I'm telling you putting a cam in a motor is one of the least fun things I have ever done, if they would go well one dam time I would love it. I'm amazed at how fast people can throw one in a motor sometimes, scares me silly.

Bret

 

In the case of an incorrectly ground cam for an LTx engine, you're better off exchanging/returning the cam to mfr. in lieu of putting cam timing back in sync with the crank during the degreeing process. The reason being.....

Normally, or rather, on a normal (pre LTx) sbc with cam timing off (in relation to the crank of course), the move (correction) can be made with either an offset bushings or an offset key for the gear on the crank, and be done with it. However...... in the case of an LTx situation, if the cam lobes are off, IN RELATION TO THE DRIVE DOWEL, (which also happens to be the opti drive dowel/pin), and an offset bushing or key is incorporated, the cam timing will be corrected, but at the expense of the drive dowel location. The opti/injectors will be off by the degree amount that the cam was rotated/corrected. Fortunately....

AFAIC, incorrectly ground cams and/or the human error element is an exception rather than the rule. However, it is common to have cam timing off due to the cam/crank linkage hardware. It is no different for the LTx family of engine, than it is/was for the gen. 1 sbc. This as 'Bret' has noted, is usually the reason for making corrections, and/or the reason for the degreeing process in the first place. IOW, correcting the stackup of tolerance errors in the linkage. So, as long as cam is ground correctly, which also implies the drive dowel is indexed correctly with lobes, any degreeing corrections will not only correct the cam/crank timing, it will also correctly index the drive dowel. This also implies if the cam timing is off, so is the opti drive dowel. The odds that degreeing an LTx cam will correct both the cam timing and the drive dowel, are.... very good!

Sorry for the novel. Few people enjoy reading a lengthy post. Wish I knew how to have stated this in fewer words.

 

OBTW, for the guys wondering how to advance/retard the cam with no offset dowel pin available to us, it's pretty simple. Most of the aftermarket timing sets will have more than one keyway on the crank gear. The cloyes I used has three. One for -4 degree's, one for straight up, and one for +4 degrees. Others have up to NINE slots broached in the crank gear, but you would want to avoid those. There is some concern about the strength with those units since there would be 8 places not touching the crank snout with each about a 1/4 inch. You get the picture..

Oh, and yes, IMHO you need to degree the cam in EVERY install, simply to make sure that the cam you are INSTALLING matches whats printed on the cam card. It doesn't happen often nowdays, but sometimes things get mixed up and the two don't jive. It would truely suck to discover that you have a .680 lift 280 duration cam when you were expecting to have a LOT less valve movement. Things can get messy very quickly, so it's best to KNOW what's actually going in that money pit under the hood!

Dave C.

 

Unfortunately.... if there is a need to move it 2º, you're screwed.
But yes, if for 3º or 4º, I agree, a good option, IF no offset bushings available. Although, it is a bit more expensive.