I usually post on ThirdGen.Org (http://www.thirdgen.org) but I like the fact that this site has more engine folk...

ThirdGen, is mainly novices.....

I would like to know yall guys opinions on a camshaft. Here is the current setup:

Engine:
4 Bolt Main 350 bored .030 over (355)
Stock crankshaft
Side polished and shot-peened rods w/ ARP fasteners
Keith Black Flat Top Pistons
Camshaft of unknown specs...
Stock 1.5 rockers with screwed-in studs and guideplates
Ported and polished bowl blended smogger heads
2.02" Intake Valves, 1.60" Exhaust Valves
Weiand X-Celerator Single Plane Intake
1" Open Carb Spacer
Edelbrock 750 CFM electric choke carb

The car as a full race weight of 3350 lbs. And the rear-end ratio is 3.73. Currently I have a 700R4 tranny with a stock torque converter (I know
the stock stall speed would kill me, but I'm waiting for the 700R4 to blow to put a TH-350 in...)
The cam swap would be done at the same time has a head swap. The heads will be World Products Sportsman II's. Click here for the flow numbers of the Sportsman II's. (http://www.chevyhiperformance.com/chevyhighperformance/techarticles/p104800_image_large.jpg) Here's the cam I have in mind:

234 intake duration at .050"
244 exhaust duration at .050"
.488" intake lift
.510" exhaust lift
114 degrees of lobe seperation

What I want out of the car: Well, I would like to put in around a 2600 stall when I finally do perform a tranny swap (hopefully far far in the future). And I would like peak HP somewhere in the low 6000 RPM range.
This car would not be driven daily, but it sees mostly street action.....

If there is any information that I have left out pleast let me know.

What do yall guys think? I appreciate the information,
Brady

Well with that Intake/Exaust ratio your definately right on with a split pattern cam. I used to have a Doug Herbert 235/245 @.050, .490/.500 lift on a 111 l/s. If thats the kind of cam your looking for. You get cam and lifters for about 100 bucks. Its a weird cam though, you can run a hydraulic or solid lifter on it....i though that was weird. Also its has fairly non-aggressive lobes wich will in turn make for long valvetrain life and less valvetrain noise wich is associated with "Xtreamly" {hahaha} aggressive lobes. {and in come the galactic defenders of the DCR} Whats a high low 6000 range???
Now for an expierement......im willing to put 10 bucks down saying that more than one person will automatically say.....compXE268 and an RPM airgap or XE272 its siamese twin, the RPM airgap......here it comes READY?????

Originally posted by Nickel333:
Whats a high low 6000 range???Thanks for the responce, keep 'em coming...
Grammatical error, corrected now.


Edit: Horsepower guesses are welcome anytime.... lol ;)

Flat top KB pistons with 72cc chambers is only about 9.4:1 CR. What is the advertised duration? I think you will be overcammed. I used the Performer RPM cam which has the specs you posted except it is on a 112º LSA (308/318 adv dur). It wanted over 11:1 to work very well and 10.5 to work good. It was extremely soft below 3000 rpm with the 9.5:1 I had. I suggest either more compression or a smaller cam. For racing, I'd go with a 108º LSA. For the street, a 110-112º LSA.

Thanks for the responce. It brings me to a point that I had forgotten to post earlier.

I would be planning on milling the heads. How much? I don't know. But I would want to bring the compression up to the low mid 10 range....

Are you running a 3rd gen Camaro? If so what hood do you have, I'm wondering about clearance.

Originally posted by Dragn70:
Are you running a 3rd gen Camaro? If so what hood do you have, I'm wondering about clearance. Yes sir I am. I am running a Harwood bolt-on 4" cowl hood.

Check it out here:
http://www.thirdgen.org/rides/index.tgo?action=view&rideid=8390

Sorry, no pics on the internet, and those times are with a failing fuel pump (I suppose)...

Have you gotten the heads yet? if not get the 64cc chambers and save yourself the hassle or send the others back in exchange

What type brakes do you have? You won't have much vacuumn with that cam so you will need manual brakes, a hydroboost or vaccumn pump.

