Time To Choose A Cam

[Some Kind Of Monster]

Everything is done on my motor and I just have to choose a cam. I am getting different opinions on what to put in my motor and I am just wondering what the masses think. I would like something to really bring the motor to life with a big lopey idle. The motor is:
454 30 over
10:1 comp
119 CC Open Chamber oval port iron heads
4 bolt main iron block
je sportsman 212135 dome forged pistons
Let me know if you need any more specs.
The two choices so far are as follows:
Crower 01206
And
Comp Cams 280H Magnum

[lilrick]

Everything is done on my motor and I just have to choose a cam. I am getting different opinions on what to put in my motor and I am just wondering what the masses think. I would like something to really bring the motor to life with a big lopey idle. The motor is:
454 30 over
10:1 comp
119 CC Open Chamber oval port iron heads
4 bolt main iron block
je sportsman 212135 dome forged pistons
Let me know if you need any more specs.
The two choices so far are as follows:
Crower 01206
And
Comp Cams 280H Magnum
I have the same set up and I run a solid...Isky Z-45 ...and I likey!!!!

[SmokinLowriderSS]

My 454 is running an Isky 280H I got custom ground from Hi-Tech, and I likey. LOL.
Made a really good base for the headers this year and porting next winter. by then, should carry my 8.5:1, 123cc open chambered 454 to right at 500 HP. My lift is slightly Higher, .565" and not a problem. Might consider it. I think the .520" lift of the Comp will dissapoint sooner or later.
Duanes kit set me back $400 or so with matching springs, Isky Superlifters, new ratainers, shims, Poly-locks. His is custom cut to increase the ramp speed to maximize open time beyond a standard .565" lift 280* Hyd cam. I had no problems on break-in folowing Duane's advice.

[steelcomp]

Why go with what "this guy said" and "that guy said". No two motors or applications are alike, and neither are their requirements for a cam. Talk to Chris Srtaub, and get the right cam for your application. CStraub69 here on the boards. You'd be very surprised at what he comes up with as compared to what the "consensus" is.

[396_WAYS_TO_SPIT]

the comp 280h is perfect. 230@.050/110 lobe/.525 lift
Heads are bone stock so there is a limit on the cam....... :) :)

[SmokinLowriderSS]

My heads from 1978 somehow had the early '70's short-slot rockers, so I did have to change those too. :boxed:
I never did figure out the 2 different colored stripe valve springs either, like 4 or 5 orange ones and the rest purple. :idea:

[Some Kind Of Monster]

I'm trying to put these cams into desktop dyno and the more cam I give it the more it likes it. That can't be right. What's up with that?

[SmokinLowriderSS]

To a certain extent that IS right .... but ... you will reachg a point where the heads will flow no more, and if you are running log exhaust, I run those as "Hi-perf manifolds with mufflers", it works really close. Do you know your head casting numbers? If so, you may find port size info here:
http://www.mortec.com/bbc.htm
You may be able to find your head's flow info here:
http://users.erols.com/srweiss/tablehdc.htm#BBFord
Most makes are there including imports.
If your heads aren't on Stan Weise, you may be able to work with comparable ones that are via comparisons of port sizes @ Mortec.
Use the "custom port flow" settings on the heads in DD.
Good luck.

[Some Kind Of Monster]

I called up Comp Cams and Maxwell told me to go with the 11-240-4 as seen here: http://www.compcams.com/Technical/Search/CamDetails.asp?PartNumber=11-240-4 This cam has a 112 lobe seperation as opposed to the 110 on the 280H and 108 on the Crower. Maxwell even ran my numbers on his Dyno sim and the 240-4 came out way on top. This is too confusing! Is there a reason why I shouldn't run the 240-4 and should stay with he 280H?

[Some Kind Of Monster]

Just got off the phone with Dave at Crower. He said to go with a 01351 which is
INTAKE: Duration: 288º Lift: 0.6 Clearence Hot: 0.022
EXHAUST: Duration: 292º Lift: 0.619 Clearence Hot: 0.024 Lobe seperation @ 107
Why is everyone recommending cams that are so different? I thought at lease they would be in the same ballpark of one another.

[502 JET]

I was told by an engine builder that it is best to run the heads on a flow bench to find out how much they flow and at what lift.Then he will have the numbers to select the proper cam.He knows about what cam will be good but with the the actual flow numbers he can select a cam that will be the best.You could go with published flow numbers but the heads you have may not be exactly the same.
Another factor in selecting your cam would be what type of boat you are running and how many rpms you would like to run and make max power at.You should contact engine builders in your area and ask their opinion for a cam.What they come up with may be totally different than the cam companies.

