Cam headscratcher

[codyshop]

Put an Andrews EV-46 in Kathy's early '85 Superglide.  Motor is otherwise stock except for a CV instead of the original shovel Keihen.  Bike is very hard to start and smoke comes out of the air cleaner.  Put stock cam back in and it runs fine.  Put the EV-46 and same problem again.  Go back yet again to the stock cam and all is well.  I've put -46's on dozens of bikes and they run great.  My guess is a defective grind or bad gear indexing.  Either that, or the first year evo motor is uncammable (like the late '80 shovel is).  Anyone?  Thanks, Ray

[tbird]

Now you have my interest. Why do you say the '80 shovel is uncammable? I had never heard that before.

[hdbikedoc]

early evos have no cutouts for valves in pistons are the valves hitting?

[bigblock6912]

84's had the valve pocket 85&86 did not

[codyshop]

To tell you the truth I didn't clay this one since it's only .495 lift.  Manual roll-through has absolutely no bind.   Ray

[codyshop]

Finally figured it out!  It seems the first few weeks of evo motor production used an 8.3:1 piston/head/gasket set that can't take a long duration cam.  Be careful when you see "...fits all big twins from 1984 to present" in catalogues!  It is a rare piston/head/gasket combo that was used for an extremely short time and nobody makes an 8.5:1 or higher piston for the first few weeks of evo motor production runs.  The EV-46 or equivalent simply will not work with that low of a compression ratio.  I'm goin to go with .010: copper base and .029" head gaskets and see if it will run with an EV-27 which is my second favorite cam.  My math brings that just about 8.48:1  Ray