Any idea why the valve came apart? I was thinking about portin my 250x head as well, but now I'm skerd! Could the piston/valve timing change somehow allowing interferance?
Porting my Head
Ok guys I have an extra head for my quad actually everything but the crank to build another engine. I took the head to the shop today and bead blasted all the funk off it it looks like a new head now. I taped up the top and bottom faces so the beading wouldn't pit them.
I will be porting the head next week sometime, after I finish my homework first, I'm carrying it to a local machine shop to have it Flow tested stock so I'll know where I'm at on factory CFM specs. Then it's off to the workbench and die-grinder dremel. I have done old V-8 heads so this one should be fairly simple. there is alot of casting defects to remove on the intake side and where the intake mates to the head I can see about 1.5 to 2 mm of the head so port matching that will be first. the exhaust side is pretty much the same way but I'm only going to drum sand the port and opening to clean it and reshape the exit to match the copper exhaust bushing. I will post up some progress pics as soon as I start.
I will be porting the head next week sometime, after I finish my homework first, I'm carrying it to a local machine shop to have it Flow tested stock so I'll know where I'm at on factory CFM specs. Then it's off to the workbench and die-grinder dremel. I have done old V-8 heads so this one should be fairly simple. there is alot of casting defects to remove on the intake side and where the intake mates to the head I can see about 1.5 to 2 mm of the head so port matching that will be first. the exhaust side is pretty much the same way but I'm only going to drum sand the port and opening to clean it and reshape the exit to match the copper exhaust bushing. I will post up some progress pics as soon as I start.
161 - 162 of 162 Posts
AHHHH Don't be skerd bro..lol my issue was entirely my fault. I cheaped out on it, I reused the valves that were in it and one of the exhaust valves had some fatigue on it and I must have missied it. but it was obvious when I picked it up off the top of my piston..lol I'm actually in the process of doing another one right now but this one is getting everything new.
161 - 162 of 162 Posts
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