Cascade Crew

blue89 · Posted: Thu Apr 16, 2009 9:50 am Post subject: Cam Suggestions

I just want a sanity check before I get it. Short story

Smallest cam

207/213 0.495/0.515 LSA 112
-14* overlap

Someone else is running this Comp Cam on his 049 headed stock bottom

218/224 0.504/0.510 LSA 110
1300-5600rpm
1* overlap

Summit has a stupid deal on this one. Same as the edelbrock 2162.

218/228 0.500/0.500 LSA 114
2200-4500
-5* overlap

Since I have little working knowledge of the subject I'm asking for advice. Seems like the Summit one might be a little better since I'll be cutting the engine off at 5k-5.5k and the extra manifold vacuum would be nice. I don't really care about idle quality or under 2k RPM operation since I have an automagic. What do you think? I would really appreciate the feedback.

chevymad · Posted: Thu Apr 16, 2009 12:58 pm Post subject:

I'm running this one in my 781 headed 10:1 454.

Duration at 050 inch Lift: 233 int./241 exh.
Advertised Intake Duration: 276
Advertised Exhaust Duration: 284
Advertised Duration: 276 int./284 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.554 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.572 in.
Basic Operating RPM Range: 2,200-6,400

http://store.summitracing.com/partdetail.asp?part=LUN%2D60204LK&autoview=sku

It's one size bigger then the lunati cam desinger Harold Brookshire suggested. I wanted more cam sound then best performance. I've got a th400 behind it, with 2600 stall. While it hasnt been on the road yet, it has torn up a few sets of tires. Very snappy throttle. Idle's actually ok, but you know it has a cam.

I think I'd run the cam he suggested for me.

Duration at 050 inch Lift: 227 int./233 exh.
Advertised Intake Duration: 268
Advertised Exhaust Duration: 276
Advertised Duration: 268 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.542 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.554 in.
Basic Operating RPM Range: 1,800-6,200

http://store.summitracing.com/partdetail.asp?part=LUN%2D60203LK&autoview=sku

Those cams you posted are small, though the summit cam definatly won't sound like it. They are mostly old grinds. Compare the 0.050 duration #s to the advertised #s. Notice how on the voodoo grinds(and the comp XE series) The 0.050s are alot closer to the advertised durations then the cams you posted. This means they ramp up alot quicker and the valve spends more time more fully open then the old cams.

The advertised duration #s affect your idle quality. Because those are the actual places where the valve starts to crack open.

What this all means, is that with a newer cam, say voodoo or comp XE, you'll get a much bigger cam with a better idle. The advertised on mine is close to that summit cam. So they'll idle similarly... but look how much bigger it is.

There is a difference between voodoo and XE as well. Comp uses fast ramps on both opening and closing. Voodoo uses a quick ramp on opening but slows the closing down a bit. This is to try and "catch" the lifter so that it doesnt make alot of clatter. Comp is known for their clatter.

That said.. the voodoo in my truck is a noisey mofo. But i think its because my spring pressure is collapsing the hydro lifters.

I wouldnt go any bigger then the 60203 unless you plan on bumping the compression up. Those flat tops that came stock in that 454 give you a really crappy 7.9:1 compression.

blue89 · Posted: Thu Apr 16, 2009 1:29 pm Post subject:

Wow, thanks a bunch for the advice! I have a Th400 as well with a stock converter and we have very similar heads. I guess I have just a couple more questions:

If I'm trying to keep it from flying apart you think it's good to shoot for a cam with a high operating range?

Do you have enough manifold vacuum to run the heater controls of a camaro?

Did you put larger springs in as well?

Makes me feel better that someone is going bigger and not having issues. The 454's are completely new to me. Thanks again.

chevymad · Posted: Thu Apr 16, 2009 1:39 pm Post subject:

I used the recommended springs. I think I cut the valve guides down on my heads cause i'm also using different rockers. Team Chevelle would be a good place to look for stock limits on lift. I'm sure there's plenty of vacuum for heater controls. The only time you'd even have an issue would be at extended idle. Just off idle you'll have plenty of vacuum. A vacuum canister should fix any issues like that. Power brakes use more vacuum then anything else. It's possible to have issues there. Of course.. you could always install an astro van hydroboost to cure that....

