engine displacement question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

tim21391 · 10-07-2009, 04:50 PM

ok.. im taking a 302 and boring it .060 and dropping in a 347 stroker kit.. what will that make the displacement be?

Moostifer · 10-07-2009, 05:14 PM

what's the stock bore diameter of a 302?

fiddy9apache · 10-07-2009, 05:21 PM

A 352? I know on a sbc 350 that's .60 is a 357, so I added seven to 347 and got 352, not sure if it correct or not. I will ask one of my turbo mustang buddy, he's building a 347 that's been bored for a customer.

Moostifer · 10-07-2009, 05:21 PM

4.0 std bore + 0.06 + 347 stroke = 355.7 cid

maybe...

cdowns · 10-07-2009, 06:30 PM

60 is a pretty chancy overbore on those small fords// make sure it's sonic checked for core shift etc

Kim57 · 10-07-2009, 06:48 PM

If you know the bore and stroke here is a calculator to give you the answer you want.
Kim
http://www.ajdesigner.com/phpengine/...lacement_b.php

tim21391 · 10-07-2009, 07:19 PM

well its bored .040 and whoever had the car before us mustve not bored it right because its got .001" too much clearance and so to get it perfect we gotta go to .060

fastwillie 696969 · 10-07-2009, 08:04 PM

Quote:

Originally Posted by tim21391

well its bored .040 and whoever had the car before us mustve not bored it right because its got .001" too much clearance and so to get it perfect we gotta go to .060

sleeve it

chevybuldr · 10-07-2009, 09:30 PM

Yea I would have that sonic checked. Ford motors are not very thick at all, unless its a prized mexico block. Better safe then sorry.

*72lb4x4* · 10-07-2009, 10:43 PM

Sorry to be a pain in the butt, but this is barely high school math...

The area of a circle: Pi times radius squared.
Radius is half the bore plus the overbore.
Pi is 3.1414 with most of the decimal places rounded off.

The volume of a cylinder is area times the stroke.

Total cubes is number of cylinders times volume above.

Area x stroke x number of cylinders.

Lots of folks want to use magic numbers, but why bother when the real numbers are simple enough?

The stroke and bore should be easily available but I'm too lazy to google them...

3.1414*((bore+.060)/2)*((bore+.060)/2)*stroke*8=displacement

Edited because I forgot the squared part, and apologies in case the beers are kicking in and I'm being an ass again...

68gmsee · 10-08-2009, 09:08 AM

Quote:

Originally Posted by 72lb4x4

Sorry to be a pain in the butt, but this is barely high school math...

The area of a circle: Pi times radius squared.
Radius is half the bore plus the overbore.
Pi is 3.1414 with most of the decimal places rounded off.

The volume of a cylinder is area times the stroke.

Total cubes is number of cylinders times volume above.

Area x stroke x number of cylinders.

Lots of folks want to use magic numbers, but why bother when the real numbers are simple enough?

The stroke and bore should be easily available but I'm too lazy to google them... 3.1414*((bore+.060)/2)*((bore+.060)/2)*stroke*8=displacement
...

I knew that...

mplex2000 · 10-08-2009, 09:43 AM

Bad, bad, bad idea going .060 on any type of small block.

Go the least you have to. If you have to go 60 to make it usable spend another 100 bucks to get a different block.

SSC's76 · 10-08-2009, 10:16 AM

I wouldent do it. Like mentioned above sleeve it or replace the block! Your gong to spend the $$ on a stroker crank might as well not skimp on the platform (block). The SBF engine block needs alot of support to live when pumping out power. If your planning on making a 350+ crank hp engine and it kinda sounds like you are a valley girdle and main girdle are nessasary. Ive seen first hand several 302 engines crack under pressure. Not to sound negative or biased since this is a gm site but ford small blocks were designed like crap. One positive I can admit since Ive had my hands inside alot of ford engines as long as you have a set of heads on them that flow these engines respond very well even with smaller cams.

Alex1 · 10-09-2009, 06:22 PM

You should be able to score a used 302 for little change. Keep it at 30 over max.

10-07-2009, 04:50 PM	#1
tim21391 Registered User Join Date: Jul 2007 Location: Salina, Kansas Posts: 1,998	engine displacement question ok.. im taking a 302 and boring it .060 and dropping in a 347 stroker kit.. what will that make the displacement be? __________________ 1972 C-10...402/400..flowmaster 40 series 1967 Mustang 347 stroker/C-4 1966 Mustang 289/3-speed 2013 Mustang V6/6speed w/300 ponies I may be 23, but i sure do knows 67-72s are sexy! Its not MPG its smiles per gallon! build started 11/25/08 build thread: http://67-72chevytrucks.com/vboard/s....php?p=2993796

10-07-2009, 05:14 PM	#2
Moostifer a fool with no money Join Date: May 2005 Location: Overton, Tx Posts: 532	Re: engine displacement question what's the stock bore diameter of a 302? __________________ Basicly stock 83 SWB with a few Bolt-ons before, during and still during http://photobucket.com/albums/y251/moostifer/truck/ http://photobucket.com/albums/y251/moostifer/motor/

10-07-2009, 05:21 PM	#3
fiddy9apache Registered User Join Date: Aug 2009 Location: ftw tex Posts: 682	Re: engine displacement question A 352? I know on a sbc 350 that's .60 is a 357, so I added seven to 347 and got 352, not sure if it correct or not. I will ask one of my turbo mustang buddy, he's building a 347 that's been bored for a customer.

