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Cam suggestions?

40K views 86 replies 16 participants last post by  66 BRONZE 
#1 ·
I'm sure I'll get some flak for saying this, but I'd like to go with a budget cam and lifter kit for my application. Something like a Summit, Elgin, or Howard's cam kit. If one of those won't work well, then I'm open to other suggestions.

My setup...

This is for an 81 Camaro.
sbc 350
Vortec heads (milled .045)
9.8 to 1 compression
Performer RPM intake
600 Eddy carb, but probably going to swap out for a Holley 670
th350 trans
Would like to keep converter stall around/below 2400rpm
3:23 rear end

Car will be strictly street use, so prefer the powerband to be in the low to mid range rpms. Won't ever spin it past 5500 rpm.


I've been looking at the Elgin E1785PM (same as Summit K00172). Many say it's a clone of the Crane 274H06. What do you guys think?
 
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#2 ·
Spend the extra 50 bucks and buy a Voodoo 262, trust me on this. You can use stock exhaust manifolds and convertor.You won't be sorry..:yes:
 
#3 ·
I noticed the summit cam kit SUM-K1102 has the exact duration and lift numbers as the edelbrock performer cam and the SUM-K1107 which is probably bigger than you want but is the same as the edelbrock rpm cam
 
#4 ·
Those are decent cams, but the vortecs will really wake up with a dual pattern cam. The voodoo line is decent. It has really steep intake ramps, and slow exhaust ramps. They are not the only split patterns out there, though. And they do have pretty wide LSA's.

I think you're right in the ballpark with your numbers, adv. duration, duration at .050". Unless those heads have been clearanced/machined for more lift, I think you need to stay around .450".

Bottom line...you need a split pattern, in the 262 to 274 range.
 
#6 ·
I just found this Howard's cam...

#112021 1600-5800 High-lift, dual pattern. Needs 4 barrel, low gears and 2500+ stall

.468/.480
284/302 adv
220/230 @ .050"
110 LSA


That might be a little big, but I'll bet it makes some good power.
 
#7 ·
If you're running headers and a decent exhaust you do NOT want a dual pattern cam. That cam you have picked is an excellent choice IMO. It'll fit your application perfectly. Be sure to have a good exhaust set up though, it makes a world of difference on a tight LSA cam.
 
#9 · (Edited)
Please go read this, before making any decisions or giving any advice about single pattern vs. split pattern cams with vortec heads.

http://www.nastyz28.com/forum/showthread.php?t=56505

no. There is no reason to wade through those 50 pages of crap. Call up any good cam guy and tell him what you have and want. 4 out of 5 will spec a single pattern... Coincidence???

Again it requires a good exhaust setup, but for your parts and application a single pattern will serve you well.

**I just noticed you're good to .525" lift, I missed that part... Why don't you get a bigger cam if you can? I assumed you were using stock vortec which are restricted to .450".
 
#11 ·
This is from the GM guy (Gary Penn) in the thread at NastyZ28:

Unported, with all the other tricks in place, the Vortecs will flow about 235-240 CFM at .500 I and 165-170 cfm at .500 E, on a 4" bore
Adding headers and mufflers doesn't change the amount of air the heads can move.

The cam guys I've talked with do not support your assertion about single pattern cams either.


Yeah, whatever you do, DON'T read that thread. You might actually get to learn what others have done...

Dirt Reynolds's car:

1
977 Z28 Camaro - full-weight, all-steel, 3760-3775 lbs race-ready with driver.

Best ET: 12.15 @ 110.52 MPH on a very worn set of BFG 275/60 drag radials, launched off-idle, in the heat of July.

Highlight notes: Home-ported Vortecs with stock valves and stamped-steel rockers, hydraulic lifter cam, dual plane intake and vacuum secondary carb.

