91greenbird

iTrader: (4)

cam 1 is 89 l98 cam 207 int 213 ext .443 .459 (1.6RR) 117 lsa
cam 2 is ram jet/ 383 ht cam 196 int 206 ext .460 .480 (1.6RR) 109 lsa

which one will make more hp and tq and whats the powerband between the different cams

reason why i ask is my l98 is old and tired and i just wanna replace it with a ram jet short block i found local for a good deal just wonder how much power id lose or gain going to the ram jet cam.

lukn4trbl

Cam 1 is for low RPM . It will peak TQ at about 2000 RPM and roll off considerably by 4000 RPM.

Cam 2 will work for mid to high RPM use, but you'll need good intake, heads
and exhaust to achieve the peak HP of about 5500 RPM on an L98 short
block.

Cam 2 has a lower vacuum and lumpier idle than Cam 1. Cam 2 will require
some engine mods to make it work well.

86LG4Bird

iTrader: (1)

Cam 2 (Ramjet/HT383) will outperform the other one across the board, because of its more aggressive lobes and better LSA. Some will argue that the "l98" cam (looks like a F/Y LT1 cam to me) will have an edge at the upper rpms, but because of its ridiculously wide LSA, who cares what it does above 6000 rpm when the other one has already beaten it to that point.
Neither cam will have an issue with low vacuum. You might detect a little lope at idle from Cam 2.
The only "mods" would be to ensure you have adequate spring pressure (110 lbs on the seat suggested for Cam 2) and retainer-to-seal clearance for the .480 exhaust lift.

lukn4trbl

Do you care to explain the misinformation? I'm intrigued...

Can you also tell me the IVC and required SCR (for gasoline) for cam 2?

Also define low vacuum and how Cam 2 could not possibly have a higher
manifold pressure at idle in the same engine.

Thanks.

86LG4Bird

iTrader: (1)

1. Of these two cams, Cam 1 is suited to higher rpm. If you're quoting tq peak/power range, you need to qualify how you'd install that cam to get there, because installed at the typical 5 deg adv would put the ICL at 112 deg, in which case your numbers are south by about 1500 rpm. Install it at 107 ICL and you'll get peak tq about 3000 rpm, but will be a low peak because of the advanced EVO event.
2. Cam 2 is a low to mid rpm use cam; yes, even in a 350. It's barely even a mid rpm cam in that HT383. Of course he wants good intake, heads, and exhaust; even on the stock cam those would help. Cam 2 is little more than a stock-type cam with more overlap to promote better mid rpm cylinder filling. That's where the good exhaust, ie. headers, will help.
3. Cam 2 will of course have lower vacuum than Cam 1, but it's not enough to be a concern. It will be perfectly tunable (I sure hope he's planning to tune it!) and won't cause any power brake issues, etc. Therefore, I don't call it "low vacuum".

I wouldn't throw any numbers regarding IVC and SCR out there until we get some shortblock and head MEASUREMENTS from 91green and if he plans to alter anything before going back together. If he's sticking with stockish deck clearance, gasket, and head dimensions, Cam 2 is gonna be a good choice.

lukn4trbl

oh really? 207 degrees of intake duration @ 0.050" is NOT a low RPM
cam? Do you know how to calculate valve open duration at any RPM,
and how much air will theoretically move by the valve at that given RPM.

If he wants to make 350 HP at 5000 RPM, do yuo know how to calculate
the required valve open duration and how much air/fuel is required to
produce that power at 5000 RPM?

Those numbers are based on a 117 ICL.

IVC weighs much more on power and cylinder pressure than EVO. You would time the cam based
on the intake valve as that is how dynamic compression is measured.

Quite posssibly. Only limited by the poor flow of the stock components.

Agree.

Nobody called low vacuum. I said lower vacuum.

Well aware.

86LG4Bird

iTrader: (1)

Whoops! Care to retract that? You may need to rev it to 10,000 rpm to ever see a torque peak with a 117 ICL!

lukn4trbl

I'm not here to impress. I'm here to help.