[Some Kind Of Monster]

I was told by an engine builder that it is best to run the heads on a flow bench to find out how much they flow and at what lift.Then he will have the numbers to select the proper cam.He knows about what cam will be good but with the the actual flow numbers he can select a cam that will be the best.You could go with published flow numbers but the heads you have may not be exactly the same.
Another factor in selecting your cam would be what type of boat you are running and how many rpms you would like to run and make max power at.You should contact engine builders in your area and ask their opinion for a cam.What they come up with may be totally different than the cam companies.
They are just stock open chambers with large valves. I shouldn't need to flow test simple stock heads to come up with a definitive cam answer. Really the numbers shouldn't be that far off from one recommendation to the next!

[396_WAYS_TO_SPIT]

I was told by an engine builder that it is best to run the heads on a flow bench to find out how much they flow and at what lift.Then he will have the numbers to select the proper cam.He knows about what cam will be good but with the the actual flow numbers he can select a cam that will be the best.You could go with published flow numbers but the heads you have may not be exactly the same.
.
That is way out of his league.....

[502 JET]

That is way out of his league.....
I kind of thought that when I was typing it.
My engine is a 509 bbc with Brodix BB2X heads and I will be running a solid roller.I am dumping a considerable ammount of money into my engine and dont want to leave any hp on the table so to speak.I said to my engine builder: Dont tell me after the dyno session that it would make more power with a different cam.The engine builder said that is why he has a flow bench.The published flow numbers for my heads may be inflated or conservative but will know for sure.

[396_WAYS_TO_SPIT]

I called up Comp Cams and Maxwell told me to go with the 11-240-4 as seen here: http://www.compcams.com/Technical/Search/CamDetails.asp?PartNumber=11-240-4 This cam has a 112 lobe seperation as opposed to the 110 on the 280H and 108 on the Crower. Maxwell even ran my numbers on his Dyno sim and the 240-4 came out way on top. This is too confusing! Is there a reason why I shouldn't run the 240-4 and should stay with he 280H?
Did you tell that guy that your heads are STOCK????????

[396_WAYS_TO_SPIT]

I kind of thought that when I was typing it.
My engine is a 509 bbc with Brodix BB2X heads and I will be running a solid roller.I am dumping a considerable ammount of money into my engine and dont want to leave any hp on the table so to speak.I said to my engine builder: Dont tell me after the dyno session that it would make more power with a different cam.The engine builder said that is why he has a flow bench.The published flow numbers for my heads may be inflated or conservative but will know for sure.
Thats the proper way of doing it;) How much did he charge you to run them on the flow bench?
396

[poncho-pwr]

The ONLY way to get the optimum camshaft for any situation is to know everything about the engine, especially head flow numbers. It is worth it to have this done if you already have the motor apart. The "experts" that you speak with on the tech line at the big cam companies are just going to ballpark you out of a catalog or off of a sim program, and that is fine if you are just looking for something ballpark performance wise. A lot of those guys have never even installed a camshaft. If you want the best performance you can get out of the package you have you need to work with someone who knows their stuff concerning cams. If money is too tight to have your heads flowed I would reccomend at least getting the casting numbers of of your heads and calling a pro engine builder/cam expert.
Another important thing you need to remember to do is to degree your camshaft when you put it in. Being just a few degrees off can kill performance. If you don't know how to do it or don't have the tools needed to do it spend the money and have a pro do it.

[502 JET]

Thats the proper way of doing it;) How much did he charge you to run them on the flow bench?
396
I purchased my heads through my engine builder they cost $2400. complete from Brodix BB2X with inconel exhaust valves cnc chambers cnc bowl blend cnc intake port match.He is going to disassemble the heads and double check everything reassemble them and flow test them all for the price above.I dont know what he charge if you walked in with heads and wanted them flow tested.

[cstraub]

They are just stock open chambers with large valves. I shouldn't need to flow test simple stock heads to come up with a definitive cam answer. Really the numbers shouldn't be that far off from one recommendation to the next!
In actuallity they will be off. . .sometimes far off from each recommendation. The techs that LISTEN and ask the most questions will get you closer to what you will need but to get as close to exactly what you need the air flow numbers need to be apart of the decision. Sure you can base them off of posted numbers but I have seen a valve job make 30 CFM difference on a head. But hell it is all relative to what you want to do. . .if this is a pleasure never going to be the fastest boat. . .then a catalog selected cam will do the job. If this is suppose to be the fastest thing on the lake then I would flow the heads.

[Barry_R]

I can add to that a bit. This'll be hard to swallow - but there is no "best" or "right" cam.
There is a huge range of cams that will work somewhere between good and great - - depending on your expectations as to idle sound and "butt-o-meter". The ones that sound the best might also have the highest peak speed - - but might also take longer to reach that peak as compared to a smoother sounding stick.

