dhirocz

iTrader: (2)

Anybody done this? I believe the LT4 Hot Cam has 112 deg LSA. I know blowers seem to favor 114+ LSA cams. I decided on this cam from a recommendation from a co-worker, popularity, price, and specs. I was offered a Paxton SN-93 and a MSD-6BTM in exchange for some LS1 parts, and want to know if this cam will preform decently under boost. The remainder of the engine (350 roller) will consist (more than likely) of Vortec heads (polished and pocket ported),Vortec TPI intake, SR, 24# SVO injectors, 1.52 roller rocker arms, and D-cup TRW forged pistons.

FYI: I want a slightly lopey idle, nothing radical, and power up to around 5500-6000. I will probably run 9 psi boost. Drivetrain is T-56 with 3.73 Torsen 4thgen rear. Looking for 425-450 RWHP. I figured I'd go 383 but then I'd break stuff with a blower, then I'd need to buy pistons, damper, and a special flywheel. (Damn!)Too much $$$!



[This message has been edited by dhirocz (edited May 13, 2001).]

89GTA5spd

That paxton SN-93 will only put out ~6 lbs of boost unless it has had an impeller upgrade, then around 10.

dhirocz

iTrader: (2)

The 'charger already has been upgraded, it has put out up to 10 psi on the vehicle it was on. It will also be rebuilt before I take possession.

Will the LT4 hotcam work decently with this blower? Never built a blower motor before.

JAYDUBB

IMO the LT4 Hot Cam might have a little too much overlap. Can you E-mail me a copy of the cam card, or give me ALL of the specs, including opening AND closing events?

QwkTrip

iTrader: (22)

If you're going to choose a cam there are blower specific designs that will get the job done for you. A blower cam for your application is going to be a very mild cam and the LT-4 HOT cam is too agressive. Check out the Crower blower cams at www.crower.com or even the TPIS ZZ9 cam at www.tpis.com Those are good places to start. I've seen a Vette run mid 10s on 12 psi of boost in a 350 with the ZZ9 cam. It works well because it's a fairly strong cam in and of itself when your blower isn't making boost.

dhirocz

iTrader: (2)

Wait a minute.

The LT-4 hot cam is too aggressive?
LT-4 hydraulic roller hot cam
Intake Exhaust
Advertised duration 279 287
Duration @ .050 218 228
lift w/1.6 rocker .525 .525
lobe seperation 112

ZZ-9 Hydraulic Roller

Intake Exhaust
Advertised duration 282 287
Duration at .050 212 226
Gross lift .483 .520
Lobe separation 112

OK, we have two different cams...If I use the LT4 cam, I'll use 1.6 rockers, so I'll get the .525 figure. If I used the ZZ-9, I'd use 1.5. OK, valve lifts are close. Both cams have a LSA of 112. Duration of the LT4 cam is slightly higher. Which means the powerband is just a little higher up, good for an intake like the SR(which I'll be using). The ZZ9 is a little less. I only plan on a strong 2-6k powerband, with decent low-end torque (another concern).

Can anyone explain why the ZZ9 is so great? Nowadays I'm kind of skeptical about using TPIs parts. I thought about using a ZZ9 a long time ago, but found another cam. Anybody have any cam recomendations? I prefer to use a known cam that's been tested and is computer compatible. I originally planned on using the LT4 cam N/A, but I found the blower. I dont trust phone techs (bad experiences).

thanks for your help.




[This message has been edited by dhirocz (edited May 11, 2001).]

QwkTrip

iTrader: (22)

At what lift are they measuring advertised duration for the HOT cam? I was under the impression that the HOT cam had quite a bit of overlap.

As far as the ZZ9 cam goes, I have a real world example for you. I had a supercharged LT-1 Vette and saw a guy run a Vette with the same setup as me except he had the ZZ9 cam and I had the stock cam with 1.6 rockers. I ran 122 mph and he ran mid 10s at 128 mph. An actually blower cam would help even more.

[This message has been edited by QwkTrip (edited May 11, 2001).]