This engine was a budget build, since I had already spent a large portion of my original budget for this project purchasing the car as a rolling chassis:
  • #817 block 400, bored .060"-over for 412.7 ci. The block would not clean up at either .030" or .040" over, so we had to go .060".
  • 11.3:1 CR w/ flat-top 2-valve relief KB pistons, .026" down in the hole, block not decked
  • ARP rod bolts, resized stock 400 rods, 5.565", rotating assembly not balanced
  • Crane 'Blazer' hyd. flat-tappet cam & lifter kit, 234/244 @ .050" .488"/.510", 114 LSA
  • Vortec heads - stock retainers had approx. 3/32" ground off the bottoms for retainer to guide clearance (worked great), Crane single valvesprings with dampner removed, stock rocker arms and valves, fully ported bowls intake & exhaust; some minor runner work consisting of contouring and straightening the runner on the exhaust, and mostly roof work on the intakes with mild contouring of the runner.
  • Edelbrock RPM Vortec intake manifold, unported; Holley 3310 vac. secondary 750 - milled airhorn, installed #31 squirter, pink pump cam in position #3, secondary metering plate installed with #80 jets (stock #72 in front),quick-change vac.secondary pod installed with the white spring (lightest)
  • Hedman ceramic-coated 1 3/4" full-length headers, 3" dual exhaust with 2-chamber race Flowmaster mufflers and 18" turn-outs
  • Stock HEI (recurved), MSD Digital6+ ignition box with Blaster 3 coil, MSD wires, NGK plugs
  • Misc.: Holley Blue electric pump and regulator (set to 7 psi), sumped fuel tank, Flexalite dual electric fans with control box,TH400 transmission with 2800-3000 stall B&M converter, 4.10 gears, full spool, 33-spline axles, c-clip eliminators, welded axle tubes to housing, aluminum Moser rear cover girdle, Lakewood drag shocks 90/10 front/50/50 rear, no sway bars, 275/60 BFG drag radials rear on 15x8 Weld ProStars; 165/15 tires front on 15x3 Weld ProStars
And another:

06sbc zero decked
Eagle 5.7" H-beam rods
Speed-pro dished pistons yeilding 10.3 compression
stock crank turned 10/10
unported vortec RPM intake
780vs carb
COMP CAMS duntov 30/30 nostalgia solid camshaft 247/254@050. .504"/.496"lift
31* total timing
1 5/8" long tube cheapy headers (open exhaust at the track)
TH400 with el cheapo 12" 3000 stall
3.42 gears
26x10" ET drags
3750lb race wieght with me in it

here is pic of my home ported vortecs
I have a few more if anyone is interested

I also backcut the intake valves with a 10* and a 20* grind and the exhaust valves with 30* 22* and 15* grinds. I can't say for sure whether or not it helped as some would say it hurts the flow of the vortec runners, but I did it anyway. I also performed the "ghetto grind to my retainers to allow for the extra lift.

I almost for got to post my times

best run to date with the above combo was a 12.35@108.9mph with a 1.76 60'. The only time I ever sprayed it with nitrous(100hp), I ran a 11.80@113.8 with a 1.65" 60'.



Maybe I'm off base here, but those combos look like they make good power, with good exhaust systems and dual pattern cams...heck one of the guys runs open headers at the track. Can't get more free-flowing than that.
 
#12 ·
I just ran a quick DD of this setup, and the 1785 cam is within 3 hp/ftlb of the voodoo 262. I say that's pretty close to splitting hairs. When you can afford it I would get some 1.6 rockers to go with the 1785 cam. The 1785 cam kit is roughly half the cost of a Voodoo kit, and it'll have a little meaner idle with a tighter LSA. Use the voodoo if you want to put that col sticker on your window, but the 1785 is pretty close to the same in this application (works really well with stock vortecs because of the restricted lift).
 
#13 ·
I agree with highway star....just didn't think he wanted that much camshaft in it. The 488/510 - 234/244 is a damn good camshaft. Thought he was keeping it a little more mild then that..Those would be my choices though..

1st - 465/488 for a mild 5500 max rpm deal

2nd - 488/510 for a little more rpm and will need more converter
 
#14 ·
I'm sure I'll get some flak for saying this, but I'd like to go with a budget cam and lifter kit for my application. Something like a Summit, Elgin, or Howard's cam kit. If one of those won't work well, then I'm open to other suggestions.

My setup...

This is for an 81 Camaro.
sbc 350
Vortec heads (milled .045)
9.8 to 1 compression
Performer RPM intake
600 Eddy carb, but probably going to swap out for a Holley 670
th350 trans
Would like to keep converter stall around/below 2400rpm
3:23 rear end

Car will be strictly street use, so prefer the powerband to be in the low to mid range rpms. Won't ever spin it past 5500 rpm.


I've been looking at the Elgin E1785PM (same as Summit K00172). Many say it's a clone of the Crane 274H06. What do you guys think?
I`d say the crane 274HO6 would be a good cam for you. This guy is claiming high 13`s with basicaly a stock engine so with your vortec heads you should run alot better. Maybe look into some 1.6 rockers. I`m thinking of going with this cam myself.

 
#48 ·
#16 ·
I just ran a quick DD of this setup, and the 1785 cam is within 3 hp/ftlb of the voodoo 262.
Do you mind posting what kind of numbers it came up with?