[steelcomp]

I can add to that a bit. This'll be hard to swallow - but there is no "best" or "right" cam.
There is a huge range of cams that will work somewhere between good and great - - depending on your expectations as to idle sound and "butt-o-meter". The ones that sound the best might also have the highest peak speed - - but might also take longer to reach that peak as compared to a smoother sounding stick.
I've tried to swallow this a few times, but it just gets puked back up. We'd all be real interested in hearing some details behind what you're trying to say here.
Thanks.

[Cas]

Since you're using Desktop Dyno, try these numbers to compare
Hydraulic
Specs at .050
Lift-
Int- .510
Exh- .510
ivo - 3
ivc - 51
evo - 51
evc - 3
Since DTD can't be real accurate, just look at the tendencies of where the TQ and HP peak and how the curves are. You really don't want a steep ramp up and down. For instance, if you have a peak HP of 500 at 5500 rpms but only have 400 at 5000, you probably won't be able to spin an A impeller past 4200. You are better off to have a flatter curve so the difference between the hp at 4500 is a closer to your peak at 5500......did any of that make sense?
The above numbers are totally arbitrary and are for an exaggerated example only

[SmokinLowriderSS]

there is no "best" or "right" cam.
Now, I think that's innacurate (or at least a grand oversimplification) as for any combination of parts, and for a set of desires (be they to the ear or to the dyno), there is a cam that will provide exactly what is desired, IF what is desired is achiveable within the limitations of the parts available. There is even likely to be several different cams capable of providing the exact (or so nearly as to be pointless) same results in the combination given that there are so many cams available today, especially when you step away from "shelf-cams" into totally custom grinds.
There is a huge range of cams that will work somewhere between good and great - - depending on your expectations as to idle sound and "butt-o-meter".
Now that, I agree with, the hard part IS finding that "best" (or "perfect") cam out of the plethora of available options.
The ones that sound the best might also have the highest peak speed - - but might also take longer to reach that peak as compared to a smoother sounding stick.
This part, I'm having trouble digesting myself. What are you trying to say? Feel free to write a horribly long essay if need be, others (who shall remain nameless :crossx: :crossx: ) do on occasion. :crossx:

[502 JET]

This part, I'm having trouble digesting myself. What are you trying to say? Feel free to write a horribly long essay if need be, others (who shall remain nameless :crossx: :crossx: ) do on occasion. :crossx:
I think what Barry is implying is that a cam with a rougher idle (high duration/overlap)makes peak power at higher rpms and may take longer to get to top speed.The smoother/milder cam makes more low end power and would get you up and going quicker.

[steelcomp]

