I read once that overbore to create power is futile when considering cost to gain ratio. The article stated that with no other changes a .030" will net a 1-3hp gain. I believe this was tested in a 350SBC but sure the gains are similar for most engines. Bottom line is yes you can create more power especially with changing compression... but if you plan on keeping compression the same the gain is not worth the money invested. Now on the other hand if the bore needs to be machined then there would be a gain and increase in reliability also.
Ive always wondered, if we were talking horsepower gains of a .030 overbore. Is there more power gained from the additiona displacement or the flow improvement from less 'shrouding'...
I know, we are talking gains on an sub-atomic level here
Unless you going something like 1/8 or 1/4 inch oversize intentionally for more cubic inches, boring the engine a small amount will gain LITTLE power however, it WILL insure that the cylinders are "straight & round" so, the ring seal could be optimum.
Regular everyday engines will leak down past the rings in the 20% range where a decent Hi-Perforormance engine will be under 5%; (usually less).
Ring seal is power ... plain and simple.
I have seen people spend hours porting cylinder heads and skimp on the valve sealing; what a waste. Valve seal is power ... plain and simple.
Moving the cylinder bore wall over .015" as in a simple .030" overbored engine, won't increase flow; at least not within readable error.
Like Randy said.........+.030" over bore is more about making the cyl. right rather than bigger. I.M.O.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
460 Ford Forum
671.2K posts
35.2K members
Since 2006
A forum community dedicated to Ford big block owners and enthusiasts. Come join the discussion about performance, modifications, horsepower, tuning, build specifications, and more!