4-pattern cam?

Posted By: DGS

4-pattern cam? - 11/18/13 06:35 PM

I just read the following article about Comp's 4-pattern cams: http://www.chevyhardcore.com/tech-storie...car-technology/

Although the article is about Chevys the same principle should work for Mopars: in order to compensate for the different intake runner lengths of the outboard and inboard runners Comp Camps uses 4 different lobe patterns.
Here's a pic for clarification

Are there any Mopar cams like these? Would a custom cam grinder be able to make a 4-pattern cam?
I wonder if the difference in power/rpms would be worth it...

Posted By: GTX MATT

Re: 4-pattern cam? - 11/18/13 06:46 PM

My opinion:

1. This is the wrong way to fix the problem, to correct this one should be in the market for an intake with equal length runners.

2. What about the headers? If you're running unequal length headers, and each is different, and each intake runner length is different, there should be 16 optimized lobes, no?

3. Its a gimmick. For you to realize a power gain you would need to optimize your cam for each runner, head port (remember they don't all flow exactly the same), and header primary tube length. The Nascar teams spend plenty of time R/Ding their engines to know what is optimal, they can get use out of a cam with different lobes. A street car, with a cam people are going to buy off the shelf, that is probably already not just not optimal but possibly completely wrong for their app? I don't think its going to make much difference.

And what are we talking for differences lobe to lobe? 2 degrees of duration? Different LSAs? Lift?

Posted By: sixpackbee

Re: 4-pattern cam? - 11/18/13 10:24 PM

If you took it to the nth degree you could have 16 different lobes.

Posted By: rowin4

Re: 4-pattern cam? - 11/18/13 10:36 PM

I was talking to a guy this passed summer about the 4 pattern cam, of course it was in a chevy. The car did run well but I really never heard of anyone doing that. I have heard of the firing order being switched around though. As stated in a previous post there would be a lot of things to conceder on intake runner flow. Unless you had unlimited flow bench time you just couldn't make it a practical . No 4 pattern cams off the shelf for Mopars and probably not for chevy's either

Posted By: sixpackbee

Re: 4-pattern cam? - 11/18/13 10:41 PM

This kind of thing is filtering down from Cup stuff pretty much. When every gram of power is precious things get this anal.

Posted By: BradH

Re: 4-pattern cam? - 11/18/13 10:46 PM

There was a somewhat heated thread on SpeedTalk about the whole 4-pattern cam deal. Some claimed it was leading-edge technology, while others screamed "Gimmick!" and said that stuff had been tried and dropped years ago by NASCAR engine builders.

What I recall from reading some article (possibly the same one) that did a comparison was IMO it wasn't really an apples-to-apples cam comparison. I looked at where the gains from the 4-pattern deal were vs. the other cam used as the baseline and thought if they'd simply tightened up the baseline cam's LSA a couple of degrees it would have shown similar improvements, too.

Interesting reading, but nothing that's going to get me all hot and bothered to buy one.

Posted By: GTX MATT

Re: 4-pattern cam? - 11/18/13 10:52 PM

Quote:

There was a somewhat heated thread on SpeedTalk about the whole 4-pattern cam deal. Some claimed it was leading-edge technology, while others screamed "Gimmick!" and said that stuff had been tried and dropped years ago by NASCAR engine builders.

What I recall from reading some article (possibly the same one) that did a comparison was IMO it wasn't really an apples-to-apples cam comparison. I looked at where the gains from the 4-pattern deal were vs. the other cam used as the baseline and thought if they'd simply tightened up the baseline cam's LSA a couple of degrees it would have shown similar improvements, too.

Interesting reading, but nothing that's going to get me all hot and bothered to by one.

I think it could be debated heavily because it can work, but for them to be selling these to your average hobbyist is a gimmick. Not bashing Comp at all by calling it a gimmick, they're just trying to get more of the marketshare when the market is FLOODED with cam options.

I think it will always be an apples to oranges comparison unless you are certain that you've already got THE optimal dual pattern cam in the engine already, and it is then changed to a four pattern cam.

If it were the four most optimal lobes for an engine, sure it would make more power. But again, it is highly unlikely that you will have the optimal four lobes. The key work is optimal.

Posted By: B3RE

Re: 4-pattern cam? - 11/19/13 03:59 AM

Quote:

Quote:

There was a somewhat heated thread on SpeedTalk about the whole 4-pattern cam deal. Some claimed it was leading-edge technology, while others screamed "Gimmick!" and said that stuff had been tried and dropped years ago by NASCAR engine builders.

What I recall from reading some article (possibly the same one) that did a comparison was IMO it wasn't really an apples-to-apples cam comparison. I looked at where the gains from the 4-pattern deal were vs. the other cam used as the baseline and thought if they'd simply tightened up the baseline cam's LSA a couple of degrees it would have shown similar improvements, too.

Interesting reading, but nothing that's going to get me all hot and bothered to by one.

I think it could be debated heavily because it can work, but for them to be selling these to your average hobbyist is a gimmick. Not bashing Comp at all by calling it a gimmick, they're just trying to get more of the marketshare when the market is FLOODED with cam options.

I think it will always be an apples to oranges comparison unless you are certain that you've already got THE optimal dual pattern cam in the engine already, and it is then changed to a four pattern cam.

If it were the four most optimal lobes for an engine, sure it would make more power. But again, it is highly unlikely that you will have the optimal four lobes. The key work is optimal.

I read a little on this some time ago. The reasoning behind the concept is that classes restricted to a single carb manifold can not have all the runners equal and will require different timing events to optimize each cylinder. It doesn't mean anything on tunnel rams with dual carbs where the runner lengths are equal and the throttle bores are positioned directly above the runners as they, theoretically, will all flow the same and have the same velocity.
Comp should be able to put those types of lobes on any shaft since the chevy ones are custom grinds, too, as far as I know.

Posted By: HotRodDave

Re: 4-pattern cam? - 11/20/13 01:04 AM

With 4 different lifts how could you ever get your rocker geometry correct with a shaft? Do you just take an average lift and use that?

Posted By: B3RE

Re: 4-pattern cam? - 11/20/13 01:45 AM

Quote:

With 4 different lifts how could you ever get your rocker geometry correct with a shaft? Do you just take an average lift and use that?

I think this stuff is geared more towards the very high dollar engines that use the individual shaft mount rockers ie. Jesel or T&D. If you used a single shaft system you would have to compromise somewhere unless the stem protrusion of the valves were at 4 different heights. That's certainly not unheard of when "thinking outside the box".

Posted By: GTX MATT

Re: 4-pattern cam? - 11/20/13 02:11 AM

Quote:

With 4 different lifts how could you ever get your rocker geometry correct with a shaft? Do you just take an average lift and use that?

I can't even think about that