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Cam Choice in a 396

23K views 52 replies 14 participants last post by  onabudget 
#1 ·
I'm working on Dom's (blue Chevelle on TC) 396. He forgot his password so I'll post the details for him.

Looking for a STREET cam for this stock 396 (specs below). Hydraulic or Solid. Car will see 95% street miles. Goal is lots of low end. Must be a stoplight to stoplight animal BUT must be able to handle some Highway trips... several hours at 70 MPH. Hydraulic is perferred but not opposed to a solid if it gives a better punch.

68 CE Replacement 396, Low Miles, stored over 25 years and recently ressurected. History unknown, but is running well with good compression, no oil consumption. Pings like mad on 93 with the small stock cam.

Heads are 1965 206's with shim gaskets. With those small chamber heads, the shims, and the small dome 396 piston...I'm guessing about 10-10.5 CR. The cranking compression is at 190-200 max.

Aluminum 180* Dual Plane Manifold
Holley 3310, 750 Carb
Electronic Ignition

Vehicle is a 72 'velle
TH400 with a 2200 Stall
10 Bolt BOP, gear will be changed to a 3.23
Rear tire is 255/60/15 which measures to about 27" Tall.

Looking fo a cam that can be swapped in without degreeing and will not have any piston-vlave clearance issues.

Thanks in Advance.
 
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G
#3 ·
For an about 10 to 1 CR'd engine...

I'd like to suggest either CC's 270S or their 282S solid lifter cams b/c they both will be darn good street engine cams.

270 more grunt, 280, more topend sorta deal is all..

And if you don't want to lash, then their 270 and 280 Magnum cams.

Note, nothing fancy at all here.

You want SOTA, then look into UDHarold's cams and the VooDoo line

pdq67

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#6 ·
I'd like to suggest either CC's 270S or their 282S solid lifter cams b/c they both will be darn good street engine cams.

270 more grunt, 280, more topend sorta deal is all..

And if you don't want to lash, then their 270 and 280 Magnum cams.

Note, nothing fancy at all here.


pdq67
nope just out-dated old techology CC no quality controlled junk
 
#4 · (Edited)
Not surprised at all that your stock 396/3225hp pings like hell on 93,that motor has very short camtiming resulting hi cyl pressures resulting in ping.

I had that same exact crane cam in my 396 for many yrs prior installed straight up/dot to dot and as Chris suggested it would be a very good inexpesive choice for a good perf cam.

My motor was a bone stock 396/325hp with stock 10;25:1 comp with m20 & 307 geared 12 bolt at the time and that cam alone really woke that motor up a lot.

The stock 396/325hp cam is somewhere like 198/198 deg dur @.05,.398/.398 lift on 114(?) deg lsa & the 396/350hp cam is 214/218 deg dur @.05,.461/.480 lift,114 or 115 deg lsa.

Now compair those stock gm cams to the crane cam (228/228 @.050 .544/.544 112 LSA)and you can see it's definately more agressive but not wild.

That cam had approx 13" vac at idle and when the motor just warm enouhg to come off the choke but not fully up to op temp yet it would idle kink ratty/souonded hot but after motor and oil was up to full op temp it would idle farily decent @850-900rpm in neutral with a slightly coppy but authoritative sound letting you know something was under the hood.

Run approx 18 deg inital/18 deg mech adv in dist in by 2800 with auto trans for 36 total.Also run a vac adv with approx 12-14 deg additional timing thats fully activated at idle for better idle,throttle resp,and fuel economy .

Thats the timing curve and vac adv setup i ran with that crane cam in my 396 and it didnt ping on 93 fuel.

But when i camed it down a smidge in recent rebuild to comp 222/224 deg dur @.05,.525/.525 lift,112 deg lsa with approx 9:8-10:0 comp thats when it would ping under WOT with 36 deg total,but under normal driving part throttle cond even with vac adv it would not ping.

But i guess reducing the dur @.05 by approx 6 deg was just enough to push the motor over the edge ceating a tad more cyl pressur being just enough to ping,i cut it a little to mild on cam. (DANG!!)

Motor runs great with that comp cam and i just run some kemco to allow me to still run the full ign timing curve.