10-07-2009, 05:21 PM	#4
Moostifer a fool with no money Join Date: May 2005 Location: Overton, Tx Posts: 532	Re: engine displacement question 4.0 std bore + 0.06 + 347 stroke = 355.7 cid maybe... __________________ Basicly stock 83 SWB with a few Bolt-ons before, during and still during http://photobucket.com/albums/y251/moostifer/truck/ http://photobucket.com/albums/y251/moostifer/motor/ Last edited by Moostifer; 10-07-2009 at 05:23 PM.

10-07-2009, 06:30 PM	#5
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: engine displacement question 60 is a pretty chancy overbore on those small fords// make sure it's sonic checked for core shift etc __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

10-07-2009, 06:48 PM	#6
Kim57 Registered User Join Date: Aug 2007 Location: Corona, California Posts: 7,998	Re: engine displacement question If you know the bore and stroke here is a calculator to give you the answer you want. Kim http://www.ajdesigner.com/phpengine/...lacement_b.php Last edited by Kim57; 10-07-2009 at 06:53 PM.

10-07-2009, 07:19 PM	#7
tim21391 Registered User Join Date: Jul 2007 Location: Salina, Kansas Posts: 1,998	Re: engine displacement question well its bored .040 and whoever had the car before us mustve not bored it right because its got .001" too much clearance and so to get it perfect we gotta go to .060 __________________ 1972 C-10...402/400..flowmaster 40 series 1967 Mustang 347 stroker/C-4 1966 Mustang 289/3-speed 2013 Mustang V6/6speed w/300 ponies I may be 23, but i sure do knows 67-72s are sexy! Its not MPG its smiles per gallon! build started 11/25/08 build thread: http://67-72chevytrucks.com/vboard/s....php?p=2993796

10-07-2009, 09:30 PM	#9
chevybuldr Registered User Join Date: Oct 2008 Location: Livermore ca Posts: 699	Re: engine displacement question Yea I would have that sonic checked. Ford motors are not very thick at all, unless its a prized mexico block. Better safe then sorry.

10-07-2009, 10:43 PM	#10
72lb4x4 Account Suspended Join Date: Jul 2006 Location: DFW Posts: 1,427	Re: engine displacement question Sorry to be a pain in the butt, but this is barely high school math... The area of a circle: Pi times radius squared. Radius is half the bore plus the overbore. Pi is 3.1414 with most of the decimal places rounded off. The volume of a cylinder is area times the stroke. Total cubes is number of cylinders times volume above. Area x stroke x number of cylinders. Lots of folks want to use magic numbers, but why bother when the real numbers are simple enough? The stroke and bore should be easily available but I'm too lazy to google them... 3.1414((bore+.060)/2)((bore+.060)/2)stroke8=displacement Edited because I forgot the squared part, and apologies in case the beers are kicking in and I'm being an ass again... Last edited by 72lb4x4; 10-07-2009 at 10:46 PM.

10-08-2009, 09:43 AM	#12
mplex2000 Registered User Join Date: Jul 2005 Location: DFW Posts: 463	Re: engine displacement question Bad, bad, bad idea going .060 on any type of small block. Go the least you have to. If you have to go 60 to make it usable spend another 100 bucks to get a different block.

10-08-2009, 10:16 AM	#13
SSC's76 No No Join Date: Jun 2005 Location: Pueblo Colorado Posts: 1,781	Re: engine displacement question I wouldent do it. Like mentioned above sleeve it or replace the block! Your gong to spend the $$ on a stroker crank might as well not skimp on the platform (block). The SBF engine block needs alot of support to live when pumping out power. If your planning on making a 350+ crank hp engine and it kinda sounds like you are a valley girdle and main girdle are nessasary. Ive seen first hand several 302 engines crack under pressure. Not to sound negative or biased since this is a gm site but ford small blocks were designed like crap. One positive I can admit since Ive had my hands inside alot of ford engines as long as you have a set of heads on them that flow these engines respond very well even with smaller cams. __________________ 1976 Custom Deluxe SWB Med FMB.3/4 Drop. Gen VI 454, Muncie HD 3 speed With Modified OE Hurst Shifter, 3.73 12 bolt, GMPP HO roller cam, Hooker headers, Performer intake with modified Q-jet, Accel distributor. Best 1/4 12.3 @108. Funnest run 19.84 @88 full 1/4 mile burn out. 1997 K1500 ext cab 5.7 stock except muffler

10-09-2009, 06:22 PM	#14
Alex1 Registered User Join Date: Jul 2007 Location: Ottawa Ontario Canada Posts: 1,156	Re: engine displacement question You should be able to score a used 302 for little change. Keep it at 30 over max.



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