1994 Merc 454 Mag EFI (385 hp) cam question

[Powerquest_Baby!!]

Does anyone know the stock cam specs for intake and exhaust? Im hearing 224/224 but want to verify. Having a problem after a rebuild...Thanks

[kraftaroni]

The part number is 431-4734 i don't know the specs I need them as well. Anyone?? I killed a piston and half my cam lobes. Hope some cam guru's chime in.

[B.A.]

i have a complete motor running very strong i will sell out of boat if either of u are interested. Its a 454 mag mpi 385 hp.
I will sell motor and drive package for 7000 or the whole boat for 12000. Contact Jason at 561 729 7902

[kraftaroni]

Good luck with your sale. I already have all my parts for the rebuild minus a cam..!!! Have my motor out and torn down. Just need cam specs so I can order a cam close to the stock profile. Looks like I'm going to have it profiled with a cam DR. and copied.

[Griff]

Is it a roller cam or flat tappet?? That may narrow it down.

[kraftaroni]

Flat Tappet. I'm sure it has a special grind because of the EFI. ??

[Griff]

Just buy a new cam from merc. It is highly unlikely that anybody else has them off the shelf. You would have to get it special ground and it would probably cost about the same $$.

[Alan454]

Here is some info from Dennis Moore on this forum - can find the link again, but here is the info - hope it's not too late. Durations given at .050" lift, and lift at the valve of course. Seems like very wide lobe centers on those cams compared to aftermarket.

"The factory GM specs are;

The flat lifter 7.4/330 horsepower camshaft is an old design camshaft from the 60's with 213/217 duration .460/.480 lift 114 LSA.

The 454/502 Magnum flat lifter camshaft has 224/224 duration .510/.510 lift 115.5 LSA.

The roller lifter 7.4/Gen VI/Vortech L29 camshaft has 206/211 duration .480/.483 lift 115.5 LSA.

The roller lifter 454/502 Magnum camshaft has 224/224 duration .483/.483 lift 115.5 LSA

These camshafts were removed from marine engines by me and measured by Comp Cams for my book BIG BLOCK CHEVY MARINE PERFORMANCE. They each came back from Comp Cams with specs that showed one degree more duration on each lobe than the factory GM specs (above).

Although these camshafts may seem to have a large amount of duration at .050 check they are very mild because they have slow opening and closing flanks for durability reasons. The flat lifter 7.4 camshaft is extremly mild compared to a new aftermarket camshaft."

Alan

[Rockfish71]

Originally Posted by Powerquest_Baby!!

Does anyone know the stock cam specs for intake and exhaust? Im hearing 224/224 but want to verify. Having a problem after a rebuild...Thanks

Here is the spec's for the cam gen 6 roller cam I some brand new if you are interested.
Merc Mag Roller
Merc# 431-850478 / GM#12551622
.004 300*/ 300*
.006 288*/288*
.050” 224*/224*
.200” 125*/125*
Lift .483”/. 483”
ICL 109*
LSA 115.5*