Scott
 
#9 ·
DD,

That's funny b/c like I said, nothing fancy at all and I bet there's been a P/U load of these two cams ran in engines just like his through the years FINE!!!!

pdq67
how many engines have you run these cams in?

I can say that I've used both of them & after seeing how they ran vs the newer tech stuff & the quality of CC's latest stuff, I would not be suggesting those 'old' cams when there are much much better choices out there.
 
#10 ·
Rob,
I run a Lunati-Harold grind UHB-276-286 with 221/230 duration at .050, and .515" lift on 110 lsa in my otherwise stock 396/325 hp (402 actually after rebuild) in the wagon.
Stock iron intake, Q-jet carb and cast exhaust manifolds...runs great on 87 octane.
 
#13 ·
Bill,
Are you still running the 'old' compression of the 396/325? Dom would love to run 87. How does it feel compared to the stock cammed 396?

He is already complaining about using 93, but he'll deal with it for the umph, but a nice low end feel and 87 he'll really be happy. All else considered if the Crane that Chris and Scott reccomend will give him more he'll definately open the wallet for 93 octaine.
 
#17 ·
IMO it's just 'a tad' big for the auto with that converter and gears & he wants to keep it as a streetcar so a looser 'verter is out.
 
#16 · (Edited)
Looking fo a cam that can be swapped in without degreeing and will not have any piston-vlave clearance issues.

Without degreeing?!?:confused:

Why waste the money on a new cam if you're not even going to install it right.:sad:

ALL aftermarket cams should be checked/adjusted for correct timing, period.

As far as "new stuff" is concerned, the voodoo line is VERY hard to beat. If they're degreed in properly, of course.:D

-----------------------------------
end rant, commence recommendation...
------------------------------------

A 60203 installed @ 104°-106° ICL should do the trick.:beers:
 
#24 ·
Without degreeing?!?:confused:
Why waste the money on a new cam if you're not even going to install it right.:sad:
ALL aftermarket cams should be checked/adjusted for correct timing, period.
As far as "new stuff" is concerned, the voodoo line is VERY hard to beat. If they're degreed in properly, of course.:D
-----------------------------------
end rant, commence recommendation...
------------------------------------
A 60203 installed @ 104°-106° ICL should do the trick.:beers:
You're right, I would love to do it 'correct'. BUT realistically it is not always done that way. I'll admit, I've had both professional and hobbyist experience, both in repair and machine shop work. I’ve never learned to degree a cam correctly. I don’t have the tools necessary to degree it either. I’ll also admit that I could use some tutoring on fully understanding the concept of cam timing/phasing and how it relates to engine performance, cylinder pressures, idle, vacuum and power. I would love to have the extra time and sit down over a few beverages and get a good lesson on it all.

Let me be bold enough to say that I’d venture to guess that over 80% of the STREET cars on this board who where done outside of a professional shop have had cams installed without degreeing. To my own credit I have done 8 cams in my adult life, all as a hobbyist in street driven classics (no race stuff here). 2 Olds 330’s, 2 Chevy 454’s, and 4 Chevy 350’s. All were installed either straight up or 4* advanced depending on the era & grind of the cam. All 8 were successfully broken in and ran for many thousands of miles without issue.

Most guys who will do a backyard or home garage swap will install it without degreeing, and yes, this is where I’m at. Maybe not right, but for a low buck street cruiser it works.

I like the Voodoo 60203, I actually have a Voodoo ~202 in my low compression 454 and it has some nice grunt. I think the 203 would be better served in this 396 as it would benefit from the added compression. I chose the 202 in my car because of my 8.7 CR, if I could have got it above 9 I would have opted for the 203.

I also like Chris’ Crane suggestion, Its old school and proven. But will I benefit more with a split duration like the Voodoo line??

My Biggest Concern:
I understand that with the small chamber heads, domed pistons, and shim gaskets I may be running into piston to valve clearance issues. That’s a big reason for posting all this. Dom has dumped a load of money into this car in the last month or two (chassis swap), therefore we are trying to keep it to a simple cam swap.
 
#18 ·
BILL,87 oct fuel with stock 10:25:1 comp & mild cam?

