TSATF, evidently my writing is confusing you. Sorry about that. I was being facitious: it would be exactly the same cam with a different name. The engine could tell. Only the owner couldn't. Does that say the engine is smarter than the owner? Sure, that happens all the time. Do I suggest that this tactic has been employed by less than honest folks? Perhaps.

I have heard engine "builders" say that they make an engine do what they want it to, rather than what Mother Nature dictates. It makes me laugh, but my kinder side feels sorry for them...and especially sorry for their naive customers.

RE camshaft design (Rectal Extraction) is rampant. Fortunately you can often get 85% or so of the way toward optimum with an RE cam. If you play in the 1% or even the 5% ballpark, that's a ticket to the bottom of the standings.

Do I suggest that someone could be duped into thinking they had a proprietary lobe (which could not be sold to someone else, by definition of proprietary) and paid handsomely for it? Perhaps. Barnum underestimated his timeline.

You can have a lobe "designed" for you by a reputable cam company for approximately 2 large. You don't "own" it however. You could also have a cam "speced" for you from existing lobes which produced more average or peak power/torque (or whatever you wanted) for about the same $ amount. You get to prove it on the dyno and/or the track before paying. If you like it and pay you get ALL of the specs. If you don't...you don't. This usually applies to higher-end racers or builders who sell multiple engines. Some consider it a bargain.

Jon

 

Jon: I stand corrected on the cost of a "custom" lobe. Keep in mind though, that we need two lobes as nearly all modern SBC cams are dual pattern, The does bring it to $4K. Also, I assume that $2K is not including any testing? IOW, the "testing" would be when you installed and ran it. Let me know if I am right, but I assume a "custom" like that is just someone tweaking an existing design enough to say "yeah sure, I designed it just for you"? As such, it unlikely to be any better than an exisitng lobe, it would just be an ego thing?

I stand by my prior post, nearly every time someone talks about a custom cam, "custom" means custom selected and that there is nothing wrong or deceptive with this. Given the variety of lobes already available, it would be foolish to do anything else unless you were a high budget racer who could pay a big bill to get something different AND better. This would have to involve both design and testing time, or it could either be a turd or at best not better than what you could have gotten for $3-400 in the first place.

Rich

 

So basically those "custom cams" and those who claim to have designed them are pretty much obsolete. Not surprised in the slightest judging the results that have been posted on the net for the last few years.

 

Kind of. What I am trying to get at is the difference between selecting from an existing catalog of proven lobes and grinding the optimal lobe separation, installing at the optimal ICL, etc.. for a particular application. Or even just selecting the right off-the-shelf cam for a particular use as opposed to unique, propietary cam. The former can work well and for a few more $$$ than ordering based on limited knowledge of the subject, or what is hot this week on the board, you can see an addtional 20-30hp. That's nearly "free"! I would say that IF you pay someone less than thousands of dollars for a "custom" you are 99.9% of the time going to get a "custom selected" cam as described above. If you getting a truly custom design, for that kind of money, it will more likely than not be less effective than a custom selected cam with proven lobes. That's for two reasons, one is that w/o testing, you become the guinea pig. The other is that your low priced lobe designer is pretty unlikely to come up with something new and better for the SBC. At best, he will be reinventing the wheel.

Rich

 

If I were confused about anything, I guess it would be why, even facetiously, a guy in your line of work would dare to bring up a question like this considering the suspicion it would arouse equally as much about yourself as it would anyone else.

I asked the following rhetorical questions in an attempt to give you the benefit of the doubt by keeping this thread focused on the brass tack facts pertaining to cams themselves, not the ethical standards of their makers.



Despite the fact that the possibility exists for a cam grinder to dishonestly rename a shelf grind and pass it off as something "custom," the cam's specs really only tell half the story. There are still yet other variables at play, (ground on a billet core, 4-7 lobe swap, 55mm journals, etc.), that could make a cam that specs and possibly even performs the same as a shelf grind, a custom.

