chevy1500z71

so i called up lunati to try and pick out a cam, and it was similar to what comp cams recommended but its not considered a blower cam, its on a 112 centerline but he says it has low enough duration to have a smoother idle. so heres my setup, a gen1 small block chevy 350 4 bolt main with forged lightweight flat tops, zero decked, 76cc chamber heads making 9:1 compression. heads are dart ss eagle irons w/170cc runners and 2.02/1.6 valves. 1500 stall converter and roughly 11 pounds of boost, maybe a tad more or less boost, hard to say, all i know is it makes 13psi now on a stock motor.

so heres the cam specs, duration-219int, 227ex, lift- 868int, 489exh on a 112 lsa. its not considered a blower cam but its looks like what i want, perfect rpm range too, 1400-5800. im spinning this motor to a maximum of 5500, any more and id over spin the blower forcing me to up the pulley size which will move the power up in the rpm range which is not what i want, its a pickup truck.

heres the link to the cam
http://www.lunaticams.com/Product.aspx?id=2324&gid=297


you may be wondering why id ask such a question after talking with a knowledgeable tech on the cam help line but i really want this motor to be perfect and would like to double check.

thanks

chevy1500z71

i also will be useing 1.6 rockers

fast82z

iTrader: (1)

I'd say it should make peak power around 5500rpm, and I wouldn't worry about the LSA. Really 114-116 would probably be better, but it's not going to kill it or anything. Might see what a custom cam would run. Mine is a solid roller, but this custom one was cheaper than shelf cams. I had a 246/254 dur @ .050 cam with a 112LSA and that ran fine with the blower. Granted it did make a good bit more power with my current cam, but that is more likely related to the increased duration than the LSA.

The 1.6 rockers make that lift .499/.522 just to be sure the springs/heads have room for that.

chevy1500z71

the heads are good for .550

what concerns me a bit is valve clearance. the motor is zero decked so the heads are closer to the pistons, they are flat tops with valve reliefs... i should probably be fine when i think about it, but idk, im a noob.

will that added lift from the rocker make this cam less driveable? wil it do much wiht the rpm range?................. decent gas mileage?... lol, i wish.

it is my daily driver, acceptable mpg to me is about 12mpg. in all honesty, iv gotten around 8mpg for the last year tho, but theres no way this stock motor eats that much, even with the blower. its just a worn out pos.

thanks for the reply. to be perfectly honest, i realy would like a somewhat nice sounding idle, a 114 would sound almost stock.

305sbc

iTrader: (3)

It wasn't enough information for me to say anything. The web site doesn't give actual valve openning and closing events or even 0.050" events.
Have you seen the cam-card for this? They always have the proper specs.

chevy1500z71

havnt purchased the cam so no cam card, dont know....

those duration specs are @.050. the lift is with a 1.7 rocker.

chevy1500z71

any more thoughts and suggestions? im having trouble deciding weather to order this cam or not.

Damon

It should work fine for what you're trying to achieve.

My concern is not so much the cam as it is the relatively high 9:1 compression ratio with 11 PSI of boost and cast iron heads. With a centrifugal blower and intercooling you might get by on pump gas. Without intercooling I think you might have a detonation monster on your hands.

Orr89RocZ

iTrader: (20)

cam will be fine, compression is abit on the higher side, but i've seen ppl throw 12 lbs on stock L98's just fine...well maybe not just fine, the one guys motor blew but it was beat on alot and probly not tuned well

chevy1500z71

got the compression covered folks, i spray methanol and always run 93 octane fuel. spraying my typical 60% methanol, 40% water setup yields 116 octane under spray. if thats not enough i can switch to strait methanol for 130 octane under spray. iv thought about all this, iv always had methanol injection, just a very nice bit of added safety.

so im sure the cam will be "fine" but is it ideal? the thing is, its kind of a trade off, do i want a killer "4x4 truck" cam or a "blower grind" cam, it seems like this is a pretty good in between to me and at a killer price too. can get it for 170 shipped on ebay with the lifters brand new. the comp blower grind cam which is comparable cost more like 250 with lifters, only real difference is a bit less lift on the exhaust side and a 114 lsa.

