I'm building a motor for a new bike (I don't have it yet, more to come on that one later). Decided to build with the 212 predator (60363) I got with a coupon for $99.00 at HF. It's nothing too wild, but here's the plan so far.
Black Mamba cam 0.275" lift, 26# springs
Bullfrog's pop-up piston
+ 0.020" billet rod (piston is 20-22 thousandths in the hole now)
0.027" head gasket
SK100 billet flywheel
22mm Mikuni
24" X 1" OD header
Going to stud the head & side cover to make things easier. If I have to take things apart to make changes, it won't strip the block with too much torquing & running fasteners in and out. The aluminum is pretty soft & I found some good threaded rod at my local supplier to make the studs. They had the flange washers as well.
Target is a motor that will turn 7500 rpm, be fairly reliable & (hopefully) durable. Building more for top end than drag racing at this point. I've done a little bit of porting on the head, nothing drastic, just knocking off the hard corners & edges to increase air flow & hopefully let it breathe easier on the top end. Lapped the valves & using stock rockers so I don't have to worry about the rocker arms giving up unless I go over my target rpm limit. Not running ratio rockers on this motor as it's a first attempt for me at building. At some point this could change....
I'm just starting on the project, so there isn't much to show in the way of progress yet. Will post more as I go. The motor was run at the factory & that's all. It'll be run-in once I get it assembled & finished. Here's the head as I got it when it was taken off.
The intake runner opened up & radiused just a bit
The seats lapped in the head
Valves showing marks on the faces from lapping, about right from the factory on this part of things
I've sent for a few parts & am waiting to get started.
Black Mamba cam 0.275" lift, 26# springs
Bullfrog's pop-up piston
+ 0.020" billet rod (piston is 20-22 thousandths in the hole now)
0.027" head gasket
SK100 billet flywheel
22mm Mikuni
24" X 1" OD header
Going to stud the head & side cover to make things easier. If I have to take things apart to make changes, it won't strip the block with too much torquing & running fasteners in and out. The aluminum is pretty soft & I found some good threaded rod at my local supplier to make the studs. They had the flange washers as well.
Target is a motor that will turn 7500 rpm, be fairly reliable & (hopefully) durable. Building more for top end than drag racing at this point. I've done a little bit of porting on the head, nothing drastic, just knocking off the hard corners & edges to increase air flow & hopefully let it breathe easier on the top end. Lapped the valves & using stock rockers so I don't have to worry about the rocker arms giving up unless I go over my target rpm limit. Not running ratio rockers on this motor as it's a first attempt for me at building. At some point this could change....
I'm just starting on the project, so there isn't much to show in the way of progress yet. Will post more as I go. The motor was run at the factory & that's all. It'll be run-in once I get it assembled & finished. Here's the head as I got it when it was taken off.
The intake runner opened up & radiused just a bit
The seats lapped in the head
Valves showing marks on the faces from lapping, about right from the factory on this part of things
I've sent for a few parts & am waiting to get started.