Good points Dan Doc And Charlie agreed Thanks Ron Parker

OK, I have a use proven facts or prove your theorys so they become facts approach to making things work. I cross examine my own theorys with related facts and am very critical of them. I do the same with others theorys, not trying to be offensive, just dealing with reality. I expect the same treatment and believe it is the path to progress. This is how I have approached cam selection for our Swinger as well. The world according the the small chevy has not made our life any better as far as cams go. I was all ready to try to put together a custom grind from Erson but the lobe selection is limited. At this point for our setup I think something with 215 degrees at .050" and .440 - .450 lift on 111 centers would be great, or at least work well. I am not sure about greater intake duration being needed with this low rpm range, or the event timing being unusual or super critical. As far as maxing out the potential of our .904" lifter, maxing out any lifter diameter also requires all the lifter bores to be machined exactly and that is not the case with most factory blocks. Engines that are built this way often get bushed lifter bores so everything is perfect. For me that is out of the question on this project. So has anyone a real world grind like this? Did I miss a lobe design in the erson list?

Just to clarify to someone who's still working through the 13 pages of info in the first post, what kind of engine are we applying this "super cam" to anyways? Street/strip, all out drag, autocross?

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The old white brick

as I recall, we were talking about a slightly modified from stock--nothing extreme

Thanks for that, bodes well for what I'm planning.

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The old white brick

So for a reality check, what is the largest cam that has actually been used with success with the stock converter? By success I mean equal or better drivability. A place to start as far as lift and duration and did it need an unusual amount of advance to work? From there tweaking the valve events would seem the next logical step. I really do not buy in to the idea that Duration at .050" of more than about 220 is going to work well. In my experience even a roller cam that is in the 240 range at .050" is getting fairly warm in a v8 and needs some stall and gears to work. Sure it seems easy to assume the long stroke of a 225 can tolerate more duration, but is it really helpful for a mid range type of setup? Or does it just weaken the engine in its prime spot for a little more top end?

How to use a long duration cam with a low speed converter?
Already solved: super-wide LSA, like 116-118 degrees.
Stable idle, smooth low speed response, just no power until it's turning fast.

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Okay, so we now have the specs on a cam that sounds, in theory, like it would work very well. But what's the cost of have Comp make a custom cam, I've never dealt with them before, or any cam company, so I have no real basis. I've seen their prices for other /6 cams. Comparable?

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The old white brick

any cam you want (assuming you see the lobes you want) from erson for $128 + shipping. info here. I'm not sure how much comp would charge for the equivalent service.

Well having no power at lower rpm is not a solution either. Going to really wide lobe centers is one of those "solutions" that is more a part of the problem, a patch job. After about 114 degrees it is really time to look at less duration. It won't work well with low compression either. At least for what I want. It might work well for a boat with a loose pump or low prop pitch. It kind of surprises me that no one has input on the 270 Erson with a stock converter. I am sure it would be great with something in the 2200 to 2400 range but am curious about the idle and low speed with a stock converter. I may end up just getting an Erson rv cam, but it is a little less than what I want. So much for progress.

"Going to really wide lobe centers is one of those "solutions" that is more a part of the problem, a patch job. After about 114 degrees it is really time to look at less duration".

I wonder when those 9 second steel-bodied auto transmission Buick GS owners will discover what you know. BTW: high LSA is also used to reduce overlap in Pro Stock motors - or do they need your advice as well?
Wide LSA has, as I said, a single purpose: making a large cam docile at low speed.
It provides far more power at peak than the cam with narrow LSA and reduced duration (your choice), and better manners than the same duration with narrow LSA with only minor peak power loss.

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If you wish to use a stock convertor the Erson 270 might be ok....depending on what driving you do. I run a split duration 270 degree can in my Vortec head tow vehicle with a very tight (900rpm stall) convertor. What makes it work is a 2 speed transfer case and the fact that the truck is rarely used in stoplight driving.

You get crappy low end performance but a a great midrange for towing.
I use the low range in the transfercase to stay in the midrange when offroad/low speed.

This cam/convertor replaced a 252HE cam and looser convertor(1500rpm) in an effort to reduce off idle driveline breakage (considerable)and improve mileage/midrange towing torque over steep passes. Think 12% grade for 22 kms in 2nd gear at 3500rpm


If you only do highway driving a tight convertor and big cam are ok....but you still have to gear accordingly.....nothing worse than a 6% grade in high gear at 1500rpm with a 270 cam.

Panics idea might be a solution for "stop and go"applications.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Sandy, thanks for the reply. Your input is right where my thoughts on this are. It seems to be on the line or just a little too much for traffic, AC and hills. I want it to run in higher elevations too, not just run but actually restart again when it is cold. It should be ideal with 3.21s and a 2200 to 2400 stall, or ok with one of the two. I own a vortec head engine too, a 350 with a 212/222 hydraulic cam in it. It pulls 2.73s with a 1800 stall towing converter and a 2.75 first gear just fine, but really never gets to use the rpm range it is capable of and would be better off with lower gears. And thats a good flowing head with a modern chamber design. I don't consider the real wide lobe centers a solution. Why try to build in top end you are not geared for and give up bottom end, not to mention mileage, in the process? To me its a case of making the wrong choice and fixing it with another wrong choice. If it works in someones 9 second 3500 lb car with a 4500 stall, I'm happy for them. But for me, starting off like a slug and then going 60 mph in first gear is not going to work.

Sounds like or Vortec is similar to ,mine....cept I run 3.73 gears with 31 " tires...and no OD.

I run a Comp 264s in the Valaint ....but with 3.23 gears I never get to use 5th gear.( 3.23 was great with the stock cam and compression) I plan on 3.73 this spring....i would go 3.91 or 411 with the Erson 270 and a 5 speed.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Actually Sandy my vortec is in a 69 wagon. No OD, I have a ATI low gear set I picked up for a song in the th350. Smaller tires too, about 26.5" diameter. It's been a good car thats been every where and towed a trailer half the time. What you told me about the 264 comp helps with my choice too. I am thinking I'll just get the erson 254, which is 210 degrees at .050". The other option might be the comp 252, a little more duration but I would like it better if it had the 111 centers. It seems that the torque band might be narrower. Both will be close. I little more lift would be nice and I am setting up a head so guide clearance will not be a problem. As far as oil holes I have known to check things like that for years. If they are off it will not be hard to fix before the cam is in. I was hoping for more real input about street only type cams. It appears most of what is available is almost stock or considerably hotter. Thanks again for the input.