I was told this is the place to post this question. Anyway I was hoping that someone could help me here. I have a 40 over 327 that's being rebuilt and i'm not sure what cam to go with. It will be composed of...

10:1 comp
Edelbrock Performer RPM heads ported
Edelbrock Performer Intake
Edelbrock 600cfm Electric choke carb
headers, and it will be balanced

I plan on putting something around 4.10 for gears in it in the future and a 4 speed, so i figure it will be cruising at high RPM's at 60. The way I see it it should probably have a rather high lift and long duration cam? I would really apreciate any advice....sorry if i left out any important info....i dont think i did?

I was thinking of going with a Performer RPM cam, but was just told that that might be too "large" so to speak. ?? Just looking to get the most power out of her as possible, at a higher RPM, but nothing crazy. I figure the gears will make up for the lower end, and i will want the power at the upper end because of the gearing.

thanks

234/244 on a 112 LSA with a hydraulic lifter? I only open this up for discussion, but thats a might too big. If it was solid, it'd be fine ( solid cams tend to look about 8 bigger than a hydraulic )

Crane makes a nice small soild cam. Take a look at the Comp XS274S. You're looking for around 230/235@.050 with a solid, and around 220/228 with a hydraulic. The solid will let your 327 zip to 6500 with the greatest of ease.

Well I really would rather go with a hydraulic cam instead. I just don't like the idea of having to adjust valves all the time as goes with solid lifter cams. Does anyone recommend a certain company for camshafts? I'm thinking I will probably just go with a Edelbrock cam, since the rest of my parts are Edelbrock, and they are fairly cheap.

For comparison, the old 327/350HP of the 60's used a 222@.050 {.447 lift} for both Int & Exh. Lobe center was 114 (I think). This was a rather potent cam for a 327. I ran one in a low compression 350CI engine that would easily pull to 6000 RPM, yet would idle in gear with a stock converter. Had a nice lopey idle also. Go with something similiar and you will be happy. Comp even has a modern version of this available. Definitely wouldn't go much bigger than this on the intake side. THe Edelbrock heads probably won't need any additional exhaust timing either. 327's will rev to 6000 and beyond with very little duration.

And by the way, Gene is right on with the solid cam. A 327 with a solid cam, something comparable to the 327/365 solid is a great ride in a 327 4 speed car.

A solid lifter 327 with gears is a blast.... I have had two of them and they can be alot of fun.

As the others have said it's not really necessary to go real long on the duration with a street driven 327.... My second 327 was very mild and it's cam was only 218 @ .050 (solid) and would pull 6000 VERY quickly....

The Edelbrock cams tend to be fairly long and they really want a fair amount of compression....Personally I would stay with something made by a real cam company...( Edelbrock buys their cams..they dont grind them ).... a good Crane / Lunati (UD) / Isky type cam company ....

BTW as far as adjusting a solid cam goes....After it has been broken in and everything takes a set ( a couple weeks ) If you adj them correctly they will stay adjusted for a long time....I averaged 1 to 2 times a year in my daily driver.....

If you must have a hyd cam just dont go to long of a duration and make sure your springs are compatable.....

My version of the 350HP cam is the Lunati 301A7LUN, 276° at .0045", 221° at .050', .454" valve lift, and 114° LSA. It's almost too big for a 327 when on a 110 LSA.
I also make a small solid, a 264F10, 264 at .020, 232 at .050, .470 valve lift, and 110 LSA. The very first one I ever sold went into a 327 Corvette, and he loved it. It needs to have the valve lash checked every year......
Both of these cams will work in your combo...

UDHarold

Lunati 301A6LUN Best performing REAL street cam. Lope at idle, works power brakes, etc. For 350-400 HOT 'daily-drivers', 4WDs, P/Us, etc.

Comp270H looks good

Crane Energizer 278H10 seems right, and its low-pricd.

Ah, I see the guru says th 110 version of the Lunati might be a bit big. He's the man!

I am a Little Duntov -097 guy but please consider going with one of Harold's modern small solids for the little motor AND I bet you will be tickled pink!!

And remember, you don't have to adjust solids until they get ta sewing machining too much, like maybe every third or fourth oil change, imho..

pdq67

PS., AND a solid 327 should go above 7,000rpm easy with good valve springs with not much trouble at all!!! My junk 301 always went up until the points bounced, then I would back off And hit it again!!

