I have various seen opinions on this subject, but no real data to back it up. The little I have seen posted always includes other mods and upgrades which will not give a valid comparison.
As far as major gains, I have not experienced any by stroking the V-6 Buick. The little increase I found in the high 9's was about a tenth in the 1/4 mile.
My first build on the TA alum engine was a 3.625" BMS stroke crank. When that crank broke at the no.1 rod journal, I installed a China stock stroke forged crank to do some durability testing which lasted 2 years. Then went back to a 3.625" stroke. All these builds had the same heads, turbo, cam and compression.
This is where I come up with only a small difference in power. My RPM's are always in the high 6000's where it would be most beneficial.
With the Buicks, the spool I have experienced in short stroke vs. longer stroke has not been any different? Only have a few GN comparisons, but personally could not tell any difference, and I run lots of races with .4ths pro tree. :smile:
Also, I have "messed" with a few 4.1 production blocks which were street/race builds and they have ALL shown major increases in torque and HP, and I have verified numbers from track experience too. In the bore vs. stroke contest, bore will win in the turbo Buick world. :biggrin:
Certainly, more cubes will give you more power, but not major from stroking a 3.8 when playing on the street, and only a little at the track unless you get into the higher RPM range.
Just a side note, when I removed the China crank after almost 300 runs, it looked and checked out as good as when installed.
My next build will be back to a stock stroke crank, as I do like the response better for racing.