I think what Barry is implying is that a cam with a rougher idle (high duration/overlap)makes peak power at higher rpms and may take longer to get to top speed.The smoother/milder cam makes more low end power and would get you up and going quicker.So basically what you're saying is that your stock headed 454 with a smoother/milder cam is going to accelerate, and get to top speed faster than my 467 with the solid roller? :idea: If that was true, then races would be won with "smoother/milder" cams. I think you're confusing two different acceleration rates, (engine rpm vs. vehicle speed) and basically wrong about both in the generalization you're making. If your cam is too radical for the rpm range you intend to use it in, then this might hold water, but that's why it's so important to choose the right cam. There is a true statement in what you said, although probably unintentional, and that is, it's always better to err on the small side when it comes to cams.
Off the shelf cams have their place, and it sounds like this is a perfect example. Something close to what you need, but it's not worth a custom grind. You're severely limited by many things with these heads being stock. You might get DTD or some other sim to calculate all kinds of power with this cam or that cam, but can you actually install that cam and run it? You get a cam based on what thede heads will flow, and you're going to run into all sorts of mechanical problems that you don't sound ready to deal with, if these are bone stock heads. If you really want to step up, and have a good, reliable, durable set of heads that you can get the most out of, here's a few things to consider:
*Valve upgrade. Get a set of inexpensive one piece stainless valves. The factory valves are OK, but they're heavy and with increased spring loads and rpm that go along with a performance cam, I wouldn't use them.
*Rocker arm upgrade. Minimum, a roller tip performance steel rocker, like the Crane stamped steel, or the Comp Roll Tip. Depending on the lift you go with, the stock rockers may not work. If you don't mind spending the $$, find a decent set of aluminum roller rockers. Crane Golds, Sharps, Scorpion, etc...all right at $200/set.
*Valve springs and retainers. You need to get the correct springs to go with whatever cam you order. With that, I'd get a good chromoly steel one piece retainer, and good hardened valve locks. This will ensure that things will stay together in the event of an over-rev, or just a good ol' high speed run.
*Have the heads valve jobbed with a good performance valve job, preferably by someone who knows what they're doing. Nothing radical, you don't even have to port them. Just the valve job will make substancial improvements, and along with a performance vlave, even better.
*Guides. Have the guides cut for positive type valve stem seals. Chances are, you're going to need to add some clearance between the top of the guide, and the bottom of the retainer anyway, and the cutter used to do this will do both. Before the heads are assembled, you need to make sure there is enough room here for the amount of lift you have or things will break, like rockers, and pushrods. If you're going to a cam that requires a dual spring, then the stock umbrella seals won't fit anyway. The spring seats may also have a step in them that will need removing (for dual valve springs). This is a very simple operation that can be done at the same time as the guide mod.
*Assembled Spring height. If you are stepping up to a performance spring, it may need more installed height. The machinist should check the installed height at each valve before assembling. They can be off a long way from one spring to another, so each valve needs to be checked. The spring pressure should be checked against the advertised pressure as well, in a spring scale. This is all critical. If the spring is installed too short, it can bottom out or "coil-bind" before the cam has reached max. lift. This will have the same result as the retainer hitting the guide. If for whatever reason the spring is installed too tall, then you won't have adequate pressure to keep the lifter following the cam's profile. The worst thing that can happen in this case is you'll beat the seats out of the head in no time. There goes your new valve job.
These are basic performance upgrades that will allow you to get the most out of your heads. This is assuming that you have typical BB Chev heads with screw in studs and guide plates. Without these upgrades, you can't come any where near getting the potential out of your heads. It's not real expensive race stuff, just basic performance upgrades, and by doing so, you can run a moderately agressive cam, get that idle that you want, run higher rpm's safely, and make way more power with complete reliability. If you choose not to do these upgrades, then you're going to be limited as to what gains you can expect from a cam change, and can be setting yourself up for disappointment and possibly way more cost that doing it in the first place. If your machinist dosen't have the knowledge or equipment to understand and do these simple, basic things, you need to find another one.
Feel free to write a horribly long essay if need be, others (who shall remain nameless ) do on occasion. :D

[Some Kind Of Monster]

Thank you Steelcomp. Your post was most informative. Here is the rest of the information that I have left out. The last three numbers on the heads are 781. The valve sizes are: 2.01 Intake and 1.750 Exhaust. They have had a valve job and are running Stainless valves. I have had the heads reworked to bring them back to what I thought would be classified as "stock with larger valves". We will also be going with matched springs, and roller tip rockers. I have also had the guides done with bronze inserts. Everything is tight and looking good to go. I just need a cam and the matching springs / rockers.

[steelcomp]

SKOM...it sounds like you have some decent $$ invested in this motor. Why not spend the $75 or so, get your heads flowed, and then you'll know exactly where you stand? You may still end up with an off-the-shelf cam, but at least you'll know that you've chosen it based on good info and not grabbing something out of thin air. If you really want to get the best out of this thing, have a cam ground for it. It would be a shame, at this point, to leave 75hp on the table after all the $$ you've spent. Think of it that way.

[RICHARD TILL]

I`ve read a lot of good replies on this site but the advise that Steelcomp gave is up there on the top. it could`nt have been said better. thats the way i`ve been building motor for 25 years and it`s worked great.

[Some Kind Of Monster]

So,
what does 110 degree or 112 degree lobe seperation do that 108 doesn't do? In other words, whats the difference or advantage to one over the other?

[steelcomp]

So,
what does 110 degree or 112 degree lobe seperation do that 108 doesn't do? In other words, whats the difference or advantage to one over the other?
Less overlap, more vacuum, help widen the power out a little...smoother at lower rpms.

[john]

how do u tell what size ur cam is by the chart

[SmokinLowriderSS]

Well, acording to your card there, that cam has a lift of .574" intake, .578" exhaust.
The open duration is measured 2 ways, from 5-thousadths (basically closed to closed) and from 50-thousandths opening. They are supposed to really mean the same thing, just measured 2 different ways/places. Duration from open to close is 284 degrees intake, 296 degrees exhaust, same as 240/246 measured from 50-thou opening.
The valve lift can be figured from the lobe lift numbers by multiplying by the rocker arm ratio (say ... 1.7), and should be the same as the gross valve lift, or VERY close.
Lobe separation on that cam is 110 degrees, but the spec numbers are at 106 degrees per that card so it is intended to be installed advanced 4 degrees. Setting it straight up or retarded will alter valve opening/closing times relative to the crankshaft/piston position.

[john]

ll

[SmokinLowriderSS]

Pix no worky. :cry: