235/261 roller rockers - Inliners International Bulletin Board

I'm looking for input on roller rockers for the stock 235/261 type head. Are they available? If not, I'm giving serious thought to start building them.

I built a set of roller rockers for our 321 GMC in our HAMB dragster and they have worked great. After thrashing the engine on the dyno and at the drag strip the lash never changes.

Do you guys think theres a market for the 235/261 rockers?

Ron

Ron, I think as long as they are a direct replacement, and don't require the user to have to buy any additional items to make the swap, and the cost factor is reasonable, there should be a market for them....

I've got agree with CNC-dude. Cost and ease of fitting will determine market acceptance.

I for one would love a set of roller rockers, and probably a set of roller lifters if they were available, at the right price. I know of others who would be willing to buy them.

With some many cam profiles available today,it would be a pitty inliner guys couldn't access them for the want of roller rockers.

Any thoughts on what they would/could sell for? What's a reasonable price?

Ron

They should cost About $300 for the full roller (similar in price to Crower 72831)and about $150 for roller tips (similar in price to COMP Cams 1417)

regards,
Leon

I agree with Leon. I recently bought a set of Crower stainless steel roller rockers for the Chevy 194-292 engine series, and they cost just a wee bit over $300.

I couldn't see anyone producing 235/261 roller rockers for that price. There are 4 different types of rockers on these motors.

Unfortunately, the material cost for the aluminum, roller tips and axles, the pushrod adjusters and nuts, and bushings(if you bush the bore for the shaft) will put you up to or over $150 pretty easily....then you still have to machine the rockers and assemble them for some amount of cost involved additionally....it would be a labor of love, more so than profit!

CNC,

I agree, and that's the reason I've abandoned the idea completely. The ones I built for my 321 Jimmy cost more that $300 for material and parts.

I've had plenty of love in my life, now the money looks better.

Ron

I like Ron have my own true roller rocker for my GMC. I designed them, supplied the bearings, roller tips, and adjusters to a machine shop. I traded electrical work in the shop for the machine work. 3 phased the entire shop, all the labor and parts at my cost (he paid). The owner said his work was valued at $2,000.00 and that was in 1987. We both were happy with the end results.

235's would need to be a labor of love. There are some Barker hi-lifts occasionally found and perhaps some Thomas Rockers but as far as I know they are not rollers. I have 2 new sets of GMC's and they would need some work to use the 5/16" or 3/8"s inch push rods..........Good Luck

Some time back, I also considered making roller rockers for these engines, both the GMC's and Stovebolts. If a person could find a supplier for those components(roller tips, axles,etc.) in bulk quantities and pricing, that would help reduce the costs considerably per set. Since I do CNC for a living, creating the fixturing and designing the rockers and setting up the tooling and programming will cost nil. Its just the out of pocket costs for materials, aluminum bar stock is mostly fixed and inexpensive, its just the add-on pieces like the rollers and other components that will make or break the whole package if you can't get some kind of price break for those items.

Reading this subject fills my head with questions.

Would anodizing be an acceptable method to eliminate the shaft bushing?
How much would one want to alter the ratio if at all?
Could needle roller bearings be used between the rocker and shaft? (provided new shafts were designed)

Curt, anodizing is mostly done for corrosion resistance, especially in higher grades of aluminum like 2024 and 7075. These higher grades are much stronger than the common 6061 variety of aluminum alloys, but they loose properties that make them more vulnerable to corrosion and other conditions. A true roller style would be a the ultimate, but would add to the overall cost considerably compared to a bushed end for the shaft. Finding a needle bearing that has an inner race that would fit the existing shaft, might be an alternative instead of one that the needles run directly on the shaft, then you don't have the additional cost of a special shaft as well. It also might be an advantage to offer or increase the ratio slightly. I got pricing on the roller tips and axles today, and that wasn't too bad, but that still leaves the adjusters to buy and they are kinda' pricey for enough to do a 6 cylinder.

JD,

The pictures you sent me got me to thinking and are the reason I built my roller rockers. Lots of work, but worth it.

Thanks for the help, Ron

Sadly boys it all comes back to the buck. Those who can know what it will cost. Those who can't don't understand volume. It has less to do with best than most! If wishes made horsepower then beggars would have roller rockers.

Not sure on the Chevies but the GMC can use the stock shaft and available torrington bearings. I actually used 2 with a space in the middle. Ferguson used 1 the widest available; both ideas worked. As for the shaft I checked and the bearing inside diameter was .002" too small for the stock shaft do I took a NOS one to a shop with a centerless grinder and had it ground to size and have never had a problem in over 20 years. Thanks Ron

Great info. Can anyone explain the difference these axles and rollers have from common hardened dowels and bushings and what dimensions of these components worked for them? Would a needle bearing pivot do more to reduce friction than the roller tip itself? IMO hardened, fully round shafts that allowed for the needles to ride directly should allow for a lower profile bearing reducing the bore size required in the rockers and possibly their overall dimensions. Any reason not to use titanium? I have a chunk laying around that might be big enough to make a set.

Ti for the shaft or rocker bodies. The only peculiar thing I have seen with Ti is that it is not very forgiving in applications where it rubs or contacts another moving metal. All valves and connecting rods have to have the surfaces plasma coated that contact a moving surface, ie. the valve stems for valves and the sides of the B/E of the rods where they rub each other or the crank cheeks. Other than that, you would definately have the most exotic set of rockers for a Stovebolt ever....