problems degreeing my mag 1622 cam in my new build
 

has anyone here actually put a degree wheel on a stock l29 454 296 cam or the mag 1622 cam? we checked the mag cam and it comes in at 120 icl with the stock chain that came on the engine ..i thought that was way way off so i put the stock cam back in it and checked,,its in at 122 degrees straight up the spec for the mag cam show a 109 icl and a 115 icl for the stock cam...i even swapped to a different timing chain setup and same numbers plus or minus 1 degree...ive been building engines for 22 years and my machinst builds pro mod engines and has done tons of marine stuff and he came up with the same numbers....the engine is completley rebuilt with stock heads and 30 over bore and stock replacement pistons,..im using a carb on this engine and with intake lobe that far retarded its gonna be a lazy pic regardell of which cam i use,...any ideas? thanks steve

ont,
The one spec that I can find right now for the L29 cam shows a 118 icl. I have more information at the shop if nobody comes up with it Ill get it Monday. Cant help you with the others.

What procedure are you using to check it ?

The lsa of the stock cam is 118 i am using a mag mpi cam which has a lsa of 115.5 and a icl of 109..seems most merc cams have 7-9 degrees of retard in them factory

How are you finding tdc ? How are you following the cam ? With a lifter and dial indicator or one of the tools that goes in the lifter bores ?

There are threads where others were seeing up to 8° off on 1622 cams.
https://www.offshoreonly.com/forums/...t-502-cam.html

FActory lifter in lifter bore with dial indicator and i have a positivie stop tool that goes across the top of deck surface ..im using a sa gear single roller adjustable chain ...ive checked it opening and closing events and .50 before and .50 after for icl... Im at 114 from 120 where i started.. few people have told me to not dial it all way to 109 icl since the more advanced it is it the more dynamic compression builds and can be a issue on 87 octane that this things gonna runn on ...

The HP500 cam is 222/230 110lsa and pretty sure installed at 105icl.

This is the 454 mag mpi cam that i am using in a carberated l29 in a cabin cruiser

I was responding to your concern of ‘too much cyl psi’ installing the mag cam to 109icl. The 500hp is at 105icl and runs great on 87.

That engine is 8.75 to one compresion and has efi and knock sensors..the carb version is 8.5 to one compression..makes a big difference...