Do you already have the Carbuerator? A 750 holley may be a touch too big for decent idle and off idle performance if this is a street motor.

Originally posted by Nickel333:
Have you gotten the heads yet? if not get the 64cc chambers and save yourself the hassle or send the others back in exchange I do not have the heads yet, but they are/would be purchased used. So the choice really isn't mine ya know. Plus I can get machine work done for free...

Originally posted by Redrum:
What type brakes do you have? You won't have much vacuumn with that cam so you will need manual brakes, a hydroboost or vaccumn pump.

Do you already have the Carbuerator? A 750 holley may be a touch too big for decent idle and off idle performance if this is a street motor. My current cam doesn't make too much vaccuum. I have forgotten the exact number though, nobody know the exact specs but an engine builder told me it sounded like and ran like someting around .480 - .490. I don't know, from an engine builder or not that information is still far from gold. I have a one-way valve in line and driving around isn't bad at all. If I "use up" all the vaccuum without getting the revs up I just got to put a little pressure into the pedal.
As for the carb, I have the 750 Edelbrock on there right now. I think it runs well.

Thanks guys...

Brady

ttt

With a stock converter and OD trans 234/244* is too much duration even with 114* LSA.

I would look at something with duration in the mid 210's to about 220* max with a 110 LSA. That's about as big as you should/could go IMO.

As for milling your heads, be carefull and ask your machinist how much they can take. Most smogger castings are also referred to as "lightweight castings" which leaves the deck surface on the thin side. They are prone to cracking.

Brody, why the 114 lsa, lots of nitrous??? It'll pull better vaccum and have a bit more low speed smoothness, but....it's a cheapie Summit grind?

10.2:1 350, 2600 stall, 3.73s, don't blow up the 700R4 keep it in good fluid and rebuild it with a fresh converter later ( IMHO), and since it's an occasional car, assume you would like 5% more torque, for free ( other than a bit of wrench time)????

#1 here is close to your "Summit" cam but a bit lighter in duration ( take 6-8 degrees off a solid grind to compare to hyd).

http://www.cranecams.com/master/apps/chevy21.htm#1.%20PowerMax

A bit too tight on lsa, but still acceptable, perfect duration would be this Isky

Grind No./Type: Z-25 SOLID Strong mid-range performance. Lopey idle. 2500 RPM Stall. 3:70-4:11 axle ratio. 650-750 CFM Carb. 10.5:1 compr. RPM-Range: 2500-6500 Valve Lift - INT: .480 EXT: .480 Valve Lash Hot - INT: .018 EXT: .018 ADV Duration - INT: 278° EXT: 278° .050 Duration - INT: 240° EXT: 240° Lobe Center: 108°

And the best for last....

Call Harold Brookshire at Lunati and tell him you *think* you want a solid cam with around mid 270 seat durations split like 272/280, .500 lift on a 110 LSA, and see what he says.

That cam will make more power than any other cam mentioned in this thread.

What are your performance goals? How streetable do you want this car to be? If your static compression turns out to be 9.5 or so, consider a Comp XE262 or XE268. I run a 9.5:1 355 with 2000 stall, 3.42 gears, and Dart IE180 heads, so all in all pretty similar to your combo. With the XE262, I have run a best of 13.65 at 99mph, and this on 215-65R15 radials with 2.0 60' times. If you are willing to go to a 2600 stall and sticky tires, the improved 60' times plus the lighter weight of your car should put you in the high 12's at over 100mph in the 1/4. My Chevelle tanks in at 3900 ready to race with me in the seat.

The XE262 specs out at 218/224 and .462/.469 on a 110LSA. The XE268 goes 224/230, .477/.480, 110LSA. Both are hydraulic. If you are willing to go with solid lifters, a solid cam with similar specs might be the ticket.

Somone owes me 10 bucks

Originally posted by Eric68:
With a stock converter and OD trans 234/244* is too much duration even with 114* LSA.I'd hate to go "too small" on the camshaft just becuase I don't have the proper stall speed convertor right now though...
Originally posted by 427L88:
Brody, why the 114 lsa, lots of nitrous??? It'll pull better vaccum and have a bit more low speed smoothness, but....it's a cheapie Summit grind?

