jrg77

Here are the specs...

Description/idle/performance: 4/7 Swap. Rough idle, Strong mid-rance torque. Also good for Pro Street use with 4000 converterL Power 3600-7000.

Adv Dur: IN-282 EX-294
Dur @ .050": IN-250 EX-259
Lift @ Valve: IN-.591 EX-.597
Lift @ Lobe: IN-.394 EX-.398
Lobe Sep: 106
C/L (In): 102
Valve Lash: IN-.018 EX-.020

What is the C/L?

From what I've read this is about as aggressive as you can get in a cam that has to at least pass a sniffer. I have a stick shift so the torque converter issue doesn't exist. As my Camaro is not a commuter, so I am not concerned with how it feels in the neighborhood. I figure it would be quite right for my sig. Do you think I could get back [some] of the low end with a 383? What give of heads would work with it?

Thanks,
Jason

Stekman

Sounds like the engine I'm working on...The cam I'm working with is a bit larger, though. Im planning for an 18° setup, though. To get that high end power, your heads have to flow.

C/L is centerline.

There comes a point, with any engine, that it becomes rough, no matter whatt you do.

I really doubt you will pass a sniffer unless you smudge some things.

What exactly do you want out of this engine?

jrg77

exactly what my sig says...

What do you have to do to a block to do 18° heads? And what does it do for the engine?

Jason

Stekman

18° pistons and valve train (rumor has it Brodix makes the 18x, which can use 23° parts....).

What do they do for the engine? Air flow. 300+ @ .600 is a common number i've seen.

88IROC350TPI

pass emissions with a cam like that? I'd doubt it

jrg77

That sounds perfect for forced induction.
Jason

Stekman

have fun finding a FI manifold for an 18° head....I haven't seen one. I haven't looked too hard, though.

jrg77

So I guess I need to back pedal a bit:

What is it about this cam that won't pass the sniffer?

Jason

jrg77

It will probably be carbed, as that is what I am starteing with, and as much as I like the idea of switching to FI I don't think I want to throw $2000+ into it.

So how far can you go with a cam and pass the sniffer?

Jason

Stekman

its huge.

Race cams like that have tons of overlap. They usually have pretty "generous" valve timing. between the 2 of those, a LOT of unburnt fuel can get by.

How far can you go? Sniffer-related? Nowhere with that cam, except the track. like i said, there comes a point with camshafts where, no matter how much fudging you do, you won't pass. Your walking that line.

Lift: .548"/.557"
Dur: 308/314
.050"Duration : 262/272
Lobe Center: 110
RPM Range: 3200-7500
Valve Lash: .028" Hot / .030" Cold

Those are my specs on my solid roller. But this will be race only (for the most part...) and no emissions testing in Michigan.

jrg77

It's $4000 for 18° heads!

If I ain't willing to spend $2000 on FI I sure as **** ain't gonna spend $4000 on heads. An I bet the intake doesn't have room for an EGR either. Sheesh!

Too bad my car isn't track only. I could probably see it then...

jrg77

I would like to get close to the edge without going over. Anyone got an idea on cam specs that will still pass the sniffer, and still run up to 7000 rpm?

Here are the specs I need to beat:

HC CO NOx
Standards: 2.00 30.00 3.00
Readings: 1.72 19.50 0.77
Results: Pass PASS N/A


Thanks,
Jason

88IROC350TPI

You have it all wrong. That cam is about the WORST cam you could use for forced induction. A good forced induction cam would be in the 112-114LSA range. With 106LSA you'd be pushing the boost/nitrous straight out the exhaust valve.

89RsPower!

were you planning on using this cam in your 305 or are you building something bigger?

jrg77

I am not sure right now. I'm kinda stuck on whether I should just rebuild what I have for now and make it more fun while I save for the king engine, or just go for broke from the start.

Ideally I am told to start with the chassis, and the suspension, and all of that, but my engine is coated with oil from the bottom of the heads all the way down to the oil pan, so I think I should make it run right first. I am 7 bolts from having the engine out.

Traditional wisdom says dump the 305 and get a 350. If your're gonna get a 350 you might as well get a stroker crank and do a 383. While all of that is fine and dandy I have a 305 and a T-5 that "won't handle the torque" of a 350, much less a 383.

So I'm thinking is I make the 305 into a revving screamer (like **** only long grain) I'll have something fun to start with until I can save up for the 383 and T56 and the 12-bolt or 9" or whatever. Then When all of that is done I can take this 305 and throw it into a 2nd gen RX-7 and have 2 cars.

