Stock versus Performance Cams

[Fortunateson]

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 tranny I'm hoping can be fitted to a'32 tranny 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!

[Tinker]

Do a regrind or another cam. Not stock lift. In my opinion. Street or race? 3 pot will need some air flow.

[tubman]

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.

[flatheadmurre]

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...

[Fortunateson]

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...

[Fortunateson]

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What about valve springs, if I went with the Shadbolt 60/ Max1 would different than stock springs be required?

[Ol' Ron]

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.

[tubman]

Originally Posted by Fortunateson

What about valve springs, if I went with the Shadbolt 60/ Max1 would different than stock springs be required?

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.

[flatheadmurre]

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...

[tubman]

"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.

[flatjack9]

I would use the Lincoln Zephyr springs rather than the 185-G springs.

[40cpe]

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#.

[tubman]

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?

[flatheadmurre]

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...

[Ol' Ron]

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

[rotorwrench]

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.

[flatjack9]

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?

[Pete]

"Now if you plan on turning 6500 at Bville, that's another story".

6500 won't even get you in the show nowadays. LOL

[Fortunateson]

I do have Frank Oddo's book...

[Fortunateson]

Originally Posted by flatjack9

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?

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?

[Tinker]

Originally Posted by Ol' Ron

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.

But you are also saying a reground or another cam is not a bad idea. Compression and porting aside.


Certainly buy the book. Ron I see your book and vanpelts. Both a good buy. But I don't see jwl on the vanpelts site??? Nothing wrong with reading.


http://www.vanpeltsales.com/FH_web/f...oksforsale.htm

[flatjack9]

Originally Posted by Fortunateson

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?

Would need to check spring pressure at installed height to see if they are in good shape.

[Fortunateson]

Originally Posted by flatjack9

Would need to check spring pressure at installed height to see if they are in good shape.

Yes, that is what I stated. But if they are close use shims? Or use shims if the valves are a wee bit short?

[Tinker]

I'm still unclear why having zephyr springs (60#) is better then a cam? I don't know??? I run zephyrs on my 38 with a ground cam but I see little reason outside of saying and wearing lobes on a stock cam.


https://www.jalopyjournal.com/forum/...prings.836524/


.

[Fortunateson]

The cam shop owner when I phoned a few minutes ago says stock springs are ok but some use Lincoln Zephyr springs.

[Tinker]

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Spring pressure is for keeping the valve on the cam lobe. Maybe at high speeds like mentioned before on this thread to remove valve flutter or float.


If you are going with a different performance cam. I say yes for sure.


If you are using the stock cam, I'm not understanding the over performance of the springs. I only say to learn. I'm asking. I don't know.

[Brian]

The springs I use in all my builds with 100% satisfaction, irrespective of cam selection, are 'stock' progressively wound offerings as supplied by numerous dealers. The important thing is that there is no coil bind. My 2c

[Fortunateson]

Originally Posted by Tinker

Spring pressure is for keeping the valve on the cam lobe. Maybe at high speeds like mentioned before on this thread to remove valve flutter or float.


If you are going with a different performance cam. I say yes for sure.


If you are using the stock cam, I'm not understanding the over performance of the springs. I only say to learn. I'm asking. I don't know.

That's the exact same reason I'm asking for help with this project. I'm really just learning myself and invoking the stored knowledge of the "mighty Ford Barn and the HAMB"...

[Tinker]

If you are using a non stock cam go with some better spring pressure. If using the stock cam, I'd say 40-60# is fine. I big lumpy cam is not the ticket always also.

I go back to.. You need to get a little bit of something going to run 3 carbs. Maybe just heads are good. 3 carbs is a lot. As mentioned 1 center main and 2 outer dumps or dummies.




.

[Ol' Ron]

The first thing you have to do is determine the operating range of the engine. Learn how to measure spring pressure at installed height. Just guessing what you have or need can be a disaster. once you've have the installed height, make a stop on a drill press and a bathroom scale and measure the pressure . I suggest 50lbs for most cams under 5k. Now if you plan on racing the engine, go with the cam manufactures recommendations.

[Fortunateson]

OL' Ron,

Thanks for the good tech tip. However, I'm letting the machine shop worry about spring height and pressure. I have full confidence in them.

[40cpe]

Originally Posted by Fortunateson

OL' Ron,

Thanks for the good tech tip. However, I'm letting the machine shop worry about spring height and pressure. I have full confidence in them.

This has all been an informative thread, but part of the original post was "will I need different valvesprings if I have my cam reground".

[tubman]

I would think so. However, what springs you should use would be dependant on the characteristics of the cam you will be using.