I don't mind going with a cam a bit more aggressive. I just want to make sure it'll work with my 3:23 rear and a 2400 stall. To be honest, I was looking at the Crane/Elgin/Summit straight 274 grind cam since it would have a rough idle but still run good due to the 106 lc. Before looking at budget cams I was thinking along the lines of the Comp xe268h which is...

Advertised Duration--268 int./280 exh
Duration at .050-----224 int./230 exh
Lift-----------------.477 int./.480 exh
Lobe Separation-----110
 
#17 ·
Elgin 1785 cam- 365hp @5500RPM, 408tq@4000RPM
Voodoo 262 cam- 363hp @ 5,000 AND 5500 RPM, 411tq @ 3500 AND 4000RPM

Goes in 500RPM increments...

It should be noted that this simulator is old and can be off by 5%. That looks to be pretty close to what I would expect though.
 
#19 ·
Why not just get the 60103, I have a 350 bored .060 with fully wroked over ported polished, bowl blend, etc vortecs milled 61cc 2.02/1.6 valves and I took out my summit 1105 cam this past weekend to install my voodoo 60103 and when I tell you it drives like a totally different car. Good LORD. 2400 stall and 2.73 gears, TCI streetfighter 700r4. Im going to post some videos of it this weekend hopefully and show you what it runs like. Runs like a rapped APE or a rapped speedy gonzales! I didnt know that just that cam change would make that big of a difference and it pulls all the way to 6000 and still feels like it wants to pull some more. Just waiting to put the 3.42 gears in there and I should be SET.
 
#21 ·
I'd like to stick with the 1.5 rockers I already have.

Can I ask you guys this...

The Crane xe268 and the Howard's 11202 have very similair numbers as far as lift, .050 duration, and lobe seperation.... but the advertised duration for the Howard cam is much higher. What does that mean or how will it affect how they run?

Crane xe268
Advertised Duration--268 int./280 exh
Duration at .050-----224 int./230 exh
Lift-----------------.477 int./.480 exh
Lobe Separation-----110

Howard's 11202
284/302 adv
220/230 @ .050"
.468/.480
110 LSA
 
#22 ·
Howard's has lazier lobes (easier on valvetrain) and more overlap.

Not claiming truth, just opinion here, but I'd say that the voodoo will give you a more powerful shorter band, and the Howard's will give you a less (but still very) intense powerband that is a little broader.

I'd go for the one with the lazier lobes and more overlap. I was just in this boat, and chose Howard's over the voodoo.



Running 1.6s does not change the cam's grind, but it does increase the "effective" duration of the cam.
 
#27 ·
I want to thank everyone who has helped and made suggestions. As I mentioned earlier, I really wanted to get a budget priced cam. The reasons are I'm already way over my original budget for this car, I'm going to be selling it this summer, and any extra money I save will go towards a cam swap for my Chevelle. I won't be cuting any corners with the Chevelle!

Through your advice and some other reading, I think I'm going to try Elgin cam and lifter kit # E1015M. It is the exact same cam as the Summit 1105 but on a 112 LC instead of 114 LC. This kit is only $90 as well.

Lift: .465/.488
Duration: 298/304
Duration @ .050": 224/234
Lobe Separation: 112 LC
Moderate rough idle, Auto require higher stall, Street/strip


What do you think? I'm concerned it might be a little doggish down low, but hopefully it'll be ok.
 
#41 ·
I want to thank everyone who has helped and made suggestions. As I mentioned earlier, I really wanted to get a budget priced cam. The reasons are I'm already way over my original budget for this car, I'm going to be selling it this summer, and any extra money I save will go towards a cam swap for my Chevelle. I won't be cuting any corners with the Chevelle!

Through your advice and some other reading, I think I'm going to try Elgin cam and lifter kit # E1015M. It is the exact same cam as the Summit 1105 but on a 112 LC instead of 114 LC. This kit is only $90 as well.

Lift: .465/.488
Duration: 298/304
Duration @ .050": 224/234
Lobe Separation: 112 LC
Moderate rough idle, Auto require higher stall, Street/strip


What do you think? I'm concerned it might be a little doggish down low, but hopefully it'll be ok.
I think its a good choice...I don't think you will have a problem with low end power. We have used this camshaft (both the 112 and 114 LS) really no difference between the two as far as we could tell. The last one we used was the howards part #110041 which is .465/.490 - 294/302 ADV - 224/234 @ .050. Great running cam with less cylinder head then you have.
 
#33 ·
rocker ratio doe not change duration. Duration is measured at the cam, not the valve.

I would love to see just one VooDoo262 cam that has 80,000 miles on it with 1.6 rockers. Just one. I'm not saying it isn't possible, just that its a foolish undertaking. Surely with all of the people claimed to be running this combo there's one that has made it 80,000 miles.
 
