351W .30 over bore = ?

A .030 bored 351 is 357cid.

Tim

A 351 bored .030 over will give you about 5 extra inches. So you'd wind up with a 356. Just for reference, a 302 would go to a 306, and a 460 would go to a 466.

and a 351W bored .060" over will give you 362ci of hot running, thin cylinder wall, overheatin' fun

Ditto on the 356.

3.5 stroke x 4.030 bore rounds up to 357 cubic inches. (unless you remove all floating points, of course, which is against standard mathematical rules)

You actually gain more cubic inches from boring a motor with a longer stroke than you do by boring a motor with a shorter stroke, but it's not usually a big difference.

If you increase the bore of a motor by .030" which has a 2" stroke, you will only gain 3 cubic inches of displacement. While boring a motor by .030" which has a 5" stroke will yield an increase of 7 cubic inches. (rounded up, when applicable)
Of course, that difference, while remaining proportionately similar, becomes far more apparent(and valuable from a performance perspective) when you further increase overbore:
2" stroke x +.100" = +11 cubic inches.
5" stroke x +.100" = +25 cubic inches.

By the way, why not take a jab at the imports and put 1.9L (x3) on the cowl?

AND more compression too

http://www.edelbrock.com/automotive/math.html


Formula for CID (cubic inch displacement)
CID = NUMBER OF CYLINDERS x SWEPT VOLUME


Note: CID = N x 0.7854 x bore x bore x stroke (all in inches)

Example: What is CID of a V8 with a “30 over”, 4 inch bore and 3.48 inch stroke?

CID = 8 x 0.7854 x 4.030 x 4.030 x 3.48 = 355 cu. inches


or you could use Volume = Pi X r(squared) X H




About Compression Ratio

Formula for CR
CR = COMPRESSION RATIO = CYL. VOLUME @ BDC ÷ CYLINDER VOLUME @ TDC


= 1 + (SWEPT VOLUME ÷ VOL @ TDC)
= 1+ (0.7854 x BORE x BORE x STROKE) ÷ (CCV + HGV + PDV)
CCV = Combustion Chamber Volume, in cubic inches

Note: if volume is given in cc’s then ÷ 16.4 to get cubic inches.

HGV = Head Gasket Volume, in cubic inches,
= Head gasket compressed thickness x 0.7854 x bore x bore
PDV = (Piston Deck Volume) + (Piston Dome Effective Volume)
= (0.7854 x bore x bore x deck to piston distance) + (volume of piston depressions - volume of piston bumps)

Example: What is CR of the engine in #9 if heads have 72 cc chamber, head gasket is compressed to 0.040 inch and flat top pistons give 0.025 deck clearance at TDC?

CCV = 72 ÷ 16.4 = 4.39 cubic inches
HGV = 0.040 x 0.7854 x 4.030 x 4.030 = 0.51 c.i.
PDV = 0.025 x 0.7854 x 4.030 x 4.030+ 0- 0 = 0.32 c.i.
CR = 1+ (0.7854 x 4.030 x 4.030 x 3.48 ÷ (4.39 + 0.51+ 0.32))
= 1+ (44.39 ÷ 5.22) = 9.5 CR



http://www.edelbrock.com/automotive/math.html

like I said

77sleeper said:

AND more compression too

Click to expand...

zwhitr said:

CID = 8 x 0.7854 x 4.030 x 4.030 x 3.48 = 355 cu. inches

Click to expand...

You talk like a bowtie boy. That's a bored over 350.

A 351 has a bore and stroke of 4.000 x 3.500

CID = 8 x (pi/4) x bore^2 x stroke
= 8 x 0.7854 x 4.030" x 4.030" x 3.500" = 357 in^3

Johan said:

You talk like a bowtie boy.

Click to expand...

Thems fight'n words.

Check the link I was cut'n and past'n

Edelbrock tends to cater to them there chebbies

on a quiet night you can just sit and here a chevy rust.

357

Hey, in my opinion, the "357C.I." would look the coolest on the cowl anyways.