what are the actual differences in the JE and SRP pistons, is material selection?
If so what are the different materials and why are they better?

Is it better tolerances or procedures in the building of the piston?

Any light that can be shed other than the standard, they are better pieces would be appreciated

 

I'd like to know aswell, I would think some SRP versions would make more power as they are lighter, like the JE 31cc piston is 460grams & SRP version is 430grams, something like that. The price difference isn't that much, about $100.

 

Most times the difference is price and material.

SRP is JE pistons economy line of pistons. The JE parts are more likely to be race parts while SRP is more likely to be a budget choice.

JE has some of the lightest pistons out there in the Superfly series. They also have better inverted dome (dish) pistons than SRP, along with N2O and blown application specific pistons where SRP has more general pistons.

The SRP's are normally made of a high silicon alloy piston which is used for tighter wall clearances but it's not as strong a the lower silicon content pistons that JE's are normally made of.

Most guys don't care about the specs of the pistons in most applications so the SRP's will do. It's when you are looking for the last bit of power and precision that the JE's make sense.

Bret

 

There's more to pistons than just getting the right size. An important aspect of piston selection is also knowing what you need. Take a look at a catalog of a major piston manufacturer. JE/SRP's, for example, is on line. You will see a large variety of pistons, wrist pins, and rings. You want the lightest (and least expensive) piston that will work in your application. Factors like rpm range, use of boost or nitrous, etc. will play a major role in determining these factors. A low hp NA motor can get away with lighter pistons and rings while a hi-po boosted app will need stronger (and more massive) parts.

I guess what I am trying to say is that an SRP piston may be perfectly adequate for your needs and other times it may not. I think JE uses the same dies for many of the SRP and JE lines. The material differs, as Bret explained, and some designs are not available in the SRP line. I think all the "customs" are the JE line whereas the SRP is all "stock" items.

Rich Krause

 

...and WISCO is the parent company of JE,SRP. Correct?

as the piston turns
I luv my 2618 alloy je custom nitrous slugs by the way.

 

The SRP pistons are made just as well as the J&E slugs are but are only avalable in the more common applications. most of them but not all are made of an alloy that is better from a long lasting point of view (skirt wear ect) and do the job very nicely. the hard core pistons are actully made of a softer more malable alloy that can handle the shock loads better at the expense of not lasting 50 thousand miles.

Doug

 

thanks, good responses to my question by all and it's appreciated.

and of course if anyone has further input, please continue

 

i seen probe pistons that are fairly cheap and only weighted 419 grams, but i know this company is fairly new but has anyone tried them. And what do you think of them anyones opinion is better than no ones.

 

Are you sure about that?

 

Not exactly true... The difference is mainly the process in which they are made. Basically JE's are made to much tighter tolerances with much more precise machinery. The SRP's are more meant to be just a good shelf forged piston. I would have nothing against using them in say a 550 hp application or less (this is by no means their limit)... They're a nice piston. JE's are definitely going to be better and lighter though.

As for Probe, I'm surprised to see them mentioned here... Everything I've heard about Probe tells me they are better than JE's. Good stuff...

Later
Chuck

 

Looking at a Probe vs a JE in hand will definately show you the difference.

Probe is more in line with SRP.


The two piston alloys are 2618 and 4032. SRP makes pistons out of BOTH of them.

2618 is a low silicon aluminum, usually 0.25% or less. Since it has a low silicon content the piston to wall clearance is larger and usually in the .0035 - .0045 range on a small block. This aluminum is used in application where there are high skirt loads and cylinder pressures are common along with high chamber temps. I.E. Blower, turbo, N2O or really high compression ratio.

4032 is a high silicon aluminum, usually around 12%. This makes it expand less and wears much better for a longer life. Usually you have around .0025 - .0035 piston to wall clearance with a 4032 piston. This is the best alloy for daily driver type motors and most street cars. It can also be used in restricted circle track motors because of it's tight piston to wall clearance.

Basically SRP and JE are the same company, but if you are looking for a custom piston from them you are going to get a JE, not a SRP. SRP pistons are made to be an off the shelf piston.

JE is much more race oriented than SRP. The off the shelf parts they have are mostly for circle track and drag racing. That's why they offer the very light weight SuperFly pistons and Inverted Dome pistons. Both are designed for cirlce track motors. The inverted dome pistons vs a dish piston help combustion chamber efficency in setups like 9.5:1 motors.

SRP's pistons are more suited for a wide variety of applications. Their inverted dome pistons are made for more punishment than a 9.5:1 circle track motor, so the ring lands are farther down the piston, the deck is a little thicker making the piston heavier and they come in more street cube applications. I.E. 383.

Basically the SRP Inverted Domes are pretty dam good street motor slugs and are designed to take a beating from blowers or N2O.

Bret

 

I am running SRP's in my motor with no problems .

 

The question was about "actual material difference" and I stand by my above post. they are both made at the same place with the same equipment. yea some of the J&E slugs have more machining cuts made to them and are made for some more specific applications. The SRP line is plenty good for most street strip builds. call J&E direct and ask them what the difference is.

DJ

 

the je and srp pistons are made in the same place the je goes through more machining steps than the srp both are a decent piston i used the srp because of the cost in a forced induction application and have no problems