Either way I am told that the power is made by the heads and cam. The heads depend on the displacement and compression ratio which I don't know yet, soI figure I would start with the cam, hence the topic. Now I am finding out that I have picked the wrong cam. I don't know what to do.

The car will have to pass a hose over the tailpipes sniffer. The specs from the last test are above. I am interested in making a screaming engine that takes as much power of the table as I can while still beating those numbers. This is not a commuter car. I don't cruise, I don't tow, and don't have an automatic.

Any help is greatly appreciated.

Stekman

The RPM band you list (and any cam manufacturer, for that matter) is for a 350. Lower it about 200 rpm for a 383. Raise it about 200 for a 305.

I'm still kind of confused on why people want a high RPM street motor. The portion of the time on the street is low(er) RPM anyway...perhaps that's just my mind.

Perhaps something you have not looked at yet: That cam is a solid roller. YOu would pretty much need a brand new valve train. That is everything from springs, retainers, and locks, down the lifters and pushrods, and of course, the cam. Whether or not you are up to that swap (and the hit to the wallet) is up to you. Call them repercussions of running a solid roller, if you will. So if you do, be prepared for that.

That being said, take a momment and examine your budget. Let that tell you where to go and what to do. Take into consideration what you want out of the engine. To me, it sounds like you just want a show off, high RPM engine . All logistics aside, there is nothing wrong with that in itself. Now, I'm pretty sure this is a street engine, so enter the logistics. That cam will pull next to nil for vacuum. You will NEED a pump to run brakes. It's idle quality will be so poor, it can't really be compared to a radical street cam. Emissions has already been covered. And the kicker: take a car for a drive. Watch your shifting and how often you spend about 4500-5000 rpm in comparison to below. My bet is not very long. So what's the point of a street engine that peaks up there if you're really not up there that often to use it. To make the most of it, your cruise speed would have to be like 4000 rpm or something crazy. Not a very logical cam selection, once you look at it. To get 7000 RPM, your heads have to be on par with heads like AFR 195's or better. Anything less, and you will choke the engine.

My suggestion is drop the idea of revving to 7k and passing the sniffer, at least, not easily. For now, drop the entire idea of "i want 7k rpm". Step back, determine at what RPM you drive now. Work from there. And don't tell me "it's in my sig." That's nothing more than a set number. Think of a logical powerband that you use now.

jrg77

I think part of the problem is that I have never [really] driven the car. When I did I was never sure of the speedo or the tach so I don't really know where I am at speed with it.

The closest that I can relate is my Spec-V and the Integra GS-R I had before that. Each of those cars were nothing special under 2500 rpm, but then they would wake up something fierce (for a 4 banger). The GS-R would pull to almost 8000 while the Spec-V redlines at about 6200. With the Spec-V I typically end up between 2500 and 3000. The GS-R I would end up around 3500. I redline(d) as often as I could because the takeoff in the next gear was fun. I figured with a Camaro built properly I could do the same only more so.

Show off? Probably right. I figure if I am gonna dump cash into a engine that is gonna cost at least what I paid for the whole car if not more then I better have something to show for it.

So far all of the parameters are made up. Any of them can change. I have no specific loyalty to any of them, as long as I can put a plate on, hit the highway to a track, have some fun, and go home.

Right now my Spec-V has no competition from my Camaro. When I am done I expect the Camaro to have no competition from the Spec-V.

I was in Lafayette, In once when this guy had a 1st gen Camaro. It looked okay, nothing special, stick shift. He went up on the main road. I heard him in first gear. That engine seemed to climb like FOREVER. At the same time he was GONE. Second gear was just as impossible. I felt and heard that like the man upstairs was tatooing on my soul and he was flying like crazy. That was my encounter with a high revving V-8. Can I duplicate that? Obviously not (now), but I sure would like to get as close as I can to it.

What do I really need? I have no idea. How much is it gonna cost? Hell just getting the car was a stretch, so I might as well have something that makes me feel like going out and turning the wrenches. What's realistic? It's my first time ever so I don't know. What I do know is this. This is my first real sports car. It needs some TLC. And I don't want to roll over at night wishing for something else. I have never drag raced, never done an RWD through the cones, and NEVER been on a road course. This car has to do them all. I won't break any records anywhere, but I do want it to be memorable to at least me.

