evilemokid94

iTrader: (6)

What is the largest cam that stock 906 vortec heads can take? I'm looking at adding ls beehive springs and 1.6 RRs but want to compair stock to modified, I'm looking for atleast 300 rhp out of my build.

Atilla the Fun

You don't need the nastiest cam possible, especially not for such an easy goal. I say don't go any wilder than Comp's 12-243-3.

evilemokid94

iTrader: (6)

the cam i was going to use for my build was a comp cams special grind( 224 duration at .50 on the intake and exhaust, a 0.352 inch lobe lift, and a 108 degree lobe seperation.) but thats if i upgrade my heads for the larger lift. but if i can net 300RWHP with the stock 906 heads with a milder cam than the stock i would go that route.

GreggymacZ28

Vortec heads actually flow better with a split duration/lift cam. They flow relatively weaker on the exhaust side, so they need a higher exhaust duration and lift to make up for that.

Another thing, i think you had a typo with the .352 inch lift. I hope you meant .452? If you're are going to put in a camshaft you might want to look at alex's parts valve springs. They werent hard to install and get vortec heads up to .550 lift. I'm running them with a 236/242 duration @ .050 and 520/540 lift and have gotten a 12.28 @ 109.45 in the 1/4 mile mph which by a horsepower calculator gets me around 345 rear wheel horsepower so 45 horsepower above what you are aiming for.

But if you are keeping the heads stock, i'd aim for something in the .468/.474 range with the duration being split as well at whatever you end up choosing!

evilemokid94

iTrader: (6)

If i go with my large cam(above) I'm going with the Alex springs. And no, no typo. If I go with the bigger build I'm going to follow popular hot roddings 450 hp vortec build. And that's the cam they call for

evilemokid94

iTrader: (6)

Pretty much my goal for my build is to make a toque monster, thst can still run with ls1s

GreggymacZ28

Oh alright then. I've never seen anyone run a .352 inch lift? Why would you need alex's springs for that?

3rdgenmaro

iTrader: (9)

He said lobe lift, not valve lift.

.352 lobe with 1.5s = 0.528
with 1.6s = 0.563

evilemokid94

iTrader: (6)

ah, so i cant run my 1.6s, its to high of a light, damn... oh well, 1.5 RRs work well aswell if i run this cam. so the other cams posted i can use with my stock heads?

GreggymacZ28

Ah ok i was going to say i swore he said valve lift and i kept looking to see if i read it right or not. 1.5 rr is perfectly fine, i know alot of guys that are in the nastyz28 vortec head guide dont switch to 1.6.

evilemokid94

iTrader: (6)

looking at the price of alex springs, i might just go ahead with the popular hotrodding build, the kit is only $90 so thats not too bad. ill stick with my stock rocker assembly for now untill i find a set of 1.5 RRs i like then ill make that switch.

evilemokid94

iTrader: (6)

do you have any information on your build? if your running into high 12s then id be happier than a woodchuck in a forest with that build.

Orr89RocZ

iTrader: (20)

Your 224/224 108 lsa cam would work pretty good. Most guys run around 224 deg in 350-ish inch motors and works well. Alot run abit more duration on exhaust side but that cam will still work pretty well especially due to the tighter lsa. Should be a blast on the street and get you into the 12's no problem. I assume its a hyd roller cam? If so, get good springs. Beehive kit would work well but aint no 90 dollars. Dont skimp on springs. 1.5 rockers would work well

evilemokid94

iTrader: (6)

im hoping it will just give me the torque im looking for, nothing like that seat of the pants feeling when you floor it going 45+ and hear those tires squal. top speed isnt an issue aslong as it will **** *** pretty well. yes its a roller cam, my block is a 96 5.7 with 906 vortecs. the springs im looking at are the ghetto grind springs, alex springs.

Orr89RocZ

iTrader: (20)

The alex kit looks like it works fine. As above, he's running a big 236 cam and turning some rpm so far and it appears to be working.

A stiff beehive should handle it tho, doesnt appear to be that aggressive but its hard to say without knowing entire lobe shape.

skinny z

I can relate some of my experiences.
Stock Vortecs (that's right out the box with stock springs and valve stem seals) with a .454" cam pushed my 3700 IROC to mid 13's around 101 mph. 3.73 gear, 12" converter (2500rpm?). No coil bind or retainer interference but 7000 on a missed shift bent an exhaust valve.
Next iteration was with Comp 26918 springs, 1.6 rockers (lift now .480" ) with the guides cut for different seals. Same chassis, 13.1 @ 103(+/-).
I've moved up to a roller cam (XR276HR w/ lift of .544") for 12.7 @ 108. More converter too w/ 1.7 60'. Still loads of room for lift, "loads of room" being relative.

GreggymacZ28

I actually am running low 12's. 12.28 at 109.45. Basically i told you the cam i have and it was purchased from a member on this board. So i have that cam, 3500 stall, my raceweight is 3300 with me in it. My vortec heads are stock as well, nothing done to them. The guides actually were cut and i have screw in studs, but i am still running alex's spring kit with a .060 shim if i remember correctly. I also am running my motor to 6800 rpms when i shift so i am up there in the rpm's as well. But like orr said you dont want to skimp on springs, beehive springs are a very highly recommended spring to go with, and if i had the money back when i was doing this i probably wouldve gone with those.

