bmfIROC-Z

iTrader: (1)

yeah i rebuilt my lb9 lastyear with the mods in my signature and aint had a chance to get it on a dyno yet ,so i was wanting some horsepower estimates and if any body has an lb9 that they had on a dyno,what was your hp/ftlbs? and with what mods?(ive beat an 89 iroc and 87 ta in 1/4 mile(both bone stock lb9s),both by 10-14 car legths)anyway any estimates would b appreciated,thanx in advance

five7kid

iTrader: (14)

You lost compression using those heads. Probably 220 or so HP.

Synful

isn't 220hp stock for a 88 iroc LB9 ?

is it only up to 220 because he started with an 86?

bmfIROC-Z

iTrader: (1)

i just talked to the guy i baught the heads from and he said they are pre-vortec heads but hes not sur on cc or what they are off of i tried finding some casting #s just to b sure what they are i found a picture of some that look like mine they have a the same casting mark on the front of them(like two lines on the front of the haeds)just hoping they are not corvette 350 heads ,and maybe someone could help me identify my heads if possible cause i cant find any numberspicture is of 64cc vortec .

bmfIROC-Z

iTrader: (1)

i found and just ran the head casting #14102193 and it says my heads are 87-up 305/350 1.94" 64cc 1.5 valves,do 305 tpi's take 58cc, 1.84s? are these heads alright for a 305 ,or at least better than the supposed "corvette heads"as far as horsepower and compression? or are they basically the same?what kinda horsepower would i b running with these heads?,any insight would b appreciated.

SpitotRs305

those heads are the 350 TBI heads.... they probably arent the best choice they have absolutly nothing to do with vortec anything.... as far as the valves you will be ok running them but do to the small bore of the 305 you will have some valve shrouding... these heads are killing you...well almost i would think that stock LB9 heads would be better than swirlports even with the bigger valves of the 193's

bmfIROC-Z

iTrader: (1)

even though they are ported and polished?what is wrong about this setup?how much hp/ftlbs should i b making with this setup?and what does sheouding mean?

sofakingdom

iTrader: (1)

Well I guess that depends on which "supposed" "corvette heads" you're supposing about.... people call just about everything "corvette heads" even though it's not, so that's not exactly the most meaningful description in the world, as far as accurately describing some one particular type of heads. On the other hand, 193 heads are arguable not better than anything else at all, except maybe 70s smoggers in some situations.

People just GOTTA jam that buzzword in there SOMEHOW. At least in this case it's not a lie, unlike calling those turds "early Vortecs" like some people do. "Pre-Vortec" pretty much means EVER head from 1955 to 1995, which those TBI heads are 87 to 95. So at least "pre-Vortec" is factually accurate, even if it's a stupid thing to say.

Porting and polishing those things is worthless. They have this giant obstruction in the intake port, that the factory refers to as a "ramp"; it's designed to promote "swirl" at low RPMs, to favor low-RPM torque. It costs MAJOR flow and therefore is an extreme limitation to horsepower.

If you started out with a 220 HP motor and you put new pistons in it and didn't deck the block, odds are they're an extra .020" down "in the hole" at TDC compared to stock, which are already about .025" below the deck. So, using that total of .045" deck clearance, a .039" head gasket, 6cc valve reliefs, and 64cc chambers, you have approxmately 8.35:1 compression. That, coupled with the obstructed intake ports, is probably costing you around 20-30 HP off of stock. So I'd guess you have something in the neighborhood of 190-200 HP.

A stock LB9 usually does about 175-185 HP and 230-240 ft-lbs on the dyno. That's around 210 HP and 275 ft-lbs at the crank.

10-14 car lengths = 200-250 feet. At 90-95 mph (125-140 ft/sec), that's a difference of somewhere around a second and a half to as much as 2 seconds in the ¼ mile. All I can conclude is that the cars you claim you've "beat", weren't racing.

But all of this is pretty much just guessing and monkey-spank. Get it to the dyno and/or the track, and then you'll know how much power it makes and/or how fast it goes.

Sonix

iTrader: (1)

What a strange combo of parts you decided to use:
Forged crank, plasma moly rings, balanced rotating assembly, gear drive, high volume oil pump....
.
.
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TPI, 193 swirl port heads, LT1 cam...

