Stock versus Performance Cams

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Fortunateson

Well-known member
I'm rebuilding a C8BA. Will be bored around .030" over, had a Merc crank installed at one time, have three 97s on a Fenton Intake, original Eddie Meyer heads, Zephyr gears in a forties truck ****** I'm hoping can be fitted to a'32 ****** mount, and a '40 car rearend with undetermined gears at this time.

So I'm thinking a Shadbolt M60 cam, kind of like the Isky Max1, or staying stock. Any comments between the two cams? Good or bad... I'll most likely use adjustable lifters but will I need different valvesprings if I have my cam reground.

I've done research and all I got was Perplexed!
 
Do a regrind or another cam. Not stock lift. In my opinion. Street or race? 3 pot will need some air flow.
 
I've got a MAX-1 in one engine (258 ci) and an 1CM in another (255 ci). Quite frankly, I can't tell the difference most of the time. They both idle nice and smooth. The MAX-1 seems to want to rev higher.
 
Matching heads to pistons will do more to performance in a normal car then a big cam.
What is the weight of the car ?
3 carbs is a lot for a stock setup...and usually more of a headache to maintain then it´s worth...
Big 97 center and blocking off the others comes to mind for a stock setup...and looks..
The mercury or EAB cam ain´t a bad choice for a fullsize car...
 
The car is a '32 5W. I have been debating just using the centre carb and blocking off the other two. More to think about...
 
If you had a copy of JWL's book, you'd have the answer. Any cam with longer duration will kill of low end torque. Raising compression will increase torque through the entire RPM range. The engine you have is almost exactly like the one in his book. Getting his book could save you money.
 
Fortunateson said:
What about valve springs, if I went with the Shadbolt 60/ Max1 would different than stock springs be required?
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A set of Isky 185-G springs (the same ones they supply with their MAX-1 cam and kit) are just a smidge over $100. It would be false economy not to purchase a set.
 
What is your target rpm...what is valvetrain weight...how agressive is the cam...that will ad up to what springs you going to need.
Most people try and ad a LOT more springpressure to the mix then they actually need...
 
"Murre" - You're right, but what's the fun in telling someone at a car show : "Yep, and then I installed a new set of stock valve springs."? "185-G" sounds technically impressive.
 
For what it is worth, Gary (GOSFAST) over on the HAMB said that the Isky 185-G spring has a seat pressure of 80# at installed height of 2.000". I read somewhere that the Zephyr spring is 70#.
 
I don't see much difference in the seat pressure, but there seems to be a big difference in price. I see Michael has them for $39.95; that sure beats $108.95 for a set of 185-G's from Summit. I do see however, that the Zephyr springs say they are "stock spring pressure". Maybe Iskenderian thinks the MAX-1 needs stiffer springs?
 
Zephyr springs isn´t that much tougher then the stock springs...i can measure a couple but if i remember right in the 60lbs neighbourhood...
Then there`s a lot of different things sold as "Zephyr" springs out there...
Stock 40lbs-Zephyr 60lbs-185G 85lbs...coarse estimate without any warranty...
 
I use stock springs with a .060" shims on all my street engines even with the L-100. I used athe short springs with rotators on the Maz #1 to improve the valve seat life. However I do use the Isky springs on the 400 jr All you need on the seat is 50lbs for most street cams, and a .060" spacer/shim is allot cheaper and works just fine

Now if you plan on turning 6500 at Bville, that's another story
 
Yup, heavier seat pressure won't allow float at higher rpm but it depends on what a person wants to do with it. For high torque, the closer to stock stuff is better.
 
I'm like Ron. Shim stock springs or go with the Zephyr springs. 185 G's are pretty much unnecessary unless you have a really wild cam. How many street engines are ever revved to even 5000 rpm?
 
"Now if you plan on turning 6500 at Bville, that's another story".

6500 won't even get you in the show nowadays. LOL
 
flatjack9 said:
I'm like Ron. Shim stock springs or go with the Zephyr springs. 185 G's are pretty much unnecessary unless you have a really wild cam. How many street engines are ever revved to even 5000 rpm?
Click to expand...

So what you are saying is as long as the original springs are in good shape use them, close I could get away with shims?
 
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