Cam swapping What If?

[coop]

What would happen if I just slid out my old cam(externally lubricated) and slid in one that was internally lubricated and I kept the spray bar?

Loss of oil pressure? Increased viscosity drag? Decreased/increased wear? Big explosion? Any recommendations here?

[Jeff G 78]

It's a common swap and works without any problems, but if your oil pressure is already on the low side due to worn bearings or pump, you could possibly run into oil pressure issues. Either swap in a turbo pump or install spray bar block off plates. MSA sells them.

Be sure you keep the rocker arms and lash pads with the cam as a set. Swapping cams and using the old arms will cause premature wear problems.

[jmortensen]

It's a common swap and works without any problems, but if your oil pressure is already on the low side due to worn bearings or pump, you could possibly run into oil pressure issues. Either swap in a turbo pump or install spray bar block off plates. MSA sells them.

Be sure you keep the rocker arms and lash pads with the cam as a set. Swapping cams and using the old arms will cause premature wear problems.

Agree with the first part. I'd run both systems and get the turbo pump.

I've swapped 2 different cams in to replace the original stocker on my L28, ran it for probably 30K miles on the first one and 10K on the second, autoxed every month for about 6 years and did some track days. No problems. I have a bunch of friends with 510s who have swapped cams, nobody ever replaced the rockers. No problems. We all used regrinds.

I think the rocker arm thing is an overblown issue and most problems come from cams with CWC billets. If you do some searching you'll find agreement and disagreement with my viewpoint, but I can say that your statement that it will cause premature wear problems didn't happen within the 40K miles I drove in my personal vehicle before deciding to swap in a V8.

Edited August 15, 2010 by jmortensen

[coop]

Thanks for the response. The spare cam I have has ever so slightly more lift than my old one which has some nasty scoring due to my neglegance. I think I'll try my spare but will also talk to Dave Rebello tomorrow morning just the same. Can't get enough advice.

[ZXatlast]

Greetings All,

Can I ask a different cam shaft question, please? I've looked up and down and either I'm missing the obvious or the specs are well hidden.... can anyone tell me, in terms of TDC and BDC, the inlet and exhaust open and close timings (angles) for the factory standard camshaft for a 1979 8.3:1 compression non-turbo L28e, please??

Best regards,

Steve

[LeonV]

http://atlanticz.ca/zclub/techtips/cam/index.htm

Not sure why you need this info though. Stock cams are already timed from the factory by way of cam sprocket provisions.

[ZXatlast]

I'm thinking about different cam grinds, so I need to know what I'm starting with. It may already be close enough to what I'm designing, but it's likely it isn't.