Wow.....sounds good, lots of choices. :D

Stupid question, but what does LSA mean/stand for?
I'm not a genius when it comes to cams. I just know the very basics. Aren't Lunati cams pretty pricy? From the sound of it the Crane Energizer cams seem like a good choice. They are pretty cheap too. $120 Which of these cams would be a better choice? (The car has a th350 with a 1500 or 2000 stall....not sure which, and an open 3.08 10bolt) graemlins/sad.gif

1.) Duration 204/204 Lift .427"/.427"
- Hydraulic says the RPM range is 1,200-4,200

2. Duration 210/210 Lift .440"/.440"
-Hydraulic RPM range 1,600-4,600

3.) Duration 216/216 Lift .454"/.454"
- Hydraulic RPM range 2,000-5,000

4.) Duration 222/222 Lift .467"/.467"
_ Hydraulic RPM range 2,400-5,400


From what you guys have said i would think the 2nd would be the best? The only thing is that given that the engine will be balanced, therefore capable of high rpm's, and that i can't hook up for crap with the set up i have, wouldn't i want a cam that gives power at a higher RPM range? Also considering that i plan on putting in a ford 9" with 4.10 gears (posi naturally), and a 4 speed, wouldn't it be better to stay with a cam that provides higher RPM ranges? The way i see it is that when i'm cruisin it'll be at a rather high RPM, so wouldn't i want the RPM range/power range to be high also? :confused: I know i wouldn't have much low end, but i could always make up for that with high RPM holeshots. I'm no expert, but i just wanted to throw that point out. I'm just trying to understand the reasoning for whatever cam you guys recommend. Thanks

I apologize for my ignorance. Just trying to learn. smile.gif

Just stay away from Edelbrock, Melling, SpeedPro, TRW, and Summit cams.

They are not going to give the best power.There is a reason they are cheap.

Well eccept for the Ebrock cams,even though they don't grind them, they still want you to pay for their name graemlins/sad.gif

The cams that you want are made by
CompCams
Lunati
Isky
CamMotion
Crane

thanks for the heads up thrasher. I found that the edelbrock cams aren't the greatest either. It seems like crane cams are the way to go. I mean for something that's not extremely pricy. The crane energizer cams seem good, and they are only $120......has anyone on here ever used those or know anyone that has?

I have used one.They are not bad.Certantly not the best either.They are a bit conservative.Also an older design,that's why they are cheaper.Summit has a sale on them right now,Energizer cam and lifter set for $99.

If you want max power you should be looking for a newer grind with lower advertised duration figures.

Check these,

CompCams XE268
268/280 224/230 477/480 110

CamMotion grind H211/2251-10+4
221/225 471/471 110

Lunati-Contact UDHarold for a grind from this company as he is their new cam designer.

I would run an 11inch converter with a 2500-2800 stall speed and 3.70+ gear with them as others have noted cams this size tend to be a touch lacking in the bottom end with the 327.

Just for a reference,
I had a 10.2:1 350 with an Energizer 278H10.To me the bottom end was a little soft.This is with a 11inch 2400 stall and 3.42's.
As most know,more compression adds more bottom end.So on a 327 with slightly less C.I. and less compression....

do you know of any websites or anything that i can go to so i can take a look at those cams you listed?

Do you think a Crane Energizer would be ok for my engine for now though? It should be pretty problem free with one right? I plan on throwing in a N02 burning 383 way down the road, but i just need to get my car going for now......might be moving out of the house, and i need to have my car running. I'm really not looking for the best parts i can get, but rather something affordable/cheap and decent. The only reason i have the Performer RPM heads and other costly parts going on the engine is because they came with the car. Unfortunately the engine destroyed two camshafts, so it will be rebuilt soon, hense the need for a cam. graemlins/sad.gif

Originally posted by pegleg71:
Wow.....sounds good, lots of choices. :D

Stupid question, but what does LSA mean/stand for?
I'm not a genius when it comes to cams. I just know the very basics. Aren't Lunati cams pretty pricy? From the sound of it the Crane Energizer cams seem like a good choice. They are pretty cheap too. $120 Which of these cams would be a better choice? (The car has a th350 with a 1500 or 2000 stall....not sure which, and an open 3.08 10bolt) graemlins/sad.gif

