jeff1367

iTrader: (1)

I have a 1990 Iroc, 350 TPI, and I want to know which cam will make the most power with the stock heads. The car has headers and catback, 1.6s, and 3.73s. I need to know which cam will make the most power WITHOUT touching the heads. I am not looking for the typical responses about doing other supporting mods first. I know all that already. Streetability is not really an issue, we are building a different engine for this car and just want to race it for the time being. We were thinking about the LT4 hotcam, zz-9 cam, and the CC305. Will anything bigger then these work alright with stock heads? We will be getting the car tuned for the cam and installing screw in studs. The cam has to be a hydrulic roller.

Thanks in advance!

Token

I wouldn't trust stock springs to anything higher than an L98 or LT1 cam. And that's just silly to go through all of that, plus tuning your PROM to run with the new cam for a measely 25-40 horsepower.

madhatter

iTrader: (1)

Well like he said until the drag motor is completed early 07, just looking for alittle more power just to toy around with this summer, plus already have aftermarket springs, and 1.6 rollers, just looking to have a little more fun with the car until the real motor goes in. Dont really care if i blow this motor to a million peices, i mean its only a two bolt.

jeff1367

iTrader: (1)

These are the kind of posts we are trying to avoid. All I am asking is what off the shelf cam we can get the most power from without porting the heads. We are not exactly new to this, we know what supporting mods are needed and have/will purchase them accordingly.

Token

And again, I gave you an answer. Without touching the stock heads, I wouldn't personally go more than an LT1 or L98 cam. You're looking at approximately 20-25 more horsepower over stock with an LT1 cam. The cam isn't what's holding you back, and I trust that you know this since you're "not exactly new to this."

You can't really go much higher lift than that. And a high duration cam really won't help much when your TPI system can't breathe very well to begin with even with the stock cam. But what I want to know is if you're "not exactly new to this" you aren't planning on changing the valvesprings, or why you're even asking a question like this.

jeff1367

iTrader: (1)

Read what I wrote before. We ARE changing the springs. This is a temporary engine so we don't want to spend much on it, just make more power, and driveability isn't a concern. If you say the LT1 cam will give us the most power without aftermarket/ported heads, I have a spare one laying around, maybe we will try that. You don't think that adding a cc305/zz9/hot cam will get us a better 1/4 mile time then the stock LT1 cam? That is all we wanted to know, nothing else concerns us, and we WILL be doing whatever supporting mods that we have to to make the engine run properly with the cam we choose.

madhatter

iTrader: (1)

Ya what he said

madhatter

iTrader: (1)

ttt

Token

Please look up the term "coil bind"

madhatter

iTrader: (1)

So anybody have any other cam ideas, only want a little more out of the car, just wondering what your ideas are for a cam, that stock heads will work with, dont want to go to big to where the cam chokes out the car completely, yet dont want it so small that it is no better than stock, once again I will mention that lifters, rockers, and pushrods will be replace along with a few other things, just need a cam idea, not pointless bickering
Thanks

Token

ANY cam is better than the one you have in there right now.

jeffsbluez

why bother? What are you going to spend! $300.00. waste of money for 10 hp. just my opinion.

jeff1367

iTrader: (1)

Maybe its time to make this post on a different site where someone could at least be nice enough to answer our question instead of criticize us. Again, we dont care about money or anything, we will buy the cam used and sell it when we are done.

The only question we want answered is: with aftermarket springs, pushrods, lifters, etc, what kind of cam will make the most power with stock heads? If anyone has anything negative to say or anything off topic, we would appreaciate it if you would not post. If coil bind is an issue with any of the cams i have mentioned, then let us know what will work. The only answer we got yet was a stock LT1 cam, and I'm sure we could go a little bigger then that.

Stekman

Cam companies have phone numbers listed for a reason. Perhaps it would make some sense to ask the people who make cams for a living, but perhaps I'm also crazy...

leeperryracing

jeff1367

iTrader: (1)

This is more of a thirdgen specific question though, basically looking for someone who knows from experience what a certain cam will do with these stock heads.

Token

Everybody is smart enough to know that stock heads are absolutely WORTHLESS. I'm really trying not to be rude, I'm just being honest.

madhatter

iTrader: (1)

so nobody has ever put a cam in a car with stock heads, because stock heads are worthless, thats what im getting out of this, simple question whats the biggest cam that will work with stock heads, and all that we get is leave it stock. I'm sorry guys, I thought by coming on a third gen site, talking to third gen people, that maybe some one could give a useful answer. I mean none of you have put cams in your cars with stock heads? I just want to know what works best, really not that complicated.

camarodarrell

Use a cam with 8-12 degrees split between the intake and exhaust duration because the exhaust ports on the stock heads aren't good so that will help with it. I think there is a certain intake/exhaust duration split that you need for tpi intake to take advantage of its air flow characteristics. Call comp cams or crane, they will know. You probably want to run between 218-226 degrees intake duration, no more on stock heads.

gearhead0384

iTrader: (7)

Wow you guys are treating these fellows like tools. Jeff send Jeremy a PM he seems to know alot about SD stuff. Funny how this site has changed hasnt it.

Kevin

gearhead0384

iTrader: (7)

Dude he really did not ask you about the heads. Any cam that is bigger than stock is well worth it. How many people on here are running Tbi truck heads still. Come on now.


