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Old 12-16-2011, 03:01 AM
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Chevy factory cams

There seems to be two different opinions about factory muscle cams, those who love them and those who hate them.Why is that? Is it because some people only like aftermarket parts and always want max hp?
Or is it because they need higher compression and high octane gas?

I think that the slower ramps these old grinds have would better tolerate low zddp oils.
SB L79 and BB ls6 cams were kings of the hill back in the day so why wouldn`t it work today?

I personally am beginning to think that because almost everything today comes from china and quality is what it is there will come a day when people start to appreciate factory parts like these old cams, double hump heads, intakes etc.

Opinions and explanations please.

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Old 12-16-2011, 04:36 AM
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the aftermarket cams are favored because they offer more variety. There is a very limited number of factory cams for a given engine while just one cam company may have 50 to choose just for your particular engine. It makes it much easier to get a cam that best suits your needs.

The new cams also have alot more technology in them. A cam grinder can sit at a computer and design a cam in minutes. Punch into a dyno sim and see what the actual characteristics are before putting a blank to a lathe. The whole trial and error process has been sped up in the digital age. My using the knowledge from the old days they have advanced the science alot. You can get more hp, better idle, and a flatter torque curve with some of the new cams.
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Old 12-16-2011, 06:08 AM
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Good points, thanks, but not enough

Some people say use dual pattern cam, some say single and yet 9 out of 10 cams are dual pattern cams.Example: comp cams xe`s are duals and old magnums are single patterns and we hear a lot about problems that xe`s gone flat and noisy valve trains etc. So there must be some reason for old magnums still exist today, right?

I know that not all factory engines are so good like GMPP:s 290hp 350, low compression and old school cam makes it pretty stupid combination.
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Old 12-16-2011, 07:52 AM
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Saying the L79/LS6 cams were "king of the hill" is a stretch in my opinion. They were what the factory installed, but in engines that were going to be seriously raced they were also the first thing that was changed along w/installing headers, tires and tuning.

AFA single or split pattern cams, this depends on the heads, induction and exhaust systems and shouldn't be done just on a whim. The 'off the shelf' grinds are a compromise by the cam makers. They will be close in some apps and not so close in others. A better idea is to get w/the manufacturer w/ALL the specs of the engine and vehicle along w/the intended use, etc. and get a recommendation for a cam spec'd for that exact combo.

Anyone who's seriously worried about cam wear should be running a roller from the get-go. Otherwise, carefully follow the well known and oft repeated recommendations on flat tappet break in and in the vast majority of the cases there won't be a failure- even w/the higher intensity profiles. Noise is a subjective matter, what bothers some is music to others. If the chance of valve train noise is a deal killer, don't choose fast lobed cams or solid lifters or Rhodes-type hydraulic lifters.
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Old 12-16-2011, 09:50 AM
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i don't think were will be a much a market for old school OEM intakes, heads, and cams except in very niche markets. Restore projects and stock class racing are the main two that come to mind. When an AL edelbrock intake can be had for $150, I don't know why you would seek out an OEM intake. The cost to rebuild the old heads cost about as much as a new set of budget heads or setting up some vortec heads for higher lift that will beat the "old school" one in just about every way. While there are alot of cheap chinese options when it comes to car parts, not all are bad. There are still plenty of American made parts too.

The comp XE problems are mostly brought on by wrong breakin procedures or a lack of ZDDP in their oil. I ran one for 40K and used off the shelf quaker state. I got lucky and never had a problem i guess. The magnum series are still around because they are a good design and make good power. If something works don't fix it. There are plenty of products that were designed decades ago that have gone pretty much unchanged and work just as well then as they do today. Thermos coffee carriers(those green metal ones) or metal Coleman cooler are pretty much the same as they were 30-40 years ago. Maybe a plastic hinge that used to be metal or an updatedseal but the same design. That is just 2 model that made it because they were good, how many didn't.

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Old 12-16-2011, 10:10 AM
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Quote:
Originally Posted by TimoFinn
There seems to be two different opinions about factory muscle cams, those who love them and those who hate them.Why is that? Is it because some people only like aftermarket parts and always want max hp?
Or is it because they need higher compression and high octane gas?

I think that the slower ramps these old grinds have would better tolerate low zddp oils.
SB L79 and BB ls6 cams were kings of the hill back in the day so why wouldn`t it work today?

I personally am beginning to think that because almost everything today comes from china and quality is what it is there will come a day when people start to appreciate factory parts like these old cams, double hump heads, intakes etc.

Opinions and explanations please.
The only reason to run one of those old cams is because it was brand new in box and was free. If you're going to pay for a cam even a cheap Elgin $100 cam kit is much better than those old cams.

The only people who love them are people who probably don't know enough about cars to change their own oil- or people who are just nostalgic about the hotrods of their youth.
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Old 12-16-2011, 01:14 PM
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Quote:
Originally Posted by ap72
The only reason to run one of those old cams is because it was brand new in box and was free. If you're going to pay for a cam even a cheap Elgin $100 cam kit is much better than those old cams.

The only people who love them are people who probably don't know enough about cars to change their own oil- or people who are just nostalgic about the hotrods of their youth.

well put
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Old 12-18-2011, 10:13 AM
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Quote:
Originally Posted by TimoFinn
There seems to be two different opinions about factory muscle cams, those who love them and those who hate them.Why is that? Is it because some people only like aftermarket parts and always want max hp?
Or is it because they need higher compression and high octane gas?

I think that the slower ramps these old grinds have would better tolerate low zddp oils.
SB L79 and BB ls6 cams were kings of the hill back in the day so why wouldn`t it work today?

I personally am beginning to think that because almost everything today comes from china and quality is what it is there will come a day when people start to appreciate factory parts like these old cams, double hump heads, intakes etc.

Opinions and explanations please.
They have MUCH slower ramp rates. If they had aggressive ramp rates the wear and tear would be severe. Todays technology FAR surpasses what was "king of the hill" in the 60's. A small roller cam will have much less duration, substantially more effective valve lift, make more power, be easier to idle and drive, and last a lot longer. It's just a total win, win, win. "Double hump fuelie" heads were the best design back in the 60's. They had ports that were around 160cc but the port shape made a big bend at a sharper angle than the heads out there now. They flowed around 170cfm. Think of intake flow as the potential power able to be produced. If you can only get so much air into a cylinder then you can only get so much fuel as well, and make only so much power. Lets not forget the horrible chamber design. A Jaguar engineer designed the first fast-burn chamber back in 1981. It is used in every 2-valve cylinder head out there now. Chevy calls it a "vortec" head design. Basically as the piston is compressing the mixture it is swirled into an area aimed right at the plug. By doing this more complete combustion is achieved, which makes more power and reduces emissions. Another win, win, lol.

There are guys out there that can make power with production iron heads from the 60's but if you factor in the amount of time they take to modify them, they will still be trumped by a decent set of AFR heads for $1400.

Look at an LS motor from today. A stock 5.7 liter engine in a '98 'Vette will make around 295hp AT THE WHEELS. It will idle at 650rpm with no lope, pull a ton of vacuum for the brakes, pass any emissions test, pull 25-30mpg on the highway and pull multiple car lengths on an L79 Nova at the track.

I love the old school stuff, don't get me wrong, but the technology is here today to make more power for way cheaper.
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Old 12-19-2011, 05:54 AM
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Thanks for the answers guys
I have CC Magnum solid roller cam in my bbc too reason: it works!
I guess some stuff just works and some not, no point to argue about it.
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