1.) Duration 204/204 Lift .427"/.427"
- Hydraulic says the RPM range is 1,200-4,200

2. Duration 210/210 Lift .440"/.440"
-Hydraulic RPM range 1,600-4,600

3.) Duration 216/216 Lift .454"/.454"
- Hydraulic RPM range 2,000-5,000

4.) Duration 222/222 Lift .467"/.467"
_ Hydraulic RPM range 2,400-5,400


From what you guys have said i would think the 2nd would be the best? The only thing is that given that the engine will be balanced, therefore capable of high rpm's, and that i can't hook up for crap with the set up i have, wouldn't i want a cam that gives power at a higher RPM range? Also considering that i plan on putting in a ford 9" with 4.10 gears (posi naturally), and a 4 speed, wouldn't it be better to stay with a cam that provides higher RPM ranges? The way i see it is that when i'm cruisin it'll be at a rather high RPM, so wouldn't i want the RPM range/power range to be high also? :confused: I know i wouldn't have much low end, but i could always make up for that with high RPM holeshots. I'm no expert, but i just wanted to throw that point out. I'm just trying to understand the reasoning for whatever cam you guys recommend. Thanks

I apologize for my ignorance. Just trying to learn. smile.gif pegleg??
My opinion but the only stupid question is the one you don't ask :D

LSA is Lobe seperation angle & it is the distance in cam degrees from the center of the intake lobe to the center of the exhaust lobe.
It is ground into the cam & cannot be changed by advancing or retarding the cam.
Again my opinion but I would not try to save a few dollars on the cam. It will cost you in performance, time & doing things twice sucks :(
As far as cam advice goes, you cannot get better than UD Harold. It is what he does & has been doing before a lot of folks here knew what an engine was ;)
Do yourself a favor & take his advice.

BTW, when you get into the generic grinds like those you listed it doesn't make much difference who's name is on the end, there is a very good chance they didn't grind it. :(

Wolfplace-Even the Crane Energizer line?

Understood, thanks for the explanation. Is there a particular cam that you would recommend Wolfplace, or Harold? Harold, I was just wondering what 301A7LUN and the 264F10 cost? It's not that I want to just try and save a few bucks, it's just that I flat out don't have much money and I ABSOLUTELY need to get the car going soon. Unfortunately. I might just have to settle for a Crane Energizer cam, so I was just curious as to what the verdict is on one of them.
I REALLY appreciate the advice guys.

Read my reply again.
I added what my observations were when I used the Energizer 278H10.

If you are serious about putting 4.10's in it then you can be abit more selective with respect to a cam.

If it were " me " I would be looking at maybe 3 different solid cams...

The GM 097 Duntov solid would be very good indeed. A very old cam that works well.382/.386 lift 228/231 dur @ .050 110 LSA.... Lashed @ .012/.018 you would barely ever hear the tappets.This one will spin 6400 with ease.Slight lope at idle and very streetable and very gentle on parts.

The Isky Z20 solid .448 lift 268 adv 228 @ .050 but have them grind it on a 108 instead of the 112 it comes with...slight lope at idle.Very streetable.Will pull 6000 rpm.

Or the solid Harold mentioned above his 264F10....
This one would likely outpower the other two and will be VERY streetable....

If you stay with a hyd it would likely be best to run something under 226 deg @ .050....getting much above that and the idle will really start to be getting rougher and have less streetable manners.A typical hyd with say 280 deg adv and 228 @ .050 will idle noticabley rougher than any of the above mentioned solid cams with the same dur @ .050.

Originally posted by thrasher:
Wolfplace-Even the Crane Energizer line? =
That's my understanding but you know how hard it is to get an answer to a question like this :(

Pegleg,
Of the cams listed I would probably go with the 272 H10

Yup.

No major reputable cam company want's to fess up to offering a line of cams under their own name that they didn't even grind.

Where can I get a 272H10? Is that just the part number?? I'm thinking this Isky cam might be a good deal...?

221/221 duration Lift .465"/.465" for $120 ISK-201271-6

RPM range 2,000-6,200

Should i go with the solid or hydraulic lifters

$114 hydraulic
$103 solid

Sorry to sound like a broken record here. I just need to find a cam within the next couple days.

