Custom cams ...

[ill advised]

I would've posted his in talk but I suppose it's tech related.

This is an email I got from a mechanic/friend talking about custom cams. He doesn't mince words so fair warning to those who might not like it. I'm not posting this because I have an agenda but I'm interested in seeing a rebuttal.

cliffnotes: Basically he was telling me that buying a cam from the major manufacturers can be well worth it if done right and that a custom cam is not the end all cams for these cars. We were talking about my (way in the future) new engine when the subject of cam choice came up.

This custom or nothing mentality that is going around is B.S. I have been dealing with cams for quite some time now and I have not been steered wrong by having the factory or cam manufacturer assist in the choosing. As long as you are honest and realistic in your needs the cam manufacturer can get you a good cam right off the bat.

Question is "What is a custom cam?" Alot of people pour a bunch of black magic and voodoo into this term. It is nothing more than a well thought out model for a specific set of parameter on a particular engine. The more correct data you can provide the cam manufacturer about your engine's parameters the more accurately they (the designer/grinder) can assign a particular grind that will fit your needs. That is all there is to it. This **** I see about how stupid particular cam companies is nothing more than those moonies following a small group of self proclaimed "know it alls". Just because they plunk down some money for some heads and a "custom cam" they are experts and now advise others they are stupid unless they get a particular set of head and cam from so and so and so. That type of mentality is like prescribing only one type of hammer for any nailing job. Not everyone needs a sledge hammer to drive a thumb tack....

Another way to select a cam is by working with the cam manufacturer grinder and trial and error. I.E. Dyno time then track time. VERY time consuming and expensive.

You get the picture. Do your home work and work with reputable people and companies. Competition Cams, Crane, Iskendarian are all VERY GOOD companies. You will NOT go wrong dealing with any one of these companies. Personally, I am a Crane Cams fan but that is my personal choice.

Competition Cams 270XE (I forget the exact grind #), Crane 2031, TFS Stage 2 (A copy of a crane cam), 1988 speed density stocker cam dialed to NMRA timing specs w/1.7 rockers......., E303 set to 4* advanced (dialed in then advanced), E303 set to 4* advanced w/1.7 rockers........the list is long but you get the idea...

Now go and do your cam homework.........................................................................................

 

[oz]

I tend to agree with your friends assesment. The cam companies survive because people are happy with the results their cams provide. They do a lot of research and testing to prove out different grinds, etc. before they put them in the catalog. If you have a rare combo, getting a custom grind may be worthwhile but if you have the typical bolt ons, there is no justification.
I called Comp Cams and worked with a tech there who recommended my cam. I am very happy with my results... I don't think I could have done any better with a custom cam.
JMO.

 

[95GTAODE]

I think everyone tends to forget that if one of the major cam company's doesn't have the exact grind you want/need, they will make it for you. In fact, there are a lot of grinds in those cataloges that started out as custom jobs for racers. Just about every cam manufacturer is a "custom" cam grinder.

 

[jdsgallops]

Just because they plunk down some money for some heads and a "custom cam" they are experts and now advise others they are stupid unless they get a particular set of head and cam from so and so and so.

This is the part I like the best. Every one buys the same heads, puts them on the same CI engine, and uses a long runner EFI intake and runs it in the same kind of car(ie same weight) and then buy a "custom cam". Wanna bet most of these are the same grind? If so what is so custom about it?

I have heard some of the "custom cams" are using different lobe profiles that are not in some of the catalogs though. They are new wave design but have pretty fast lobe profiles which I would imagine are hard on valve springs and seats, meaning they aren't for your average daily driver. Thus I believe this gentleman is correct in saying the properly choosen OTS unit doesn't give up a ton of power or driveability to a "custom cam".

 

[maverick0716]

I agree that there are some very good cam manufacturers (Comp, Crane, Lunati, etc.) But there are a lot to choose from and it's very easy to choose the wrong cam for your setup if you don't know what you're doing. If you put a lot of thought into it, and get some reccomendations from different manufacturers, then you can pretty much safely choose an off the shelf cam that will perform just as good as a "custom" cam.

