[75c10]

I have been enjoying my truck for awhile now but I want more power. I am buying aftermarket heads (probably Dart 180 or 200) next month. I am also buying a 2500-3000 rpm converter. In conjunction with these two I want a better cam than my .462/.469 cam. I am looking at a Lunati Bracket Master 00012LK. The specs are hydraulic .515 on both sides and 246/246 @.050 with 108 lobe sep. My truck has a posi with 3:73's. Is this a good choice for a combo?. I might go to the track once a year just for fun but mainly a weekend warrior. Thanks in advance.

 

[Bob West]

what kind of performance are you getting now? timeslips?

 

[75c10]

I have never had it to the track yet. Right now it runs good but the power is only "fair".

 

[Bob West]

ya gotta have something to compare too...go to the track,make 2-3 passes...the "butt dyno" does not tell the truth.

 

[travis g]

The cam you are looking at is 300* advertised, 246@.050, .515 lift. It is a nasty sounding beast but in a heavy truck with only 3.73's you will be way overcammed. That cam works better with a minimum of 4.10's (and thats with short tires like 26" tall) and at least a 3500 rpm convertor. My uncle run a near identical PAW cam in his 355 '80 camaro (PAW 246@.050, .509 lift) with 10.5-1 compression and it sounded absolutely brutal, but with 3.42 gears and a 3000 stall convertor, it would just barely spin a set of 235/60-15 street tires. He later switched to a cam dynamics/crane energizer 284 (228@.050, .480 lift) and cut almost exactly .5 seconds off his 1/4 mile times.
If you want a rumpity bad ass sound, and still have decent performance, I think the biggest lunati hydraulic I would run would be the 285 streetmaster. It is 235@.050, .507 lift, on a 108 lsa. And thats still a lot of cam for a 4000 pound+ truck.

 

[Guest]

What is your compression b/c anything over 270 to 274 advertised duration really needs more compression then pump gas will generally tolerate.. (From 9.75 to 1 CR. to just under 10, imho)....

Please consider a CC 270 Magnum, an Isky 270 Mega cam, one of Harolds cams or even a smaller one like the old CC 268HE for more grunt yet...

Jmho.. pdq67

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[75c10]

My compression with my new heads should be between 9.1 and 9.5. It sounds like maybe I should stick to between .480 and .500 lift. I thought those Magnum cams and 268HE were old school grinds. I appreciate the responses so far. I definitely don't want to be overcammed. I thought the verter would compensate if the cam was a little too big. Maybe I should go XE268 or Xe274. Anybody else want to chime in?. I'm open to any brand.

 

[ddeennis]

http://www.deltacam.com/


give this place a try......i bought my cam thru him and he ground me a custom cam for my ride.........i gave him all the specs and he made a recomendation and he said if i didnt like the cam that he would grind for me then he will take it back and make it right........he reground me a custom cam for 49.00 bucks plus shipping..............if anything give this guy a call and see what he has to say.......

 

[Pat Kelley]

You might want to read up on the relationship between cams and compression here. It might help you keep from being over or under cammed.

 

[427L88]

In the Lunati line, you would like something like the 301B2 better ( that's a short oval track/hot street cam), but even the 301A9 might be a better fit than the big drag cam you're considering.

.246 is fine duration in your case WITH A SOLID LIFTER CAM!!! You get that big in a hyd and they get sloppy down low, idle poor, etc.

Pure balls?? take a look a tthe 401A4. Puppy comes on at 2500 and should ROCK your truck! Even with 2800 stall and 3.73s.
http://www.holley.com/HiOctn/ProdLine/Products/IEC/IECC/Chevy4.html

To fit the best cam, defintely use Pat's advice above. Only way to do it right , IMHO.

 

[75c10]

Thanks for the replies guys. Pat, my head is still spinning from that reading. I'm just waiting for it to sink in!. I wanted to calculate compression but didn't know all the parameters to fill in.

 

[427L88]

75, let it settle in your brain some. I'm a 'numbers' guy by vocation, and it took me a while to grasp it. However, bear in mind that higher DCR is more power, until the gas quality becomes an issue. If you were to run that big bracketmaster with, say 9.5:1 compression, the DCR would be 6.7-7.2. STONE. You need to keep it near 8:1.

 

[Pat Kelley]

Yeah, it's a bunch of info. It's pretty important to get the right data for the calcs. You can make a few educated guesses but the more accurate the input the more accurate the output. If your pretty sure the CR is in the 9-9.5 range, setup the CR calculator section to that, then put the cam and rod lenght info in. As Gene said, a 300º cam with that CR is a real dud.

 

[Guest]

BTW, yes, Harold's old CC 268HE and the other CC magnum grinds are older cams BUT IMHO, They are winners regardless!! (268 to 274 advertised duration cams)..

I mention Harold here b/c he designed the great old CC 268HE cam for them a long time ago if I rember him saying that in one of his VERY informative, long-winded posts that went through cam design history!!

I just wish he had more time to post more stuff like that b/c it is fascinating reading to say the least!!!

Bet he could write a book...

pdq67

PS, and please realize that even an old-fashioned cam like the long duration GM cams of old run GREAT when they are used in a motor combination that they were meant to be ran in..

But the trouble today is that long advertised duration, easy going ramped cams like the old ones need the older motors compression to make them work properly and that's where we have a problem b/c of the gas octane being so low now!!!

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[75c10]

Thanks guys. I have a question about rod length. What is the stock rod length?

 

[427L88]

5.700"

 

[Harold Sutton]

Stock rod length for a small block is 5.7".