What's my cubic inch?
 

If my bore is 3.328 with a 4" stroke, is my motor 278.xx ci or am I missing something?
Thank, Joe

Re: What's my cubic inch?
 

278.36

Re: What's my cubic inch?
 

Thanks Tony!

Re: What's my cubic inch?
 

It is the volume of a cylinder - (pi x r sq) X stroke OR (pi x d/2 sq) x stroke.

3.328/2 = 1.664 sq = 2.769 x pi = 8.699 x 4.00 = 34.795 which is volume of one cylinder so x 8 = 278.36

Re: What's my cubic inch?
 

Or just do what I do . . . as I'm lazy . . .

http://www.wallaceracing.com/cid.php

Re: What's my cubic inch?
 

.

This is the way I've been figuring it since I first started reading "Hot Rod Magazine" around 1961.

Bore X Bore X Stroke X .7854 X Number of Cylinders.

3.328 X 3.328 X 4 X .7854 X 8 = 278.36 Cu. In.

Re: What's my cubic inch?
 

Yep, there are always short cuts.

Re: What's my cubic inch?
 

Thanks everyone!

Re: What's my cubic inch?
 

3.328?????? 3.312= 3 5/16. 3.328 = 3 5/16 +.016. Strange bore?
Gramps

Re: What's my cubic inch?
 

Cylinder wear?

Re: What's my cubic inch?
 

3.328/2 = 1.664 sq = 2.769 x pi = 8.699 x 4.00 = 34.795 is volume of one cylinder so x 8 = 278.36

Re: What's my cubic inch?
 

I've seem pistons for 3 5/16" (3.3125") and 3 3/8" (3.375") but 3.328" not so much.

Re: What's my cubic inch?
 

Ron, Unfortunately, Gary (GOSFAST) is no longer with us for me to ask him.
I do remember him telling me he wanted to keep the bore as tight as possible and not remove to much material because it's a blower motor.
There's a note on my paperwork that says "8BA-Std Bore-Needs O/B (.040")
I hope this makes sense. Thanks Joe

Re: What's my cubic inch?
 

3-5/16" (3.3125") is a standard overbore. IF your bores actually measure 3.328", that means that you're going to have roughly 0.016" PISTON CLEARANCE in each bore, which some of us are finding a little hard to understand.....IF the pistons ARE actually 3-5/16" pieces.

Are you sure that your bore isn't 3.228" rather than your stated 3.328? That would make sense as a +.040" oversize. DD

.

Re: What's my cubic inch?
 

Quote: "Are you sure that your bore isn't 3.228" rather than your stated 3.328? That would make sense as a +.040" oversize. DD"


...in which case your displacement would be 261.88 cu. in. :)


Terry

Re: What's my cubic inch?
 

Sounds like it is just .040 over to me . . .

Re: What's my cubic inch?
 

Pistons can be cut down and new ones can be custom made but Egge does make some larger oversizes than 3.3125" in the Mercury type 4-inch stroke. No telling what Gary came up with.

The Egge 3-ring pistons go up from .125" oversize in .010" increments.

Re: What's my cubic inch?
 

V8, I believe you're onto something! I just found paperwork for my compression numbers from Gary and it says the bore is 3.228!
Thank you! Joe

Re: What's my cubic inch?
 

I miss Gary, bought a Stricker assy from him a few years back, still running fine. Ses if your gona run allot of boost it's best to keep a thicker wall. 10 lbs of boos will do more for power then a large Overbore. Have a 294 blower motor putting out 235 hP on 4 lba od boost at 4500. Makes a nice street machine, Wonder what it makes a 5k, but he shut the beast down to sabe it. #$$$$$$$

Re: What's my cubic inch?
 

Ron, I run this motor up to 5500 rpm with 8 lbs. of boost all the time!
Air/fuel is 12.3 at WOT at that rpm
Thanks
Joe