Piston bowl shape?

[Immortality]

I'm not familiar with the piston you talk about unfortunately.

Yeah I could have just turned mine around and then had to fabricate a whole new neck but it's better to be different. Also, I think your tuned length one performs better than what we have.

 

[2seater]

I have not flow tested one of the plastic ones but the aluminum version in my photo flows a bit less than the stock style, what I call a short ram style. My records indicate 204 cfm for the standard style and 182 cfm for the aluminum TPI. This is flow average per port at 28"wc. It seems to work well with my mild turbo setup of only 4 psi.

 

[losh1971]

Are you wanting to use keith black silvolites they are a very good pistons

 

[2seater]

Are you wanting to use keith black silvolites they are a very good pistons

They are what I generally use for normal rebuilds.

 

[delcowizzid]

The factory pistons in the ln3s take a great deal of boost we are at 23psi no issues over 350kw at the tyres

 

[2seater]

The factory pistons in the ln3s take a great deal of boost we are at 23psi no issues over 350kw at the tyres

Thank you. That's pretty stout and I can only dream of that. My fwd transaxle would likely scatter in many pieces and I was told a couple decades ago the LN3 would spit the crank out at about 500 crank hp. I truly appreciate all the insight. In this case, this was a very low mile engine, 5500mi, that was stored poorly. Water got in through the missing pcv opening and built up in a couple cylinders where the intake valves were open. The crankcase, valley and heads are clean as can be, but the intake ports, intake valves and a couple cylinders rusted. #1 cylinder in particular has a fairly large spot on the minor thrust side that I am in the process of determining if it can be saved. Since it will need new pistons for sure, I was revisiting my options, when I found the Holden piston. The unique bowl shape caused me to question what the purpose is? The compression ratio is sort of middle of the road, 8.6:1, if the bowl volume I received from Silvolite is accurate, 34.7cc., or about 8.82:1 if I have the deck cut a bit to close up the squish distance to the head to about .035". If I understood your nomenclature, this piston is for what you call an Ecotec, similar to our short 8.5" deck Buick 3800 Series II, but quite apparently, not the same.

 

[2seater]

This is a photo of the piston I received from Silvolite. Does it look familiar? My best guess is it is for a supercharged application. What has baffled me has been the dimensions are correct for an earlier engine used here in the U.S. I did notice when reviewing the specs again that the U.S. Series II engine uses a smaller diameter pin but only the N/A version. The supercharged does use the larger diameter pin to match the earlier engines but the compression height is quite a bit lower to match the low deck. I must admit I am confused by the very limited information I can find but I do like the look of this piston.

 

[delcowizzid]

Iv'e seen similar in a couple of customers l27s they have built one took less timing than normal and they other was a skid car for burnouts and threw the piston off the end of the rod at rpm lol.are they just hypertectic cast pistons they tend to explode with boost or any sign of detonation.we got 8 years of boost out of stock rods and pistons before we lost oil pressure on one rod and decided to finish the engine off in a skid comp and build a fresh one as it had hundreds of drag passes on it and had lived long enough lol.

 

[delcowizzid]

 

[Immortality]

That poor little motor got raped till the very end....