hello my Scooby pals
ive been trying to find out what piston type belong to what engine
i have type A in my v3 STI engine
but in another engine i have:-
1 x type A MR2
1 x type A L72
1 x type B L72
1 x type B ME2

any wisdom would be appreciated

 

Wouldnt worry too much about the MR2/L72 codes as they are batch codes.
Compression Height,shape of the crown/Crown ID marks and cast or forged would identify what engine they came out of.

Failing that, post some pics up


Mick

 

they are in the engine. i dont want to sell the short block if the pistons arent right thats all

 

i just managed to find out:-
The "B" piston has an outer diameter of 3.6211 to 3.6214 inches

The "A" piston has an outer diameter of 3.6214 to 3.6218

This way you can select an "A" or "B" piston to get the correct piston to sidewall clearance. Measure the bore, do the math, and select the correct piston for that bore

lol 3 tenths of an inch, that is mad!

 

i think you will find that is 3 thou, not 3 tenths.

 

Isn't it 3 ten thousanths of an inch?

 

no its 3 thousandths of an inch. after the decimal point it runs

1/10
1/100
1/1000

the difference between 3.6211 and 3.6214 is 3 thousandths

 

Surely

.6 = tenths
.62 = hundredths
.621 = thousandths
.6211 = ten thousandths
.6214 = ten thousandths

so .6214 - .6211 = .0003

i.e. 3 ten thousandths

is that not right?

 

im an engineer so here goes - 0.1 is 100 thou. 0.02 is 20 thou. 0.003 is 3 thou. 0.0004 is 4 tenths. I was right.

 

Me too. I think he misunderstood your earlier post as 1/10 instead of your abbreviation for 1/10,000.
I agree with you, how mad is that? The piston rings should handle that difference quite easily.

 

oh i see. Ye that is mad. Sod honing someones bores. Lol just realise what ive just said :O

 

on looking at it again, you're right. it's 3/10000. so used to working in 1/1000s. i think 3/10000 is pretty close not to worry.

 

Whats the difference between 3.8277 and 3.8280?

 

that would be 3/10000s you smart **** ****. i apologised, it was a mathematical genius' moment of weakness. what mechanics work to ten thou of an inch anyway?

 

toooo many 0s to be meaningful. (Unless it was £££!).

 

Now now