AZ Power & Sound

iTrader: (2)

So lately ive been thinking to myself how it seems like everyone is ragging on "shelf grinds" like the G5X3 etc and telling others how much better "custom grinds" are for every application... So I want an explanation on why they are so much better, especially since even the guys with stock heads are getting these lectures by others...
While youre at that im going to explain my views on things and I encourage you to analyze it and give your response...

As Most of you know, im a very large LG Motorsports cam supporter as ive installed many, and seen results of many... yet when threads pop up like "which cam for my combo" people instantly say "custom grinds are best NO MATTER WHAT!"... So I got to thinking didnt all cams start off as a custom grind for someone? The G5, G5X2, G5X3 and G5X4 were all at one time made for a given car... usually a stock head, bolt on, 4.10 gear ratio car... So figuring this, and theoretically speaking this custom grind, say the G5X3 in this case, was perfect for Joe's 1999 trans am with bolt ons, long tubes, 4.10s, stock heads etc. This cam is now a custom grind made for Joe... but soon after people see Joe's results and now want that cam for their car... which happens to be the same combo. Now this "custom grind" cam is still custom because it was made for Joe's car, but now Arnold wants the cam for his car... he just so happens to have the same mods Joe has on his 2001 camaro...
Now the explination... why is the G5X3 a bad choice for Arnolds car because it came off the shelf of Lou's shop? Its still a custom grind so to speak because at one time it was custom ground for Joe's car, and Arnold has the same mods... so techincally wouldnt it just still be that custom grind cam?
Then lets go further on that... hundreds of people run the G5X3 cam... and sure enough the majority have stock heads, bolt ons, and have LS1 based FBodies with similar gear ratios... So in theory isnt that cam also a "custom grind" for them as well? I mean they have the same car... what would Lou change to make the cam different if it worked so well for Joe in the first place with the identicle combos?

Now lets hop to the other side of the spectrum... For those who tell everyone "Custom grind is the ONLY way to go!"... Lets say you got a custom grind cam from XXX cam distributors made for your car... Now youre bragging to the whole world how your custom grind is the best ever made and it smokes the G5X3 because its custom taylored to your setup... Then Mary comes along and has that cam duplicated because she noticed in your sig she has the same combo as you and wants those numbers... Is your all-so-holy custom grind cam now an "Off the shelf" cam? I mean by most of your theories, the X3 is off the shelf because hundreds of people use it... now that your cam is in production and people with the same combos are using your cam, what does that make it?

Enjoy

AZ Power & Sound

iTrader: (2)

Also this is more towards stock head cars... obviously those with strokers and head/cam cars are in a different ballgame due to the fact the engines can be EXTREMELY different!

AN1313

I'm driving a stock cam, but I will comment.

Different applications (i.e., drag, autocross, roadrace, street, etc.) as well as individual tolerance for drivability, maintenance, and reliability issues will require different cams.

A custom cam will, theoretically at least, allow someone to best match their individual needs.

critter

iTrader: (9)

I don't think that anyone who knows what they are doing would ever make that statement, as it is clearly false. For a simple example, suppose your customer is cash poor and wants a cam with a nasty lope to impress the squirrels at the drive in. In this case, a used GX3 for half price or less is the correct cam, not a $400 (or up) custom one. In fact, don't waste money on good springs because he/she clearly does not need them. Spend the money instead on a loud muffler so that everyone can hear the cam lope.

In general, if you don't really care whether you get the maximum out of your combination, a custom cam is of no value as the real value of a custom cam is getting the maximum from your combination. Of course, a custom cam will not hurt anything, so there is nothing lost in using a custom cam. It will not perform worse than an off the shelf cam. In fact, if the off the shelf cam happens to be optimum for the particular combination, a custom will do no better, but it will also do no worse. So it is pretty much a case of nothing to lose and everything to gain by using a custom cam, modulo unusual requirements like the example above.

Perhaps the attempt at education by J-Rod et al has only succeeded in replacing the mindless "use a GX2/3/? cam" mantra with an equally mindless "use a custom cam" mantra ...

jrp

iTrader: (16)

i guarenttee you no one would be able to duplicated my custom cam by just looking at .050 spec's. hell, took me a while to find out the exact lobes ed used and they suprised the hell out of me.

the X2 and i assume X3 (not sure if its X3 or X4 thats different) are straight off the shelf grinds. 3726R/3730R HR114+4 will get me an x2. and 3727R/3731R or 3728R/3732R will get me an x3.

AZ Power & Sound

iTrader: (2)

While the specs wouldnt get them the grind... someone somewhere knows how to make your cam unless you did it in your garage... And if Someone were to call that shop looking for a "custom grind" with your same combo and the shop sold the cam to them, happened to like it, then they sold more, would your cam now be an "off the shelf" grind? Basically what im getting at is someone somewhere had to start with just one of everything... the G5X4 was briefly a "custom Grind" when Sean ordered it for his car... I got ahold of the 2nd one... so is it still custom?

