CP Piston's X-Forging... Awesome! (Custom 1UZ)

**timbosaurus** · 26-09-2009, 06:16 PM

Ed, I'm also unfamiliar with the 2UZ (and can't read your members only thread

), do you think the 1UZ heads are a better design than the 2UZ? In other words, if you didn't already do the work on yours, would you use 1UZ or 2UZ heads on the 2UZ block next time?

Those pistons kinda remind me of the BMW F1 Pistons of some years ago! They look great.

ed · 26-09-2009, 06:23 PM

the 1uz vvti heads, and the 2uz heads are basically identical, with a few minor differences such as the combustion chamber dia etc. the ports and valve sizes, tho, are exactly the same, and flow the same.

the std 1uz (non vvti) heads, on the other hand, are crud compared to the heads mentioned above. although they are by far the more common head available, they have smaller valves, crappier port sizes and shapes, and even when ported, only just catch up to unported 1uz vvti/2uz heads. thats not to say they cant flow more, but its a bit of an epic effort to get those heads to really impress. the other cool thing with the vvti/2uz heads is they run a shim under bucket lifter from factory, which is a no brainer for anyone looking for big lift, big rpm cams

ive got the 1uz vvti heads, AND ive ported them and done other machine work to them. so no gain to me whatsoever to use 2uz heads (if you can find them) except for the slightly better matching combustion chamber size... but the pistons fixed that anyway, and now ive got an extra squish band

**Sam_Q** · 26-09-2009, 09:30 PM

so basicly the best combination of everything. It sounds like a total beast your building there. So how are you going to reduce the stroke?

**fixeruperer** · 26-09-2009, 11:10 PM

get a girlfriend....... (bom tish) bahaha

**Celica RA45** · 27-09-2009, 10:34 AM

hi edd 1 question on the fly cut inlet side at its deepest how close is this to the no 1 top ring land .and 2 how thick is the fly cut to the under side of the piston

ed · 27-09-2009, 10:54 AM

from deepest part of flycut to underside of crown is about 5-6mm (the forging has a bulge on the underside where the flycut is.

relative to the #1 ring land... at the closet point that i can see, it gets within 2mm of the very inside top corner of the land

**jeffro ra28** · 27-09-2009, 10:58 AM

That seems close!

**Celica RA45** · 27-09-2009, 11:19 AM

well at least there not ross pistons where the top came off on the inlet side and he had 1.5 mm from top ring down to inlet valve fly cut and the piston only had 3mm from fly cut to the under side ,so these should be ok

ed · 27-09-2009, 11:23 AM

yea, just remeasured, its pretty much 2.0mm from the deepest, closest arc of the flycut to the inside top corner of the land. its only that close over a very short arc as the flycut 'turns away' from the land quite quickly

**jeffro ra28** · 27-09-2009, 01:25 PM

Arias pistons are also shithouse in that regard, depending on what engine make of course.

Should be fine unless some chronic detonation occurs.

ed · 28-09-2009, 09:27 PM

no detonation please!

**The Real Roadrunner** · 29-09-2009, 01:11 AM

Originally Posted by oldeskewltoy

heh...... I'm not expert, but recently had a few similar issues

1) concerning the pins.... it depends on how long you want/need this engine to run. titanium were 44 grams. Problem is the titanium would eventually gaul(30k+ miles)

Hmmmm,

That should give Ed about 4 rebuilds then, i say go for it