What cams are yall running

[98SilveradoZ71]

Ok so im looking to buy a new cam and i know absolutley nothing about cams. i need something that will give me some lope and some more power. i want something that i know wont be abnoxious but something that ill be able to tell a difference when i step on it. So i was wondering what cam u guys would suggest that i look at and what u gues noticed power difference wise. I will most likely be getting my heads ported and a new intake manifold. so let me know.

Thanks for bearing with a newb. cheers.gif

[BeaSSt]

First off, your NOT going to be able to run a loopy cam in the '98. Cuz, it will drive the EPROM crazy trying to adjust the timing. Unless you dis-connect the EPROM/computer and I'm not sure you can even do that on a '98 model.

Anyhoo, try giving Crane or Comp. cam a call and talk to them about it. I did this back when I was starting the overhaul on my 5.7L and they(Crane Cam) advise me to go w/ the Powermax. To get better lo end and mid range torque. Which I did and I'm very pleased w/ the Powermax cam from Crane.

Good luck,
Don

[step-a-side]

Hydraulic flat tappet cam with .448"Int/.472"Exh valve lift
112 lsa
1,6 rockers

[Boosted-Z71]

Blower cam:

Duration @ .050: INT: 220 EXHT: 229
Lobe Lift: INT: .3420 EXHT: .3400
Lobe Seperation: 114.0
Specs For Cam installed on 112 Intake Centerline
Crane Gold Race Series 1:60 Roller rockers

This thing lopes like crazy at 900 rpm through full exhaust, 700-750 idle rpm is just amazing, you can hear it dropping each cylinder over.

You will have a problem with 2 things (1) Tunning, which can now be overcome do to Tuner Cat (forget any handheld tuner - it wont work)
(2) You will be short on fuel & air do to the limitations of the Vortec manifold, 19 lb injectors & no injector upgrades, and all the crap in the air path inside the manifold. There are a couple manifold options here, Marine intake, RamJet intake, or go back to a carb setup, The first 2 being a greater cost than the last. You will starve the thing once you change cams on 19 lb injectors. Dont ask how i know, its a long story, but it looks like it now has a happy ending. If your not going to change any other components get a cam with a low rpm powerband, nothing above 5000 rpm, You wont have the air or fuel to support anything in the upper rpm range.

Boosted

[THoy702]

[QUOTE=
(2) You will be short on fuel & air do to the limitations of the Vortec manifold, 19 lb injectors & no injector upgrades, and all the crap in the air path inside the manifold. There are a couple manifold options here, Marine intake, RamJet intake, or go back to a carb setup, The first 2 being a greater cost than the last. You will starve the thing once you change cams on 19 lb injectors. Dont ask how i know, its a long story, but it looks like it now has a happy ending. If your not going to change any other components get a cam with a low rpm powerband, nothing above 5000 rpm, You wont have the air or fuel to support anything in the upper rpm range.

Boosted[/QUOTE]


where can i get a marine intake? i thought those were limited in production?

price?

[TXvortec350]

Lingenfelter 213/219 @ .050 Int. .493/ exhaust .502 on a 112 LSA

[bigredz]

Why does everyone say thet you can't run a big cam in a vrotec truck? How much power can I get with a bigger cam? Can I get a custom tune by edwright or westers for the camshaft? Thanks, Brett

[TXvortec350]

Because what alot do not know is if you run beehive springs and retainers and you get retainers (locks) that are +.050 then you will get added clearance!My heads are bone stock and have more than plenty of clearance to run more lift!

[chevydad]

Hydraulic flat tappet cam with .448"Int/.472"Exh valve lift
112 lsa
1,6 rockers

94 lt1 cam

[chevydad]

Lingenfelter 213/219 @ .050 Int. .493/ exhaust .502 on a 112 LSA

how's it work? i saw it on ebay i was gonna buy one. are you using 1.5 or 1.6 rockers?