10.2:1 350, 2600 stall, 3.73s, don't blow up the 700R4 keep it in good fluid and rebuild it with a fresh converter later ( IMHO), and since it's an occasional car, assume you would like 5% more torque, for free ( other than a bit of wrench time)????

#1 here is close to your "Summit" cam but a bit lighter in duration ( take 6-8 degrees off a solid grind to compare to hyd).

http://www.cranecams.com/master/apps/chevy21.htm#1.%20PowerMax

A bit too tight on lsa, but still acceptable, perfect duration would be this Isky

Grind No./Type: Z-25 SOLID Strong mid-range performance. Lopey idle. 2500 RPM Stall. 3:70-4:11 axle ratio. 650-750 CFM Carb. 10.5:1 compr. RPM-Range: 2500-6500 Valve Lift - INT: .480 EXT: .480 Valve Lash Hot - INT: .018 EXT: .018 ADV Duration - INT: 278° EXT: 278° .050 Duration - INT: 240° EXT: 240° Lobe Center: 108°

And the best for last....

Call Harold Brookshire at Lunati and tell him you *think* you want a solid cam with around mid 270 seat durations split like 272/280, .500 lift on a 110 LSA, and see what he says.

That cam will make more power than any other cam mentioned in this thread. Wow, lots of information. No, this car won't be on the bottle. I see that all three of your camshaft recommendations are solid lifter cams. I know that if you have two cams, one hydralic flat tappet and one mechanical solid lifter, of the same exact specs the solid cam will make more power.
Now I have read on here that setting and re-setting valve lash very frequently with solid lifter cams is a thing of the past with some good poly-locks. I am running stock GM stamped steel 1.5 ratio rockers though, can you run poly locks with these? (I know I REALLY need to go get some full rollers, but as always $$$....)
Originally posted by Georgia69:
What are your performance goals? How streetable do you want this car to be? If your static compression turns out to be 9.5 or so, consider a Comp XE262 or XE268. I run a 9.5:1 355 with 2000 stall, 3.42 gears, and Dart IE180 heads, so all in all pretty similar to your combo. With the XE262, I have run a best of 13.65 at 99mph, and this on 215-65R15 radials with 2.0 60' times. If you are willing to go to a 2600 stall and sticky tires, the improved 60' times plus the lighter weight of your car should put you in the high 12's at over 100mph in the 1/4. My Chevelle tanks in at 3900 ready to race with me in the seat.

The XE262 specs out at 218/224 and .462/.469 on a 110LSA. The XE268 goes 224/230, .477/.480, 110LSA. Both are hydraulic. If you are willing to go with solid lifters, a solid cam with similar specs might be the ticket. Thanks for your example. I am not too concerned with how streetable it is. It has to run on pump gas and the power brakes have to work "alright" with a vaccuum canister. This car has no AC, no heater, no defrost, so it's not going to be driven in the winter, but I do drive it quite often (read, everyday) in the summer. This car also sees its fair share of highway miles. In fact it might be going on a few 200 mile trips here soon. So no, I don't think I need a whole lot of vaccuum at idle for my breaks, and yes I am planning on a 2600-2800 stall speed convetor some day, but regardless of those traits it still sees daily use sometimes and it still sees miles of 70 MPH speed limit highways...

I am not sure on the issue as to go with a solid lifter cam or not. Reason is I just don't know enough information to make a wise decision on it. I have heard that people have to set rockers once a week (that would be impossible for me) and I have also heard of people running around with a solid lifter cam that acts exactly like a flat tappet camshaft. If a solid can be just as "user-friendly" as a hyrdo cam then I don't see a reason not to go solid since it makes more power.

One thing to keep in mind though is that I do not want to rev my engine over ~ 6200 or so RPMs. Therefore I know I need peak HP at or below that point.

I would like for this car to have the most HP it can out of those Sportsman II heads and have it reach its HP peak at a RPM that I can reach when I take it to the drag strip. I can't be setting rockers on a weekly, or even bi-weekly basis. I really want to make 350 RWHP. I know this might be hard with my heads and cam selection, or do yall guys not think so?

