I recently purchased another 109 long block. I'm trying to decide whether to go with a forged stock stroke or stroker. I am looking at the kits from GN1. Is there really any down side to stroking with a 109 block? I understand maybe a little less rpm. Is there any major block clearancing that needs to be done? (I intend to do a girdle) Bad rod angles? I saw different rod lengths, how should I pick one?
Based upon our experience of building many 3.8 and 4.1 with a stroker crank, I will try to answer your questions best as possible.
One downside could be a small base circle billet cam will be needed if you are going all out for performance as you will need a high lift cam. You should be able to get 600 HP at the wheels with a normal cam.
There is more assembly labor required as the rotating assembly must be mocked up once or more to assure there is no interference.
As far as "bad rod angles" there really is no such thing in a Buick V-6, at least in all the engines we have built and worked on there has never been any indication of excessive wear on the piston or cylinder wall due to rod ratio? As far as any gain in HP, you could never measure any difference.
We prefer a stock length rod as it allow the pin to be lower in the piston.
I do not know what you mean by "a little less rpm"? Our stroker engines will RPM as much as a 3.8, and one of my personal stroker engines will pull to over 8000 RPM.
Added displacement is always a plus in making more HP, but until you get above the "normal" range, especially on the street, you will see very little increase.
