that makes no sense whatsoever. So your telling me a forged "blower specific" piston is only as good as a stock piston?I think thats very wrong. Stock pistons are safe to 8psi and they are not forged and dont have thicker ringlands. Ive heard of many people running over 10lbs with no problems whatsoever. It should be more like 10-15psi and SRPs are good..15+and JE.

 

I understand your point, but that's what they told me. Sounds like a stupid piston to me. Ask engineermike how is SRP pistons worked out for him--i think I read a couple threads about his bad luck with those.

 

Roger that. SRP's did not work out for me at all.

However, I never broke one under 15 psi. Actually, I don't think I broke one under 20 psi. I think that they are just very unforgiving. It doesn't take much detonation will kill them so it's not really a boost limit.

 

I beat the crap out of my JEs for a few years and just had the engine freshened up. Pistons looked great got it reringed and new bearings thats it.

 

Well that was my point right there..I think 5-8psi..stock pistons could be ok...8-15 SRPs will be fine and up to 20 they MIGHT be ok..the tune has to be dead on though.(kinda like pushing a stock piston to 9-10psi) but I think for people looking to make 10-15psi the SRPs would be fine. If I was building a 1000+hp motor...SRPs wouldnt even pop into my head.

 

What would the CR be with stock heads?

 

When I inquired with JE, I said it would see 15psi MAX and they still said no SRP. That was just one guy though, maybe if I called back, another guy might say it's fine.

 

Well, you shouldnt talk to tech guys who think what it will handle, you should talk to the guys that actually used them. Like Emike..who said they broke over 20psi. If your tune is good, 15psi shouldnt be a problem..unless your running a large frame turbo or have a ****ty tune.

 

800 hp is not an average build, so the parts used to support that amount of power should be the best one can afford. I considered the SRP F.I. pistons, but after comparing the price of the SRP pistons vs. the simular JE pistons, there was so little of a cost difference, that the decision was obvious. Because of the difference in materials used, the decision should be a no-brainer.

With a 355, it's going to need every bit of 15 lbs. of boost to make 800 hp. In order for the motor to live any amount of time, the rotating assembly should consist of the best parts one can afford. I'd rather have a motor that uses top quality "blower" pistons (ones with a lower silicon content) and an overseas crank and rods rather than a rotating assembly that consists of "marginal" pistons and a top quality crank and rods. (This is an exaggeration though to make a point, as I would never choose to use any overseas parts in a F.I. application)

I'm of the opinion that boost is not so much the killer of a forged piston as is detonation and/or a lean condition. Pistons with a higher levels of silicon content are less forgiving and therefore more likely to fail if cylinder conditions aren't just right. + or - a couple of lbs. of boost will probably not be the determining factor if a forged piston lives or dies.

Most anyone who has been down this road would probably agree from experience that when building a performance motor, purchase the best parts you can possibly afford and if they are not designed for the application you are using them for, then be prepared for a possible failure. It's important to constantly be asking yourself is "what is the weakest link in the chain" as that part will most likely be the one that fails first.

 

I guess we standed off course a little with this topic and that is a good point. If I were building an 800hp turbo car SRPs wouldnt even come up. Id go with Ross or possibly JE pistons. Im just saying, I dont see how SRP forged pistons would be good for the same amount of boost as a stock piston..just doesnt make sense, and for people wanting to push only 10psi I think theyd be more than fine.

 

Very true. The pistons are BY FAR the most likely part to fail in an FI engine.

BTW, I've ditched my SRP's for Ross pistons.

One advantage of the SRP pistons. . . I got really good at swapping pistons with the engine still in the car. I can swap out a piston in a day now.

 

Awesome thread. Would love to see what everyone is running.

Just curious, how many miles/abuse do you guys go for between tearing the motor down for a check up/refresh ?

 

I usually run mine until the pistons break.

 

Every 2-3 years unless something breaks.

Rich

 

I went 4 years this time and my engine builder said if I would have made one more pass I would have spun a bearing I guess I was lucky when my blower exploded it kept me from making more passes and destroying my engine!