more lift-- big rockers or built in?

[Schtauffer]

Re: more lift-- big rockers or built in?

I agree completely, based on the cams I've personally failed. I'm getting tired of changing bearings cuz metal from the cam got in the oil. BTW, the cams and lifters that went flat for me were from one of the "reputable" companies listed in the HR article, and "not off-shore junk." HA!
Perhaps we should start a new thread on this-- do the same oil needs apply to roller cams?

[JeffMcKC]

Re: more lift-- big rockers or built in?

Both yes and no, but for what your doing a Mobil 1 oil changed a lot will work fine I think. Its when your running tons of spring pressure and ramps that you start down the more complex road

Your asking good questions just the answers are ahead of where you are yet, and there is not a direct answer to them, at least I am still trying different things to fix the same problems on a higher end

[Robert1320]

Re: more lift-- big rockers or built in?

Jeff is right on both counts but that is not the whole story. The principal ingredient you want in oil for wear properties of the valve train is zinc phosphate. As he said the EPA has blackmailed all the companies to remove (or lower its content) in gas motors. That has not happened in Diesel motor oil. They still have large percentages of zinc phosphate. If you are not running specialty oil, then the diesel oil you have is a fair compromise.

The cam failure you have witnessed in the past years has nothing to do with lobe configuration or any other geometry. It was a materials or manufacturing problem. Speaking about GM only, the problem started in the early 80’s. They outsourced crate engines to Mexico. The cams had a bad heat-treat and were failing with regularity. By 86 the stock OEM cams were now all rollers. Since a bazillion OEM flat tappets were no longer needed the quality and manufacturing of flat tappets deteriorated. Today, most of the mail-order stuff is manufactured off-shore and is of dubious quality. If you check eBay, new GM flat tappets, in original boxes (prior to 86) command a premium price because you can't get that kind of quality today.

As Jeff said, the cost of a stock-like roller set-up is fairly reasonable. Considering the state of the flat tappet industry, it is not in your best interest to go that way. IMHO, I would be going roller only, even for a stock motor.

The diesel oil now have a reduced the zinc as well. It is not gone but reduced.

http://www.gmpartsdirect.com/results.cfm?vc=1&wtype=v4

I would stay away from an API certified oil. The API certification guarantees that the additive package is developed around EPA requirements and does not have the key ingredients that will help your roller nor flat tappet lifters survive. Generally I like to see a decent amount of Moly, Zinc and Boron in there and API almost guarantees these additives are not there, or diminished greatly.

API is any of the oil witha STARBURST logo.

Take a look at STP, right I know STP????. Yes, STP oil additive has the stuff you are looking for.
Another engine builder, ED, showed this to me years ago.

I agree completely, based on the cams I've personally failed. I'm getting tired of changing bearings cuz metal from the cam got in the oil. BTW, the cams and lifters that went flat for me were from one of the "reputable" companies listed in the HR article, and "not off-shore junk." HA!
Perhaps we should start a new thread on this-- do the same oil needs apply to roller cams?

Even as of last year there were still some bad lifter out in the market.
BUT, a roller will move you to the next level. If you have it in the budget a roller is always a good add.

Oil, nothing wrong with an oil with the additives just makes everything last a little longer.

[sawracer]

Re: more lift-- big rockers or built in?

I know an engine builder that won't use flat tappet lifters in any of his customers engines just for the aforementioned. My buddy was thinking the guy was hellbent on upselling him. I didn't think so either.