Guys,

I'm looking for a little help with valve train noise that I now have after a cam change. The bike is a 93 Fatboy that I bought used. It has10 to 1 Wiseco pistons and ported heads (not sure who did them). When I pulled itapartI found a Crane FB 316 cam, Jims Powerglide lifters, and what I think areCrane adjustable push rods. The cam had wear on the journal at the bearingend and two of the lifters were rough when you turned the roller. The valve springswere after market but I wasn't able to determine a manufactuer.The bikewould have a slightvalve train noise every once in a while when hot.The head gaskets were leaking a little oil so I pulled the heads off. One of the cylinders lifted off the case, soI pulled both to replace the base gaskets.

Here's the parts I used. V-Thunder EVL-5010 cam, .244 at .053 with .585 lift, V-Thunder springs good to .675 lift, new torrington bearing, two Jims Powerglide lifters and Cometic gaskets. I removed the gear from the old cam by heating it with a torch and then installed it on the new cam which was frozen. I had to clearance the rocker boxes because the new springs are 1.50 diameter. The springs have plenty of clearance at max lift. The rocker arms are not contacting the retainers and the retainers are not contacting the valve guide seals.

When I started the bike it had a fair amount of valve clatter. The lifters pumped and the noise quieted but was still there. If I reved the bike it got louder. I re-adjusted the push rods but the noise was still present. Pulled the rocker boxes off and did a visual inspection and found nothing out of the wrong but clearanced the rocker boxes a little more. Using an extension you can hear a slight tick at idle if you place it against the both of the heads.

Iposted this in the engine section and was told that since I didn't degree the cam when I installed the gear I was problably hitting apiston with a valve. I pulled the motor back down to the cases and haven't found any signs ofanything hitting anything else. The heads have been disassemble and thethey are good. The only thing I can really find is a mark or two on the case where the tabs of the cam thrust washer ride. I'm not sure if these were present before the cam change. Help.



Thanks,
Bill

 

With the engine running, push/pull on the front exhaust push rod cover. This is where my ticking was, the adjustable pushrod ticking on the cover. I cut some length off of the internal cover but it didn't help. My ticking only went away when I went back to stock pushrods, with a bolt in cam. I could have left the hi-lift cam in there and gotten some fat pushrod tubes, but I wanted more torque and less hi-RPM power anyway.

 

You got you answer,with the clearance checks.That is a big cam,learn to love the soundonce you are comfortable with everything else.

 

How much end play did you set in your new cam? Also You should have checked the clearance of the cam lobe closest to the case to make sure you had plenty of clearance there, I had appx .080 with my cam any closer and I would have releived it some. I also see that you only replaced two of the lifters, If they were all installed at the same time which one would assumeyou may have enough wear in the two used ones to make the noise, when I had a lifter go bad it would make a snapping/ ticking when hot, usually when I stopped at a light. When I pulled it apart and found the lifter that the roller was bad on I was suprised at how little wear at that point would make that much noise. Hope you figure it out.

 

The rollers were the problem on the other two lifters. They were pretty bad but didn't make any noise. Clearances are good. No sign of anything rubbing on anything that it shouldn't. I really haven't ridden it yet but I had it running last night and I noticed that the slide on the Mikuni is rattling alot more than it did. The engine is a lot crisper when you crack the throttle. I think I might need to get some roller rockers so I don't wear out the guides prematurely.