I can swing $200 a month. If I pay as I go, and learn to do what I can where can I end up?

Jason

Stekman

Anything can be done, given enough time. If you alot yourself a long enough period of time, trust me, things will fall into place. I don't plan on starting my engine for a few years, but I'm gathering parts as I can afford them.

Now, don't get me wrong, please, the last thing I want to do is shatter someones goals or dreams of what they want out of their car. If you want a high revving engine, by all means, it's your car. Like i said, I am merely stating some of the repercussions.

Now, step by step. Where do you want the powerband to be? Does a 2000-6000 sound good? There are plenty of STREETABLE cams that can do that, and have a much better chance at passing a sniffer, perhaps with a little fudging, but it would be possible. I would suggest an EFI type grind. They have a slightly larger valve overlap which will increase streetabilty (a tad). The tricky part comes when you start doing the high RPM stuff, like a road course, but yet having to pass a sniffter. Would this be for fun, or competition?

Think about this, an 8000 rpm engine. Think on par with a NASCAR engine. You've got to build like that to have an 8000 RPM engine. On street parts, things don't last very long (in terms of miles and lifespan) at those numbers, so don't expect that.

Ever used eBay? Used solid roller things pop up all the time there. Springs (new) to lifters (new and used) to rocker arms to cams. Everything. Just take a look. If you want rev's, mechanical roller is the way to go.

But, valve train aside. Heads are probably the biggest factor, which you probably realize. You need good heads, no not good, great heads to get that kind of power. And here's where the compromise comes into play. High RPM engines need lots of runner volume to flow the air needed for high RPMs, however, with that, you lose low end velocity which will hurt low end torque. Vice versa is true as well. Street heads have plenty of low end velocity, but lack the top end flow.

So i guess, for now, determine a powerband and what you are willing to compromise, things can be worked from there.

jrg77

The car's for fun and education, not real competition.

Can I not be left behind by STIs and EVO8s? Can I leave the RX-8s from a roll-on? Can I feel the accleration in 5th from 55 without downshifting? If I choose to downshift can I have a couple of gear to choose from (angry vs. freekin mad)? How much of the stock stuff under a Z06 can I own? Can I run with a M3? How 'bout an M5? If they are just passing the sniffer too (like me) can I give 5.0s something to cry about? Can I waste some tires without trying really hard? What does it take to do this stuff?

How much low end torque do I need? How much can I trade and get back through displacement? How much am I gonna have to make up with gearing?

2000-6000 is gonna have to be it if that is all that realistically can be done.

I am flexible. The sniffer is cast in stone, as I don't have a truck or trailer. Gas mileage isn't an issue because most places I want to go are withing 300 miles. Brakes are essential so whatever vaccuum is needed has to be there. Idle can be smooth or rough. What else do I need to consider?

jfawcett10

Ever thought of turbo or supercharging?

F-BIRD'88

That cam is a tight lash dirt track (modified) or bracket race solid . It is a radical cam to run on the street.
Probabily will not pass a sniffer test without some sharp carb/ ignition set up and catylitic converters.

That cam likes 10:1 to 13:1 compression. 13:1 will require 110 octane racing fuel. 10-10.5:1 is just right for the street on 92-94 octane. That cam likes a a 750cfm holley DP and a vic jr single plane intake manifold.
Any good big valve ported head will work with that cam.
as long as it the head flows over 225cfm it will work well. (bigger is better) The power band is 3000 to 6500-6800 rpm.
A automatic car would want a 3500-4000stall converter.
the car will want a high gear ratio 4.10:1 minimum 4.56 better.
That cam needs to breathe. big- long tube headers and big dual exhaust and or open headers. It will not like your typical third-gen exhaust system.
that cam will want about 120-135 psi spring pressure on the seat and about 300-330 open pressure.
Use 1.5:1 rockers. periodic valve lash adjustment is nessessary.
The cam is ground on 106 LSA and installed in the motor 4 deg advanced (intake CL 102) (ex CL 110)
It will have a rough idle but not unmanageable.
It will require lots of ignition timing advance at idle.
usually a "locked out" distributor is best. 36deg at idle 36deg at high rpm.
With good cats and a functional A.I.R. system and sharpe carb idle circuit tuning you may get it to pass the sniffer. I've run bigger cams than that and the P/brakes were ok. (but just)

jrg77

Turbo or Supercharger would mean that I would have to go Fuel Injection, so instead of 3 or 4000 bucks it would become 6 or 8 thousand on the top of the engine, never mind prepping the endgine for heavy breathing.

