.

Sent from AutoGuide.com App

 

[morricus]

For what reasons are you guys going to custom pistons? It seems like there are quite a few instances of guys going the customer route vs off the shelf, but I've never seen many reasons for it.

 

[Kooldino]

We use custom pistons for our builds. Arias. The reason we go custom is because it allows us to tweak the design as we see fit.

CP pistons are also very good.

 

[Englando]

For what reasons are you guys going to custom pistons? It seems like there are quite a few instances of guys going the customer route vs off the shelf, but I've never seen many reasons for it.

Off the shelf will limit you to what you can build. For you to correctly choose the right piston you need to know several factors. Obviously the block height (some call it deck height), then your connecting rod length followed by crankshaft stroke length. This will give you your compression height which is the height of your piston from the center of the wrist pin. Leaving the piston choice till last will allow you to have a custom piston made to suit your build.

If you choose your piston first then you would have to build your motor around the piston which could be challenging and may result in a build that wont perform to your goals and expectations.


Sent from AutoGuide.com App

 

[morricus]

Off the shelf will limit you to what you can build. For you to correctly choose the right piston you need to know several factors. Obviously the block height (some call it deck height), then your connecting rod length followed by crankshaft stroke length. This will give you your compression height which is the height of your piston from the center of the wrist pin. Leaving the piston choice till last will allow you to have a custom piston made to suit your build.

If you choose your piston first then you would have to build your motor around the piston which could be challenging and may result in a build that wont perform to your goals and expectations.


Sent from AutoGuide.com App

Ahh, got it.

 

[Englando]

Ahh, got it.

So say deck height of the Evo X is 230.1mm and you know what rods and crank your using (in my case Manley 94mm and TT I beams). That would give me a rod length of 143.662mm and stroke of 94mm. Compression height calculation = block height - rod length - (0.5 X stroke)


Calculations would be: 230.1 - 143.662 - 0.5 x 94 = 39.438mm which you can then have a piston made with a compression height of 39.438mm.






Sent from AutoGuide.com App

 

[UT_EvoX]

I know this thread is old as hell, but I figured I would chime in.

Our shop has a very good relationship with CP/Pankl/Carrillo and we prefer their off-the-shelf 2618 alloy pistons for most builds. The block I just put together for a 6266-powered X has their pistons as will 2 of the following 4 motor builds we are doing in the next month. The off-the-shelf piston design from CP is very strong and is rated at 200 BHP per cylinder but of course can handle more. For the first customer to come to us wanting to make insane power, we will have CP produce custom pistons capable of handling at least 300 BHP per cylinder.

My own motor has AMS-spec JE pistons as I had a partial set of them lying around and they're technically a very good piston. I will be setting PTW at around 40 tenths so we'll see how much cold slap I end up with.

In general, skirt coatings are overrated as you'll find with any motor torn down with any significant mileage. The coating also affects how you set PTW initially, so as the coating wears thin, your PTW will grow larger.