Stock pistons are horrid. So if you plan on 400+ and plan on running it like that for a while as a daily it'll break .

 

Rods will be fine, same with crank, sleeve same but I suggest getting a different sleeve setup or something similar, pistons will go

 

This is what I was trying to get out of James. I don't think that the S20G Hahns turbo can yield over 500WHP. On his site they specifically states:


Model: TDO6H-20G-TDO5H-10CM2

Maximum HP Capacity: 500 HP
Optimal HP Range: 300-450 HP
Mounting (turbine inlet)*: T3 style

Exhaust (turbine outlet)*: 3-bolt flange, part number H TZ-7180

Compressor Inlet: accepts 2 ˝” hose

Compressor Outlet: accepts 2” hose

Oil Inlet*: 12 x 1.5mm straight thread

Oil Outlet*: 2-bolt flange, part number H TZ-7190

Optional water-cooling ports: included


This tells me that to the wheels, around 480whp +/-. I just can't see 500+ to the wheels. If I'm wrong then please explain. At 30psi(which I know it can do) it would be out of its efficiency range being that optimal efficiency is 450hp. James?

 

I never once stated a 20g can net 500whp.


I even have you the explanation above.

I'm no longer on the 20g anyhow

 

i never broke with 442whp.... stock top and bottom end, trans and so forth.

 

I didn't break either but that isn't the point. Point is the piston ringlands are **** and will break. No matter a good tune or not. If the car is in boost regularly making 400+ they will go sooner then later

 

I would agree that the stock pistons over 400whp need to be replaced.
Upon further inspection of the pistons looking for signs of this and talking to different shops that collectively have about 80years of experience, all mentioned(while looking at the rings) that under boost it looked like they could of been touching ends.The ends showed cleaned spots of metal. This indicates that they touched at one point while underboost. This would cause them to never be circular in shape again. So this just comes to shows what 26psi on a BNR can do to stock pictons. You can see also that combustion was taking place after the first ring from the crown. Its ok to see slightly a little but not in access like mine.






Cmiller added this to my conversation with him:

Also I noticed when I took my engine apart the first time that the ring gaps are very narrow from the factory, this I believe leads to the ring failures and such because they touch under higher boost where the motors are not built to see from factory.

Just for ♠♠♠♠s I went out and put a stock ring in the bore that was even honed for the wisecos, .015 lol. Way to tight for a high boost motor. The top rings on the wisecos are set at .018 seconds are .020 on my car. I am thinking about total seals for the new motor tho. John what do you think on those?


USMCFieldMP commented:

I have commented on this before. The top rings are usually very, very tight... especially on the LSJ's, so I'd imagine the LNF's are in a similar boat.

John Powell:

I have only ever used stock rings /stock pistons or diamond pistons/total seal on an ecotec, so not sure I am a good source of information. Correct ring gap for a forced induction motor has to be essential, but too large a ring gap especially with oil control rings may result in high oil consumption...

For blown or
nitrous application it is recommended to increase ring gaps
to: .0239 to .0269 for top ring and .0209 to .0239 for second
ring.
from the GM build book

 

Thanks

ya most likely they did it didnt say of course so thats a prolly a good guess, also james how much did it cost to convert the 20g? Did you send it in to a company or do it all yourself?

 

He did it himself, he's a badass like that.

 

James, You remember this? hahaha

400whp + stock Piston = Fail
Broke mine in 3 spots

 

sweeeet!

 

james much to build me one???? you should market that ****

 

Oh wow, glad someone else has taken pics of their pistons.

 

Always lol.

This was my #3 piston...

 

all this negativity towards 400+whp....lol

alright, i have decided to trade the balt for a heffner twin turbo lambo....lolololol

 

Wheres the "Like" Button in here?!?!

 

Again.... you changed your mind. Lol

 

i take it he does that ALOT? lol

 

Really I'm getting scared now. I was saving up for cams and valves. I guess I'm saving to build the motor and that too now. $6k+?

 

If you build it yourself you shouldn't spend 6k lol
You don't really need vavles..
New pistons, stock rods are actually fine for 400+

 

I did my setup myself...

 

James ur a lint licker

 

Since everybody is showing off their piston pics, I might as well get in on this action.

Piston failure #1: Cylinder 1, ring bind causing cracked ring/land.



Piston failure #2: A couple years later. Cylinder 4. Royal Purple oil detonation.

 

Only if its in the belly button haha