VIN 9 Cam swap to roller?

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69hurstolds

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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?
 

TURNA

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Would be cheaper and easier to buy a 7A headed 307 and just use the short block
 
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Streetbu

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I understand your thinking behind all of this, bit here's the real question. How many miles per year will this be driven? Furthermore more, I firmly believe that some of the cam failure claims are exaggerated. I built my engine and have driven it approximately 40k miles and the cam is perfectly fine. And its a Summit cam at that.... Take it for what's it worth
 
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69hurstolds

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Thanks for the feedback.

TURNA It would be easy to find a VIN Y engine, but then it wouldn't be numbers matching any longer. Since this would be for a restoration, I was trying to find a way to be better than stock, yet run and act, and more importantly, LOOK exactly like stock, at least externally. Kind of like those PerTronix kits for points conversions. Looks normal on the outside, but inside it's improved. If you do it exactly to factory specs, that means a plastic cam gear, which isn't going to happen no matter what.

Streetbu Exactly why I said I'm leaning to a no on doing this. It's not going to be a garage queen, but it's also going to be driven some. Again, not a DD. I believe you are correct in that there's a myriad of other issues that can cause cam damage. Like using recycled oil, bad break-in, or crappy materials on the cam, etc., so the horror stories may be a bit overblown. But zinc is leaving the oils, and stricter rules call for even less zinc in the future. So there is somewhat of a concern. I'm not discounting the fact that the risk for damage increases.

But I also realize that flat tappet cam damage can and does occur. Just don't want it happening to me. I was thinking even if done, it could be undone if using the retrofit lifters for the stock size, and whether or not there's a machined spot for a Torrington front block bearing for the cam is a bonus either way I would guess so returning to factory stock would still be a PITA, but still could be done.

Just musing of what might be and whether something like this would be worth the time and $$. If I were going for max performance and a custom grind cam, sure, I think it would be a no-brainer since the cat and computer would be gone anyway.
 
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84 W40

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Dec 9, 2009
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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 would leave it stock, you would see no gain by adding a VIN 9 roller cam it will feel like the stock cam you just removed plus wasting time and money. If you can find a Crane Cams EMS thats the way to go with a stock Vin 9 motor that system woke up my motor. I wouldn't worry about the cats, leaded gas was killing them.
 
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TURNA

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Cars have no valve either way so as for restoration no loss there
 
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fleming442

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I think it has more to do with soft, offshore cam blanks than the lack of ZDDP in the oil. I put a bunch of miles on a 63 Olds 304 and my n/a 3.8 just using 15w-40 diesel oil....
 

1bad79

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I run a Howard’s roller in my 455 with the link bar 821 roller lifters with great success that would be way easier that a stock conversion on your original block I have beat mine hard for 10000 miles
 
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88hurstolds

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I wouldn't bother, maybe if it were going to see daily use and high RPM but many are still building older plants and using flat tappet cams... heck I just did a 430hp Olds 403 and as long as it's properly broken in with the right oil there's nothing to worry about:
 
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