 

First of all I'm not in the cam business. That's my son. We do talk a lot about this stuff, as you might expect. He doesn't plagiarize others' cams because he does as well or better than others tailoring a cam for a specific engine combination. Not everyone agrees with that statement, of course, but a great many paying customers do.

Yes, of course if one specified a steel vs cast iron cam or a different core it wouldn't be the same cam, but if the valve motion and valvetrain stability were the same I expect performance would be very similar. Would it then be a "custom"? Sure, if you want to call it that. Polishing a turd doesn't make it less of a turd.

Rich made a good point about having new lobes designed specifically for you. The ~$2K does not pay for any Spintron testing, etc. If the guy doing the design and using the high-end software they have uses his normal parameters for velocity, acceleration, jerk and perhaps the next couple of deriviatives of lift, there is a very good chance it will be a "good" lobe. Even if you stay within a family of lobes, the number of combinations of lift, duration, LCA, ICL and rocker ratio add up to hundreds (or thousands) of possible combinations to be evaluated. Finding the right combination is more important than having a new lobe designed, IMO. I suggest the most succesful cam guys are those who find the best combinations, and continue to evaluate all of the lobes available to them. As they find a better combination they offer it to their customers. Call it continuous improvement or planned obsolescence or whatever you wish. If you are not going forward you are getting passed.

New lobes (or families of lobes) are regularly added to a cam company's database. Some of these may be misapplied by some folks and at times may be removed from the database. The selection is probably way more than most engine designers ever need. OK, so if you are responsible for camming a leading NASCAR Cup engine you probably do need some new lobes. You also have the money to test them, and the testing equipment which can accurately find the fraction of a percent in power of torque or BSFC.

Choose your engine/cam designer as carefull as you choose your surgeon. In any case, check their record of success. DIY cam design is a lot like DIY brain surgery and often about as effective.


My highly opinionated $.02.


Jon

 

I'll give you a clue doc, the guy who pioneered this "modern sbc cam" idea designed my cam, with proprietary lobes that do not (yet) appear in any catalog.

 

That right there is just funny, especially considering what I've learned about your 'custom' cams in the context of this thread.

I have a new marketing name for your son's cams: "The Sledgehammer Series". Kinda has a kick, no?

 

Let's see - I found someone with proven results, and a long rich history of cam design, and who wasn't a pompous a$$hole touting qualifications he doesn't have on an internet board.

It was ground by Custom Camshaft Company, it cost far less than 5-figures, it was worth way more based on my lengthy conversations with, dare I say, a f'ing legend in the industry, and I got a cam with lobes designed for me, for the lifters I'm using, for the way I drive the car, for the weight of the car, for the gearing, for the longevity & ease on parts, etc. Are they lobes he will use elsewhere - probably, as I don't 'own' them and I don't need to.

Contrary to e-belief, Spintron analysis is not always necessary for seasoned cam designers. As you probably know, even it does not account for everything that may affect the way the cam works. This guy has designed thousands of cams, pioneered software design for it, has cams still being used in cam company libraries, and has a real resume.

Trust that I'll post my results after I get the car tuned and some miles logged in on it.

 

Ah, so when he said

and you responded

You meant,

Which, using your own definitions, makes yours a "custom cam" from a "designer."

 

If you are calling me a pompous *** you can take it to PM. Please leave that out of the public area of the board.

Rich

 

A related question - if I design a new cam that works great with engine combo X, is the second one I sell to somebody else with the same engine combo a custom cam?

It's all semantics. Go to the cam source that meets your needs best.

 

What an idea!

steve, you have a way of sifting out the bovine scat and getting to the point. I like that.

Jon

 

Not sure I follow, but whatever - I'm not that smart. My lobes are not in a catalog (yet), were specified by a camshaft designer for my application and my cam ground for me. Is that clear? To me that's a custom cam.

Picking lobes out of a catalog could be considered semi-custom I suppose, so I see your semantic argument. That assumes the guy picking the lobes knows what he's doing, of course.

You see this all the time in the residential market where houses are marketed as custom, but look just like another house four doors away, or the developer copies a successful tract plan and markets it as an 'original' custom.

 

Never called you a pompous ***.

PM sent with apology for confusion.