272H10 is the grind number.The Summit cam and lifter part number is CRN-100052

The 272 H 10 is the one you listed with 216 /216

If you email me I will see what I can do on an Isky with lifters for you tomorrow ;)
Just use the link in my signature below

Wolfplace-
Have you ever used,or know of anyone that has used the

Isky 274 Megga
274 226 490 108

Pegleg,
You have to make some realistic decisions. Having to cut money on a cam purchase is ok, but if the cam is too much money ($50 - $100 differential), then why are you looking into Edelbrock Heads and a Ford 9" setup? Those 2 items alone are worth $3500.00 minimum. I first took this that you had a 4 spd already, if not use the 350 Turbo and the 8.2 10 bolt. In your plans don't be pennywise / dollar foolish. If you have the motor ready to go, great, but by the time you have the engine built, balanced and installed with a 4 spd ,9" rear and a good exhaust system, not including all of the misc. expenses you will run into, you are going to be looking at ultimately going through $6000 - $8000. If money is tight, stay conservative and use what you have, lay out your plan accordingly.

Pegleg, along the same lines as above, you;re talking maybe $50 difference here. I thought my cam from Harold was pricey at $175 ( they're less now!). But when I was running 117.5-118.5 trap speeds in the 1/4 from alittle 427, ( in a heavy car!) it was an additional $50 that was well spent.


www.cranecams.com (http://www.cranecams.com)
http://www.holley.com/lunaticamshafts/index.html

www.compcams.com (http://www.compcams.com)

And one more thing, for any type of performance work, you are really shortchanging the revability of that 327 with a hydraulic cam. You'll need to set lash maybe 5 times initallly when new before it take a "set". Then its once in a great while. With 4.10s you'll be shifting at 6300-6500. Your engine wont mind that at all. Make sure your cam is capable! Use Harolds or the Comp 270S

Originally posted by thrasher:
Wolfplace-
Have you ever used,or know of anyone that has used the

Isky 274 Megga
274 226 490 108 =
Yes :D

The plan for the 4 speed and ford 9" is for WAY down the road. Right now i'll be putting the engine together with what i already have......

Edelbrock performer RPM heads -came with car
Edelbrock Performer intake - came with car
Edelbrock 600cfm electric choke - came with car
headers, and k&n
Accel HEI ignition

Th 350 w/ b&m shift kit 1,500 or 2,000 stall....don't know, i didn't but it

Open 3.08 10 bolt

I just wanted to clearify that. I just plan on getting the car going in a rather cheap, but well chosen fashion. The deal is that i might have to move out of the house, and if i don't have the car going i'm going to have to sell it, and i sure as hell don't want to do that. I don't make much money at all since i'm a college student, so i don't have much choice financially.

When i get set up with a decent job and really start working on this car i'm not going to skimp on anything. That's when i plan on putting in the 4 speed and ford 9" as well as other things. I just figure if i could build the engine so that it would work well with that combo, way down the road, then i'd like to do that. That's all really.

I'm actually interested in going with a set of solid lifters. I've just heard that they need to be adjusted fairly frequently, but apparently that's not quite true. When you guys say "set the lash" do you mean adjust the rockers? Also, how do you know when you have the rockers set just right? The only way i've been told is that if it's clicking, tighten it down a little more until it doesn't. I just don't like the idea of not knowing where they are actually set.

I only ask because i'll be having to do it. Once again, i apologize for my ignorance. redface.gif

thanks

No need to apologize for anything. Everybody has to start somewhere. Now, let me give you my opinion on this. From the sound of it the 9"/4 speed is what, months, years down the road? If you build the engine for 4.11's and a 4 speed and drive it for the next year or 2 with a mild th350 and 3.08's, your going to be stuck with a fairly unresponsive gas guzzler that sounds cool cruising around, but won't get out of its own way. I would cam it according to what you have NOW if it is going to be that way for a while. Compared to a 4 speed/rear end swap, cam changes are quite simple. For a decent cheap cam to use right now, the 266 energizer would work just fine with the rest of your setup. The 272 wouldn't be bad either and has a nice authorative sound in a 327. Later, as things progress, then you can step up to a "real" cam ;)

Of course, if the 9"/4 speed will be added in the next few months, then just ignore me :rolleyes:

Wolfplace, care to elaborate a bit on the isky 274 mega cam? I have a brand new one that I bought last year for a project that ended up getting "supersized". I'm still trying to decide what to do with it.