Here you go Jeff. Some people know how to ANSWER a question.

https://www.thirdgen.org/forums/tpi/...am+stock+heads

91Z28-350

I can't answer your question directly....cam that makes the most power on stock heads. I don't think anyone really goes that route here.

Honestly, the heads do suck in stock form.

Taken from rhuarc30 on his 083 head porting job. Stock #s.

Stock
Lift Intake Exhaust
.1 53.9 41.6
.2 111.2 95.2
.3 157.3 112.4
.4 182.0 116.6
.5 192.0 116.9
.6 193.6 117.6

You'll probably get more power by changing the heads instead of the cam. Get the heads you would for your new engine and put them on the current as a stop gap. Unless the heads are outrageously huge, you'll make more power with a head swap. The heads are where the power is made.

You also didn't say what you are doing with the intake, so assuming you stay completely stock with the TPI, untouched. If you insist on going cam first, look into a comp cams grind. Look into the 08-302-8 grind if you're staying stock intake. If you're going to mod the TPI, such as hogging out the base, plenum, and runners, look into the 08-304-8 grind. Check the valve lift clearance relative to your valve stem seals to determine your maximum lift. Also keep in mind, that the heads flow like crap so going really large lift won't help a whole lot. Notice the plateau between 0.500 and 0.600 lift on intake and the plateau on .400 and .500 on the exhaust. Stay with relatively small lift, and relatively small duration because the intake will not feed too much in stock form. Notice the flow between .500 lift and .600 lift, teeny tiny bit. It's more than the head can handle, and I'm surprised it didn't go turbulent. Going large over .500 lift is a waste of time on stock heads. Keep an an aggressive ramp up, exhaust bias, and stay around .500 lift max...assuming you have checked your clearance.

I wouldn't go larger than the comp cam grinds, you'll overcam easily. If you want to be cheap, pick up a ZZ4 cam. It's got a heavy exhaust bias, a lazy ramp, and can really use more intake duration, but it's fair and cheap. Look into offset keeps to give you some more retainer to valve stem seal clearance....or machine the guides for more clearance. Put 1.6 rockers on the intake, and keep the stock on the exhaust. That'll give you a hair more duration (not much), and more intake lift, if you really want to try and push it.

jeffsbluez

what a waste of a thread. IMHO

Shadygrady

iTrader: (3)

im going to run the L-T4 production cam ive been told its a decent cam.I will get a more drastic cam when i go with a tpis(or something comparable) manifold and runners.Ive been told about 30lb/ft and 15 or 20 hp.thats not bad for $125.i did go with all the supporting mods and my heads have only minor work.Now if i could just get the motor finished and in the car

LedHeadRed

with stock D113's? i would suggest the LPE 211/219 cam. its designed to add power and torque with real nice manners on a 350 TPI with stock heads like yours, it'll be the perfect street warrior: http://www.lingenfelter.com/Merchant...Category_Code=

jeff1367

iTrader: (1)

Thank you kevin, 91Z28-350, and LedHeadRed, these are the answers we are looking for!

92RSZ

iTrader: (6)

Just happened on this thread and wanted to bring it back to life. I am running the tpis zz-409 cam (226 @ .050 intake and exhaust .520" lift) with just their springs on bone stock 91 l-98 iron heads. These things have never been off the block and are the only stock part left. So far I have managed a best of 12.90 at 106mph. I'm pretty sure I'm close to the limit of the heads and I've never heard of anybody else getting 12s with them.

thegooseman

Wow 12.9 with stock heads. What are your other mods?

madhatter

iTrader: (1)

Holy four year old tread

thegooseman

Yup and I found it doing a . Im thinking about getting a ZZ4 cam with my stock heads and was wondering how much work needs to be done. It seems to be the springs and screw in studs. Maybe I can use the stock pressed in?

92purplehaze

iTrader: (8)

dont worry, if you started a new thread they would still complain. damned if you do and damned if you dont.

madhatter

iTrader: (1)

Just busting ***** thats all. And to answer your question, top of the motor has to come off. you can get away with leaving the heads on. And yes, new springs, probably change the valve seals while in there as well, timing cover got to come off, to put the cam in, i would also recomend puting in new cam bearings, cuz odds are they will go if you just put in the cam, new timing gear. I personally would go with something a little lopeier that a zz4. Your not really going to see much in terms of power gain, but she will deffinately sound sexy

Stephen

iTrader: (12)

What supporting mods does your car have....Cat-back single or duals?
Custom PROM tuning?
Stock intake plenum, runners & base?

12.9 on a stock headed TPI sounds very interesting.

92RSZ

iTrader: (6)

Wow let me see if i can remember lol. I did it with a miniram, 52mm tb, modded stock airbox, 160 t-stat, underdrive pulleys, edelbrock shorties with a cutout in the stock cat location (single cat car), accel ignition, heads were stock with tpis springs for the cam. (still pressed in studs too) trans-go shift kit, vigilante 3200 stall converter, 3.73 gears, and bfg drag radials on stock rims. prom was a junk tpis level IV (hadnt learned my lesson here yet).race weight was 3630 with me in the car (175lbs at the time) also suspension was fully worked over so i could get all the power to the ground. it went 12.90 at 106mph with a 1.73 60ft. it wasnt a fluke as i backed it up with a 12.97 and a 12.99 the same day. if i knew how to tune at the time, it could have maybe gone 12.7X i think. i kno im forgetting some little things, but thats the combination that worked for me