 

[Blown00GTAuto]

This is the part I like the best. Every one buys the same heads, puts them on the same CI engine, and uses a long runner EFI intake and runs it in the same kind of car(ie same weight) and then buy a "custom cam". Wanna bet most of these are the same grind? If so what is so custom about it? ...

Exactly.

Ill Informed's friend summed it up well in his first sentence: "This custom or nothing mentality that is going around is B.S.".

It is annoying how some people go out and pay for a high output setup then come on acting like experts, claiming everyone must get a cam specifically ground for their combo. And notice how some of them will recommend a specific company or individual to obtain this "custom" cam from (promoting their business). And as someone else recently point out, if a cam is ground to work optimally for a specific setup, how optimal is it if a part in that combo gets changed?

Some guys have reported getting "custom" grinds but you wouldn't know it by the before and after results.

 

[5spd GT]

A custom cam is not all about track times...

Yes, there are some nice cam companies out there...but ideally you want an expert in the field (custom cam grinder like Ed, Jay, Buddy, etc.) that work on "our" particular cars on a regular basis and not all kinds of models of engines.

You pay for customer service/reliability/etc.

 

[illwood]

A custom cam is not all about track times...

Yes, there are some nice cam companies out there...but ideally you want an expert in the field (custom cam grinder like Ed, Jay, Buddy, etc.) that work on "our" particular cars on a regular basis and not all kinds of models of engines.

You pay for customer service/reliability/etc.

It's really a double edged sword. Buying an off the shelf cam of a close profile will probably meet most of our needs. You are right that it is nice to be able to call up Ed and say I have a this compression, trick flow/afr setup with this intake and I plan on doing this. You should be able to do this with most of the major cam manufacturers, but I there is definitely a comfort level that is associated with getting a "custom" cam from someone that has a really good rep on the forum.

If anyone that actually grinds cams is reading this thread, can they please answer me what the major variations are between the cam designs? For all of you that don't know, there are some more factors that affect cam design than just duration, lift, and lobe separation. Any automotive cam that I can think of is either a RFD (rise-fall-dwell) or a RDFD (rise-dwell-fall-dwell). What are the rise and fall profiles that you use? 4-5-6-7 polynomial, spline. . .

(I designed and built a "Cam Dynamics Test Machine" for industrial cams for my Master's in Mechanical Engineering that I'm finishing my degree in now.)

 

[5spd GT]

illwood - Most likely they will not devulge the characteristics that you are looking for. Give them a call/email and see Yes there are more than just lift/lsa/duration on a cam. Ramp rates and all that have to be considered...and are usually done well.

Their is always "custom cam" jealousy

 

[illwood]

A little bit of Cam Envy eh?

I'm not looking for *exact* answers, just "yes, we play with the profile in these general areas".

 

[5spd GT]

A little bit of Cam Envy eh?

I'm not looking for *exact* answers, just "yes, we play with the profile in these general areas".

I was not talking about you (seperate paragraphs in my response above derived from your screenname) when I referenced the cam envy comment.

 

[90mustangGT]

Camshafts are complex, most people don't know much about them. Yes, there is lift, durration, and LSA, but that's as far as most people go to know. Ramp rates and other valve events, which I will not pretend to know much about, are things that arn't even advertised much and most don't really know about. Two cams, same lift and durration as well as LSA, made by two grinders may be two totally different cams.

The fact is, the "custom" cams only cost a little more, but usually have more happy customers. It seems to be more so with "unusual" combos I think because Ed, Buddy, Jay, ect have more experience. People mess up even then. People call up and say they want the most power possible, then they bitch because of poor street mannors, or vice-versa.

 

[90Notch]

I just don't see how everyone spends $$ on bolt ons but is convinced that spending another $100 or $200 on probably the most important part that brings everything together is a waste of time? Cam companies have some knowledgeable people working for them and if you get one (big if here) they can steer you in the right direction. I once called Comp twice for a cam recommendation on same combo, got two different people and two different cams.

Another thing I'd like to see added to the above is when people speak of driveability the stock cam is recommended 95% of the time for a vareity of different combos. How can the stock cam be right choice for different combos? There is no doubt you could pick the right off shelf cam and run hard but why not pay a little more for the expertise that comes with a custom?