I would hate to see you fire up a motor and immediately damage it.
I know its a pain, and with the lift being low, you may very well be in the clear. But that cam has a lot of duration and you want to make sure you get this right so get a spare head gasket and spare timing cover gasket, make up a piston stop like in my photo I purchased the steel bar on ebay), a checking spring, degree wheel, dial indicator and a way to rotate the motor with the balancer off (I like the Comp Cams version that lets you adjust the degree wheel independently of the crank turning function although they are not cheap). Find true TDC (btw, I have had at least two sets of gears that were marked but the marks were off just a tiny bit so they are not totally accurate). Once you know where true tdc is, install your checking spring, put the head back on with a gasket (the old one is fine), put a push rod in, install the rocker assembly and adjust the valve for No. 1. Back the motor down to 10 degrees btdc and take a measurement, the 5 btdc, then tdc, 5 after tdc, 10 atdc. If your measurements are all above .070 you are golden and may proceed in confidence that you will not have any issues with valves hitting the piston. You could even get away with .060. But if you get any number smaller, you have to either flycut the pistons for a valve relief, or have the cam reground so that it does not hit. With my boy's motor, we opted to have a cam reground to solve the clearance issue but even when I get the cam back, I will still go through the above to double check.
All the above advice can be condensed down to the slogan that Sun Electric Co. put on all their equipment back in the early 1950's- - - - -"We Test- - - -Not Guess!" Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Hey DragSix - Thanks for the Schneider Cam recommendation. I sent the info on my cam to them and got a response from Jerry. His thoughts were similar to others posting here that the cam was little big unless the engine had 9.5 to 10.6 compression. He suggested a cam grind with about 214 @ .050" and about .435" lift. He mentioned that my Lunati cam could be reground.
I am telling you, I just don't understand why more don't use Schneider. They are really good to talk to and do really good work. No settling on some catalog listing. They will grind you a cam for your specific motor. Send that cam out and get it reground and I think you are going to be very happy with the results. That, and there will be no issue with the intake hitting the piston with that cam.
I would be willing to bet that cam is in the 264-268 advertised duration range which is a nice decent street cam for a motor with stock pistons. Similar to what Tom Langdon sold for years as his Bull Dog cam.
Mike- - - - -got a question about Schneider- - - -are they willing to duplicate another cam grinder's profile, such as Melling or Elgin, or do they prefer to offer their own equivalent grind? I have Elgin and Melling cams- - -new in the box, never run, but my cam guy isn't answering his shop phone. He made a master cam for the Elgin for me and reground one cam a few months ago, but I'm afraid his health might have taken a downturn. No news yet from the guy in Texas who thought he might have a line on a cam grinding machine for me. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
It’s a good question, one that I don’t know the answer too but this much I do know, if you call and ask for Jerry Cantrell, you will get him, and he is the owner and the boss over there. He has always been terrific with me on the phone, and I like his workmanship. So I would give him a call and see what he says. He may very well be able to do it.
He has two of my cams right now for regrinding. The other thing I will mention is that he can reface lifters so if you have a set of lifters and you want to do everything possible to avoid a cam failure, you might consider sending him the lifters and have him grind the correct crown for his cam profile.
A cam with that much extra duration has 2 predictable effects: 1. longer overlap period reduces idle and low speed vacuum 2. later intake valve closing means lower DCR and CCP and torque
If the engine had other breathing mods, some power might be added, but as-is it reduces power in the range you use most: anything below maximum torque.
Panic, can you expand on the "breathing mods" comment. What modifications can be done on these old heads?
Ron - - Dusty53 1954 Chevy 3604 In the Gallery Forum "You can't dance with the Devil and then wonder why you're still in Hell." "They will forget what you've said, and they will forget what you have done but they will never forget the way you made them feel."
Static CR increase Tighten piston to head clearance @ TDC to .035" Larger/more carburetor area, better manifold Split exhaust or header Multi-angle valve job, reduced intake stem diameter to 7mm or 5/16" Port clean up Stronger valve springs
None of these are "linear" (produce results proportionate to expense, etc.) but cumulative: work best in combinations.
Panic, I dont think that is a lot of duration. Clifford, Howard, Isky, all sold cams in that range describing them as nice street RV type cams. Langdon's Bull Dog cam I think was in the 254 range on the intake side and longer on the exhaust side, like 264. My cams on the other hand, at 284 degrees duration are pretty big cams. When I get home tonight, let me see if I can find one of my old clifford catalogs. His cams were usually pretty accurately described.
Ok here is a snapshot from a middle to late 80s Clifford Catalogue although he used this same page for quite a few years prior. I ran a couple of his cams and his description of operating ranges were usually reasonably accurate.
I had a good conversation with Jerry at Schneider cams yesterday, and I'll be sending him a couple of new cams (Elgin and Melling) to duplicate, plus a handful of cores. He says he can grind a roller lifter lobe onto a forged steel cam core- - - -216 and early 235, for instance. (No worries about ZDDP, break-in runs, etc.) I can add a sleeve to the bearing area on those cams to increase the diameter, and run them in a 235. MOPAR big block roller lifters will fit a stovebolt block if I sleeve the lifter bores down a few thousandths. Fun and games! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I am really glad you called him as I find Jerry Cantrell and Schneider Cams to be really terrific to deal with. As to where you are headed, I cant wait to see this! I can build a motor, do a lot of the modifications that can be done to these motors, but nothing as sophisticated as what you are contemplating. And truth be told, if this works, I would absolutely love to follow your footsteps, flattery and all that, lol!
Along with the crankshaft and block modifications to run big block Chevy V8 bearings in the main webs (all the same size) that should give those "boat anchor' 216's a new lease on life. There's nothing like a 250+ cubic inch "216" with H beam connecting rods and a roller cam to liven things up a little! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
