With all the discussions over the years about oils and lubrication of flat-tappet cams, zinc, and catalytic converters, it got me thinking about a camshaft conversion in the 85 442. I have a couple of NOS GM 86-up VIN 9 roller camshafts, but nothing else right now to support it as far as extra parts. I can get the other parts for a conversion, but then once you go, there's really no coming back as to do it right, you would need to open the lifter bores to .921 if you use GM rollers, and machine a spot in the front for a Torrington bearing (totally optional, but you need something to help prevent that front block wear). Sourcing the camshaft retainer, lifter retainers, cam spring and button, lifters and pushrods, etc., wouldn't be terrible. Maybe use some of those conversion lifters so the bores wouldn't need to be opened up, but then the pushrod length would be critical as any variance from stock length could cause issues. They use the same VIN 9/diesel valve springs and rockers as flat tappet, so I would be good there.
I'm totally aware of why people don't do it, but I was apparently thinking outside the box, scratch that, atmosphere, since it seems like there's no oxygen to my brain.
My concern is that with the low zinc oils they have now, they obviously forced the roller cam era to save the cats. Not a bad thing, but oil isn't really made anymore for flat tappets AND cat converters.
Would it make sense? Would it be worth it? I'm leaning to a no, because it's not like the car will end up a daily driver. I just don't like the idea of eating cams, but I sure don't like the idea of killing the cat either.
I've used Mobil 1 with a capful of the old GM E.O.S. added to it for a good while now. Been doing that on my flat-tappet cars. No issues as of yet. At least I can notice. But it's not like they're driven every day either. I have used Amsoil, as it has a good heap of moly in it and not quite as much zinc as others, but it does have plenty of zinc in it around 900+ ppm. A bit pricey and not available everywhere like Mobil 1, but seemingly worth it in the bigger picture. Most other oils that tout 1400 ppm or so don't have any moly in it. Amsoil seems it has better all-around anti-wear properties than some others. l don't give a flying flip about VR-1 or any Brad Penn or other oils with mega zinc in them because of the cat concerns in this application. The non-cat cars it would probably be very adequate. In fact, this thread isn't really about oils. Because I'm either going to continue to do the Mobil 1 and E.O.S. or use the Amsoil stuff however it goes. So that's already settled.
The question is, as already asked, is it worth the expense/trouble to go the other way on the cam- from flat to roller? Especially for a basically STOCK rebuild on a 307 that has to run on the computer? I don't know what a stock VIN 9 roller cam would do to the 85 VIN 9 as far as what the computer would see/do in response. Would it be better, the same, or worse? I can deal with the first two. Wouldn't want to have the 3rd. Granted, the rebuild wouldn't be a factory stock rebuild, but converting is a way to have less worry about the zinc and wiping a flat tappet cam. And unless you opened it up, nobody would know. Unless it ran like crap.
The option I'm leaning toward is to simply stick with the flat-tappet system and call it a day. At least I know what I have. I guess I was doing a little day dreaming thinking. First-world problems.
Thoughts? Opinions?
I'm totally aware of why people don't do it, but I was apparently thinking outside the box, scratch that, atmosphere, since it seems like there's no oxygen to my brain.
My concern is that with the low zinc oils they have now, they obviously forced the roller cam era to save the cats. Not a bad thing, but oil isn't really made anymore for flat tappets AND cat converters.
Would it make sense? Would it be worth it? I'm leaning to a no, because it's not like the car will end up a daily driver. I just don't like the idea of eating cams, but I sure don't like the idea of killing the cat either.
I've used Mobil 1 with a capful of the old GM E.O.S. added to it for a good while now. Been doing that on my flat-tappet cars. No issues as of yet. At least I can notice. But it's not like they're driven every day either. I have used Amsoil, as it has a good heap of moly in it and not quite as much zinc as others, but it does have plenty of zinc in it around 900+ ppm. A bit pricey and not available everywhere like Mobil 1, but seemingly worth it in the bigger picture. Most other oils that tout 1400 ppm or so don't have any moly in it. Amsoil seems it has better all-around anti-wear properties than some others. l don't give a flying flip about VR-1 or any Brad Penn or other oils with mega zinc in them because of the cat concerns in this application. The non-cat cars it would probably be very adequate. In fact, this thread isn't really about oils. Because I'm either going to continue to do the Mobil 1 and E.O.S. or use the Amsoil stuff however it goes. So that's already settled.
The question is, as already asked, is it worth the expense/trouble to go the other way on the cam- from flat to roller? Especially for a basically STOCK rebuild on a 307 that has to run on the computer? I don't know what a stock VIN 9 roller cam would do to the 85 VIN 9 as far as what the computer would see/do in response. Would it be better, the same, or worse? I can deal with the first two. Wouldn't want to have the 3rd. Granted, the rebuild wouldn't be a factory stock rebuild, but converting is a way to have less worry about the zinc and wiping a flat tappet cam. And unless you opened it up, nobody would know. Unless it ran like crap.
The option I'm leaning toward is to simply stick with the flat-tappet system and call it a day. At least I know what I have. I guess I was doing a little day dreaming thinking. First-world problems.
Thoughts? Opinions?