What???

five7kid

iTrader: (14)

The dual cat '88 LG9 had 220, the single cat had 195. Stock '86 was 190.
I was giving credit for the improved cam and exhaust, and assumed better heads; but you're probably right - at best, it's what it made stock.

Grim Reaper

I too say, those heads are killing you. They are AT LEAST 64cc, which on a 305 greatly reduces the compression ratio. The aluminum Vette/ZZ heads are a far better place to start for a 305 because they too are a small cc head, so the 305 doesn't loose any compression.

Also, the low compression will greatly reduce the ability to go with a better cam. The LT1 cam is not much of an upgrade and I would normally have told a person to go bigger. But, you would need more compression to truly get the benefits of a bigger cam.

The ONLY way this combo makes sense, is if you plan to run nitrous or a supercharger. Then everything, including the forged crank makes more sense.

bmfIROC-Z

iTrader: (1)

is that all you people do is dog peoples **** and try to make people feel stupi d?i mean come on ,i cant even ask a question without someone telling me how much of a piece of **** my car is, or how stupid i am for not knowing exactly how to word a question,im no einstein if i was i wouldnt be asking for advice,and those two cars i said i whooped were most certainly racing! on a marked 1/4 mile and i spanked both off the line and top end and my car only came with 190hp and 285ft/lbs, pretty good considering the 87 t/a came with 215hp and 295ft/lbs and the 89 iroc came with230hp and 300 ft/lbs so whats really goin on? if my car only has 190hp tops then why am i beating basically the same cars as mine that came with 25-40 hp more then mine EVERY time 10-14cars+???(twice with the ta and three times with the iroc ,both friends of mine)and they both know how to drive and they both have excellent running 5.0 tpi's,oh and the cam,crank and HEADS were actually on the car when i got it ,i just put rings bearings,oil pump,free mods,all the bolt ons ,and lapped the valves and put valve seals in the heads, thats how i know they were ported and polished but the a@#hole said they were corvette heads ,i dont know what he was doin or why he chose them parts,im just tryin to make it better and i now know he pretty much lied thru his teeth to get $1500 out of the pos ,but hay its my problem now and i love it and i will continue to make it better and faster no matter what anybody says and ill smoke any stock 305 any day of the week!!ILL PUT $ ON IT,even with my piece of **** heads,i live in central illinois if any wanna try!!oh yeah one more thing sofakingdom my heads have NO obstructions in the intake ports what so ever ,i know this for a fact!its a straight open shot from intake to the top of the valves,so obviously somebody ground that restrictive "ramp" out when they ported and polished them,or am i mistakin'?

91 camaro racer

iTrader: (2)

well that was uncalled for....we are just trying to help you, you wanted to know what heads you have, they told you. you wanted to know hp/trq number guesses, they told you what they thought. you will find a lot of good info on here, sometimes the answer isn't what you want to hear, sometimes it is. and shrouding is when the valve is somewhat surrounded by the chamber, doesn't let it flow as good as they would other wise.

sofakingdom

iTrader: (1)

Precisely.

We're not here to tell you what you want to hear; we're here to give you the benefit of experience.

You can't argue with what the parts are. They are what they are. They do what they do. Numbers do not lie. You can take all of that to the bank.

I'm not seeing any time slips or dyno sheets; so I don't believe that what all of us are telling you is wrong. Still don't in spite of all your protests to the contrary, won't until I see proof.

Yes I'm blunt. Sorry.