I took exception to the line in your reply which stated my information was
misunderstood.

Now I thought we could have a decent discussion and learn about camshafts,
but it appears you don't want to discuss them any further.

So instead of pointing fingers and suggesting that my 1st reply to the OP
was incorrect, you should have asked for more information.

NOw that you realize everything is fine, I hope that we can move on.

86LG4Bird

iTrader: (1)

OK......truce!
I've gone back and edited the confrontational remarks from my posts.
Also changed some of my wording that as you pointed out is misleading when taken out of context.
To your "do you know how to calculate......" questions; Yes, I can run the numbers.....if we had them But........I've been around the block a few too many times to put a lot of faith in those calculations. They're just not developed enough to take into account all of the important and often overlooked variables. The main point I want to make is that there is such a night and day difference in the merit of these two cams, all of the calculations in the world won't make a difference. Given these two cam choices, I cannot be swayed from recommending the HT383 cam
But of course we can discuss

pandin

On a 383 the lopey idle starts between 40 and 45 degree overlap @ .05 lift. 40 will carry 17 in hg @ 750 idle (smooth), stock tpi setup. This from a comp 12-408-8 cam 110 lsa 106 iicl 1.5 rr. go to their web site to get all the specs.

I enjoy the "you said, your wrong stuff."

Unless your setup is Exactly the same, things will be a bit different.

Are you helping the op to build his car or your dream car????

A lot depends on the rest of the set up, intake, exhaust, drivetrain, too name a few.



Brake vacuum is gets iffy at around 10 in vacuum.

Orr89RocZ

iTrader: (20)

My L98 cam peaked at roughly 4900-5100 rpms. it was very flat up top but lean, so i think it would have been able to peak at 5000-5100 and maybe hold 5200. I consider that a low rpm cam.

I like that ramjet cam for the reason of more lift, tighter LSA for abit more overlap which should give it a edge at 4000-5500 rpms. If i had specs i could run them both in my desktop dyno to give an idea of what will happen. WIth stock L98 heads, i dont think the difference in hp/tq is anything to get excited about, especially if you still have TPI. TPI wont allow either of the cams to hit peak potential.

Both will work great for TPI. If you check my idle clips of my L98 cam, you can tell it has some "lope". Sounds bit more aggressive than it is due to the chambered tube muffler. a 109lsa would be a great sounding cam i'd think with my exhaust.

1989GTATransAm

iTrader: (3)

By the way I have that Ramjet cam brand new if someone wants it cheaply. I installed a GM HT383E crate motor in my Tahoe and it came with that cam. I put in a slightly larger cam while the motor was still in the crate and have that one available from the take out.

pandin

The smaller the CID the more radical this cam will be.

91greenbird

iTrader: (4)

the reason i asked this is because my l98 is worn out and i have a ramjet short block vortec heads and cam number 2 in it i was wondering if i was going ot lose or gain performance going with the ram jet cam or should i put the l98 cam in it. THIS IS NOT A TPI all my mods are in my signature it is a carb motor the top end is going to be stock vortec heads 1.6 roller rockers gm high rise vortec intake 650 double pumper my exhaust is hooker 2055 headers and y pipe and 3" hooker catback. I just want to kno which one will give me the best power and torque idle to 5500 rpms. There both tiny so i kno it will run fine with the carb because the l98 cam in the car right now idles perfectly fine. The only reason i think id lose power with the ram jet cam is because the l98 cam has 207 duration int 213 duration ext and the ram jet has a weak 196 duration int 206 duration ext while the l98 oddly has 117lsa and the ram jet 109lsa

Orr89RocZ

iTrader: (20)

sorry man i forgot your combination. lol did you ever get 12's with that setup?

I think with your carb you can benefit from the tighter 109 lsa.

