i've been reading up on cam's and i find that you can get just about any grind, for any type of driving you want. i'd like to go with a hyd. cam and roller rockers, of course new lifters. looking at about a 284 adv. duration and a bit over .5 lift. this reads like it very closely matches the performer high intake, headers, 410 and 4 speed. sound like a good plan? i'd like some lope in the idle (just to be cool) the overlap is 110 and it will go in a 461 motor with 11.5 to 1 comp. ratio. any thoughts or favorite comb. out there? thanks john

------------------

Sorry, but I have zero experience with big block cam applications but the small block cam I currently use closely matches what profile you are considering for your big block. You may want to consider a little more aggressive profile.

Call these guys: Lunati Cams (901) 365-0950. Give them your application and they will perfectly match your cam to your application. I use these guys and their cam pics for my 383 (both times) were the strongest cam profiles according to PC Dyno and DragStrip Plus. (Makes me wonder whether they ran the numbers through these programs first and then built the cam!)

I am sure that Crane and Comp Cams' techs would do the same but I have never used their help. Good luck!

------------------
70' Malibu - 383 'Dental Gas' Inhaling Stroker! Gold Member #39
Chevellz Alwayz!

My favorite for street BBCs is the grind I'm running in my 427. It's a Crane Mechanical Commander CC-304-2 with 238/248 and .544/.567. Excellent pull from 3000-6500. Good idle vacuum, a little lope. It not as long in duration as the stock L88 cam and a bit more streetable. It's a solid lifter so you can slightly tune it by opening/closing the valve lash. With roller rockers and polylocks the lash doesn't creep at all no matter how hard you flog it. So essentially you can adjust it once, check it when hot, and never worry about it again. BTW, when you're assembling a motor, a solid cam with it's precise lash setting beats the heck out of the "roll in your fingers" method hydraulics use.

Solid cams rev faster than hydraulics.

If your exhaust note isn't defening you hear that wonderful little clattering of 16 valves opening and closing. To my warped mind, very cool.

I think they call this a PowerMax cam now, not a commander. It is a wonderful street cam. Call Crane and see if they give you a better one with your combination. Or you can dial one up on their website.

Wes is right, with that kind of compression you want some more overlap. Careful of your piston valve clearances when you get into .550 or more lift.



[This message has been edited by Gene Chas (edited 08-02-99).]

John,I have the Comp Cams 280 Magnum cam in my 68. The engine is a 11:1 4 bolt 454, KB pistons,performer RPM. 800cfm spreadbore holley.TH400,3.55s Car has a nice mellow lope at idle and no traction with 295/50s http://www.chevelles.com/forum/smile.gif I do have low vacuum at idle but I suspect my booster on the brakes might be dying. Otherwise I love this cam http://www.chevelles.com/forum/biggrin.gif
SPECS- duration=280/280(224/224@.50),lift=.566in/.566ex.
Gene, thanks for the info about solid cams/roller rockers. My next project is going to be 427/solid L88 cam,4spd,4.56s

------------------
Jeff ACES#841 TCG#158
68 SS396(454)
68 L78 Project
87 MC SS

Someone needs to write a FAQ on what all the cam #'s mean.. i think i have most of em figured out but I have never seen proof that im right or wrong..

id tell ya what I think they all mean but id rather not http://www.chevelles.com/forum/smile.gif

Mike

Jeff, HUWAH! A solid litler 427 L88. Man that's cooking! BTW, 67RAt runs that exact combo. ( well I don't know his carb, but Holley told me 850cfm). Mike, share your thoughts, we can use John's post to flush it all out. I hope you don't mind John.

Be careful in that the roller designs and standrd designs I don't believe are apple to apples comparisons when it come to duration figures. The ramps are different. I think they should come up with an "effective" duration figure, but it'd be hard to calculate. It would at least add to comparisons between standards and rollers.

[This message has been edited by Gene Chas (edited 08-03-99).]

gene, sounds like a great idea. it would save a lot of us time and $$$. i looked up the stats on a ls6 chevy cam and they seem mild compared to even the 280 cam i've been eyeing. could be they had to make it very streetable?? thats kind of what i'm looking for with a little bit more. i don't understand why solids are better compared to the newer anti float hyd lifters? and also how much overlap would you recommend? this cam has 110. i assume you had pressure bleed off? thanks john

I had to make a cam choice muself last winter. I went with a Summit grind, 224 int. 238 exh. @050 with I think 540 lift. and 114 degree lobe separation. Brought the power band down to 2500 to 5800 rpm with float around 6600 rpm. The cam I pulled was a comp. 292h, 244 and 244 @050, 555 lift and 110 deg. lobe separation. The more overlap the rougher the idle. The power range was 3500 to 7000 rpm. I wanted more bottom end torque since I am running a m20 with 3:31 rear gear ratio. Amazingly. I could really tell the difference, and with the 114 deg. lobe separation, (less overlap), I got much more vac. to brakes now also.
I have not had it to the track yet, but I really do like this cam. It does pull hard, at least to 6000 rpm.

[This message has been edited by DUANE OCHS (edited 08-03-99).]

John, I'm not qualified to recommend a cam for you or even an overlap figure. The deal i=on the lifters though is a bit more strighforward. The issue isn't anti-bleed hydraulics its a matter of hydraulic, solid and roller lifters all support an increasingly aggressive ramp profile. I supoose the hydraulic rollers are probably the best of all for street applications, but I have a resto-rod and am trying to stay with period components. I wish I could post a diagram here because a picture would show you what I'm referring to.

I don't know what pressure bleed off is, relative to solid lifters. My Crane cam supports power accessories well, although my 67 has none. My cam is slightly less agressive than Duane's old cam, running out at about 6600, which is just perfect for a 427. The motor will run up to 7000, but it's wasteful since no more power is made.

I really would call Crane, Cam Dynamics, Isky and see what they recommend. And if you can swing the buck a roller, with their wicked quick ramps ( meaning heavy springs) are the way to go.

FWIW I know a local racer ( 7.00/6.99 in 1/8) who has tried a bunch of cams and claims the L88 is still one of the best in his car. ( 4500 stall, .100 over 454, 4.88's). Go figure 30 year old technology.

[This message has been edited by Gene Chas (edited 08-03-99).]

thanks guys, great information, and conversation. i guess i'd rather talk cars than just about anything else. i went to a show here in milford michigan last night, wow the bucks some folks throw at these cars. it was the longest ride i've taken in my chev. so far and did nothing but build my confidence. what a pleasure to drive, and the looks are pretty cool too. see ya john

my turn
heres my favorite cam, crane cam dur at .050 int 266 exh 276. advertised dur int 310 exh 320.lobe center 110.open /close at .050 int
28 73 exh 58 23. lash int .026 exh .026. lift
int 600 exh 610. rpm-4400-7400 this is what I run in my 427,spec card dont lie,looked up my card after 7 years I guess I went a little bigger than the stock blueprint L-88, hell its been so long. works good with 4.88s well good day 67rat member #199

67RAT, you're a cammed maniac. Man, I thought the L88 cam was a little long in duration. Whoa!

yea its a little steep but works good with 88s,I have to idle it at about 900 rpm. it will run to 7400-7500 makin power, sure frys the nostalgic red lines,sticky tires make it hook though.I want to post a picture of the stock looking beast,when I fig out how to do it.day,good,have.
bob h
67rat member #199

Yeah, I'd like to see it. My photo guy charges me $2.50 to scan a pic. Al was kind ebough to format for me so I could post it here.