I called Comp to get a recommendation for a cam and I think I got some bogus advise. The combo is 200cc aluminum ProActions, StealthRam, 1 3/4 SLP headers, 3.45 gears, and maybe a ~2800RPM stall. I want a max of 6000RPM which I think is reasonable with a modifed valvetrain. Comp recomended a 08-502-8 Xtreme energy. 218/224@0.050, .495"/.503" and a 112* LSA This seems VERY mild to me, especially given how well these heads are supposed to flow (havent flow tested em yet) and a mid-high RPM intake like the HSR. If Im not mistaken, this cam is made for near stock engines with TPI. Does this seem odd to anyone else?

 

Dude, you're right about the bogus advice. I'd never go by only Comp Cams cam help line for picking out a cam. The last time I called them, I got some complete idiot who didn't even know what a Super Ram was. He also couldn't explain the difference between a hyd. roller and a solid roller! What a lame butt. The cam they recommended you actually isn't bad, it's about like the hotcam, which Mike Davis is running into the 11's with. If I were you I'd run an even more aggressive X-treme engergy grind with a Stealthram. Even on a 350, I'd run a cam with at least 230 degrees of duration and about the 240 on the exhaust side. Definitely go with a dual pattern cam with that intake and heads. Your heads also like a lot of lift. If you can afford it and would consider going to a solid roller, Id recommend that. People on here have run the solid roller Comp cam w/ 236/242 dur. at .050 with .6XX/.6XX lift, which is where these heads really shine. If you want to stick with a hydralic roller I'd go with the 306 cam, which I think is around 230/244 dur and .527/598 lift or close to that. You could also order a custom cam and add more lift on 306 grind, which is what you should really do. If you go with more duration than 230int. then you're going to need at least 3.73 gears, if you're running a 350. On a 383+ your 3.45s would be okay up until about 236int. duration. Go with a stall of at least 2800 or preferably 3200 depending on how radical you get with the cam. And yes you can tune cams this big with your stock ECM once you get into prom burning. I think MAF is easier to work with and SD gives you more options for fine tuning, but they'll both be fine for making at least 500+hp.

 

IMO being you have a fairly mild stall and 3.42 gears and if you want to keep it streetable then that cam is pretty much on the money, now if you stepped up to a 3.90 gear and a 3,500 stall it would love a much bigger cam

 

Tempest is really right, I guess what we don't know is are you looking for a streetable really quick car or an all out rocket that's not quite as streetable, and I'm not talking drag car only either. You can still run a big cam and gear and as long as you have EFI it can still be streetable, but it's up to you on what kind of manners you want the car to have. Do you want mild or wild out of your engine? How much hp do you want? The more you have the higher you're going to have to rev the engine to get it.

 

I love the rims by the way, they look familiar, I know I've seen them somewhere??

 

Comp, and the other major cam mfrs, always tend to err on the side of being conservative. That's safer from their point of view, considering that they don't know that (by virtue of your visiting this site) you're a little more technically savvy than yerbasic average street stroke, who would buy too much cam and then complain that their 2.73-geared TBI 305 won't spin the tires in the high school parking lot any more.

The Stealth Ram will work well with any cam that a carb car will, except that you should up the lobe separation if the intake duration goes much above about 214°. Carb cars tend to like pobe separations in the 108-110° range for the most part, FI motors will behave better with LS of 112-114° with cams in the duration range in question.

Here's some more suitable ones.... http://www.compcams.com/catalog/084_085.html Look at the 08-306-8 right at the top or http://www.compcams.com/catalog/082_083.html the 305 at the very bottom.

 

What I would do is just hang around sites like this one, and other SBC performance-oriented sites and just see what cams/cam kits seem to be popular for a similar set up. A combo like yours seems to be relatively common for a 3rdGen, so it shouldn't be too hard to notice a 'trend' with cams for a similar engine to yours.

 

JR305 is running nearly the same engine combo as mine and I believe he is running an XR276HR grind with decent results. 224/230 .537/.544 112 @.05 I think hes got a sixspeed with 4.10s, though. Theres another member running AFR195s with a SteathRam and a 700R4 and almost the same cam as above with maybe a little less duration on the exhaust side. I am willing to give up a little low end for the sake of max power (hoping for around 380hp with tuning) and I really want to exploit the full potential of these heads. RB88L69, the links dont work for some reason.

