Capacity when re-bored?

[Neilmac]

Just out of interest, does anyone know how to calculate the cubic capacity of a 1340 engine when it has been re-bored at +30?

[Strawhead]

I believe that

+ .010 = 1342
+ .020 = 1345
+ .030 = 1353
+ .040 = 1361
+ .050 = 1369

according to an old manual i had, could be wrong though

[Neilmac]

Thanks Strawhead, I appreciate your quick response.

[Limey_Dave]

Originally Posted by Neilmac

Just out of interest, does anyone know how to calculate the cubic capacity of a 1340 engine when it has been re-bored at +30?

Displacement=1.571 x BORE X BORE X STROKE

CUBIC INCH X 16.387 = CC

Example
BORE 3 1/2"
STROKE 4 1/4"
+0.030"

1.571 x 3.530 x 3.530 x 4.25=83.198cu" x 16.387 = 1363cc

Check your own bore and stroke.

I'm amazed these new fangled engines run at all with upside down valves.

[grbrown]

The volume of a cylinder is: = π x (diameter)² ÷4 x stroke.

Writing that longhand: pi x (diameter squared) divided by 4 x stroke.

According to my workshop manual the standard bore is 3.498 inches, or 88.8 mm (= 8.88 cm), + .030 is 3.531 inches (x 2.54 = 8.97 cm) and stroke is 4.25 inches, or 10.80 cm.

So a standard Evo cylinder is 3.142 x (8.88 x 8.88) /4 x 10.80 = 668.5 cc

There are 2 of them, so total capacity = 1,337 cc

+.030 oversize cylinder is 3.142 x (8.97 x 8.97) /4 x 10.80 = 682.6

So the answer to Neil's question is: 1,365 cc.

[Neilmac]

Wow! - Thanks for that

[grbrown]

Originally Posted by Neilmac

Wow! - Thanks for that

Neil,

It's a pleasure!