The cam you running isnt that stout to bleed off that much cyl pressure,are your also running a full perf ign curve like 18 base/18-20 mech for approx 36-38 totaol with a vac adv?

I find it kinda funny with the cam your running & stock 10:25:1 comp that it will not ping on such low octane 87 fuel esp if your running a vac adv at part throttle cruise with full perf ign curve.

But if you running the timing fairly retarded like 10-maybe 12 deg base along with 32-34 total that may work with 87 furl . But with over 10:1 comp & full perf ign curve on 87 fuel that just doesnt add up to me but stranger things have happended.

Maybe there is flatops in the motor or heads have larger chambers then you think lowering comp and your not aware of it or your running more cam then you realize like possibly the wrong cam was iplaced in the box at the mfg and then you bought & installed it ?

Not saying it isnt happening in your case ,just would not be normal for 87 fuel to be ok with that setup with full 10:1 comp and full 18 base/18-20 mech =36-38 total ign curve along with the farily mild cam your running unless the timing is significantly retarded,in that case 87 fuel could work.

What ever the case your lucky to get away with it becasue 87 fuel is significantly cheaper then 93 and if the motor performed well enough for you with that setup it's all good.

Happy motoring!!!!!!

Scott
 
#22 ·
BILL,87 oct fuel with stock 10:25:1 comp & mild cam?

The cam you running isnt that stout to bleed off that much cyl pressure,are your also running a full perf ign curve like 18 base/18-20 mech for approx 36-38 totaol with a vac adv?

I find it kinda funny with the cam your running & stock 10:25:1 comp that it will not ping on such low octane 87 fuel esp if your running a vac adv at part throttle cruise with full perf ign curve.

But if you running the timing fairly retarded like 10-maybe 12 deg base along with 32-34 total that may work with 87 furl . But with over 10:1 comp & full perf ign curve on 87 fuel that just doesnt add up to me but stranger things have happended.

Maybe there is flatops in the motor or heads have larger chambers then you think lowering comp and your not aware of it or your running more cam then you realize like possibly the wrong cam was iplaced in the box at the mfg and then you bought & installed it ?

Not saying it isnt happening in your case ,just would not be normal for 87 fuel to be ok with that setup with full 10:1 comp and full 18 base/18-20 mech =36-38 total ign curve along with the farily mild cam your running unless the timing is significantly retarded,in that case 87 fuel could work.

What ever the case your lucky to get away with it becasue 87 fuel is significantly cheaper then 93 and if the motor performed well enough for you with that setup it's all good.
Hi Scott,
This motor is exactly what I stated it is. Honestly, it does not ping.
I bought this engine from a fellow TC member and good friend of mine. Came from his '66 Elky and had about 3K miles on the rebuild at time of my purchase. I do know all the internal specs of it and have the cam card which was supplied thru Harold when he first came to Lunati. It has never been decked and HEI is setup at 14 initial, 36 total...stock convertor & 3.36 gears.
Right now the carb is off the car and shipped out to be restored. Once it's returned, I'd can do a cold crank compression test if interested.

Same topic, different motor...
I run a true 11:1 CR with 210 lbs cranking in the 540 on 93 pump with no octane issues either...numerous street miles.
However, I do add 4-5 gallons of 110 if I plan ahead for some track time just as a safety margin precaution.
The key I believe is to keep them running cool.
 
#19 ·
Agree with Dan,203 cam would be better choice for his setup.

scott
 
#21 ·
yes then the 60204 or maybe even 60205 since it is a light car
 
#23 ·
WOW Bill,that's one in a hundred for sure with the setup your running in the 396 but i think the only running 14 base helps a tad insted of running the full 18 deg base timing many perf cam like but to run on 87 fuel like it does is just great.

You have to admit before you had that motor if someone told you they had a 10:1 comp 396(402) with a mild perf cam running on 87 fuel your likely to think,i dont know about that one like id did.

But if you say its got 10;1 comp with that mild cam and running on 87 with no ping i have to believe it because thats your 1st hand exp with your motor ,not heresay,its a great setup,thats for sure.

I too have always thought just what you said about keeping the motor cool at a good temp like 180-190 deg f most of the time sure helps keep detonation down too.

