i have seen some 489s and 496s make good power but imo the best bang for the buck is bigger bore vs bigger stroke.it unshrouds the valves and helps airflow.

OP regardless of price I would steer clear of a 454 with a 4.340 bore. Sounds like a very worn out motor to me.

I just noticed that as well. Yea I would stay away from that setup. If it's a chevy block it's dunzo..

I noticed this at first but thought it may have been a typo and I would let someone else comment about it. Since it went 3 pages and not a mention of it thought it better to. With that said. There are some old 427 tall deck blocks that will go 4.600 it's only certain block numbers that will do it. But that's old school stuff and not really worth the effort in my opinion.

Hmm... you guys are throwing in a lot of assumptions. lol Nobody ever said anything about a used engine... or a 454 bored to it's limits.

Let's not let or imaginations get carried away, try to stick to the scenerio in question... This is a STROKE vs. BORE thread, not "Factory 502" vs. "Worn out 454 stroker" comparison. Strictly speaking... I was looking for opinions on how to make power... stroke or bore. I guess I could've used different measurements to make it more realistic to what i'm looking at, but the 502 cid seems to be the most common stroke vs. bore comparison i could come up with for this thread.

Thanks everyone for your input. I still enjoy all the other considerations.:popcorn:

Mike Tkach happens to have one of those sitting around he going to build something out of. Old 427 tall deck 4 ring truck block .

there are many variables that need to be addressed such as compression ratio, cylinder head flow, cam profile... etc.. intended usage.. but IMO bore size influences HP while stroke influences torsional twist (torque).. again this is a general vague statement... many factors unanswered

You said availible for purchase, that sounds used to me... If not then post more detailed info and it does seem the bigger bore is a better choice over stroke, you left many variables on the table for us to assume or guess at.

Bore stroke
 

BIB,

We performed simulations to gather data addressing your questions. Both are based on a BBC.
The example engines were;

Big bore / short stroke;

Bore __4.500”

Stroke_4.000”

Rod length_6.385

Rod Ratio__1.596

Displacement__508.939 CID


Small Bore / Long Stroke;

Bore__4.365”

Stroke__4.250”

Rod Length__6.784”

Rod Ratio__1.596

Displacement_508.789 CID

Rod lengths adjusted to equalize the rod ratio variable.

When comparing the peak piston velocity data stream from both engines the long stroke is

6998.3 FPM
Vs
6586.6 FPM_____ for the short stroke.

While the piston speed is 6.25% higher (+411.7 FPM) in the long stroke engine, all other parameters, including CFM demand at the intake and cfm demand at the piston crown are identical in both engines. Airflow requirements are the same.
This would dispel the myth that long stroke engines and higher piston speeds “eat up head flow and camshaft” at a greater rate than short stroke engines. Airflow demand is based upon swept volume and RPM

It would appear the tradeoffs of bore unshrouding vs. frictional loss etc. would result in a zero sum game however the answer wasn’t that straightforward.

Bob

Swept volume is swept volume... no ifs and or buts about it... the bore size vs stroke question I understood to be 4.470/4.00 vs smaller bore vs longer stroke... the 4.470 would allow for better flow and with that being said!! WTF put a 4.250 crank in it too... these's no replacement for displacement!!! says the oldest guy in med school