L98 cam has -24 degrees of overlap at .050" lift. GM383HT or cam 2 is like -17. I think that will really help build some power in the 4000-5500 range where you need it most. I just wish it had a bit more duration. i think a nice cam would be the L98 on a 107-109lsa with abit more aggressive lobes. basically a "cheatr" cam

91greenbird

iTrader: (4)

next race season is when im putting this motor in. my l98 hasnt given up yet just has alot of miles on it and the crank has alittle too much play for my taste
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next race season is when im putting this motor in. my l98 hasnt given up yet just has alot of miles on it and the crank has alittle too much play for my taste. This season im going with 3.70 gears, 1.6 rr, bbk pulleys, and 2800 or 3200 stall whichever allows me to footbrake at 2500rpms i havent ran it since last year still only 13.8's @ 97.5 without the list of parts above

Orr89RocZ

iTrader: (20)

good luck with that. 2800 works well. i think 3200 may help too tho. either way i dont think it will make much difference with the 3.70s my car loved 2800 but i feel 3000 and/or 3.73 gears would have helped alot. i only had 3.42's which seemed to be a good compromise between the street and track

pandin

Check out gm horsepower.com

"The GM Performance Parts HT383 has been specifically engineered for low-rpm torque, and it’s packed with durable parts that are all brand new. It produces 435 lb.-ft. of torque at 4000 rpm, but more importantly, it produces more than 400 lb.-ft. of weight-moving torque from 2500 rpm all the way up to its 4000 rpm peak. In other words, your trailer’s worth of weekend fun is barely noticeable when hooked to a vehicle equipped with the HT383."

HP 340 @ 4500-----Tq 435 @ 4000-----max rpm 5000

© 2006 GM Horsepower Web Design by Link 2 Communications

Has a whole page of tech data. Check it out. Even a dyno chart. Install tips.

pandin

Same cam install in ram jet 350.

HP 350 @ 5200----Tq 400 @ 3500----Max rpm 5500
"Possible Applications

• Update the Stingray
• Round out any hot rod that needs a little “something” under the hood
• Use it to start a conversation on Friday night "

Per the gm HP web page.

WDYTAT

gmgod

I think I'd try and sell both of em to finance a ZZ4 takeout cam.

Either one of those are barely adequate for a 305.

Sonix

iTrader: (1)

I was wondering why there was arguing over microscopic stock cams! Those are both weenie, and the average joe wouldn't even know the difference is someone snuck up to his vehicle and swapped cams overnight. I mean maybe 10HP total. Time to step up to the big league and have some fun!

pandin

91 TPI L98 came with 245 hp has 345lbs of torque.

His question got answered quite well.

JUST the FACTS.

91greenbird

iTrader: (4)

dont want a zz4 cam im sticking with factory cams for a replacement engine for a daily driver i just want to kno what cam is better most agree ram jet but pandin u say l98? btw my cam is a 89 l98 littler hotter then the 91

pandin

I did not give a opinion on the cam ,it was on the info.

245 hp and 345 tq or so are Factory TPI numbers.

The ram jet is not a carb set up. 350 hp and 400 Tq. If you looked at the build sheet on the ram jet, it had their FI set up on it.

1 It would look like the ram jet is 100 hp and 55 Tq better then the L98.

2 If the L98 is higher miles and has more wear, then that is a factor.

If it was me, since both cams run same rpm range, and the ram jet Tq is likely at a higher rpm than the L98. I use the Ram jet.

It is matched to that engine like the L98 was. cam and heads are a team.

Also stall has to match Tq rpm.

You ask if you would loose power? Like was stated ram jet less 500-3000
more 3500-5200. More Total power for the ram jet.

Need to find and compare to L98 dyno.

I hope this helps you decide.

Orr89RocZ

iTrader: (20)

i'd love to see the ram jet actually put out 350 crank hp. I think it would struggle to hit that mark. ZZ4 only hits 345 in most cases when rated at 355hp and its got a bigger cam.

L98 may be rated at 245 but its more like 265-270 on crank cuz they put down near 220whp. Take off TPI and throw on the ramjet intake and you have 300-310hp on crank, or 254whp.

pandin

Real world vs paper numbers, I love it.