Did you send your q-jet to Sean Murphy for rebuild/resto?

Scott
 
#25 ·
Rob,I highly doubt you will have p/v clearance issues with any of the cams discussed.Its the duration that really reflects it. That 396 won't need much either to wake it up..remember BB Dave's 396 in his 67? I bought it a few years ago from him and guess what..it was nothing special..stock 325 HP/396 with a 240/246 @ .050 .517/.530 114 LSA Crower solid lifter cam..cam was installed stright up..no big valves or anything fancy..and it ran a 12.45 @ 107-108 MPH
And I hear you on everything you said about degreeing,etc. :)
Go for the 228/228 .544/.544 112 LSA Crane..it works very well..that 68 Camaro we put that cam into turned on very nice to say the least when you hit the throttle.
 
#26 ·
Not to beat a dead horse here about degreeing but,,,
Here are two examples of why you want to degree a performance cam & timing set as suggested by Michael above,,,

I have two 540's sitting in the shop
Both have cams I wanted the ICL to be at 110, one is ground on a 112 the other on a 114 LSA
This means one will be 2° advanced the other 4° advanced
After degreeing
According to the timing gear sets, one is 4° RETARDED, the other is 2° RETARDED,,
This is a 6° discrepancy most likely in the timing sets as I have seen this before
The point is both of these cams would have been no where near where they should be installing "dot to dot"

While I agree that most of the time the cam will end up very close to where it should
Degreeing is not a big deal to do & spending your money on what you feel is the best cam for your application & then just sticking it in does not make a lot of sense,, kind of like sticking your distributor in & tightening it down because timing is a pain & what the hell, it runs doesn't it :D

The deal is if it runs but runs like a pig or it detonates when you feel it should not
If you don't degree I can guarantee you will be wishing you had
If you do at least you know the problem is most likely not because you felt it was "too much trouble" to do it correctly ;)

Hell, you don't even need a degree wheel to check that it is close just use Harold's old "quick & dirty" degree method

If the cam is already in and you want to check, use my 'Quick-n-Dirty' method......
Take off the driver's side valve cover, turn the engine to TDC. If Nr 1 cylinder has both valves on the seat, turn the engine over again.
Both valves should be OFF the seat at TDC, and Nr 6's valves should both be ON the seat.
Using something like a Machinist's 6" Steel Rule, measure from the spring seat to the top of the retainer, 1st on intake, then on exhaust.
The intake retainer should be .030" to .060" CLOSER to the head than the exhaust retainer. If it measures anywhere in that range, it is in the engine just fine, and will run good.
If the exhaust retainer is closer to the head, the cam is retarded, and you need to advance it.
Always recheck after moving the cam.....
This system has worked for over 20 years.

UDHarold
 
#27 ·
Not to beat a dead horse here about degreeing but,,,
Here are two examples of why you want to degree a performance cam & timing set as suggested by Michael above,,,

I have two 540's sitting in the shop
Both have cams I wanted the ICL to be at 110, one is ground on a 112 the other on a 114 LSA
This means one will be 2° advanced the other 4° advanced
Not beating the horse at all, good info here. Now how did you know you wanted to install them at 110 ICL? For the novice like my situation how would I know where I wanted the cam to be? Take for example the Crane that Chris reccomends has a 112 LSA, but who, how, and why should it be installed...where??

Then again Mike above reccomends the 60203, it has a 110 LSA and he states to install it at 106 ICL. What I do understand about that is it will be 4* advanced I just don't understand how you get to that determination.

Now lets go 'shadetree'. Years back you would install all cams using the 4* advanced keyway. Why? I don't know but thats just what we did.

In recent years, we've been told to install them straight up. Dot to Dot, because the manufacturers have already put the 4* advance into the grind.

OK I'm confused, I need a simple explanation of what this all means.

Hell, you don't even need a degree wheel to check that it is close just use Harold's old "quick & dirty" degree method
OK, I get this...sort-of :clonk:

If I use the Q&D and check my cam and find its advanced what does that tell me? 2* 4* 6* 8*???? Or does it just tell me I'm not retarded (or maybe I'm getting there;))

So in your example above with the 540's if you would have installed sraight up you really would have been more advanced then the 2 & 4* you wanted, therefore the Q&D method would have checked out good either way??? Or am I missing something?
 