my nly true concern are 2 things with this motor, will higher ratio rockers affect any other aspects of the cam like rpm range, or do they do nothing more than add a bit more lift and a fuz more duration. and my second concern is can i re-use arp head bolts, seems like nobody an answer that one lol, i always seem to just get an "i would" or "why not". i dont care to spend money if i dont have to.

chevy1500z71

heres the comparable blower cam from comp cams
http://www.compperformancegroupstore...ory_Code=HFTBT

i found an overlap calculator on google and the blower grand cam actualy has 44* overlap and the lunati has 41*, go figure....

the lunati has a lower rpm range, im really leaning towards it... my 1.6 rockers should move the rpm range up a tiny bit too shouldnt they?

Orr89RocZ

iTrader: (20)

higher lift will help alittle. But for your goals i honestly dont think you'll see a difference between those cams. blower grinds vary from application to application. So you may see 3 blower grinds with all different specs but similar rpm ranges.

Lunati will be fine

305sbc

iTrader: (3)

Is that actual overlap or overlap @ 0.050" ?

Your application is going to want a relatively late and short intake opening event and a relatively late but longer exhaust event. I would look for a small negative overlap @0.050" like around -5*.
Without the real specs on the cams you're just guessing and trusting.

As far as what the extra ratio on the rockers will/could do for you, that depends on the flow profile of your head ports. In most cases they help power, but sometimes rarely they can hurt power by putting the valve at a lift that causes stall/turbulence in the port, or by adding a little too much to the overlap period for a particular application.

Orr89RocZ

iTrader: (20)

thats overlap at advertised, not at .050". The lunati 219/227 has -1 at .050

chevy1500z71

so i need to be ordering a cam pretty soon here, need to make up my mind. the comp blower grind has a tad more duration which is probably why the rpm range is moved up a bit, its a cam designed for a mainly stock car with a blower. the lunati is a 4x4, marine, heavy old hotrod/truck cam, which happens to spec close to a blower cam and have low overlap...

i guess ill just order the lunati and get it over with.

its just seems so wrong to be building a purpose built motor with foged pistons and all and then not getting a true blower cam, but on the other hand, its a killer 4x4 truck cam, and it is a 4x4 truck... to much to think about! i put too much thought in to every damn detail.

305sbc

iTrader: (3)

Yeah it would be better to know the actual specs and/or get a custom grind, but like he said, the Lunati will probably be fine.
Engines with Whipple aren't all that cam sensitive.

Confuzed1

iTrader: (4)

Have you looked at this cam? More than 10 degrees duration diff between intake and exhaust, 113 LSA.....

http://www.compperformancegroupstore...Category_Code=

305sbc

iTrader: (3)

I was able to see the specs on this one.
IMO It looks more like a maximum effort blower cam for open exhaust, and not really for a very streetable combination like his truck.

It has 57* overlap and a relatively early intake opening event.
These kind of cams waste power down low to make more up high - that is with open exhaust. It's a worthy tradeoff for a track car, but it wouldn't pay off for street driving through a muffled system.
FWIW.

Orr89RocZ

iTrader: (20)

There are guys making big numbers with stock type cams, so you dont really need to get crazy with a blower cam. Keep the overlap down alittle and you will be fine

305sbc

iTrader: (3)

I found the cam card with specs on Holley's site.
http://www.holley.com/data/Products/Technical/60102.pdf


It doesn't look so bad. It should be a strong midrange cam like they say.

Confuzed1

iTrader: (4)

I don't know what you mean by "maximum effort blower cam" - but you're joking right?? It's a perfectly streetable cam. Why do you think the exhaust duration is longer than the intake? - Yes -through mufflers.

chevy1500z71 - Just do a google search, and you'll find out alot more about blower cams, and cams in general - I did. BTW, that cam was highly recommended by 2 different techs at Comp on 2 different occasions for a street car with 9.1:1 compression. Go figure....

Confuzed1

iTrader: (4)

That Lunati cam isn't bad, but ideally, you want at least 10 more degrees on exhaust duration than intake, and 113 plus LSA....