BLOWN85/TA

iTrader: (2)

The ZZ9 cam is misleading in it's "TRUE" lift & duration measurements, I think the only thing that's correct is the LSA. I am not the only one who has seen this, I saw a thread on it a while back. The cam is little more than a ZZ4 cam, with a slight LSA tweak.

dhirocz

iTrader: (2)

I understand about the overlap, that would not be a good thing for a supercharged engine. Boost in, boost out. Keep in mind that the cam I'm looking for would be one that would preform decently under boost. I'd like a cam that will work fine without a blower just in case it needs to come off (for repair or something). Prom change, belt removal, quick ignition adjustment, no longer supercharged. I also don't want a cam that is a total POS when used with a 'just because I have it' blower application. That's why I'm staying away from blower-specific grinds. I'd like to use a known cam that will work with or without a blower. I know I'm being a PITA. Unfortunatly, all the figures I have are in my last post. Any ideas? I have the chance to buy a HOT cam for cheap right now, and know someone who may part with a ZZ9...what a coincidence...

Willie

iTrader: (1)

LSA figures should be taken with a grain of salt. My cam, a Crane 2032 has a 112 LSA. This in itself would probably eliminate this cam from contention in a blown application.... but wait!! If you examine the valve timing events, one realizes it has ZERO overlap. That makes it perfect for a blower and/or nitrous.

In order to make an informed decision, check all the specs on a cam, not just the lift, duration and LSA.

Well, you can't have a lopey idle with a cam with no overlap. But the whine of a supercharger takes all attention away from a "smooth" idle -- believe me!!

As for my setup, the Crane 2032 cam has a power range of 2000 - 5500 rpm. I use it with 1.6 rockers for an effective valve lift of 482/496. I shift at 6,000 rpm.

I will run as much boost as needed to run mid-11's. So far with 5 pounds, I have run a 12.26. Drivetrain consists of a modified 700R4 and a 10-bolt with GM 3.73's, a Torsen and Moser axles.

With my old setup (Paxton), I was dynoed at 421 rwhp.

Keep your 350. I achieved my numbers with my 305!



------------------
Willie

Supercharged 1987 305 IROC-Z, Daily-Driver, Emissions-Legal.
Former Paxton (6-psig): 12.57 @ 111 mph.
Former Paxton (6-psig) & former 50-hp nitrous: 12.04 @ 114 mph.
Current ATI D1SC (Initially 10-psig): Projecting high 11's.
Future ATI D1SC (15-psig): Gotta catch them pesky 26-psig boosted TTA's!!

http://willie.camaro-firebird.org/

1987 "20th Anniversary Commemorative Edition" Z28 Convertible -- Super Chevy Show Class Winner, 1998.

dhirocz

iTrader: (2)

Right now I'm leaning toward the ZZ9, although I don't want to give up the Hot cam on a guess. I dont have either cam card, all the info I know is in this thread. I don't want the best blower cam, just one that doesn't have so much overlap that the cylinder never gets a decent charge.

Willie

iTrader: (1)

Although the ZZ9 is an excellent cam with an asymmetrical lobe design (the secret why it makes more power than specs alone would indicate), it will not work in a blown application. I checked with TPIS and it has about eight degrees of overlap -- way too much. That's why I did not choose it.

If you don't find a cam of your liking, have one ground to match your specs. Any of the cam manufacturers can do this for minimal cost.

Willie

[This message has been edited by Willie (edited May 13, 2001).]

dhirocz

iTrader: (2)

****. Well, I guess the HOT cam is all that's left, although it probably won't be much better...Just gimme a cam that's works by itself and under boost with a nice strong-sounding idle and power to 5500 and I'll be happy.

Guido

Do yourself a favor and call comp cams. For what you are going to give for the hot cam, comp cams can sell you a BLOWER cam. Thats what I did. It was $250 from them. Roughly.

ive got a 230/236 cam which is probably way too much duration for you but mine sounds lumpy.

Call them and ask
tech line: 1-800-999-0853

------------------
-86 IROC
Jacked up like a mother!
this years goal: 10.50 @ 130+ mph
-=ICON Motorsports=-

BLOWN85/TA

iTrader: (2)

How about the ZZ4 cam with the blower? This gives good manner's during the 99% of the time your not on the boost.

afgun

Ok, anybody have a cam card for the LPE 219/219 "super ram" cam? This is the cam that I have for my engine currently, and of course I have NO idea on its suitability for forced induction.

--andrew