#34 ·
rocker ratio doe not change duration. Duration is measured at the cam, not the valve.

I would love to see just one VooDoo262 cam that has 80,000 miles on it with 1.6 rockers. Just one. I'm not saying it isn't possible, just that its a foolish undertaking. Surely with all of the people claimed to be running this combo there's one that has made it 80,000 miles.
I think MOST guys here building a performance engine for the street don't expect to get 80,000 miles out of a Hot Rod engine. My foolish undertaking are well worth it especially when I grab 2nd gear at 5700rpm:D. Does the new camaro or corvette have an 80,000 mile warranty with there rollor cam engines?????
 
#36 ·
no, 100,000 mile. And I expect the engines I build to last that long. I would hope most people here do.
Can you give us some specs for your engines/ cr/ cam/induction, and use of car, trailer queen/daily driver/street/strip/ is it driven easy like grandma would drive or is it driven like a performance car. Does it have a set of nuts.???
 
#37 ·
I've built a lot of different cars, but the lowest compression was 9:1, the highest was 11:1, cams ranging from 214 to 250something (intake @.050") pontaics, buicks, chevys, fords, daily driver/toy (i have too many cars to drive them all daily, and honestly I drive my truck more than any of the others and its a stock 2500HD), all of them were pretty fast for what they were. None of them were pretty enough to deserve a trailer. I've also hotrodded riding lawnmowers, gocarts, boats, etc.

Still haven't done a plane (but I plan to), nor have I done a VW bug, which I want to do just because those engines are so cute.
 
#42 ·
did i miss something?
Remember this from a few weeks ago?


Regardless, raising the ratio from 1.5 to 1.6 shouldn't be much of a problem as long as standard precatuions are taken.

For a given valve lift you are better off running the 1.6 than the 1.5.

The rocker ratio DOES NOT ALTER THE DURATION AT ALL.

Perhaps money would be better spent on a custom cam than a rocker change though...
I know that the change in rocker ratio does not change how the cam is ground, but I also know that the valves will be off the seat faster and farther. In crank degrees, depending on cam lobe profile, a valve might spend x degrees coming off the seat and reaching a height of .100"...with a higher ratio rocker, it will get there quicker, so maybe we can call this the 'effective' duration or something. The valve lifts higher, and opens/closes faster.

Here...I just found some backup...Read:

http://www.pontiacstreetperformance.com/psp/RockerArms.html

and from crane cams FAQ section...
How does an increase in Rocker Arm Ratio improve the engine's performance?

The lobe lift of the cam is increased by the ratio of the rocker arm to produce the final amount of valve lift. A cam with a .320" lobe lift using a 1.50:1 ratio rocker arm will have a .480" valve lift (.320" x 1.50 = .480"). If you install rocker arms with an increased ratio of 1.60:1, with the same cam, the lift would increase to .512" (.320" x 1.60 = .512"). The engine reacts to the movement of the valve. It doesn't know how the increased lift was generated. It responds the same way it would as if a slightly larger lift cam had been installed. In fact, since the speed of the valve is increased with the higher rocker arm ratio, the engine thinks it has also gained 2? to 4? of camshaft duration.

The end result is an easy and quick way to improve the performance of the existing cam without having to install a new one. See the Buyers Guide section for availability of increased ratio rocker arms. Remember, whenever you increase the valve lift, with either a bigger cam or larger rocker arm ratio, you must check for valve spring coil bind and for other mechanical interference. Please review the previous sections concerning these matters.

Anytime we're talking about an engine "thinking" it should raise an eyebrow. How does an inanimate object think? Seat to seat duration remains the same, .050" duration remains the same, BUT the amount of time the valve spends at or above a certain lift does increase. Cam timing remains unchanged but any duration at a net valve lift does increase.


Not trying to cause problems, just trying to kill an old myth.
Like you, I am also not trying to cause problems, but you're adding ammunition in support of the "myth" here. We both know the engine doesn't "think", it only does, but in that regard, it does keep the valves open more, longer. I guess this is splitting hairs now, and it comes down to how you want to define the word "duration".



Quote: The rocker ratio DOES NOT ALTER THE DURATION AT ALL. Unquote.

Changing rocker ratios will not change seat duration. It WILL change duration at .200 cam lift. Duration @.200" is what gives the engine its upper end power and rev limit.

Changing ratios will have an effect. Adding lift and duration to the intake MAY give a few more HP. Adding lift and duration to the exhaust MAY add to or decrease torque curve width.