You're absolutely right travis. What's a extra few hundred dollars and a little work down the road when it'll take thousands to get it where I want it in the long run. graemlins/thumbsup.gif I was just kinda looking for a cam that was inbetween. If I go with a crane energizer cam i'm going to take wolfplaces advice and use the 272H10. If I can get a deal through the guy who is building the engine for me, then i'll get a better cam. Maybe a Lunati or Isky.
Thanks

Yup, thats what I would do given where you are and what you have to work with.

BTW, you can't use ( well you can but its not recommended, adn some racers do it) solid lifters on a hydraulic cam. SOlid cams are ground slightly differently for use with solid lifters.

Agree with Travis, Energizer 266 or 272. If you are sure of the 10:1 I would almost opt for the 272 to ensure you can run this on pump gas.

That small solid lifter cam from Isky (Z20) that Al (69LS1) was talking about would make a real nice street cam in a 327-350.

228 deg @ .050, have it ground on a 108 lobe sep and install some 1.6 rockers for .478" lift.

327 were made to have solid lifter cam in them! graemlins/thumbsup.gif

sounds good. Yeah, i wouldn't use a hydraulic cam with solid lifters. It will either be hydraulic/hydraulic, or solid/solid.

What sort of RPM's do you guys think I could safetly pull with the set up i described, if i were to use a solid cam and lifters. The Isky one that Al recommeneded.

A Z20 should pull 6000 or there abouts pretty easily....Especially with a 4.10 gear....with 3.08's it takes abit longer....

Even that cam is almost borderline to big if you stay with 3.08's....If you have a TH350 it wont be too bad but if you have a powerglide then you really need something smaller....

My last 327 was very mild and had a Crane F218/2933-12..... .440 lift 218 dur @ .050...lash @ .022..... It idled smooth but crisp...no lope but crisp sounding....was dead under 1500 RPM started to run good from 2000 or so but from 4000 to 6000 the thing just went nuts.....I really wish I had it ground on a 108 instead of the 112... oh well....

This was with a TH350 and 3.07 gears...I later put a RG ST10 with a 2.88 / 191 / 133 gear set in it...
Nice increase in gear and available power....Even with this small solid cam it wanted GEAR....

You may think I'm nuts ( most people do :D ) but I tried several different carbs on it.... 600 Edelbrock.... 600 Holley .... 780 Holley and last but by far the best....A 390 CFM Holley....That little pip squeek of a carb flat out ran stronger than any of the larger carbs .... ESPECIALLY at higher RPM....sounds crazy....but with limited gearing and a modest engine it simply couldnt consume 600 plus CFM of air .... But it could consume 400 ....took some minor modifying (jetting /discharge nozzle / secondary spring and converting to 4150 ) but it was worth it....Even the old HP Rochester FI units of 1957 - 1965 could only flow roughly 500 CFM...they werent very large and could spin the 283/327 FI engines to near 7000 RPM.... So dont over carb the thing especially with not much gearing...

yeah, it will have a turbo350 in it. I don't think the 600 will be too big for the engine. This new engine will almost be the same as the other one, except it will be a .040, or .060 if i have to, 327 rather than a .030 327. Also it will have roller tipped rockers and a slightly larger cam. The 600 worked great on the previous setup I had on the engine. But I know what you mean about not having the power until around 2,000rpm and then from 4-6k rpm it just screams. Would having it ground 108 instead of 112 have given it more torque? The thing that really sucked/sucks for me is that I have an open 3.08 10bolt. The best 60ft time I could cut with it was a 2.3.....which I guess isn't too bad considering. If I put the pedal to the metal off the line it would just burning out for a couple hundred feet......it was rediculous. :mad:

My story above wasnt to convince you to put a 390 carb on it but was just a caution not to over carb it... as far as the LSA...This is just my opinion but short stroke engines like the 327 seem to like a tighter LSA.These short stroke 283/302/327 respond better to a tighter LSA than say a 383/406/413/427 type long stroke engines would....If mostly street/strip driving a 108/109/110 would work great....I would leave the 104/106 type stuff for the race track.

