OEM GT500 piston strength: power rating?

[RedVenom48]

Does anyone know what the known good safe power limit for 07-12 GT500 OEM pistons are? If the OEM Mahle built pistons are capable, Id prefer to just replace the rods, wrist pins, piston rings and bearings. I know the 13-14 piston design is unique and only JDM engineering has a drop in rod spec'ed for them. Im hoping the 07-12 pistons are not that unique.

Ive done a few searches, but cant seem to find the information Im looking for. Most of the search results pop up individual mentions of pistons, a vast majority being for brake pistons. A google search comes back inconclusive for me as well.

Im probably not going to build a super monster power car. Most likely in the 700-800 RWHP range. I am however wanting to beef up my short block so I can beat on it at the track RELIABLY. Not competition mind you, but just make hard runs every time. Id like to be at the track doing that 1, possibly 2 times a month for Friday night drags.

Im going to be upgrading the timing components here in the next few months. Depending on if I can reuse the pistons for my desired power rating, I may get rods, wrist pins, bearings and rings and pull the motor.

 

[GT Premi]

Well, according to Carroll Shelby, the stock long block "can comfortably handle 1,000 HP." BJ at VMP has an '07 or '09 GT500 pushing 900HP on stock internals for several years now, and he beats on it regularly. As long as your tune and fueling are good, you have nothing to worry about with your power wishes.

 

[Catmonkey]

BJ at VMP has an '07 or '09 GT500 pushing 900HP on stock internals for several years now, and he beats on it regularly.

BJ's been in the low to mid-800s on stock internals, but before he hit his 900+ pull, he rebuilt Christine's bottom end with Manley pistons and H-beam rods. He broke a balancer in the mid-800s with the G2-R, which left the crank in pretty bad shape. But I believe he had fairly high miles on that engine.

I believe the Mahle pistons are not that bad. The rods on the other hand are the weak link in these engines. The 13-14 piston had a weird taper at the wrist pin, so none of the aftermarket rods will work with them. I believe the JDM rods are standard aftermarket H-berms with some additional machining to the small end to clear the piston configuration. The 07-12 pistons are not constructed the same way.

This is a 13-14 rod. You can sort of see the taper on the small end, but not the best photo to accentuate the difference.

 

[PistolWhip]

At 700-800 RWHP, I think you're probably ok with the stock bottom end but Catmonkey knows what he's talkin about up there. There are plenty of 500's running around at that power level and holding up just fine but if you need the peace of mind the rods are the weak point. If you're going to take the bottom end apart, get billet oil pump gears for sure.

 

[rotor_powerd]

I made 750+ and all the way up to 1000 wheel on the factory longblock with nothing but a billet pump gears and ARP head studs for a while. Not sure how long that luck would hold out. That said; pistons are cheap. It would be dumb to open the motor and not do them and the rods.

 

[RedVenom48]

...That said; pistons are cheap. It would be dumb to open the motor and not do them and the rods.

Damn, made total sense in the moment reading this. wtf was I thinking. Do it once, do it right. Thanks for bringing me to my senses lol

 

[GT Premi]

I made 750+ and all the way up to 1000 wheel on the factory longblock with nothing but a billet pump gears and ARP head studs for a while. Not sure how long that luck would hold out. That said; pistons are cheap. It would be dumb to open the motor and not do them and the rods.

That's what I would do. If the engine is going to be opened anyway, might as well fortify it while it's apart.

 

[hotford]

if your pulling it down it only makes sense to do a rod and piston

 

[1st usa car]

might want to throw in cams too -- drop that boost level and get +50whp

 

[RedVenom48]

Lmao, well... it sounds like this project next year will be a full engine build. RIP my wallet... lol

 

[rotor_powerd]

Careful. I pulled my engine in November to do rods/pistons, a clutch, and bigger turbos. Here we are 7 months later, the block is sleeved and filled, heads fully redone, cams, single turbo, car is getting front quartered and caged, TR6060 got sold in favor of a TH400, and I'm over budget by about 500%.... and still am nowhere close to having the car together much less running. Lol

 

[Papaw]

Sounds like you're a slippery slope kind of guy.
Like the rest of us.

 

[rotor_powerd]

Yeah, it's a problem

 

[RedVenom48]

Well... Im fortunate that it will take me a while to save up for the parts. Even as a professional wrench I dont feel comfortable DIY'ing my own long block. Id much rather have an experienced professional engine builder handle my engine.

That said I have a heart attack when I get labor quotes from other shops for work on my own car I cant perform. One of the pitfalls of being a professional mechanic lol

It should keep me in check.

.... of course if the heads are coming off it might be a good time to have them ported.... fml... haha

 

[GT Premi]

Well, if the heads are coming off, you definitely might as well put some cams in it. And while you're at it, BPS has some lightweight cam gears you can install. Might as well slap those on, too. Matter of fact, might as well get some titanium valves and springs and a nice grind on the valve seats. Oy! See how quickly this stuff can get WAY out of hand?!?

 

[PistolWhip]

^^^LMAO^^^

Ain't it funny how that happens... while we're at it, it would be stupid not to do this, this, this, this oh and this, and this....

And this is how top fuel funny cars are built... LOL