 

I fixed them. They changed their page names slightly.

 

RB, Im really leaning towards the 306. (230/244 .510/.540 112LSA) It may be on the edge of streetability, but that problem can be solved when I can afford a decent stall. Does the intake lift seem a little low to anyone? Maybe a set of 1.6s on the intake side would be beneficial? This cam is quite a bit larger than Ive seen used on other AFR/ProAction combos, I hope its not too much.

 

You'll be wanting the higher stall converter about 100 yards out of your driveway after you install that cam. Happiness is often a smaller cam than you think you need.

Keep in mind that a stock cam usually has about 200-205* of .050 duration and WIDE lobe sep angle. 25* more duration and a tighter LSA is a BIG change.

I don't think their recommendation is too far off.

 

Id rather go conservative than over-cam the engine, but with the awesome flow of these heads and the HSR, I think this combo has some serious potential up top. The lack of lower rpm power does worry me though, especially since the engines only got 9.5:1 CR and the excessive overlap is going to drop the dynamic considerably. Maybe a custom grind with a little more duration and lift on Comps recommended cam would work...

 

Not to sound critical, but your thinking is a little backwards.

Since you have lower (not that 9.5 is "low") static comp, the best way to compensate for it is to build more dynamic comp. The way to do that is run a cam that has less duration and overlap. Of course the other thing is to advance the cam a c-hair, but that's up to you.

With the HSR and the fuel injection of it, you don't have to worry so much about loosing low-mid range torque from large runners in the heads. The metering control of the FI can compensate easier than if it were a carb.

IMHO, stay a little conservative with the cam until you get the static comp up. Running a mean cam without enough static compression to make up for the loss in dynamic compression makes for a engine with no *****.

 

"Comp recomended a 08-502-8 Xtreme energy. 218/224@0.050, .495"/.503" and a 112* LSA "
that would be a valid choice on a TPI, but its not taking advantage of the stealth rams far greater airflow and normal effective operating rpm range, your not at pressent set up to effectively use the stealth rams higher flow rates, I think they made that choice to match the gearing , compression and stall speed NOT the intake and heads,potential if your combo was correctly matched for max hp, no doubt to keep you running faily well at the cost of some higher RPM hp potential lost. you can,t blame them for trying to make the best of a slight mis-match of parts.


EXAMPLE
you MUST get the DYNAMIC compression ratio of your engine,
(should be about 7.8- 8:1)

the cams LSA/
(should be about 112-116)
overlap
(should be about 45-75 degrees)

AND duration
should be about 225-235 degrees (intake)

and rpm range
4000rpm-6500rpm)

to match the engines static compression
(should be about 10.5-11.2:1)
and intended effective rpm range of the intake, the holley stealth ram is designed to run best in the 4000-6500rpm range, that will most likely require
3.73-4.11 rear gears and a 3200-3600rpm stall speed)
below is a cam that comes close on an 11:1 cpr 383

http://dab7.cranecams.com/SpecCard/D...1=Display+Card

if you want that car to run youll need to kick up the compression, (and a change to a 383-406 would sure help also!) and rear gear ratio,there are ways to cheat!!
a good shot of NITROUS in the 100-200hp range with the larger cam will make everything look totally differant , in that youll build cylinder pressure and tq much faster, partly over coming your lack of gearing, and stall speed

here read this
http://cochise.uia.net/pkelley2/DynamicCR.html

links youll need to figure out corect rear gear ratios

http://www.miata.net/garage/tirecalc.html

http://www.wallaceracing.com/reargear.htm

http://users.erols.com/srweiss/calcmph.htm

http://users.erols.com/srweiss/calcrpm.htm

http://users.erols.com/srweiss/calcrgr.htm

http://www.prestage.com/Car+Math/Gea...o/default.aspx

http://www.geocities.com/z28esser/speed.html

http://server3003.freeyellow.com/gparts/speedo.htm

http://www.pontiacracing.net/trannyratios.htm

http://www.tciauto.com/tech_info/gear_ratios.htm
read this

http://victorylibrary.com/mopar/cam-tech.htm

http://www.mercurycapri.com/technica...e/cam/lca.html

http://victorylibrary.com/mopar/rod-tech.htm

http://www.zhome.com/ZCMnL/PICS/deto...etonation.html

http://www.chevytalk.org/threads/sho...rue#Post397334

if cams are a mystery please take the time to read these, it will get you a good start