305sbc

iTrader: (3)

Is this the cam you're running in your 83 camaro with 408 and 5-speed ?

chevy1500z71

a cam with more duration will move my rpm range up to about 2000, i really need it to be around 1500 or lower becasue i do offroad the truck too, high stall sucks offroading and pulling people out, ect.

the lunati seems like more of a truck cam then a blower cam, but it has less overlap than the comp blower grind cam, the comp cams blower grind comparable cam does have more exhaust side duration, on a 114 centerline. i like it, but the rpm range is 1800-5800, vs lunatis 1400-5800. wont my 1.6 rockers adding more lift move the rm range up a tad as well? another reason i want a low rpm cam is becasue with the Whipple this truck will lug through overdrive from as low as 1200rpms up like crazy, i dont want to loose that insane lugging power.

hydraulic flat tappet is the only option for me.

chevy1500z71

still no answer on re using head bolts?

chevy1500z71

also, who would make a custom grind cam and how much would it cost me? would it be worth the extra money, what would it be good for, 10 more hp?

Confuzed1

iTrader: (4)

Comp will make you a custom cam grind, AFAIK it costs the same. I've never paid extra to have mine cut on a small base circle. Is it worth it? -Only if you've thought up a custom cam that'll make more power than a "off-the-shelf" grind I guess. I didn't realize you had a Whipplecharger...that's a nice blower from what I've read about them.

Ever try giving them a call to see if they recommend any particular cam for your setup? Honestly, I'd give a few cam companies a call and give each one the same exact information on your setup, and want you want from your truck and compare them. If you get a couple that are kinda close, you might want to consider a grind close to what the two recommend.

Just like Orr89RocZ said - the right stock grind cam will work - it doesn't have to be a "blower specific" cam. You might want to think hard about the duration so your peak power is in the right spot.

As far as head bolts go for me anyway -Personally, I'd reuse a good aftermarket head bolt like ARP, but I'd shy away from reusing stock head bolts with a blower, and I'd use good head gaskets. No particular reason - just me.

Street Lethal

iTrader: (16)

There are a lot of companies out there that can customize a cam for blown applications, and these custom cams do make a difference. Yes, it is worth the money. The idea is to tailor the camshaft around your engine, not shove in any old camshaft and spend the rest of the time searching, and trying to maximize it's power. My cousin Rob is waiting on his D1SC, I purposely talked him out of an F1A, because the camshaft he's getting, although won't peak as high, overall will maximize his setup, and perform on the same level....

chevy1500z71

im probably just going to order that voodoo cam, the only thing that concerns me is loss of boost do to overlap. the comp blower speced cam has .043* of overlap, which is very low. the lunati has .041*, so it shoudl work great. but my concerns is that my 1.6 ratio rockers will increase duration, thus increasing overlap, but the question is how much?

the reason i dont think ill go through the trouble of a custom grind cam is becasue i think im better suited with a good truck cam, not a blower cam, all the blower cams seem to have higher rpm ranges than what i need. i dont think i could do a whole lot better then the lunati getting a custom grind, only thing id change is the centerline, but even then, it doesnt have enough duration to make my overlap anyways. like i said tho, i need to know how much more duration those rockers will truly add before i make up my mind, i dont want a ton of overlap, i must admit tho, i do want a tad bit since you can get away with a little bit and still have a good sounding idle.

this is a daily driver, im not shooting to squeeze every last ounce out of it performance wise. i want it to be a very efficient setup, i want to get around 12 mpg out of it but that probably wont happen. i also want about 500hp, but that probably wont happen either, one thing will be for sure tho, itl be an absolute torque monster.

thanks for the replies, glad to hear i can re use them arp bolt, seems like a waist to buy new ones, they ran 2 races and then sat fro 2 years.

ill keep calling some more cam companies and ask about custom grind and what they'd recomend. reason id rather ask around on forums then make a ton of calls is becasue my only day off is Sunday and nobody's open to call. the onyl 2 companiues i called were comp and lunati, crane didn't answer, all the others close earlier and i have to call past 6:00.

Orr89RocZ

iTrader: (20)

1.6 rockers will not change it significantly.