Big thanks for all the help and please keep it coming. Especially since I'm a 3rd gen F-body guy...

Brady

Brady, the only variable with stock rockers is the slot length vs. lift.( you have screw -in studs I assume). just use the Crane "Kool-Nuts" as your posi-locks. I've never used them, but they look superbly designed for a stamped rocker/solid cam.

Once the motor is run in ( and it took my .600 lift cam a bit to do this ), and takes a "set", you won't have to do it much at all. E.G., I just drove 5 hours, played on the street, raced, drove 5 hours home ( total 650 miles) with no lash issue. Actually, it's been over 1000 miles since my last 'lashing'.

I think you should open yourself up to the choice. BTW, I installed a vacuum gauge sicne I sometimes hear the valves and wonder. But if it holds a steady vaccum, you're OK. Fluttering, a few are off.

Dont fear a mechanical lifter (solid ) cam.They have been used for something like 100 years.It wasnt really until the late 1940's that hyd cams even began to be accepted.

Since 1974 I have only gone 3 years without a least one solid lifter cam engine in at least one of my cars...I useually have around 3 cars at any given time.

Once you understand how they work and how to adj them properly a mechanical lifter cam is pretty easy to live with...

The Crane " Kool Nuts " are a quality poly lock. During that 3 year hiatus from solid cams I had a CC XE hyd in my BBC...I HAD to run poly locks on it as that darn XE would pull they stock ones ( brand new ) out of adj quick...They behaved better with the poly locks....I later remeoved that EX hyd and put a custom ground Isky mechanical cam in it's place...Much better.

Originally posted by 427L88:
Brady, the only variable with stock rockers is the slot length vs. lift.( you have screw -in studs I assume). just use the Crane "Kool-Nuts" as your posi-locks. I've never used them, but they look superbly designed for a stamped rocker/solid cam.

Once the motor is run in ( and it took my .600 lift cam a bit to do this ), and takes a "set", you won't have to do it much at all. E.G., I just drove 5 hours, played on the street, raced, drove 5 hours home ( total 650 miles) with no lash issue. Actually, it's been over 1000 miles since my last 'lashing'.

I think you should open yourself up to the choice. BTW, I installed a vacuum gauge sicne I sometimes hear the valves and wonder. But if it holds a steady vaccum, you're OK. Fluttering, a few are off. Yes, I do have screwed-in studs. I could definately live with once every 1,000 mile type of thing. So even a big lumpey cam should hold steady vacuum at idle? Or are you talking about it fluttering at say, 2500 RPMs?

Originally posted by 69LS1:
Dont fear a mechanical lifter (solid ) cam.They have been used for something like 100 years.It wasnt really until the late 1940's that hyd cams even began to be accepted.

Since 1974 I have only gone 3 years without a least one solid lifter cam engine in at least one of my cars...I useually have around 3 cars at any given time.

Once you understand how they work and how to adj them properly a mechanical lifter cam is pretty easy to live with...

The Crane " Kool Nuts " are a quality poly lock. During that 3 year hiatus from solid cams I had a CC XE hyd in my BBC...I HAD to run poly locks on it as that darn XE would pull they stock ones ( brand new ) out of adj quick...They behaved better with the poly locks....I later remeoved that EX hyd and put a custom ground Isky mechanical cam in it's place...Much better. How would you set the rockers with a solid cam? I really don't understand exactly how a solid works, but judging from the description I would guess just that. It's a solid connection with no give???

I am open to a solid cam, I have heard from quite a few people now (and not just on here) that a solid lifter cam may have a "bad rep" but it really isn't bad at all...


Thanks again

Brady

Originally posted by Nickel333:
Somone owes me 10 bucks Maybe you can take that $10 to pay the entry fee at your local 1/4 mile and back up some of that smack you're talkin'

I'd go with a solid for sure

Brody, no I mean at idle. If you have a few valves out, the vacuum will flutter a bit ( other things such as idle mix, etc will also cause this).