And Also, what is the definition of custom? Is it only if you ask for a cam and it doesnt already exist? Or if shop after shop thinks a certain preground cam is the best choice for your setup... would that not be custom because you picked something that wasnt on a menu so to say?

QuietTahoe

I totally agree with your thoughts, SS. Cam development grows by developing custom cams that then become popular for various applications. The real problem with "custom" grinds is that they are nothing more than a "SWAG" by the cam designer based on his experience designing cams for somewhat similar applications. Because it is a "one-off", the cam company sure as hell didn't fund development for that particular application. Hopefully, it works well enough to satisfy the customer and make him/her think they really have "something special"! The problem for the cam designer is that the performance of the vehicle is in large part going to be dependent on the talent of the person doing the tuning. Even after initial tuning, there is usually a great deal of performance left to be found with additional tuning. (There are so many parameters to vehicle performance: air-fuel;timing at each engine speed and load; tire size and pressure, engine coolant temp; spark plug heat range, collector length; etc.) Years ago when I was working on a 7-second dragster, we stumbled on .3sec just in collector length and this was after we had over 500 passes on the combo. When you read the threads on this site, it is obvious that a great many people have read a lot and learned very little. In reality, if you wanted to make sure you had the best cam for your vehicle, you would have to have at least 8 grinds done to begin with (various LSA's, duration splits, etc.) and then dyno test and track test (because the speed of air past the exhaust changes the scavenging effects at speed). Warren Johnson and other pros do this all the time. For the most part, "custom grinds" appeal to egos and this is an ego driven sport/hobby. Shelf grinds are not as far off ( and could be much closer to the target) than many "custom" grinds!!!

cyphur

iTrader: (10)

While I agree with QuietTahoe to an extent about the best way to find the "perfect" cam, most one-off custom grinds are typically made for cars w/aftermarket heads on them, or larger CI's. Due to the fact that you would want to flow your heads and then have a custom cam designer such as EDC to take those flow numbers, all the stats on your car/setup, plans for the car and your desires for certain things(where you want the power, drivability, spray friendly, etc) and come up with the best cam for you at the time.

For stock heads I think many of the off the shelf grinds will do just fine, due to the fact that the shops typically put in the time and effort to find grinds that will work for the majority of customers, across a varation of setups. While this can result in great numbers, both on and off the track, keep in mind many people are electing to the the "cam only" route these days to save the cost of doing a head package. IMHO many people would often do just fine ordering any number of cams from FMS, TSP, Thunder, etc.

I'm just going to run an "off the shelf" grind until I go for bigger cubes/power adder. At that point, I will most likely have my heads/intake spec'd out, and consult multiple vendors/cam designers to see what will work best for my setup.

QuietTahoe

Are you saying that the cam designers at Comp, Crane, Crower, Isky etc have never considered stroker motors or aftermarket heads? No one in any type of serious racing runs stock heads anymore! Those guys are working with "super-custom", "high-buck" combinations every day. They ARE working with the guys who order up 8 or 10 cams with the same lobe but with different LSAs and duration changes of 1/2 to 1 degree. If anyone is on top of equating head flow numbers, etc. with cam design it is those guys. Are you suggesting that the LS1 "tuning gurus" (and I mean that totally respectfully) are supplying the entire lift table to the cam manufacturers. I suggest that, more likely, they are telling the big guys' cam designers what they think will work and the cam designers are designing the cams! These same cam designers are the guys who design the "shelf" cams. I'm sure they don't try to design bad lobes so that some guy with a used cam grinder can show them up! If I was going to have a custom cam made, I would certainly track down the most talented guy at one of the big cam companies! It's not just ability and passion, it is also about resources and personal networks!

critter

iTrader: (9)

When I called Comp, I didn't get to pick the guy that answered the phone. He told me that I had to have R lifters for my XE-R lobes and that the 918 springs would not work. When I called Comp again after a disasterous experience with another brand of springs, I still didn't get to pick the guy who answered the phone. The tech support guy who answered the phone this time told me the 918s would work and I didn't need R lifters. Exactly the opposite of the first tech. As it turns out, they were both right and both wrong. 918s did not work, but I did not need the R lifters. If you can "track down the most talented guy at one of the big cam companies", you must have some magic us mortals don't have. I can't speak for all the 32,000 members of this forum, by my "personal network" does not include the most talented guy at any big cam companies.

Racehead

An off the shelf cam is just the cam designers idea of what YOU would want for running characteristics in your car, while assuming he knows exactly what mods it has.

A custom cam is a cam designed for YOUR exhaust system/intake system/compression ratio/mod list, not to mention YOUR expectation list.