You can have a cam made for a 'blower' motor for any rpm range you want, its just that most off the shelf favor abit higher rpm ranges

chevy1500z71

so if a custom grind doesn't cost an arm and a leg then i could do that. if it cost alot then ill just order the lunati becasue i can pick that ca p for about 180 shipped on ebay with lifters, pretty good price.

Orr89RocZ

iTrader: (20)

well i dont know hydraulic cams pricing but i can say my custom hydraulic roller for my 383 was 370 shipped, and my new cam will be only 326 shipped. Most off the shelf cams are going for 250-300 anyway so its not all that much more to go custom depending on who you get it from.

junkcltr

iTrader: (1)

For your truck app. I would also consider going with an even smaller cam for more torque down low. Something like a 212* I / 218* E duration @ .050 on a 112LSA. That would give a -9* overlap at .050". Then again, the lunati cam you chose isn't bad either.

I still think with the smaller cam you would reach 500HP with that setup. That is guessing you will make around 9PSI of boost and 350 BHP N/A. The smaller cam would help with MPG. Your 12MPG estimate is reasonable. I get about 15MPG average with a stock boosted 305ci TPI in a 5000lb 4x4 truck moderate driving. If I am light on the throttle it goes closer to 18MPG which is not often.
From what you describe in terms of what you want for power output and engine characteristics the lunati should work well for you.

Usually when you call the cam companies it is just people entering data into a program to match up a cam for you. They usually don't like to talk cam timing events because they aren't engine builders.

chevy1500z71

thanks for all the replies guys, im ordering that lunati up tomorrow.

Confuzed1

iTrader: (4)

Your gonna have more toque than you can handle.....you'll need serious mods in order to get the kind of torque to the ground without spinning...good luck with it!!

chevy1500z71

4x4 and 35x12.5" baja claws shouldnt spin, ill just blow the crap out of my 10 bolt rear end and my wimpy ifs front diff and cvs lol

the way the truck used to be with the stock motor and 13pounds of boost it wold burn the tires off like nothing in 2wd if i hit the gas anywhere, even just from idle it would light em up. but in 4x4 it comes outa the hole like a spider monkey, with this new motor im going to have to stay away from 4x4 and baby the 10 bolt. i blew my first 10 bolt up just hitting the gas to about 1.4 throttle from a red light, didnt let the rear end load up first. now i always load it up a tad first, get the slop outa the gears before i do anything, the 10 bolts don't like to be slammed around.

14 bolt semi floater is next on the list. hard to do since i have a detroit locker and 4.56 gears in m 10 bolt but it needs to be done, the 10 bolt is just a massively polished turd with what i have in it lol. ill just put a 14 bolt in, dont use 4x4 for racing and let em spin.

Street Lethal

iTrader: (16)

.... be sure to post the cam card when you get it.

chevy1500z71

will do.

when i get all my parts together maybe ill start a buildup thread. i though i had everything together on summit but of course i just realized i forgot about the flexplate.

how many teeth do i need, theres a 153 and a 168, i have an after market racing starter ill be using. its a 4l60e and the block is a 2 piece seal, internal balance.

305sbc

iTrader: (3)

Here's a good online series from David Vizard called "GFN Porting School" you might be interested in reading through. It has a lot of info on how the cam timing events work with the cylinder head ports.
The discussion on his forum is particularly interesting when it gets into how good low-lift port flow and higher ratio rockers increase the effective duration of the camshaft and allow shorter durations on the lobe. This seems to be something you are concerned with. The pressure differential (depression) of the cylinder in relation to what you will provide with your Whipple is also important in that cylinder filling begins earlier or closer to the intake valve opening event. I think you will like it by the time you get to Part-8 of the series.
http://www.gofastnews.com/board/tech...d-airflow.html

Vizard also has a book called SBC camshafts & valvetrains that's quite good.
If you soak all this information in you'll understand exactly why knowing the actual degrees of the valve opening and closing events is so important when matching a camshaft to your combo.

chevy1500z71

my order from summit came today, heres the cam card.


parts!


painted up the dart heads to match the block