SE204 cams in a 103
6th Gear
Joined: May 2009
Posts: 14
Likes: 0
From: Omaha, NE
I think my fingers got ahead of my brain. I believe I ended up with 9.5:1 compression, but I'll have to see if I can find the paperwork for my head porting. He told me over the phone the chamber volume and I wrote it down, if I can find it, but I'm almost certain it calculated to 9.5:1 with my pistons, head gaskets and chamber volume. Either way, it runs well on premium 91, ethenol blend 89, or 87 regular depending on what I can find. It does however, prefer premium, and delivers best fuel economy and probably a bit better performance using premium.
I have read that the 204's can be a little finnicky with compression. I believe the police bike 103's have the same pistons as the 103 Ultra and they're a tad less compression than the 103" SE flat tops. I'm playing it safe and going with stock head gaskets. According to the Big Boyz calculator at my altitude I'll be at 9.85 static and 9.29 corrected. Should be safe with most varieties of premium gas...
Last edited by troop; May 23, 2010 at 11:26 AM.
I have read that the 204's can be a little finnicky with compression. I believe the police bike 103's have the same pistons as the 103 Ultra and they're a tad less compression than the 103" SE flat tops. I'm playing it safe and going with stock head gaskets. According to the Big Boyz calculator at my altitude I'll be at 9.85 static and 9.29 corrected. Should be safe with most varieties of premium gas...
I went ahead and changed lifters and put in the baisley spring while I was in there. Running straight 50w dino oil, and the valve train is quieter than it was prior to the change.
I'm sure there's lots of cams that make more power than these do, but I really like the way these ride.
Thread
Thread Starter
Forum
Replies
Last Post