Going from 1.5 to 1.6 on an engine with a bad exhaust port usually shows some improvement. With a good port, you may lose power. I could tell a slight difference going from 1.5 to 1.6 ex with my Sportsman II heads. Changing the intakes made no difference since the engine was exhaust port limited.

If you are curious, find a junk block in a shop's dumpster. I suggest a useless 400 SBC because the stock rods, pistons, and a junk crank are also useless and obtainable for nothing. I've seen a lot of 400's with holes in the sides. Next, buy an engine stand and everything needed to degree a cam. With a block, a bad crank with a good #1 throw, a decent rear and front main bearing, 1 rod, and 1 piston, you have what you need to check duration numbers. For flat lifters, any stockers will work. For a roller cam, you will need a roller lifter. For roller cams, I use a piece of 27/32" drill rod about 6 inches long, flat on one end and a 3/4" ball bearing, press fit and centered on the other. Small block rollers are typically 3/4" in diameter. The drill rod should be fitted so it falls in the bore by its own weight.

Get some junk heads to check out rocker ratio effects.

The most important thing to realize is that most of the pieces you need can be found for nothing, or next to nothing.

Comp Cams makes a nice adapter that fits over the crank snout and mounts the degree wheel. Using one of those means you will only have to find TDC once.

While we are on the cam subject, remember that getting your cam ground on a small base circle will change the cams duration numbers, some being larger, and some being smaller. Discuss this with the cam grinder before ordering any small base circle cam.

and...this is the article from pontiac street performance:

The cam is rated at some duration at .050 lifter/tappet rise. This of course cannot be changed and will remain the same regardless of the rocker arm ratio. However, the valve lift is normally specified with standard 1.5 ratio rocker arms. This can be changed by installing different ratio rockers. As a 1.65 ratio rocker is 10% higher ratio then a 1.50, the lift provided by the 1.65 rocker will be 10 % greater with all cams. This also can be seen on the attached graph. Note that the graph shows a 1.72 ratio rocker, but the action is similar between various ratios. What happens to valve open time with the higher ratio rockers? Because the higher ratio rocker lifts the valve to a higher point in the same time period, it has to lift both quicker and steeper. As the valve begins to open at the same point regardless of rocker ratio, and it opens at the same time as the cam lobe, the duration of the valve opening in crankshaft degrees at the initial opening and closing points is identical to the cam lobe duration. However, because of the quicker and steeper opening/closing rates, the valve open time is greater from any point after initial opening when a higher ratio rocker is used. This is also obvious on the graph. How much more duration? I devised a method to actually measure it. As a standard lobe measuring point is .050 lifter rise, and lobe lifts are normally specified with 1.5 rocker ratio, that means the valve will always be at .075 when the lobe reaches .050" lift (when a 1.5 rocker is installed). By using the .075 point, and determining where it occurs in relationship to the crank in degrees, a yardstick is provided from which to reference any different rocker ratios. As expected, a higher ratio rocker will allow the valve to reach the .075 lift point earlier in the lift cycle (and later in the closing cycle). As the .075 valve lift point is the industry standard when specifying cam duration (1.5 standard rocker ratio X .050 tappet/lifter rise), it becomes a valid reference point. In the Wolverine 234 degree intake lobe, the intake valve was open 4 to 5 degrees longer when measured in reference to the crank when the larger ratio rockers were used. This is also easy to see on the graph.


In searching, I came across this one, and agree with what it says....that in a lot of cases, adding 1.6s may change lift and duration numbers effectively, but it may not improve performance. Actually in some cases, it robs power. http://www.popularhotrodding.com/enginemasters/articles/hardcore/0511phr_ratio/index.html

The funny thing here is that we both agree, if the engine wants more cam, instead of giving it more rocker ratio, the best thing to do is give it more cam, and let the valvetrain be happy too.




 
#43 ·
In searching, I came across this one, and agree with what it says....that in a lot of cases, adding 1.6s may change lift and duration numbers effectively, but it may not improve performance. Actually in some cases, it robs power. http://www.popularhotrodding.com/enginemasters/articles/hardcore/0511phr_ratio/index.html

The funny thing here is that we both agree, if the engine wants more cam, instead of giving it more rocker ratio, the best thing to do is give it more cam, and let the valvetrain be happy too.




YES YES YES, (Ace Ventura voice) thats sounds GREAT Jake. If you want the engine with more cam then just give it more cam instead of a rocker arm ratio.:thumbsup:
 
#46 ·
Well, you know what they say about opinions and armpits (;)), right?

Answer this question...

In the same engine, over the same cam, changing only rocker ratio, on the opening ramp, will the valves reach all lift values at an earlier point in time...and on the closing ramp, will the valves reach all lift values at a later point in time?
 
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