http://www.newcovenant.com/speedcraf...camshaft/1.htm
(read LESSONs 1-8)

http://www.mercurycapri.com/technica...e/cam/lca.html

http://www.wighat.com/fcr3/confusion.htm

http://www.cranecams.com/instruction...in/camfail.htm

http://www.mercurycapri.com/technica...cam/index.html

http://www.idavette.net/hib/camcon.htm

http://www.cranecams.com/master/adjustvt.htm

http://www.centuryperformance.com/valveadjustment.htm

http://www.totalengineairflow.com/tech/valvelashing.htm

http://www.chevytalk.com/tech/engine/Cam_Selection.html

http://www.chevytalk.com/tech/101/Cam_Theory.html

http://www.babcox.com/editorial/ar/ar119736.htm

http://www.mercurycapri.com/technica...e/cam/vtg.html

http://www.n2performance.com/lecture1.shtml

http://www.symuli.com/vw/camp1.html

http://www.symuli.com/vw/camp2.html

http://home.wxs.nl/~meine119/tech/camqa.html

http://www.chevytalk.org/threads/sho...rue#Post200511

http://www.crower.com/misc/valve_timing_chart.html

http://www.speedomotive.com/Building%20Tips.htm

http://www.kb-silvolite.com/page05.htm

http://chevyhiperformance.com/techarticles/94138/

http://www.aera.org/Members/EngineTech/engine.htm

http://www.zhome.com/ZCMnL/PICS/deto...etonation.html

 

Your motor will run a whole lot better if you pay less attention to Desktop Dyno buzzwords, and instead pick a cam whose intended RPM operating range is consistent with your induction system's properties; and then don't put an induction system on an engine it has no business being on (dual-quad tunnel ram on 8¼:1 305, for example).

IMHO 9½:1 with iron heads is plenty for any of the larger cams people have mentioned. None of them is particularly radical.

 

I'm thinking of changing my cam, about how long should it take?? I can probably have 2-3 people doing this, at least 2 (including me.) How long should it take for two people to do this? I know you got to pull the motor to get to the timing cover and the cam, then you gotta change them out, re gasket a lot of stuff, and hook it back up.

 

you don't have to pull the motor.
just take out the radiator, and bend the front support bars slightly.

remove 2 bolts on the front of the oil pan and you get the chain cover off and on just fine.

 

Ive got a fresh-built 3.45 nine bolt, and I dont want to go to any higher (numerically) gear, Ive only got a 700R4 and four speeds, and I want to be able to drive the car on the interstate below redline. I was hoping to recoup some of lost low end with a higher stall rather than deeper gears. AJ_92RS, what you said about my dynamic cr was what I was trying to get across, perhaps I was a bit vague... Thanks for the all the advise, guys.

 

You have good street gears. If you you want a cam that'll work good with them and a good stall conv. I'd rocommend a cam with around 224/230 dur at .050 lift. That's if you're going with a 355. I'd go up to around 230-236 if you decide to do a 383. Comp has a cam with 224/230 dur. and GMHTP ran it with a stealthram in a 355 Iroc. That car put out 330rwhp and around 350rwtq. That's with a stock chip too with only fp and timing adjustments! I'd go with that same cam if you use your car as a daily driver and don't want it too wild. You could probably get another 15hp by going with something a little bigger, but with your gears you'll notice some low end tq loss. Make sure to go with at least a 2800 stall with this cam. I'm sure one of the guys can give you the part # for the 224/230 comp cam.

 

Does anyone have a part number or grind number for the cam camarojoe mentioned?

 

The XR276HR is a good cam. You have the specs right, 224/230 .537/.544 112 @.05, that’s with 1.6rr. I think it would be pretty streetable with the 2800 stall and 3.45 gears in a 350. That’s the cam I would go with if I were you. If you want a little more the 230/236 cam would be a good choice but I would step up to some thing like a 3.73 gear. I have not driven my car much, just haven’t had time for it (still have some bugs to work out). Now that I am out of summer school I should be able to get everything worked out and start fine tuning it. But as it is right now it is a vast improvement over the 305 TBI.