Looking for anyone who has an idea who makes a forged OTS LOW COMPRESSION piston for a 5.3. Mahle used to, but no longer makes them.

Also, can anyone here point me to someone that has run a 3.905 pison in a 5.3 under boost and if they had any problems.

 

A 3.905 piston is a LS1 bore not 5.3L, and Diamond makes one for that. It might not be as low as you want, but it is a dish made for the LS1 bore and stock stroke but with aftermarket 6.125" .927 pin rods.

http://dagostinoracing.com/index.ph...167_21948_21949_21977_21979&products_id=16272

Pair that with a set of 6.125" Compstar or SCAT rods and you will have one super strong shortblock.

These too, and they look like they are for a stock length 6.098" rod, but with an aftermarket .927 pin.

http://www.summitracing.com/parts/MLE-LS1314905I16/

 

This is a customers engine. He has a 5.3L block. He bought 3.905 Mahle pistons and was gonna turbocharge it. We are concerned about how thin this makes the bores.

We can't find any OTS pistons that are for a 5.3L size bore, forged, and low compression.

 

Thin bore???? Look for a different block.

5.3 bored to 5.7 and boost link
https://www.theturboforums.com/smf/index.php?topic=103675.0

Interested in selling the pistons at a discount?

 

I would just poke it out and be done with it. That link TTFBDY just posted is the exact one I was going to put as well, and that's a LS1 bore 5.3L. The 3.905 was a .007 hone that was made for when LS1s were the only thing going and couldn't be bored without sleeving. If you want pistons for a 5.3L bore I think you're going to end up with customs, but then the price will be a lot more if you buy the recommend set of 10 for a couple of spares. Having the block sonic checked should be a pretty simple affair and settle any doubt on the block. Or...you pick up a cheap 6.0L shortblock for a few hundred and open up to all of the 4.00" bore LQ4/LQ9/LS2 pistons.

 

Wiseco makes stock 3.780 FTs with -2.2 reliefs and I believe 3.800 with -7ish dish, don't quote me on that however. How low of comperssion is he looking for?

 

I forgot about those. Page 10 and 11 you will see 5.3L and 5.7L pistons.

http://www.wiseco.com/Catalogs/Automotive/Chevrolet.pdf

 

I did find those, but I'm not sure how much compression and boost the LS style engine can get away with.

I think he mentioned doing methanol injection. This should be a street car, I believe, so some of the tricks like filling the block are probably outta the question. I'm just looking for some real world, 5.3 based motors that are boosted.

Unfortunately, the pistons he has now probably ate up a bit of his budget, and no one will give him anywhere near what he paid.

 

well...most of them are bone stock

 

Shoot me a part number.....

Lot's of people running near stock or stock stuff and low boost. Some not so low boost....

 

Here is you a stock 5.3L with a cam/spring upgrade and TC78 on it.





If a set of pistons ate up his budget then it's almost guaranteed that a stock 5.3L can handle more power than he can afford to build a transmission for. Personally I would run it as is, maybe with a rod bolt swap.

 

save your money. the pistons arent the weak link in the motor. weak link 9/10 times is the tuner. personally if i wasnt shooting for anything over 850 rwhp stock motors is all ill run. at that point over 850 its time to really consider how to hold the heads down. Up till about 850 ish the internals arent an issue, be smart and tune right and have the setup properly done and it will live for along time. Ppl that have motors fail below 850 did something wrong

 

Quik, do you feel the same way about LQ4/9s? I want to get a 6.0L running in my car first, then figured on some Compstar rods (ARP2000 bolts) and Diamond pistons. First goal would be <6.99 in the 1/8 in a ~3800lb (with me) car, then <5.99 in the 1/8 on the second phase. Would you keep it bone stock until you are ready to change the crank/rods/pistons, or is there a middle ground where you think the rods/pistons are a good upgrade with the stock crank? In the end I am thinking Compstar 3.625" crank, Compstar 6.125" rods, and Diamond 4.030 pistons after a fresh bore/hone, fed by a GT88.

I know this is off the subject of 5.3L, but for all intents and purposes the crank/rods/pistons are identical. To think you can throw $2k worth of parts into a $200 junkyard engine and have a shortblock capable of holding over 1000rwhp is just amazing to me.

 

heres my thoughts, ppl dont have to agree and im a no name person but this is how i see things. Gm built one hell of a fucking motor. the internals are stronger then ppl realize. No one has truly found the limits of the internals. motors fail every day and then they say its cause it cant handle xxx amount of power. but what was the conditions it failed?

was it harmonics from a poorly designed crank pulley which caused crank to break or timing chain to snap?
was it from to high ECTs?
was it from to lean of a AFR?
was it to rich of a AFR?
was it from to high of IATs
was it cause tuner was an idiot?
was it cause you have a weak sealing of heads and leaked coolant into combustion chamber and bent a rod?
do you mechanically over rev the motor?
did you have valve float?
did your fuel system find a restriction and starve your motor under load?


fact is no body truely tells the truth of what happend or alot of ppl are to dumb to know and they pay a builder which says it was tune or etc jsut to make owner happy. any of the GM LS motors are stout if handled correctly. Good compression, good leak down are keys, good ECTs, good IATs are also good things to look for. So with that being said no one truely have found the limit of stock internals yet.

i plan to see what my LS2 can take and doing so with stock TTY head bolts. Now there is a point in which the weak link is the 4 bolt design. at the point id look into O ring setup, Firering setup or 6 bolt setup. Again this is just my take on it from years of researching and studying of ppls builds and playing with mine and a few customers.

so yes a 6litre would work the same in theory, but the smaller motors are more lenient

 

something to think about, an aftermarker piston has that asshole factor into it. where as if you hiccup the motor a few times you have a cushion. Stock piston if you hiccup it once your FUBAR, so with that being said you have to have your A game on when using a factory motor. Be smart about it and not be a fool.

cause even a forged motor will fail, ppl build a forged motor for 700 hp and it still fails cause builder or tuner are morons. Now if you if everything is on point and you lift a head then its to point where mechanically you need to look into other options.

 

I can't imagine I will ever be a a point where a set of aftermarket thick deck heads and head studs won't be enough for me, meaning no 6-bolt stuff. To be honest, a set of 317s with head studs will probably make enough power for anything I'll be able to afford a chassis for. Thanks for the input, Quik!

 

something to add into mix. for price of a big dollar motor you can have probably 10 stock motors in its place. if you need 10 motors to learn your mistakes then youre in the wrong hobby.

remember its a learning curve and not a learning line. we make mistakes and finding the limits is fun. So next time around instead of pushing 18 psi and 25* timing and afr of 11.8. you might be safe at 18* 20* and 11.5 afr.

yes its alot of work to swap a motor but its a lot cheaper if you do you own work to swap a motor for another stocker then it is to rebuild a built motor. If you blow a stocker you dont care, if you hurt a built motor your hurt and upset.

 

I figure after popping a couple of stockers I'll have enough spare parts to build a good one without down time, lol.

 

Wiesco I believe is the only company who has On the shelf forged pistons for these motors. Good luck!

 

What fuel are you using for all your testing. Good info by the way.