If you think it runs good now, just wait until you get those crap heads off of it, and put even the STOCK 305 TPI ones back on. You won't believe it's the same car. It's a shame somebdoy downgraded it like that. But, now you know what you need to do next, to make it faster.

bmfIROC-Z

iTrader: (1)

right tell me your professional opinion dont write a poem on how crappy my car is that seems uncalled for to if u asked me

jonmark1985

hey bmfiroc how far are you from effingham? Scheid deisel has a chassis dyno. I wanna hit it up one day when i get all my classes paid for.

bmfIROC-Z

iTrader: (1)

and there are no obstructions or "ramps" in my intake ports of these heads ,its a straight open smooth shot from intake to the top of the valves,there is nothing restrictive in the intake ports,so did somebody grind them out or what?
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ah about 3 1/2 hours,how much do they charge?

jonmark1985

personally i think the 193's look better on the intake side than the 187's. Their is a ramp on both, and the ramp isn't completely removable, but it sure is shapeable.
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I think around $100 and hour. I'm sure you can find something closer to yourself

bmfIROC-Z

iTrader: (1)

yeah but there is no ramp or anything what so ever in the intake ports of my heads,not even a lump where the ramp used to be ,what does that suggest,do you know where i can find apicture of 193 intake ports?

jonmark1985

I could get you one tommorow.

bmfIROC-Z

iTrader: (1)

ok thank you.

bmfIROC-Z

iTrader: (1)

OKAY here is a picture of a stock swirl port heads intake portand this one(bottom) is exactly how mine look (no swirl or obstructions to it at all)but mine are ported a polished a little better than this one(they look like they were done by a cnc)

Sonix

iTrader: (1)

If someone ground that out they had a LOT of time on their hands...
That makes it a decent head, if they knew what they were doing I guess.

We aren't insulting your car, you didn't build the engine eh? We're insulting the previous owners choice of parts.

That is however a very good truck or low RPM setup.
Low compression - run 87 octane
small roller cam - low end torque
TPI - low end torque
swirl ports (well, if the swirl ramp was there) - good for low RPM torque.

That car probably launches you back in the seat pretty good eh? But i'd guess it runs out of steam around 4500RPM or so?

That engine would be fantastic in an S10 or something. Dollar for dollar that's a hard combo to beat for a torquey street motor. However the bottom end strengthening was all but a waste.... Hey, if you think it's fast now, grab a 200HP nitrous setup and go to town. Now THAT'D make things fun.

brandoz28

iTrader: (1)

if you can do your own porting, then i'd do a simple cleanup on some stock TPI heads and put them on. You'd be able to pick up some power.

BTW go to a real dragstrip and post up your MPH, and race weight, then we can actually calculate your horsepower.

bmfIROC-Z

iTrader: (1)

actually it comes on strong all the way up to 6500rpm smooth,no valves floating or pingin at all.

five7kid

iTrader: (14)

Stock TPI runners, plenum, and base?

It might rev to 6500 RPMs, but it isn't pulling to 6500 RPMs.

TraviZ

iTrader: (2)

6500 ? TPI? better check that tach versus a laptop connected to your ecm.

brandoz28

iTrader: (1)

My LB9 is DEAD by about 5200....the cam wants to do more, and i've spun it as high as 7K (wasnt lookin at the tach in the burnout box ) but there's no power up high with it.

Grim Reaper

bmf, like the others, you shouldn't get all bent out of shape when people are offering you advice. Yes, the big problem with those heads is the combustion chambers are too large and will greatly lower compression.

This is not good if you plan to stay "naturually aspirate". But, if you re-read my post, I said that your combo would make great sense if you plan to run nitrous or a supercharger (hint).

bmfIROC-Z

iTrader: (1)

OKAY like i said before i dont mind people telling me what im doin wrong a little constructive critisism isnt bad sometimes,but when people talk to me like im stupid,or say im lying,poke fun at my engine parts or when people tell me what i said was a stupid statement i tend to get a little irritated,i dont talk to people like their stupid so i dont appreciate being talked to like im stupid cause i aint ! on the engine aspect of it ,i know i aint got the best setup in the world and i wasnt expecting anybody to tell me that im making 500hp and i have the baddest 305 in the world,i just wanted to know what i had as far as hp and i got the answers i needed but some seemed to take it a little further than just a simple answer,some didnt even give an answer just post something to make u feel stupid ,now how helpful is post #9 i mean i would only post something like that if i were trying to make somebody look/feel stupid but i guess thats just my opinion but if people keep talking to me like im an idiot, ill just delete my profile and there wont b a problem anymore! no biggie.