I recommended "185-G"'s for a MAX-1 clone, because that's what came with my MAX-1 from Iskenderian. I am not in a position to second guess the "Cam Father".

[40cpe]

Point is, he's leaving it to his machine shop to determine spring pressure, height, etc, after asking for opinions here and disregarding information Ol' Ron and others offered.

[tubman]

No disrespect for anyone involved, but this sounds like an uninformed value judgement to me.

[Fortunateson]

Originally Posted by 40cpe

Point is, he's leaving it to his machine shop to determine spring pressure, height, etc, after asking for opinions here and disregarding information Ol' Ron and others offered.

The point really is I'm leaving my machine shop to determine if the stock springs are up to spec. A further point is that I haven't disregarded a single thing as I'm considering all comments, except yours of course, in determining which way to go.... I'm doing research independent of this forum as well and am thinking stock, Zephyr, as well as the Isky springs.

[40cpe]

deleted

[Tinker]

Why again was the question asked??? Cam?

[Fortunateson]

Yes, I was looking for guidance regarding stock versus performance cams. In listening to the pros and cons of both and speaking to my veteran cam grinder I will be going with Shadbolt's M70 ( though I posted M60).

That lead to info required as to valve springs. I read/heard about stock, LZ, and those supplied by Isky. My cam grinder said stock are fine but some go to LZ. I'm not going to be high revving this engine. I'm happy with good low end torque. Higher spring pressure I understand is for high revving and/or radical cams.

But stay tuned as this journey continues...

[Fortunateson]

Anything special about a C1BA cam?

[Fortunateson]

Well after working on my trans, converting a postwar light truck open drive trans to a closed drive system with most of the LZ stuff I went back to the cam question.

I'm leaning towards Ol'Ron's advice but them I found a little more out... I have two cams actually, one marked 8CM and the other EAC-A. Are either of these cams a good cam for my plans or should I get the Max1 style regrind? No sense spending money if there won't be a noticeable improvement.

[tubman]

"Noticeable improvement" and "no sense spending money"? If either of those cams check out good, use it.

[Fortunateson]

I'm not sure I get your meaning. Are you saying that both of those cams are very close to the Max1 so I should use them? Or are you being a little facetious?

[Phil Gillespie]

Originally Posted by Fortunateson

I'm not sure I get your meaning. Are you saying that both of those cams are very close to the Max1 so I should use them? Or are you being a little facetious?

See comments on these cams in John Lawsons book Flathead Facts.
He has checked and dyno tested cams.
If I had the choice I would go with the Merc cam 8 CM.
Phil NZ

[flatheadmurre]

What are you aiming for ?
You want to cruise mostly with good mileage...go merc cam and single carb !
That 32 will move as fast as you need...and then some..
You want lumpy idle...or have a real heavy rightfoot frequantly used...then maybe a more agressive cam.
I think overcamming and overcarbing engines is the most common fault made...

[Tinker]

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It's a balance. No one thing is right.

Nice car. smoked a few transmissions and clutches.

[tubman]

I am serious. In my opinion, the "seat of the pants" increase in performance isn't worth the extra expense. The specifications of the 1CM are closer to a MAX-1 than a regular 8BA cam.

[flatjack9]

Go with the 8CM.

[Fortunateson]

Originally Posted by tubman

I am serious. In my opinion, the "seat of the pants" increase in performance isn't worth the extra expense. The specifications of the 1CM are closer to a MAX-1 than a regular 8BA cam.

Thank you and I hope you weren't offended by my comment. It seems that the 8CM is the one then. I bought the C8BA engine which never has had any machine work but the interesting part is that it came with a Merc crank, Pistons, and cam. Maybe the factory ran out of C8CM blocks that day...

Any imput on the EAC cam? I'd like to know just so I know for future reference. Thanks!

[tubman]

I have no technical knowledge on the EAC cam, but would expect it to be as good or probably better than the earlier Mercury cam. That extra 15 HP in '52 and '53 didn't all come from an increase in compression.

Anybody have the specs?

[flatjack9]

The EAC cam is essentially the same as the 8CM.

[Ronnieroadster]

Originally Posted by Pete

"Now if you plan on turning 6500 at Bville, that's another story".

6500 won't even get you in the show nowadays. LOL

Pete stop giving away secrets! About the cam I like the 8CM good choice.
Ronnieroadster

[Tim Ayers]

Originally Posted by Fortunateson

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?

Original style or type. I would not even think of using used springs once everything is taking apart for a rebuild. Think of the absolute pain in the neck it would be to replace one if it broke. Stock -style springs are under $100. Cheap insurance in my book.

[Tim Ayers]

Originally Posted by tubman

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.

Agree 100% with going with new springs.