Sirius wrote:
That's a reasonable amount of miles although not massive so not really possible to draw any great conclusions although its interesting.
Something from your previous post did catch my eye as well:
TBDevelopments wrote:
If you really look at what's available these days, there clearance and material specs are all extremely similar and negligible.
Really?
Most CP's are made from 2618 Alloy but pistons made from 4032 Alloy are also widely available from manufacturers (including CP). These materials are massively different. The aluminium is alloyed with different elements, so to say they are extremely similar??
yes but if you look at the expansion rates between the 2 units and what's is suggested by the manufacturer then they are very similar the high silica alloys being recommended in the 0.0027" and the low silica stronger units in the 0.0035" which are actually still within Toyota specs for a OEM piston.
Now the test i did was between a high and low silica piston, the low silica was the normal 2618 alloy, and then the high silica was a tweaked 4032 setup that gave a 0.0012" clearance. nearly 2.5 times smaller than the off the shelf 4032 alloy. I know 60k isn't a huge amount of miles but its more than enough to see how the pistons are wearing in the bores, skirt witness marks etc. and between the 2 extremes they was negligible differences.
now remember there isn't even a piston off the shelf that uses that material i tried so really between the 2 extremes of modern day piston setup of 2618 vs 4032 your talking 0.0008" difference in expansion rates. But the high silica are more prone to cracking by definition alone.
This is why I said with modern day forged piston materials its more important to go via design over advertised material specs. Long gone of the days where high silica was 0.0027" and stronger high silica was 0.0075" (where you compromised longevity for strength) As I said earlier I've used the 0.0035" CP piston in engines running 950bhp at 9500rpm and 2.7bar of boost pressure without issues.
There also isn't a huge difference in design between all the brands on the market place, none are comparing full length to cut back skirts or ultra lightweight etc.
So there isn't a night and day differences, I just found wiseco a little noisy, and wossner has a weaker skirt in some of the applications i was using. where with CP i've never had an issue from any piston, plus they work along side me with some development work i've had done where the others weren't very interested so i've just stuck with those pistons for the engines i build as i feel i can trust the product. But i woudln't flat out refuse to use the other brands if people asked me to.
Tim
TB Developments