Originally posted by Wolfplace:
</font><blockquote>quote:</font><hr />Originally posted by thrasher:
Wolfplace-
Have you ever used,or know of anyone that has used the

Isky 274 Megga
274 226 490 108 =
Yes :D </font>[/QUOTE]:rolleyes:
I guess I should have asked if it worked well or if you had good sucess with it.

Originally posted by travis g:


Wolfplace, care to elaborate a bit on the isky 274 mega cam? I have a brand new one that I bought last year for a project that ended up getting "supersized". I'm still trying to decide what to do with it.

Understood 69LS1....I just thought i'd mention that it worked good for me before. I was wondering if you wouldn't mind explaining how LSA affects performance? Honestly I don't completely understand what that is or how it affects performance? :confused: I understand lift and duration, just not LSA. Thanks again.

If you look at a cam sort of from the end.... locate the intake and exhaust lobes for and given cylinder... You will notice that they are displaced away from each other.... If you were to figure the the " centerline " of each lobe you would find that they are seperated from each other by a certin number of degrees....most often 104 - 116 degrees.... 108-114 being the most common....This figure is ground into the cam and is not changable once the cam is ground.

The LSA ( Lobe Seperation Angle ) is another tool that can be used to determine where the valve events will take place....IE when the intake and exhaust valve will open and close .

Take the Z-20 Isky we used as an example.... When ground on a 112 LSA it has the timing as follows...

Intake opens 22 deg BTDC
Intake Close 66 deg ABTC
Exhaust open 66 deg BBDC
Exhaust Close 22 deg ATDC

If the same cam was ground on say a 108 LSA it would have it's timing...

IO = 26 deg BTDC
IC = 62 deg ABDC
EO = 62 deg BBDC
EC = 26 deg ATDC

You will notice a difference between the two...

The 108 LSA opens the intake sooner and closes it sooner....thereby producing more cylinder pressure.
The Ex valve opens later and closes later there by producing a longer power stroke ..again producing more torque...

This also means that the " overlap " period is longer...this is when the intake valve is opening at and the exhaust valve is near closeing in the vacinity of TDC....The overlap period is when both of these valve are open at the same time...

A longer operlap peroid tends to make for a rougher idle and a reduced manifold vacuume... A shorter overlap period tends to produce a smoother idle and more manifold vacuume...

LSA's are very important to anyones engine combination .... A complete discussion of LSA's and what they do and how they do it would result in a very very long thread.... because EVERY engine combination will likely respond a bit differently to them.... much depending on the design of the lobes themselves.... Some lobes are very gentle and others very agressive and everything in between.

Often times people will say that a wide LSA always produces more high end power due to the later intake closeing and earlier exhaust opening... this would seem to make sence.... BUT.... it doesnt always work that way.... sometimes a given LSA will produce better power over the entire RPM range.... not necessarly where the magazines tell you it will.... Other times a given combo will react in a more traditional way.... IE EVERY combo is different and will act or react to cams abit differently... There are generalities but they are not absoults &lt;sp&gt;......

If you were to take say 5 cams with the same lobes but different LSA's it is possible that one given LSA will out power all the others in the entire RPM range.... And depending on the engine combo that might not happen either....

Different cam mfg have different theories on what LSA's they like to use.... Most Comp street cams are on a 110.... Crane energizers are on a 110 and thier PowerMax dual patterns are often on 112...Most Iskys are on a 108 ect ect...

For most street use it's often best to away from the extremes and stick with something in the 108-112 range for most N/A uses.... N2O and supercharged engines useually are ground on wider LSA's ... this reduces the overlap period and there is less tendancy for boost pressure to blast A/F right out the open exhaust valve during the overlap
period....if that happened the wasted A/F would be consumed in the header rather than in the cylinder where you can use the power....

Anyhoo this subject tends to produce arguments due to the tremendous amounts of variables involved...