#31 ·
Thanks for the lesson, Mike (wolfplace). It is starting to become clearer.

Now down to the choices.

1st. Choice is the Crane 228/228 .544/.544 112 LSA (higly reccomended by Chris, who has lots of success with stuffing cams into otherwise stock Big Blocks)

2nd Choice is the Voodoo 60203, the "268" cam. (problem is, Voodoo and Lunati has vanished from Holley's website. I can find them on-line in stores but the 'manufacturer site' for them seems to be gone??? What gives?)

More News... Dom, (remember its his car I'm working on) has thrown in the proverbial Monkey Wrench

He said today, "what about a retrofit hyd-roller?" He would like me (us) to explore the roller option and costs increase. It seems that he'd be willing to spend the extra money to go roller for the extra margin of safety he would get not having to worry about break-in failure.

I've never done a roller, and don't know if a roller grind will benefit him with perfromance. Opinions on this please!!!!
 
G
#32 ·
Great thread, imho................................

I got kicked earlier when I mentioned the old school cams, but does everybody realize that the OLD, 268 to 272 cams in SB's and the 278 to 282 cams in BB's just seem to run FINE in STREET engine about 9.75 to 10 to 1 CR. combinations like we want/have to run b/c of gasoline octane nowadays.

And they are easy on the valvetrains too. Not as easy as stock, but still..

And RIGHT, there are a whole bunch of MODERN grinds out there if you want SOTA and the last bit of power they can give you.

To continue....

Several have asked about cam timing/phasing so I strongly suggect hunting up Pat Kelley's GREAT "Dynamic Compression Ratio Calculator" site and reading it at least three times!!

I'm dense as owl-sh-t so had to read it three time's!!

Here is a link to it!!

http://cochise.uia.net/pkelley2/DynamicCR.html


I know it's book-learning, but still, I think it will help to understand the concept of matching the cam to the engine's static compression ratio and then after doing so how it actually will run, "dynamic compression ratio".

pdq67

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#33 ·
Wow, after searching around the performance section for a while it seems that there are many unhappy Hyd-rollers out there. Almost as many as the flat tappet failures.

I've always had good luck (I"m knocking wood as I type) with Hyd-Flat-Tappet cams and wouldn't mind giving this 396 a shot...but Ultimately its Dom who is spending the $$ and if he's OK with the increased cost for a Hyd-Roller...who am I to complain?

Like many have said, a flat tappet cam swap in a BBC is a gamble no matter what you do.

Still can't find the Luntai/Voodoo site.

Please more opinions.
 
#34 ·
Roller if you have the money

Degreeing a cam is fun. What messes with a lot of guys is the term ICL and how to find it. If you throw away that concept and substitute the concept of max lift it gets easy to understand in a hurry. Just stick a lifter in the #1 intake and mount an indicator. Roll the engine and stop at max lift, read the degree wheel. Do it a couple 3-4 times and notice how easy it is to stop within a degree or so each time. Then do it by the 50 lift coming and going method, and discover that the two methods yield damnear identical results. Then you can also look at your degrees at 50(/RR), just for grins. Sometimes you find a cam card that is wrong or a cam that is ground a few degrees off. You degree the cam by the ICl, you cannot alter the 50 lift degrees without altering the ICL. I never degreed an unsymmetrical cam, hope to some day because I anticipate it will show a difference in the max lift method vs the at 50 coming/going method.

Coarse it's a lot easier with a degreeing indicator, I finally bought one a few years back.
 
#36 ·
I the only thing that I don't like about the crane is that it is a single pattern cam.

Now is Dom running headers? If yes then the single pattern is good, If no then stick with the voodoo.
 
#37 ·
What Dan said,stock ex manifolds can use a few additional deg ex dur but with headers thats less of an issue.

scott
 
#43 ·
I have a stock 396/325. I replaced a Comp Nostalgia series LS 6 hydralic with the same thing because I liked the way it ran. I would have preferred a Crane cam for durability and ease of breakin, but I knew how the Comp performed. Probably are lots better choices, but this sure makes a nice combo with intake, Holley and headers.
 
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