Bore or stroke

I want to go from 540 to 572. Currently 4.50 stroke and 4.375 bore.
Pro's and con's on which one to do it with ??

 

bore + stroke

pistons are cheaper.

 

I assume that bore is a typo, that only gives you 425 inches.

 

4.5 and 4.5 =572 you are already half way there.

 

Ok guys, i know how to do it, i'm looking for opinions on the performance/life difference's between doing it with bore or stroke. Thanks

 

from what I understand the chy doesn't make any better power with the bigger bore. I think because the smaller bore center to center ends up with a thinner wall. The Arias/Fontana with the chevy bore center will have stronger cyl walls. I know some of the MBR billet blocks have 4.6 bores. I would think the bigger bore would unshroud the intake valve some, if that's any gain??

 

i dont think you need that cubic inch if its a blown motor if you need more hp add more boost are a better blower if im thinking right its a lot of rotating mass to sling around and not as high of rpms im thinking smaller cubic inch more rpms more boost more hp

but what do i know just my 2cents and i dont have any friends so i get on here and post comments cause im bored (lol)

 

It would help to know what your present combo is and what you're using it in. T/D, Class, dragboat, monster truck, tractor pull. What rpm do you want to run, do you have a Hemi-Chevy-Ford? Is it a standard cam block? If so 4.50" stroker is about your limit. Oversize OD sleeves? If not then 4.50 bore is pretty risky for a blower setup. A little more info will go a long way, because there is no cut and dried answer to your question.

 

TWD truck pulling. want to turn 8 to 9000. BAE hemi, raised cam, .100 tall, #5 heads, K11 superman, 40-45 lbs @ 50%

 

A raised cam block gives you a little more leeway on stroke, I'm running 4.625" in mine, with right profile on rods you might go as much as 4.750" without getting into clearances issues. I know of bigger strokes in N/A engines but using smaller(less bulky) rods than a blown/alky rod. I don't know if you meant BAE block and don't know their sleeve dimensions, but the oversize KB sleeve is 4.700", which at 4.500" internal bore leaves you .100" sleeve thickness, which is the absolute bare minimum in my opinion for a blower motor. The standard KB sleeve dimensions escapes me but it seems like its 4.620", so a 4.50" bore would really be thin. As far as valve shrouding, a smaller bore isn't near as big an issue on a Hemi as it is on a wedge/pro stock style head since the valves are aimed at the center of the bore. JMHO

 

That is not 425 cu.in. it is about 540, I would go for bore over stroke, valve unshrouding is not the issue, blower motors make alot of torque anyway so a longer stroke is not needed. the longer the stroke the more rod angle which is a no no, also you will be sacrificing top ring land thickness, more bore is the ticket.

 

If I had quoted his post, it would have showed the original numbers on bore X stroke that he listed. If you'll notice, he edited his post when the mistake was pointed out. He originally posted the bore at 3.875".

 

I apologize, whoa ! 3.875 ? Yeah that would be a little small.