[Straits15204]

Im putting a performance package together with a retailer, they said they'd give me a discount if i bought all the parts from them, and want to sell me some of their custom ground cams.. Ive heard alot of good about Hi-Tech cams, and some bad about Comp cams. Im assuming custom ground means they grind the cams themselves... but that doesnt tell me much. I get the basics of how cams work, controlling the inlet and exhaust valves and how that relates to torque and horsepower, but only from reading. Are custom ground cams something i should be weary about? should i opt to leave out the cams and just get Hi-Techs from some one else? I just dont know specifics about how the brand names and such relate to the cams....

Thanks for any input.

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Originally Posted by Straits15204 Im putting a performance package together with a retailer, they said they'd give me a discount if i bought all the parts from them, and want to sell me some of their custom ground cams.. Ive heard alot of good about Hi-Tech cams, and some bad about Comp cams. Im assuming custom ground means they grind the cams themselves... but that doesnt tell me much. I get the basics of how cams work, controlling the inlet and exhaust valves and how that relates to torque and horsepower, but only from reading. Are custom ground cams something i should be weary about? should i opt to leave out the cams and just get Hi-Techs from some one else? I just dont know specifics about how the brand names and such relate to the cams.... Thanks for any input.

I wouldn't worry about buying everything from one company. You want a combination that works, not a discount if you buy all parts from one supplier.

I am not a camshaft expert but I do have a grasp on how an internal combustion engine works and what the components of an internal combustion engine do. There are people (such as Jay Allen) that can explain things in much more detail.

The camshaft is the brains of the engine. It tells the valves when to open, how long to stay open and how far to open. Its purpose is to fill cylinders, empty cylinders and control cylinder pressure. Cylinder pressure equals horsepower. In my opinion the camshaft should be the last part chosen on an engine combination and after that you can choose gearing and a torque converter if applicable. I also don’t believe in race or street camshafts. An engine will run good at the track and on the street if the combination is matched. The camshaft needs to match the rest of the combination. If you put a maximum number on cam specs because it is a “street cam” you are going to compromise power and possibly driveability. If you are stuck on limiting camshaft specs then you need to limit the rest of your combination as well.

Off the shelf cams are designed to fit a wide range of applications which is why they list minimum compression ratios, rpm ranges, gear requirements, torque converter requirements, generic intake and exhaust requirements, etc. Let’s look at two different engines that both fall into the guidelines of a generic off the shelf cam. Both engines are 302 cubic inches and both use single plane intakes and headers (generic requirements listed in cam catalogs) and have compression ratios that fall in the generic guidelines, lets say 10:1 for argument purposes. Engine 1 has AFR heads with 165cc intake runners. Engine 2 has Canfield heads with 192cc intake runners. Now you have two engines and both match the generic criteria for a particular off the shelf cam. Is this generic off the shelf cam going to be optimal in both engines or either engine for that matter? The same argument could be used for two engines with identical components but different cubic inch displacements. Off the shelf cams give a pretty broad cubic inch guideline. Assuming the same compression, cylinder heads, intake and exhaust a 302 cubic inch engine is going to have different camshaft requirements than a 347 cubic inch engine even though both will probably fall into the same cubic inch “class” for a given off the shelf grind. An off the shelf grind is not going to match your engine’s performance needs unless that cam was designed around specific engine characteristics that identically matches your engine. The chances of that happening are probably worse than your chances of winning the lottery. Off the shelf cams will work and the engine will make power. However, when guys like Jay Allen spec a cam they take into consideration your entire combination which will give you a camshaft that will perform better across the rpm range than any off the shelf grind. That is a fact.