InfernalVortex

iTrader: (4)

No one said you were stupid or that your car was crap. Your question and description of hte parts made it obvious that you arent entirely aware of what your parts are. If that makes you feel stupid, then that's your own damn fault. Everyone here is just trying to inform you.

What heads your car has does NOT make your car a piece of crap. Your car is your car, and your heads are your heads. They may make your car slower, but they do not make it crap. You are making that leap all on your own.

The only thing people are saying is that with the heads you've got, your compression is low, and that's going to make you lose power, not to mention they're swirl ports, which adds insult to injury. Ported as they are, it changes things a little, but your compression is still way down.

Have fun with it, you've got plenty of torque and you can run 87 octane gas. Great for the street, but when people are telling you that you can swap to a different set of heads and make more power, dont bitch at them for making you feel stupid, they're trying to help.

85_ZED28

How quiet is the Quiet Pete Jackson Gear Drive?

Grim Reaper

I don't think your combo (or you) is stupid. Yes, sometimes the truth can be "cruel" and we may regret our choices. But I still think you have a great starting point for NOx or a Supercharger; and that what I initially thought you were planning to do when I saw your parts list in Sonic's reply in post #9.

Just tell everyone that you intend to run NOx or a S/C at some future date, and everything will make perfect sense (and it looks like a well thought out plan...which is my initial thought)

And if you chose later to NOT run NOx or a S/C due to financial limitations, it is not a crime to "change your plan later".

bmfIROC-Z

iTrader: (1)

thanks i appreciate the advice man.
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i dunno its not to loud but you definately can hear it whine especially at cruisin speeds and sittin at the stop light.

bmfIROC-Z

iTrader: (1)

hey did i say anything to or about u mr vortex? NO, i didnt think so , i wasnt bitching AT anyone ,i was bitching about people ,people like well........YOU,people that talk down to people ,so if your gonna talk down to me ,save it buddy ,keep your two cents to yourself there CHIEF!!!!!!!

19doug90

lol this is a message board the whole point is people giving their two cents.

and how in the heck do you get so upset with these posts, ive read them all and theyre nothing but polite and informative.

First of all people are giving you funny comments because the bottom end of your motor is made for something making 500+ hp, just a lot of money on parts not doing a whole lot of good. Doesnt make any difference good or bad, just a waste of cash.

secondly every time someone says your heads are not good for making horsepower, you take it as theyre ragging on your car and saying your motor is ****. This exact statement is said earlier but its not a comment that your heads are "****" theyre simply not good at flowing air as far as the laws of physics are concerned, therefor not good for making horsepower.

You said the motor was already built or you had it built?

i cant imagine someone would go to the trouble of having the rotating assembly balanced, get the machine work needed done on the block and not deck the thing . So his compression probably isnt as low as that, but its definitly not going to be way up there.

have fun with your car mang! and stop being such a jerk to people that respond to your posts, and youll have all the help in the world

bmfIROC-Z

iTrader: (1)

what do you mean it doesnt pull at 6500rpm?it pulls damn good all the way up to 6500 after that yeah it doesnt really pull anymore,i dont know what all exactly has been done to those heads but my car isnt as doggie as you guys are describing ,my tach flies past 5200rpm and pulls hard right up to 6500 and then the tach slows ,i dont know ,it just aint as doggie and slow as you guys are sayin'.

91 camaro racer

iTrader: (2)

well are you sure your tach is correct? the stock is almost always inaccurate in our cars now. it is a very common problem, mine was reading 7000 at 3500, when compared to a new tach.

19doug90

my tpi 350 with a stock cam would fall flat on its face around 4600, sure the motor keeps spinning higher but the car would lose all of its pull.

the TPI intake as a fact dont flow air well abover 4500 rpms
get your car on a dyno and your power curve will tell you exactly where you stop making power

on a 350 with some dart iron eagle heads (not a whole lot better then stock) and an xe274 cam i make peak power at 6000, shift at 6200

bmfIROC-Z

iTrader: (1)

im not being a jerk and im tired of explaining myself,JERK!!
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OKAY ,I GUESS IM LYING MY CAR STOPS MAKING POWER AT ABOUT 2500RPM AND WILL ONLY DO ABOUT 55MPH AIGHT!!!

bmfIROC-Z

iTrader: (1)

not for sure never checked it yet.