That's the ONE thing I havent got used to, sometimes I get too anal and think somethings wrong, I glance at the gauge, see it holding a steady 10" at idle, adn I know all is well.

Just an aid, and not neccessary.

Plus exhaust leaks still sound like loose valves to me, so the gugae lets me know what the status of the valve lash is.

Setting a solid cam's lash, to me, is much , much easier than a hydraulic since it's so darn precise! There's none of this, "rotate the pushrod until you get some drag". No way man, the only trick is to use the feeler guage properly ( I' use a "no-go" feeler to help ), adn when you get very close to the final setting, lock the set screw down tight, and torque the nut to finish.

Don;t worry about all that now, but if you do go solid, many, many here will be able to square you away on setting lash.

Ain't no big shakes for the easy revs and free torque IMHO.

And Nickel, about your $10, the only comp cam I'd use in this case is the new XS274, and I don't know how it works. Unfortuntely all their small oval track cams are 106 lsa, which is a bit too narly , IMHO, for the street. Also, the good ol 282S might be OK.

Brody, I run a short track cam in my Chevelle, and it's spot on the right cam, but on a 110 lsa. 243/251@.050 for a 439ci. So something just a bit smaller would be about right for you.

Guys, keep in mind this guy has a stock crank & rods. He would be pushing his luck going over 6K on revs.

The largest I would go with the 9.4 CR is a 274 hyd or a 282 solid cam. With a solid, due to the lash, you need to add about 8º duration to get approximately the same size cam.

Then the XS274S might fit the bill to a T. I would caution on going much over 10:1 static with that cam. But Brody , off Mr. Kelly's singature you can download a DCR calculator, I would use it. It was immensely benficial in selelcting my own camshaft.

Brady,

When an engine is fired up and run and goes from a cold temprature to a fully warmed up temp.. the whole engine will expand to some degree... A hyd lifter and cam is designed to adjust itself and take in stride these various temp swings.They also take into consideration the small deflections and various movements in the valve train into consideration also.
Once they are adjusted they generally dont require readjustment ( unless it's a real aggressive acting cam profile ).A hyd cam mechanism is designed to work on the principle of zero valve lash ( clearence ) and a preload.This preload when you adj the rockers is useing force from your valve springs to depress the plunger in the hyd tappet.Properly adj this preloads or lowers the plunger anywhere from .020 to .060 into the lifter body after you have reached zero lash.The opening and closeing of the valve causes some movement with the lifter it'self as the hyd mechanism automaticlly does what it's suspose to do.This in a normal hyd cam design results in a very quiet valvetrain that works over a broad RPM range..... But due to it's Zero lash and because it's ALWAYS working against the valve spring pressure there is parisitic power loss from this design.That is normal.

A mechanical lifter ( Flat , mushroom or roller ) does not have any of these automatic mechanism to do it's work.If you were to operate a solid cam at zero lash as it got warmed up and the various parts expanded you would actually hold the valves off their seats when the valve was suspose to be closed.This would cause rapid destruction of the valve.A mechanical lifter cam requires a certin amount of " Valve Lash " or clearence to work correctly.Where the hyd cam when it's on the base circle of the lobe ( the part where no lifting is taking place ) you always have the preload of the valve spring pressure pushing on the valve train.A sold cam when the lifter is on the base circle has clearence ( generally from .010 to .035 ) depending on design.This allows the engine to expand and NOT allow the vlave from hanging open when the valves were suspose to be closed.Being as there is clearnece there there is NO parasitic power loss as the valve spring pressure is not pressing against the vlave train.This is why a mechanical lifter cam has some valve train noise or clatter.Depending on design and lash they can be nearly quiet to very noisy.But since there is no automatic adjusting mechanism " YOU " must be the adjusting mechanism with a mechancal lifter cam.They require peroidic lash adjusting.If you a really abusing your engine you may have to adj more friequently than one that is not abused.Depending on design some are aggressive and fast acting and others are gentle and slower easier on parts designs.

Sorry but this is just a very basic description of how these mechanisms work.They are actually far more complicated.