First, lets talk about that special treatment Comp Cams offers, for an additional $110 dollars. It's true that nitrating a cam raises the Rockwell hardness to 55-60, however they do nothing to increase the hardness of their lifters. In fact, the tech at Comp Cams told me that once the cam is broke in, the nitrated surface breaks down and eventually matches the hardness of the lifter. Right.... Clay Smith, Isky, Crane, and several others, experimented with nitrating several years ago. They found that nitrating offered no advantage, simply because they couldn't offer a lifter with the same hardness, at an affordable price. Yes, lifters can be made to match the hardness, but at a considerably higher price (which is probably why Comp Cams doesn't offer them). Next they discovered that a cam, or crankshaft, that had been nitrated was more prone to cracking due to stress resulting from flex and temperature fluctuations. Once the surface is damaged in anyway, it cracks and eventually disintegrates, which accelerates wear at an even faster pace. And as expected, the mismatched cam and lifter hardness accelerates wear on the weaker component (lifters), which is true on all metal parts where the hardness is mismatched, such as distributor gears. On a final note, the nitrated cam carries the same warranty as a non-treated cam. If the process is as good as they say, why don’t they offer an extended warranty on the treated cams?
Cam manufacturers found the better solution was to produce cams cores with a higher nickel content, which raised the hardness to 42-46 on the Rockwell scale. By using lifters that match the hardness of the cam, which are affordable to produce, wear is greatly diminished. Today there are literally millions of consumers using high nickel cams, of which a very small percentage have had wear issues that are directly related to cam hardness. Cam failures, or lobe wear, can almost always be traced back to improper break-in, the use of cheaper motor oils, or the use of high volume oil pumps. As such cam manufacturers don't offer nitrating, simply because it isn't needed, especially if you use a good quality oil and follow the recommended break-in procedures, including a high quality break-in oil. On the other hand, if you insist on using a high volume oil pump and/or high pressure valve springs for boosted applications, then a treated cam might be better suited. Just be prepared to change out the lifters on a regular basis, which means pulling the cylinder head frequently, or spending several hundreds of dollars on chilled lifters.
Comp Cams is a huge cooperation with thousands of employs, which finds itself in the same position that Crane Cams was in not long ago. Considering many of the engines produced today don't benefit from cam swaps, and the dwindling economy, the demand for aftermarket cams is steadily dropping. So how does a large corporation suffering from a lack of sales, up the anti to get you to shell out those hard-earned dollar bills? Easy, they dream up a new product and convince the average uninformed consumer that it’s something they can’t live without. Sound familiar? Personally I can find better uses for my money.
As for the 302 springs, I’ll post a few facts and let you guys make your own decision. Personally, I think they are perfectly suited for the applications they are recommended for. Not only do they work well, they are less than half the price of aftermarket springs, and they are readily available from Classic Inline or any local parts store.
AK Miller (hot-rodder, racer, engine builder, and the Godfather of inlines) used stock SBF springs on every motor he built with excellent results, and commented that they were adequate for motors up to 6000 rpm with a .060 shim. He even used them successfully on his turbo charge motors, as did Bill Strobe (racer and engine builder). Mr. Miller was also a Performance Advisor for Ford Motor Company and Ford Racing, and was considered by many to be the worlds leading authority on inline sixes. Miller and Strobe joined forces on several inline projects, and wrote numerous tech articles for Ford Motor Company and the various magazines. In the 60’s he authored an article entitled
“Horsing Around with the Mustang Six - Parts 1&2” for Hot Rod Magazine. In that article, he used stock 289 springs with a 260 duration cam, which raised the rpm capabilities of the Falcon six from 4500 rpm to 5500 rpm. Not bad for a piece of junk.
The Schjeldahl Brothers, authors of the Falcon Six Cylinder Performance Handbook (our bible), have used SBF springs in their motors successfully, and recommend them in they’re handbook as an alternative to stock springs.
Jack Clifford, founder of Clifford Performance and one of the most respected pioneer’s in inline performance, stated that spring pressures should not exceed 100# closed, for our inline sixes. Ed Iskenderian, founder of Isky Cams and the manufacturer for a majority of the camshafts sold by Clifford Performance, supported those recommendations as well.
Next we get to Comp Cams, which only stocks two different profiles for the small inline six. While they will custom grind any cam profile you want, so will any other cam manufacturer, and usually for less money. A few years ago, before Classic Inlines came about, the most popular cam was Comp Cams H260. The spring they recommend for that cam, part number 902-12, is rated at 48# closed, and 146# open. This is actually weaker than our stock springs, which are rated at 54# closed and 150# open.
Stock 289 springs are rated at 60# closed and 175# open, while this is only marginally better than the stock springs, I would use them over the Comp Cams springs or stock springs if I was given a choice. Next we have the stock 302 springs, which are rated at 80# closed and 200# open. Stock 302 springs are considerable stronger (40% closed, and 27% opened) and are perfectly suited for mild performance cams within a given rpm range.
The suggested applications posted on the Classic Inlines website, were recommended by George "Honker" Striegel, who is the owner of Clay Smith Cams, multi record holder in drag racing, and another pioneer in inline performance. While George is renowned for his V8 race engines, he is no stranger to our inline sixes. Back in the sixties and seventies, AK Miller, Bill Strobe, and George built and raced a drag boat powered by a Falcon Six, setting numerous records. While racing boats, George won numerous world championships, and was the first driver to acquire the APBA Triple Crown with his competition jet-boat (the American Revolution).
Ask
anyone in the business (manufacturing or professional racing), that has personally met George, and you'll get one common answer. He is perhaps one of the most knowledgeable persons in the business, and is certainly one of the most respected.
Clay Smith grinds all of the camshafts sold by Classic Inlines. We currently stock seventeen different profiles (about 150 cams), on the shelf, ready to ship. However Clay Smith Cams has more than a 1000 masters on hand, which gives them the capability to make up just about any cam profile you can dream up.
I could go on, but I think I’ve made my point. All of the above professionals, all experts in inline performance, have used and/or recommend the use of SBF springs. Therefore, if I’m an idiot, at least I’m in good company.
For more information on Valve Spring Technology or Valve Spring Recommendations, please see the
tech article on our website. We also have a good
tech article on degreeing camshafts, which covers both methods.
Sources include: Clay Smith Cams, Comp Cams, Isky Cams, Clifford Performance, SI Industries, Hot Rod magazine, the Falcon Six Handbook, the Web, and the advise of a retired GM employee who spent 30 years in R&D, at the GM proving grounds (his expertise was in cylinder head, camshaft, and valve train development). He currently runs a small shop rebuilding and porting race heads. Not only is he a personal friend, he also does all of Classic Inline's work.