As for the rpm issue, I've found that Harold seems really conservative on his cams. It seems to me that they act alot smaller then they should. Several of us have taken his recommendation, then later stepped up a notch or 2. I was trying to avoid the "step up" by jumping one larger.

I think you'll find the 60203 he originally recommended for me to actually peak in the mid to high 5ks, but be useable up to 6200.

Besides bumping my compression up, when I had the motor apart I added ARP rod bolts. My motor started out as a pickup motor as well. They should both have the small bolts for a bb. That and the pistons themselves are the weak links in your motor. Assuming its all in good shape.

blue89 · Posted: Fri Apr 17, 2009 10:04 am Post subject:

I called up Lunati and asked for their suggestion.
8.5:1 CR
454
400HP NA
6000RPM max
EFI and Boost friendly (cause that's the ultimate goal)

He suggested the 302A4LUN which is 217/217 @ 0.050 (272/272 advertised) 0.515/0.515" and 112LCA. -7* overlap. The only thing I don't like is the cost since I cannot buy it as a kit, $160.

I did find a 06206 with 218/218 (268/268) 0.518/0.518 and 110 with -2* that's much cheaper so I can get the lifters as well, $180.
------
Both are computer controllable. I'm leaning more towards the cheaper one cause I can get the springs/retainers as well. Think I'm going to mess it all up?

Twilightoptics · Posted: Fri Apr 17, 2009 10:54 am Post subject:

Anything is EFI friendly if you're tuning.

If you're going boost, you might think about what Brandon is saying. Lunati's recommendation is very conservative.

8.5:1 is gonna run like crap without boost. Period.

blue89 · Posted: Fri Apr 17, 2009 12:27 pm Post subject:

I didn't have any luck trying to tune the idle my speed density V6 with -10*. That's why i'm a little scared to run with less vacuum. I guess the only reason they can work is if you run a MAF. Here's a collection of everything put together so far.

Desc INT EXT LCA Overlap
Stock LT1 202 207 117 -29.5
LT1 HotCam 218 228 112 -1
V6 cam 206 206 108 -10
Small Cam 207 213 112 -14
Lunati 06204LK (like 302a4lun) 210 210 110 -10
Lunati 302A4LUN lunati recommend 217 217 112 -7
Lunati 60204LK -Chevymad running 233 241 110 17
Lunati 60203LK -Chevymad wants 227 233 110 5

Twilightoptics · Posted: Fri Apr 17, 2009 3:22 pm Post subject:

-10º?

My cam is

Lunati Solid 239/247@.050 .555/.576 lift(1.6) 110ºLSA, 104º Centerline.

MAP setup, idles like a kitten.

blue89 · Posted: Fri Apr 17, 2009 9:12 pm Post subject:

No way. Well sheesh, if you can do then there's a chance that I could figure it out eventually! Laughing

Using the same calculator your cam comes out with 23*. The 60203LK might be the one to try out then. Right price, right parts, and now that I know it's tunable, right on? I really do appreciate all the feedback guys!

Twilightoptics · Posted: Sat Apr 18, 2009 9:32 am Post subject:

You have to figure overlap by the advertised duration.

276/282@Adv 110/104
I have 59º of overlap.

Use this calc:
http://members.uia.net/pkelley2/DynamicCR.html

blue89 · Posted: Sat Apr 18, 2009 8:02 pm Post subject:

I was using this one:
http://www.wallaceracing.com/overlap-calc.php

Main thing was I found someone doing what I want to do. That comforts me.

Dewey316 · Posted: Sat Apr 18, 2009 8:04 pm Post subject:

Its hard to find something brandon hasn't done, or isn't doing. Wink

blue89 · Posted: Tue Apr 21, 2009 1:53 pm Post subject:

I've been reading this

http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/index.html

David Vizard is a pretty experienced guy. I like how he coorelated valve size and engine displacement into a ratio for determining acceptable lobe centerline. So the 454 should run great on an LCA of 102 and an overlap of 80-90* (according to Vizard).

Duration = (OL/2+LCA)*2
Duration = (85/2+102)*2
Duration = 289

That's a huge cam though. So again, the lunati seems good.