I wish I had a nickel for every adds XXX HP just buy and install.

I would have a 500 Hp stock motor.

355 hp no fan, oil pump, water pump, and ect ect ect......

91greenbird

iTrader: (4)

since its a carb setup and can breath better then tpi im looking more for a 3500-5200 power gain also ill either do a 2800 or 3200 stall

Orr89RocZ

iTrader: (20)

Thats exactly what it is, they say they dyno it with some accessories sometimes but most its bare motor. In fact most ZZ4 dynos i've seen are averaging in the low 340's on motor and i'm not sure if that really included power steering, mech water pump, etc. That aint horrible but its a good 10-15 hp shy of advertised.
Ram Jet i fear will be the same way with that little cam. Certainly with full L98 style accessories i dont think it will touch 350hp but i havent seen the numbers for it yet.

L98 cam is good for 300-310 i estimate from my L98 full bolt on dyno of 254whp. I had almost all accessories on the motor with underdrive pullies, just no ac or smog pump. The HT cam 2 i would think is good for the same, maybe 5-10 more due to alittle better overlap and lift.

91greenbird

iTrader: (4)

id love to hit 275 rwhp do yo uthink it will be possible with full bolt on l98 with vortec heads and ram jet cam?

zz4 and ramjet are odd zz4 has better cam but has l98 alum heads probaly the worst flowing alum head gm ever made out the box. while the ramjet has a small cam it has way better flowing vortec heads which are probaly about 20hp over the l98's. Never seen it on the dyno up close but every magazine article i seen when the start with l98 (alum) and switch to vortec tey always gain atleast 20hp it seems.

Orr89RocZ

iTrader: (20)

I think it is possible. I ran 254 but realllly lean. I think i had 260's easy with better timing and fuel. 275 could be had with good tune and that cam with heads. in fact, you SHOULD have atleast that i'd say.

It is really possible that the vortec heads are responsible for the ramjets hp rating. That very well could be the reason its hitting 350hp (if it is true as advertised) when L98's hit much less.

But the way i look at it, vette L98's are basically the same as a ZZ4 but with tad higher compression, and slightly smaller cam. Swap in the ZZ4 cam and same carbed manifold as the ZZ4, you should have a ZZ4, basically 350hp on motor. I estimate full bolt on L98 motors however at around 310hp crank. ZZ4 cam aint worth no 40hp.
I could be underestimating, cuz if there is a 80% loss thru the auto, my motor is more like 320 crank. which means the ZZ4 cam is capable of 20-25hp or so which is realistic for that cam.

Ramjet cam should act very similar to the L98, maybe a bit more power in spots. vortec heads must be like the ZZ4 cam as far as power increases go. Its a good chance they are worth atleast 20hp over stockers with stock cam. I just havent seen the numbers from anyone yet.

pandin

It seems to be really tough to compare stuff, with all the other factors.

Like differant intakes (air cleaner to intake port), Heads (port size to valve size), exhaust (headers to tail pipes), drivetrain (torque converter to tires), FWHP, RWHP, The tuning, and all.

Each piece can add or subtract HP. Get things mismatched and numbers will be down from "The Best".

As Grumby (rip) always said "Take it to the track. Then you will know"

gmgod

The ZZ4 cam is perfect for vortec heads and their weak exhaust ports. It's still a WAY mild cam with only 208 degrees of intake duration.

I would in no way shape or form be afraid to run it in a DD.... I also gotta question the logic of running a 3000ish rpm stall with a microscopic cam???

Orr89RocZ

iTrader: (20)

peak torque will be around 3000-3500 rpms with those cams. You'll get the best launch using a converter stall speed around that. They say 500 rpms or so below your peak torque for best performance, but it'll vary. I ran a 2800 in my car and it peaked at 3200-3300 rpms or so but remained relatively flat till 3700. I feel i could have gained alittle more by goin with a 3000. It felt alittle soft on the launch and ppl have told me that the car looked like it leaves the line soft but i surprise them with sub 1.75 60 foots
But the 2800 worked well and REALLY opened up the car from a rolling start. Much more fun on the street than stock stall speed.