Originally posted by thrasher:
</font><blockquote>quote:</font><hr />Originally posted by travis g:


Wolfplace, care to elaborate a bit on the isky 274 mega cam? I have a brand new one that I bought last year for a project that ended up getting "supersized". I'm still trying to decide what to do with it. </font>[/QUOTE]=
I have used a couple of them in 383's & they seemed to work extremely well. Really nice crisp engines.
Had a pretty good "lope" to it if you are into that lumpy idle thing :D
One had Vortecs on it & was a 12.0 comp. circle track 2bbl bomber type deal & the other was about 10.0, AFR 195's, EDE air gap & a 750 demon & made about 420HP @ 6000 or so as I recall. don't remember the torque but I can look it up if you want it. Been a while ;)

Naw that's not necessary.
Do you think it would work well for a street SB355 with 10.2:1 comp,TH-350,11inch converter,3.42's with a 26 tall tire?
Thank's

I'm thinking hard about getting a set of the ProTopline Vortec replacement heads.

If I do I will be looking your way.
I wish I could find someone that has used them so I could hear some input or opinions about them.

Originally posted by 69LS1:
If you look at a cam sort of from the end.... locate the intake and exhaust lobes for and given cylinder... You will notice that they are displaced away from each other.... If you were to figure the the " centerline " of each lobe you would find that they are seperated from each other by a certin number of degrees....most often 104 - 116 degrees.... 108-114 being the most common....This figure is ground into the cam and is not changable once the cam is ground.

The LSA ( Lobe Seperation Angle ) is another tool that can be used to determine where the valve events will take place....IE when the intake and exhaust valve will open and close .

Take the Z-20 Isky we used as an example.... When ground on a 112 LSA it has the timing as follows...

Intake opens 22 deg BTDC
Intake Close 66 deg ABTC
Exhaust open 66 deg BBDC
Exhaust Close 22 deg ATDC

If the same cam was ground on say a 108 LSA it would have it's timing...

IO = 26 deg BTDC
IC = 62 deg ABDC
EO = 62 deg BBDC
EC = 26 deg ATDC

You will notice a difference between the two...

The 108 LSA opens the intake sooner and closes it sooner....thereby producing more cylinder pressure.
The Ex valve opens later and closes later there by producing a longer power stroke ..again producing more torque...

This also means that the " overlap " period is longer...this is when the intake valve is opening at and the exhaust valve is near closeing in the vacinity of TDC....The overlap period is when both of these valve are open at the same time...

A longer operlap peroid tends to make for a rougher idle and a reduced manifold vacuume... A shorter overlap period tends to produce a smoother idle and more manifold vacuume...

LSA's are very important to anyones engine combination .... A complete discussion of LSA's and what they do and how they do it would result in a very very long thread.... because EVERY engine combination will likely respond a bit differently to them.... much depending on the design of the lobes themselves.... Some lobes are very gentle and others very agressive and everything in between.

Often times people will say that a wide LSA always produces more high end power due to the later intake closeing and earlier exhaust opening... this would seem to make sence.... BUT.... it doesnt always work that way.... sometimes a given LSA will produce better power over the entire RPM range.... not necessarly where the magazines tell you it will.... Other times a given combo will react in a more traditional way.... IE EVERY combo is different and will act or react to cams abit differently... There are generalities but they are not absoults &lt;sp&gt;......

If you were to take say 5 cams with the same lobes but different LSA's it is possible that one given LSA will out power all the others in the entire RPM range.... And depending on the engine combo that might not happen either....

Different cam mfg have different theories on what LSA's they like to use.... Most Comp street cams are on a 110.... Crane energizers are on a 110 and thier PowerMax dual patterns are often on 112...Most Iskys are on a 108 ect ect...

For most street use it's often best to away from the extremes and stick with something in the 108-112 range for most N/A uses.... N2O and supercharged engines useually are ground on wider LSA's ... this reduces the overlap period and there is less tendancy for boost pressure to blast A/F right out the open exhaust valve during the overlap
period....if that happened the wasted A/F would be consumed in the header rather than in the cylinder where you can use the power....

Anyhoo this subject tends to produce arguments due to the tremendous amounts of variables involved... Great tuturial....can you ellaborate on advancing and retarding the cam and how it relates to LSA?

It doesn't.
How's that for the short version :D

Advancing or retarding the cam mearly changes when the valves start their journey.

LSA can't be changed as it is physically ground,or set.

Originally posted by thrasher:
Naw that's not necessary.
Do you think it would work well for a street SB355 with 10.2:1 comp,TH-350,11inch converter,3.42's with a 26 tall tire?
Thank's

I'm thinking hard about getting a set of the ProTopline Vortec replacement heads.