I think the xe274 is a really good cam for vortec heads though, it's alot less of a lift than mine and a little less duration but people are running similar and faster 1/4 mile times than me with it.

skinny z

I'm not disputing anyone's results. By the way, 12.28 @ 109 is pretty good as far as I'm concerned.( Curious: what was your best 60' ? )
I'm just answering the OP's original questions.
My stock Vortecs handled .454" lift. There may have been more room than that but I never explored it.
Modified with 26918 springs and a cut valve guide (although I can't say by how much), they took .545". Still room to go as far as coil bind or guide/retainer interference.

GreggymacZ28

I had a small lift cam too i think it was right around the lift you are talking about. And my best time was a 12.97 and it had around 196/204 duration. So alot can be had with smaller cams! Also, my best 60 foot is 1.68. I average 1.70. That is with a 10 bolt rearend with just an eaton posi and i still have stock lca's.

skinny z

If the compression ratio is right, yes as small cam can go a long way.

evilemokid94

iTrader: (6)

so is the cam i picked,greggys, or atlias cam the best for my 300+ rear wheel horse power want and torque want?

here is the torque and HP range if i use my cam

GreggymacZ28

In that article it says they are not even running vortec heads? Also, they do maximize other things with the engine to get those results in those magazines so i wouldnt expect exact numbers when copying a build.

I'd say your cam choice is pretty wide for making over 300 whp but what will make it even wider will be if youre are doing the upgraded springs or not.

evilemokid94

iTrader: (6)

they are using a set of vortecs, just the aftermarkets. also im going to upgrade the springs because i have to using the cam. just havent decided on the alex springs or the beehives. im copying the build pretty closely, minus some of the block work like milling and using the upgraded heads and using the stock heads.

GreggymacZ28

Looks fine to me. I havnt personally seen anyone running that cam, but noone was running mine either and it worked out for me! I'd say go with what ever cam you like best! Thats the beauty in it being your build.

evilemokid94

iTrader: (6)

thats the thing though, im lost!!! lol this is my first engine build and being only 17 i have no clue as to what i need to do or want to get what i want out of my engine.

Orr89RocZ

iTrader: (20)

What other mods are you planning with the build? Carb or efi? What intake? How well can you tune? Lots to consider than just the cam but i do like the grind comp spec'd

Atillas is good too but flat tappet. Similar grind in roller would be nice but i like the tighter lsa especially if carbed

evilemokid94

iTrader: (6)

intake is an eldabrok RPM proformer intake
holy 750 carb
roller timing chain
custom grind roller cam
vacuum advanced HEI dizzy

GreggymacZ28

Like orr said other things apply as well. Should get an elderbrock rpm intake. Also david vizards book says that chevy 350's and 1.94 valves that your lca should be 107.5. He has alot of good things in his book that have helped me learn alot about how to buy not just parts, but the right parts.

GreggymacZ28

Very similar to my combo besides the cam.

evilemokid94

iTrader: (6)

so should i expect similer rhp numbers or atleast numbers like you? i really am clueless on the build. aslong as i can light the tires up and stay above or around 300 rhp ill be extremly happy, i know factory my engine is rated 255 hp, and 350 torque, so its not bad from the start but i want more.....smoke lol. is my cam smaller than yours?


also should i up my exhaust lobe lift? maybe like 24/28?

GreggymacZ28

Well my car didnt run 12.28 its first time out. It took alot of carb tuning. You can go to the drag section and see that i had alot of trouble getting it to run what it runs. Alot of people think(including myself at one point) that just throwing parts at it makes it fast and i was let down. My car was only running 13.6 for awhile. I did have carb issues so that was a main problem, but i was running a 12.67 when i changed to manual steering and an electric water pump which got me the 12.28.

Also, im pulling 1.68 60 foots so im hooking really well which i dont think should work because my lca angle is all out of whack.

Yes your cam would be smaller than mine, i am running a 110 lsa though, but my duration is larger and lift on the exhaust side, its in my sig.

GreggymacZ28

http://www.nastyz28.com/forum/showthread.php?t=56505

I read all of that when i was doing my cam, it helped me out alot.

evilemokid94

iTrader: (6)

well im not going to take my car to the track, its more street driven and a street toy. so im not worried about times really. even 13s id be extrembly happy to get away from the v6 i have now, its a dog and can barley pass a car after 60, it struggles and wont even break the tires lose from a dead stop. i just want something funner to drive that will hold its own against todays cars, and shove me into my seat when i get into the gas.

GreggymacZ28

Then your setup should do the trick! Will definitely feel alot better than the v6.

evilemokid94

iTrader: (6)

also forgot i have a set of longtube headers aswell

evilemokid94

iTrader: (6)

i hope so, the v6 struggles so much to pass a car around 60, by the time i get around them im near 85 trying to pass them and it takes forever to pass. have you driven your car on the streets any? is it fun to drive if you have?

GreggymacZ28

Yes i drive it on the street, and it's very easy to drive i have no issues with it. It's a fun cruiser for me. I dont street race however, so ive never pulled the car on the street against someone, i leave that for the track.

Orr89RocZ

iTrader: (20)

For street driving most of the time, i'd stick with the 220's duration cams. it will run fine.

Greggymac's big cam was better suited to his goals of trying to hit 11 sec 1/4's and also because its 10.5 to 1 compression with iron heads. Thats a good bit of compression and that motor needs a bigger cam to try to hit 11's. I think theres some more left in that combo with some tweaking and better air.