[Pauly]

You arent going to run out of injector until the 330 rwhp mark, seeing that the Vortec 350's dyno at 200 rwhp, that leaves a huge margin for inprovement. 330 rwhp can be achived with the LT4 hotcam in a 383 with ported Vortec heads.
The stock intake is horrible for 5000 rpm and higher power, its to restrictive to take full advantage of the cams available. Go Marine, Ramjet or carb intake converted to fuel injection

The 1996-98 dont use and EEPROM or MEMCAL, they use a PCM and MAF sensor.
The stock LT4 cam would be a great choice for a dialy driver , not much lope though. 203/310 i/e dration at .05." of lift and lift is .476"/.480" with 1.6:1 rockers, roughly .030 with 1.5:1 rockers.
You could also run the LT4 Hotcam with its 218/228 duartion and .492/.492 lift with 1.5:1 rockers or .525/.525" lift with 1/6:1 rockers. This cam has some lop and has strong bottom end, I wouldnt use this in atruck except in a rcsb, the others are too heavy, but a higher stall converter would help this 1 out for sure.

That Lingenfelter cam also looks great, they are $100 brand new from Lingenfelter Industries on Ebay.

I am also using the marine intake, go to the PPE forum, there is 1 for sale still, it is a very complete kit.

Hey guys, the L31 Vortec 350 uses rollercams, using flat tappet cams is a step backwards.

Lift of over 0.475" cannot reliably be used on the STOCK vortec head. You can get a tool that modifies the sping pocket and seal casting that will increase the clearance and allow larger cam lifts. Ther are other means of increasing Vortec head cam lift.
peace

Pauly

[Boosted-Z71]

Yes the marine intakes are hard to come by, price by the time your done will be $1000+ easy just for parts. Just depends on how much you spend on injectors & some incidentials. There is also some fabrication work to make this manifold work on the truck for all the emmissions & coil mount. There is a guy "Pecos" on http://www.pacificp.com/forum/index.php forum that has these on occasion, they are salvage / take off units. Right now there is only 4 or 5, of these on trucks, running in the USA & Canada, only 2 are SC, 1 on a built 383, the other 2 are stock L31's with bolt-ons. Pecos takes orders & fills them per the waiting list, when he gets the manifolds. There is a huge thread on there with more particulars. He puts together one heck of a "kit", and is a class act guy. Not sure about the availability now.

As far as running a big cam, springs are an issue, but easily solved with the previously mentioned beehive Comp / Crane springs, the real issue in seeing performance gains is fuel & air flow with the stock manifold. Its just not possible to see the big gains you should see from a cam swap on a L31 Vortec.

I also have an 87 SB with a built 96 Vortec / TBI motor combo that has a LT4 stock cam with the beehive springs & 1.6 RR, It runs very good for a NA motor. I have no clue how it would work with the Vortec injection manifold.

LT4 specs: GM LT4 Stock Cam
Duration @ .050: INT: 203 EXHT: 210
Lobe Lift: INT: .297 EXHT: .300
Lobe Seperation: 115.0


Boosted

[Pauly]

I will also vouch for PECOS, he is a standup guy and puts together an awesome Vortec marine intake package. It was pretty easy for me to do, I do have access to a well eqipped shop though, I am no mechanic but have a lot of mechanical knowledge, there is quite a bit of fab work invloved, but it is quite worth it IMO, no more crappy poppet injectors.

I spoke with him today, and he has 1 left for sale as I type this messgae.. These manifolds work great, and they look very stock under the hood. They flow so much better than stock also.

peace
Hog

[THoy702]

I will also vouch for PECOS, he is a standup guy and puts together an awesome Vortec marine intake package. It was pretty easy for me to do, I do have access to a well eqipped shop though, I am no mechanic but have a lot of mechanical knowledge, there is quite a bit of fab work invloved, but it is quite worth it IMO, no more crappy poppet injectors.

I spoke with him today, and he has 1 left for sale as I type this messgae.. These manifolds work great, and they look very stock under the hood. They flow so much better than stock also.

peace
Hog

$$$$$$$?

[Boosted-Z71]

Go to the thread mentioned above, PM Pecos about the $$$.
Tell him how you found out about the intake

He will get right back to you.


Boosted

[95nProgress]

see sig for my cam