If I do I will be looking your way.
I wish I could find someone that has used them so I could hear some input or opinions on them. =
At 10.2 I think it should work pretty decent.
Iv'e had pretty good luck with Isky's stuff. Sometimes I think half of it must have been designed by Harold :D

I looked at the Vortec heads at the PRI show & they looked real nice. Very clean casting & heavier than the stock ones.

Originally posted by thrasher:
It doesn't.
How's that for the short version :D

Advancing or retarding the cam mearly changes when the valves start their journey.

LSA can't be changed as it is physically ground,or set. yea..I understand that...what I was wondering is..the LSA..be it 104 or 110 changes the valve timing also..would it more advantages to run a 108LSA str8 up or a 110 advanced 4º....I guess its apples and oranges and it depends on the combo. Tyring to make it more complicated than it really is...

Originally posted by bigjimzlll:
Would it more advantages to run a 108LSA str8 up or a 110 advanced 4º....I guess its apples and oranges and it depends on the combo. Tyring to make it more complicated than it really is... Remember you said it not me ;)
Think ya answered your own question smile.gif

Yeah, but you're starting to understand and think about it, its a good thing.

Originally posted by 427L88:
Yeah, but you're starting to understand and think about it, its a good thing. =
graemlins/thumbsup.gif graemlins/beers.gif

Trouble is,,,it makes my head hurt :D

Thanks for the explanation and examples Al, I think I might have to read it again to sink it in. lol But it's nice to know so I can make a more educated decision for my cam. graemlins/thumbsup.gif

Pegleg71,

The unfortunate thing about all this is that the understanding camshafts is a VERY complicated subject..... that is often subject to interpretation..... There are the basics and then there is the more indepth subjects... like this one..

If you can happen to get a chance to compare various cam mfgs catalogs and just read through them you will get to see just how crazy the subject of LSA's can be !

This thread here barely and I do mean barely scratched the surface of this subject.

I dont think there is anyone on this or any other forum that doesnt wish they understood more about LSA's graemlins/beers.gif

That's why we are so very lucky to have Harold graemlins/thumbsup.gif

lol Understood Al. You guys sound like you know a good deal about LSA's, and you say you don't know much, so I think I may be screwed. :confused: but that's ok. I'll just throw in a decent cam to the best of my knowledge and worry about perfecting the combo later. graemlins/thumbsup.gif

Just wondering.....Do any of you guys know how a performer intake compares to a performer RPM intake in flow performance? I'm just wondering if there's a big difference or not.

One last thing..... :D Stupid question, but what exactly do you gain by using a carb spacer? Better flow?

thanks again......this thread is getting huge. :D

The performer intake is good for low rpm..and thats it..the rpm is a much better performance intake...a carb spacer fools the carb into thinking its bigger...it sometimes can hep performance and sometimes not

Open spacers increase the plenum area ( the open area under the carb prior to the runners) which typically gives better upper rpm. A 4 hole spacer increases the velocity under the venturi ( the carb bores), which typically adds some low end torque and response. So all spacers arent created equal. My test bed was a 6800+ rpm 427, and I found the 5000+ pull was nicer with a 3/4" open spacer. Again, that may not be best in all apps. But, if you're stuck with a Performer ( which I hear poops out at 5000-5500), an open may help a bit up top.

Another advantage of spacer is some isolate the carb(s) from heat. I made my own "holed" spacer from canvas phenolic. Really keeps the carbs cool.

I see. I think i'm going to throw in an open spacer then. I dont know about the performer intakes starting to crap out around 5500? When i was running my car it seemed to pull all the way to 6500+. graemlins/thumbsup.gif Would you loose torque by throwing in an open spacer?

it might of pulled to 6500...but...it might pull harder with a RPM manifold :D

Hey, that's what I hear, but it mostly on big 454s, so ...fwiw....

No worries......the Performer RPM will be on the N02 burning 383 that will be going in the car way down the road. graemlins/thumbsup.gif

Oh....I was wondering, how can I find out what the LSA is on a cam if the company doesn't list it in the description of the item in their catalog? I'm just going to get a Lunati cam through summit.....do you think they would know what the LSA of the cam is if I ask? j/w I will either way.

thanks