V8Astro Captain

iTrader: (1)

I wish I saw this post earlier...

I've used the Ram Jet cam in an L05 and a well prepared 310. Both had a good idle, were easy to tune (both TBI) and ran well up to 5500 rpm. The 310 had ported heads and was zero clearanced. It took nearly 35° total timing and was 9.8:1 compression.

I've used that cam with great success twice. If I were to build another street-able SBC to thrash on r1cers stoplight to stoplight I use that cam again. For the money it can't be beat.

pandin

The stall of the Torque convertor has everything to do with peak torque rpm.
It does not matter about the Dur, only as to how that affects the torque curve vs rpm. Lift is independent of the TC.

If the motor makes more torque then it will raise the advertised stall. Like using the S-10 TC with a V8.

Question. Does your TC give a nice even change from 2:1 to 1:1 or does it all come in at the last sec? That rate of change makes a big difference in how the car acts after "hook". Good TC for racing are matched to the motor and the car. A Big Motor Light car vs smaller motor Heavy car. Will not act the same.

Ever wonder why the 2 speed power slide is so popular today in drag racing?

They went out of OEM production around 1965.

Big motor light "Fast" cars don't need or have the time for 3 gears. And the TC allows the motor to set at peak torque till the car catches up then takes the car on to the HP peak.

A poorly matched TC will just spin the tires (ramp in too long) or bog from over loading the motor too soon (ramp in to quick). Thats why the "good stuff" is $1000 and up.

A properly set up peanut cam, matched to the engine, matched to the drivetrain, matched to the car, will be better than just a "man's cam"

Quit bracket racing and join restricted class drag racing and you will learn a lesson.

gmgod

I thought we were talking about a street driven DD here???????

pandin

The more changes from stock, the more the mismatch. more HP means up dates, better tune, more add on's.

A person can spend $15,000 getting a DD perfect. Or did you mean a "work, beater car"?

BTW mine is a DD, beater, Work car. The garage queen is 100% stock.

pandin

This TC cam is a close match. Real good 60 Ft.

pandin

The stock TC for a l98 TPI is 2000 rpm stall. For my car it is verified by the Datamaster log. When you "stomp the gas" from a stand still, no brake. The rpm climbs to 2000 rpm then the car moves. It does this very consistently. It takes .85 sec for this to happen. At 1 sec actual gear ratio is 3.07 (rear) x 3.06 (1st) x 1.87 TC = 17.56:1 3.73 x 3.06 x 1.87 = 21.34:1 21% more torque 21% less rpm

So OEM L98 TC and Cam 2000 rpm. The 2800 TC really looks good at 60Ft.

I do not know what your S-10 TC would stall at. A data log could verify it.

Plot the mph vs the overall gear ratio. you will be able to see the TC slip.

Orr89RocZ

iTrader: (20)

i've always read the stock converter is 1600 stall and the s-10 was 2200 or something like that?

2800 made my TPI car BLAST off the line. When i added HSR, the torque curve flatlined and it felt alittle lazy off the line but in fact, it was quicker off the line than the TPI was. I think a 3000 stall would have been perfect for best ET.
My best 60 with TPI was 1.74-1.75's. HSR i hit 1.70 on a run and if i could brake stall a TAD more at the line, i could have hit 1.69's. 3000 stall OR 3.73 gear probly would have done 1.6x's

pandin

Stock vette

Orr89RocZ

iTrader: (20)

oh ok, yeah vette converter i've heard was near 2000. thats a decent stall for stock cars but more is always appreciated

91greenbird

iTrader: (4)

the s10 converter i have is rated at 2025rpms but will only foot brake to 1800 and with that and the 3.27 it is lazy off the line only a 1.9 60 foot on slicks