Thread: 20V pistons vs 16VE pistons (20V pistons are weak)

16VE piston top vs 20V piston top (to the first ring)



My concern do not use 20V pistons in high-hp applications, because its top is thin == as soon as EGT pass 700-800 deg. Celsius it will stuck because of piston-to-wall clearance issues.

What's how all my four pistons look:

the 16ve first ring land is defiantly thicker than the 20 ve that would also help keep the top ring away from heat good information src

src wondering are the ring thicknesses the same or different between the 16 ve 20 ve

the oil ring is diffefantly different

So what was your setup?

Interesting how similar the damage to your 20V pistons are compared to my SR20VET piston

Was the cylinder wall damaged?

It was completely stock SR20VE 20V. Just some external bolt-ons like CAI, headers, exhaust, flywheel, clutch, pulleys. I ran standard VE program I use in all my built VEs. I used the same tune on 3 VEs before (classic ones, not 20V) without a problems for a while.



Yes, I see your thread. My cylinder walls are perfect, minor scratches in 2d cylinder from broken rings, they doesn't matters at all.

The damages look like they are from detonation or thermal shock(wot on cold engine). Evident by the damage around the quench pad area on the intake. Nothing to do with 20V piston not being able to handle 700-800 degree celsius heat.

It's almost impossible for the top ring land area to expand and get stuck in the bore. There is a really big clearance up top. The closest piston to bore clearance is in the piston skirt area and not on top. If there was a piston to bore problem, your bores would have been scratched up.

Robert, the detonation was my first point, but I can't figure out WHY 20V detonates on my standard 20VE ignition table. BTW, quench pads are removed now.

Well here are a few things to consider.

20V motors have a better cylinger head, they have a higher thresh hold on detonation. The 20V cylinder head has more coolant area above the cumbustion chamber which helps to stop detoanation.

Also consider the 20V piston is higher in compression, so running your standard timing tables in the mid range might be to hot for the compression. This is generally where most hard detonations happen.

I have a 20V motor and have put over 30,000 hard miles on it. I rev it up to 8500 every day and have had no issues. I take it to the track on street tires and it runs 13.4 @ 104 to 105 MPH. The car with me in it comes out to 2470 pounds.