Cam question

[buildinthrillz]

All right all my parts finally came in for a build. Disassembled motor got all the new parts out and ready and I noticed my new cam has a rough Edge on one of the lobes no and both lobes overall have a sharp edge. I’m no expert But my logical brain tells me this is not good. I was wondering if this is normal with a CL-bp2 cam. Or if anybody else has had this problem I got the cam from ARC It’s a Dyno cam. Also I did a test fit of cam to crank and the crank is hitting on the exhaust lobe of the cam is this normal? Am I able to grind down the crank shaft for clearance? Thanks -will also srry if this is in the wrong thread feel free to move it I’m still learning this forum..

 

[Flyinhillbilly]

As long as the face of the lobe is nice it should be fine, I’ve seen guys have to cut into the lines for clearance on a big stroker. I often have to grind the crank a little on my builds too, you just gotta make it all fit.

 

[buildinthrillz]

Thanks man just wanted to be sure before I went to town.

 

[Mrmonk7663]

Yes. I had a mod 2 that was much rougher cast than stock. I contacted DynoCams and they said it’s fine to grind down the interference area. I used an air sander with a 1/2” wide belt. If you search my username and posts you will find my thread with all information and pictures.

 

[buildinthrillz]

Have another interesting question this is my first predator build so I blind bought parts before disassembly and from all I read I thought I would order a ft piston. I open up the motor and what do ya know it case stock out of the box with a flat top piston is this new to predator 212 hemi I haven’t read anything that said they come with flat tops now?

 

[KartFab]

hemis had always had flat tops? At least all the hemi's I have messed with. Also, i would contact customers service about the cam that has that rough line through the lobe, edges dont matter. A lot of people do the longer connecting rod for the hemi, and keep a thicker head gasket, or use a stock length billet rod and go with a .010" head gasket for higher compression.

 

[buildinthrillz]

Thank you for looking at the picture that rough edge is what worried me I will contact arc. I’m guessing that everything I was reading was talking about the non hemies and there dished pistons as far as connecting rod goes I bought the plus .020 and a .010 head gasket to boost compression I was under the impression that this would still have clearances? I have read so much on these engines that I may have mixed up my knowledge anyhow I can always purchase another head gasket I was planning on running a Pauls kart head with bigger valves aswell and welded chamber to really boost compression.but as I stated this is my first go kart engine build I have tons of experience with Car engines I didn’t think this would be so confusing .thanks again -will

Contacted arc and there sending out a new cam awesome when things go so smoothly.

 

[Snaker]

All right all my parts finally came in for a build. Disassembled motor got all the new parts out and ready and I noticed my new cam has a rough Edge on one of the lobes no and both lobes overall have a sharp edge. I’m no expert But my logical brain tells me this is not good. I was wondering if this is normal with a CL-bp2 cam. Or if anybody else has had this problem I got the cam from ARC It’s a Dyno cam. Also I did a test fit of cam to crank and the crank is hitting on the exhaust lobe of the cam is this normal? Am I able to grind down the crank shaft for clearance? Thanks -will also srry if this is in the wrong thread feel free to move it I’m still learning this forum..

That cam is a cast part. The area's that aren't critical dimensions would usually just get a deburring, nothing very precise. The critical areas are cast oversize and machined down to precise dimensions (the shiny area's). That line across the lobe was under sized during casting and the spec'd machining didn't go deep enough to cut into that spot.

That cam is very much defective and should be replaced for that reason.

 

[buildinthrillz]

Arc completely agrees with you aswell there sending a new one and said I can keep the paper weight for the trouble lol they actually have really good customer service next day delivery too