If it just so happens that the cam designer designed a cam that perfectly matches your car and expectations, then a custom will bring you nothing.

And a custom is only a custom as long as the original owner is the guy running it. If someone else goes out and gets one for himself it's an off the shelf cam to him. Even if their mods are the same, their expectations will always vary at least to some degree. It was a cam designed for someone else .... end of story.

There's nothing wrong with off the shelf cams, I've ran many. But there's nothing wrong with a custom cam either. Most of them are almost the same price as some of the latest darling, off the shelf designs. Why wouldn't a guy get a custom cam ??

02Reaper

iTrader: (2)

On the XE-R lobes on comps online catolog, it has 918 springs listed for all of them. Do they really even know for sure which ones to use?

critter

iTrader: (9)

Well, that is sort of the point, isn't it? I got two totally opposite answers from Comp hot line techs. Maybe someone there knows, but the people they hire to help us mortals with our problems don't seem to know. After my experience, I have to shake my head whenever I see a poster here recommending that someone call a cam company for adivce/help.

I should say that I think the techs try to help. In fact, the second Comp tech contacted me because of a post here. But the fact remains that however sincere he was, he was wrong about the 918s because he was not given correct information by someone above him.

J-Rod

I'm not ready to post all of my data, YET.

But I will say that a custom cam made more power, and so far has better drivability than the "box" cam that it replaced...

Take that for what its worth...

CAT3

iTrader: (9)

My thoughts, as inexperienced at cam grinding as I am. I am currently running the TSP 231/237 112* in my A4, and I like the cam. With the stock heads, it has been very nice, and will most likely perform better with the H now, although it isnt running right so I cant compare. If i have to swap cams, or whenever i get settled into a new home (thanks Uncle Sam) I will contact some grinders and provide all the info on mods, flow and desires, and ask for several cams to be cut, for comparison as well as to find THE cam for my application and desire. I believe the CG cam is the best way for many ppl, but in the same light there is nothing really wrong with a well informed off the shelf cam, so long as the vendor can get the same info and the customer understands the end results. And by the time I get ready to swap cams, there very well may be a SG cam that fits my needs....and yes I would probably get it in that case. But to say a cam is more all purpose to me is horseshit. There will be, in the overwhelming majority, some sort of sacrifice for the serious enthusiast using a SG cam, be it idle, lope, powerband........My stock heads flow significantly less than stock 241's, so the results and power will be different as well, thats where the modder separates from the enthusiast IMHO. A modder is just as happy with cam x, or FM ro whatever. An enthusiast will seek that perfect grind.

AZ Power & Sound

iTrader: (2)

One of my customers had a similar experience with Comp saying the 918s would work with a G5X2 and also stated that they had many vehicles using that combo... However Lou and Louis said not to, and the fact that he was already shattering Rev dual springs left and right, we went with Lous recommendation and got the 921s...

02Reaper

iTrader: (2)

How did you figure out that the 918's did not work?

QuietTahoe

Maybe a clarification of terms is needed here. Are you calling a "custom cam" a totally new design with new lift tables, etc; or are you talking about "custom recommendations" (i.e. using existing lobes-of which the cam companies all have tens of thousands- and pairing an existing intake lobe with an existing exhaust lobe on a different LSA or basecircle diameter). It's necessary to make the distinction, because custom recommendations are easy and almost as cheap as a catalog grind. Most companies still refer to them a shelf grinds since they are in their lobe inventory, although they aren't a catalogued number. New designs that include new lift tables usually cost a significant amount more! (Then there is the issue of compatibility of the lift table to the valve spring harmonics. I submit that a great deal of the spring breakage reported on this site is not the result of a bad spring design, but rather the lack of compatibility between a given lift table of a lobe profile and the harmonic characteristics of the spring on the engine. A good cam designer assures that his lobe is compatible with the intended spring. That has hardly been discussed on this site and I know it to be significant and critical.) Finally, given the number of lobe designs that most cam companies have and the number of LSA's available; there are literally millions of combinations that they can come up with based on existing lobe profiles. Also, with all the possible permutations of performance product combos and lobe profiles, who can even come close to saying what the exact correct cam is for any application. After 30 years in the performance industry, one thing I have learned is that no one person and no one company has all of the answers!!

critter

iTrader: (9)

The valves float at about 6500 RPM. This is about the HP peak, so it needs to go past that.

critter

iTrader: (9)

IMHO, in the context of this forum and these cam discussions, "custom cam" has always meant "custom recommendation" from one of the knowledgeable independents, including but not limited to EDC, cstraub, denzss, etc, that is based a complete description of a combination, usually including head flow. It would not include cams recommended by a call to the tech support line at Comp. It would not include cams recommended by the counter man at the local speed shop unless he gathered all those variables and took them into account. I could arguably include CamMotion as they do gather that kind of information before making a recommendation.