Need advice on upcoming cam work!

[bjones]

So I'm about to tear my L31 down to the block soon to fix a nagging issue. Ever since I had a rebuilt short block installed (old one threw a rod) the engine has been eating distributor gears. It's done it across 2 camshafts, a stock L31 and a Comp 218/224. I've been doing a lot of research on the subject over the last 2 years, and I've found that the 4 main reasons for this is vertical tolerance in the distributor (affected by a decked block), camshaft end-play, gear load (high volume oil pumps and such) and gear to cam material mismatch.

So my solution is to take the truck down to the short block, and check for decking by measuring piston in hole at TDC and looking for the stamped numbers on the passenger side head pad. I'm buying a new cam for the truck and I'll use Comp's recommendation on distributor gears while using a HV oil pump. What I need y'alls help for is how to check end play, and how to deal with the issue IF it's out of spec (which IIRC is .004-.012)

Thanks again for the help guys!

 

[MazingerZ]

Question, have you used the melonized distributor gear from GM? Since the camshaft gear is made of steel, Compcams will most probably recommended the hardened melonized gear from GM. - please double check with them and let us know their response.

Have you used a OEM GM distributor assembly? or a cheaper ebay alternative?



Somewhere in the back of my mind I think this is the source of my cylinder missfire on my newly built engine. i have the same 218/224 XR270HR compcam (pn 12-422-8)

 

[bjones]

Currently running a Comp 224/230 @112 with a composite distributor gear. Only modification to the distributor was a sleeve to go from .427 to .491 shaft OD and cutting some oiling grooves in the ring above the distributor gear. Pulled the distributor this weekend at 1500 miles on the new cam and the gear looks brand new!

The truck is driven normally, occasionally aggressive, and has a high volume oil pump running 5W-30 conventional.