I think my best bet is a 6000 redline and see how much I can increase my average torque across the widest band possible.

Jason

jrg77

Thanks for thinking about possibilities, and not hindrances.
When I looked at the website it was the mildest one there. I recognize that it might require some body English, but I was thinking if the right supporting components were around then maybe I could make it happen.

I run 91-93 Octane in my Spec-V so doing that in my Camaro is no big thing. There are also a good number of places locally where I can get 100 Octane unleaded.

It sounds like this cam may not be so great for my 305, but for the 383 it sounds pretty good. Do you have to use the Holley carb?

Will the rear work with a numerically lower (say 3.7X) gear if the car is a stick shift? Will it sput and sputter below 3000 or will it just be slow?

Will one of those 2 cat y-pipes work? I have one to install. If I run the driver header around the front to the passenger side can I make them big enough?

How do these cars slow down if they have no brakes? Can you modify the amount of vacuum needed to power the brakes?

Jason

Stekman

Yes, that cam will be tamed down with a manual transmission, to a point. You don't have to worry about a stall speed or a gap between the stall and where it SHOULD be dumping you into (when you under-stall it).

You can use whatever carb you want. Holley carbs are, though, very popular on high performance engines. Demons are there for people with cash to spend and want good looks up top.

I would still keep the car geared somewhat numerically high. That will help the low end acceleration cause by the cam (and maybe heads) lack of low end grunt, relatively speaking. You originally asked if you can regain low end with the 383. That's where the gearing comes into play. Another thought, if you do cruise, yoru cruise RPM will be fairly high with either 4.10s or 4.56s

is it an aftermarket or factory Y-pipe? i would run an aftermarket such as the one offered by SLP. Factory Y's are notoriously tiny.

I've driven a car with 12"Hg and it stopped ok. You had to be a bit careful, but it worked. Down to 10 or so I'd say it would be ok. Perhaps not the best idea, but doable. They do make vacuum cans which store vacuum created while the engine is running so the brakes can access adequate vacuum when stopping. If that doesn't cut it, there are electric vacuum pumps to run the brakes exclusivly.

Yea, in a 383, it's definitly a cam to consider. But not a 305. In a 383, yea you'd have quite a potent engine, assuming all else matches. For octane, I agree, about 10.xx:1 should be about perfect. If you really want to run the cam, try getting a timing sheet ahead of time. That will aide in planning around it.

jrg77

How many inches of mercury are you supposed to have?

Thanks,
Jason

Stekman

Factory is like 18-20 or something I think. It's high. Moderatly built street engines can go from like 12-16ish. More aggressive engines will be lower yet.

Nothing is set in stone for vacuum.

jfawcett10

Ummm.... roots style, twin screw, they both work

Even Vortech makes their centrifugal superchargers adapt to carbuerated vehicles....

Carb vortech supercharger info here

JakeJr

This is a REALLY big cam for a engine that will see the street. Not only does it have a lot of duration, but it's ground on 106 LSA. It's a race cam, period.

I'm betting it can never be made to pass emissions in the practical sense. Idle quality will be very radical, vacuum will be low (so power brakes won't work) and low end power in a 383 will be all but non-existent.

A friend of mine installed one with almost the exact same specs in a 434 SB with 15 degree Brodix heads that I built for him. It pulls 7" of vacuum!!!!

Bottom line: it's just an awful choice for a street engine; especially one that has to pass emissions.

I believe 224 in/230 ex with a wide LSA is about the limit for passing emissions without a lot of custom tuning.

I don't mean to seem harsh, but I'm just trying to steer you far away from that cam.

Jake

kd5boc

Want a good cam...I've gotten similar numbers from mine...

Lunati Hydraulic 07104 kit
Adv Dur 290/297
.050 Dur 235/240
Lobe Lift .327/.327
Valve (1.5) .490/.490
intake centerline @ 108*
lobe sep 112*

This supposedly gives me:
392hp@6000 (avg 269)
393tq@4500 (avg 333)
smooth curves

Yours would give me:
399hp@6000 (avg 252)
383tq@4500 (avg 306)
peaky curve after 3500rpm

However, mine is matched to a Holly 300-70 intake and Edelbrock 1407. (w/ Dart Iron Eagle 200ccw/ 64cc chamber)

It's worth a look..

Tom