engine and drivetrain Toyota 20R piston weight and pictures

[PatAllen]

piston with rings=538g

pin= 128g

missing: circlip

this one measure 89,45mm so it is +1mm oversize from the stock toyota spec, so for the BMW engine, if you have a stock piston of 88,97 that means it is 0,48mm bigger than the BMW piston, or sliglty less than 0,01889 thou oversize.

note the recessed crown around the top, the top of the piston (at its highest point) should be zero deck, not the crown.

Note 1: second ring is very thick, perfect for a lot of boost

Note 2: the pin seems to be heavier and thicker than the bmw pin, maybe stronger ? it is 0,001" larger iirc.

[TobyB]

What's the pin height, Pat?

or, put another way, what's the dimension from the

top of the pin hole to the top of the crown?

(that would be easier to measure...)

Cool!

t

[PatAllen]

I am measuring about 1.2140" or 30.84mm.

My measurement is not super accurate. I am measuring about 0,032" of heigh difference over the flat-top next to it.

[TobyB]

ooo, so shorter. Hmmm... wonder if Jeff Ireland's long rods would work.

Thanks for the pic and dimensions.

t

[PatAllen]

ooo, so shorter. Hmmm... wonder if Jeff Ireland's long rods would work.

Thanks for the pic and dimensions.

t

i decked the block on mine to make it zero deck and adjusted the camshaft gear to bring it back to tdc/0. not that much of an issue.

[PatAllen]

ooo, so shorter. Hmmm... wonder if Jeff Ireland's long rods would work.

Thanks for the pic and dimensions.

t

i decked the block on mine to make it zero deck and adjusted the camshaft gear to bring it back to tdc/0. not that much of an issue.

[TobyB]

I found myself looking at the 22r pistons and wondering if an

older (thicker) block could handle the 91.5mm bore....

but they're dished, not crowned. And $150- a set, not a pop!

t

[PatAllen]

I found myself looking at the 22r pistons and wondering if an

older (thicker) block could handle the 91.5mm bore....

but they're dished, not crowned. And $150- a set, not a pop!

t

the distance pin to deck is way off iirc on the 22r

[PatAllen]

ok, i got the exact numbers from one of the parts book i have

20R: distance center pin to top of piston: 1.625, pin diam. .8663, 0,100" dome included in pin distance to top

early 22R (81-84):distance center pin to top of piston: 1.775, pin diam. .8663, 0.250" dome head with recess in center, included in pin distance to top

late 22R (85-95):distance center pin to top of piston: 1.358, pin diam. .8663, recessed head 0,230"

2002: distantce center pin to top of piston (flat top as a reference): 1.665, pin diam. .8662

it seems that early 22R could be used and machined on the top with desired dome...

Disclaimer: THESES PISTONS ARE NOT FORGED. only the ones meant for the 22RTE are, and are of the late style type. the 22r ones are 92mm diam.

weirdo dome pictured is the early 22R. one could easy shave the top/ring dome for desired compression ratio

89,95 for a set of 4 !!!!

http://www.store.partsdinosaur.com/product5.html

[Guest]

4 pistons with rings for 90$ THAT is CHEAP!

[PatAllen]

since they are 92mm stock , i would say they could be used CHEAP for a s14 block/2.3-2.5L conversion...