diek421

Yeah, I talked to Kevin at HJR. I'm probably going to send the jugs out to him and have him do the work. Trickedcarbine, you hit it on the head. My local guy is a very knowedgable builder and does great work but its mostly on mx bikes and 4 strokes. Thanks for the suggestions, guys.

Thanks for the replies guys. I forgot to mention, I already have a pro design cool head. So I understand the idea of swapping domes. I just want to understand the implications of cutting the domes vs running a spacer plate. I'll talk to my builder and see if he is familiar with porting to match a 4mm crank and go from there.

Hey guys, long time lurker, first time poster. My latest project is to build a stock cylinder (stock bore and port), 4mm stroker motor. I've owned several banshees in my time but never built a stock cylinder 4mil. I've done some research and thought I knew what I wanted/needed but I need some confirmation from BHQ. Here is what I've gathered from researching: To run a stock length rod (110) 4mm crank you can run regular pistons but you'll need to get cut domes or run a spacer plate. To run a long rod (115) 4mm crank you must run 795 pistons (modified pin height) with either cut domes or spacer plate. I talked to a local builder and he suggested the first option: stock length 110 rod 4mm crank with regular pistons and a spacer plate. I understand the advantages of a long rod crank (decreased rod angle) and will probably opt for this option. I will also be getting a mild trail/woods port. What I don't understand is the advantages/disadvantages of running cut domes vs a spacer plate. I've read at least 50 posts in which people dismiss the spacer plate because it introduces another "leak point". While this may be true, it doesn't matter to me. It's just another gasket surface. If properly installed, it will be no less reliable than any of the other seals. I've also read another handful that say the spacer plate looks ghetto or tips other off others as to what is done to the machine. Again, neither of these arguments matter to me. I want to focus solely focus on the performance aspects of both options. The only difference that I can see between the spacer plate and the cut domes would be where you gain the extra 2mm clearance needed. Using cut domes would add the 2mm of clearance above cylinder ports while adding the spacer plate would add the clearance below the ports. I can't help but think that one over the other has an effect on the performance of the motor. So, can anyone offer any valid arguments (and back it with some kind of evidence) for running cut domes over a spacer plate or vice versa? I'm about to dump a considerable amount of money into this and just want to make sure I'm getting the best option. Thanks.