19doug90

why do you take this personally

all of these stealth ram, and super ram, lt1 intake conversions, why do you think people change off from the tpi, or switch to a modded tpi?
because the stock tpi doesnt make power over 4500 rpms period

maybe you have aftermarket runners and dont realize it?
a ported intake base helps the tpi too but just take the runners off the car and look how small the tubes are, they seriously cut down on horsepower

five7kid

iTrader: (14)

A session on the dyno would show you what I mean.

You should be able to read the ignition pulses from an Auto Xray, if you have one or can get your hands on one. You can compare what it's reading out compared to what your tach says. Mine is about 100 RPMs off at idle, about 250 off at higher RPMs (3500). Higher error rates have been reported.

This car didn't start off as a V6 by any chance, did it?

jonmark1985

I think most here are failing to recognize a key item about his powerband.

1. While generally lacking in performance, the modified heads may have more than sufficeint air flow capabilities for this engine.
2. He is also using a camshaft designed for the bigger 350".
3. He is using the TPI intake on a 305.

Now i don't claim to be any sort of a TPI enthusiast, personally carb seems cheaper.... But if a 350 were placed between the haunches of this paticular car.. same heads, cam, intake and exhaust.... I would think then he would have a much lower power band. Maybe the one your talking about. Bigger cubes needs more cfm, when this isn't present the tourqe curve becomes lower.

Personally i wouldn't make major assumptions on the powerband. No one is sure as to what has been done to the heads. If he says it pulls then it pulls.


Hey BMF sorry i didn't get those pics, the heads i have are 191's not 193's if you still want a pic I could email them to you.

Sonix

iTrader: (1)

Hmm, you might be onto something... But it is a Z-28 so I doubt it.

Yea, I didn't want to argue the 6500RPM point, why bother? It's hard to convince someone across the internet.

bmfIROC-Z

iTrader: (1)

no its an 86 iroc-z

bmfIROC-Z

iTrader: (1)

its cool man i found some pics,i appreciate the help though

bmfIROC-Z

iTrader: (1)

convince me of what?

Grim Reaper

Bmf, I think there may be some symantics over your car "pulling" 6,500 rpm. Do I believe your stock TPI can rev to 6,500? Sure, and that is what I believe you mean by "pulling 6,500 rpm".

But, what the others mean by "pulling 6,500 rpm"; is "making useable power" (before you are are better off up-shifting). And, generally, anything between 4,700 - 5,200 tends to be the point where you are better off upshifting. Beyond that, you are just reving the engine and probably accelerating slower than if you just upshifted.

This is why guys experiment with their shift points when they are at the track - to find the optimum shift point. And, for most "stock to mildly built" TPI engines, 4,700 to 5,200 rpm seems to be the optimum shift point.

Also (as five7 was alluding with his dyno suggestion), I've seen a number of dyno runs on "built" TPI engines. And what I've found is, that beyond 5,000 rpm, the HP really "flat-lines". In other words, past 5,000 rpm, they HP stays flat. I have seen some go way past 6,000 rpm and make the SAME HP as 5,000 rpm....just flat like Nebraska.

Now, don't get me wrong as I wouldn't say those engines were "all used up" past 5,000 rpms. In fact, those engines offer some interesting experiments in testing the optimum shift point at the track. (But, when the testing was done, their quickest times were still by shifting in the low 5K range...but those engines did pull ... and quite hard ... past 6K. They just ran quickest by upshifting in the low 5K range).

BTW, back to your motor. It is VERY NORMAL to keep switching parts...in spite of all the planning (and experience) you may have. One of my buddies has changed every major part at least twice, except the block. He's now on his 4th cam and I think he's finally happy. It took a solid roller cam to finally make him happy. But, constantly changing & upgrading parts is all part of the learning process.

If you wish to remain naturally aspirated and want to stay with the 305 block, look at some ported Aluminum Vette heads, a different intake like the HSR and the LT4 Hot Cam when you are ready to do some more upgrading. And, if you should kill your 305 block sometime in the future, all those parts bolt nicely to a 350.

I convinced a few people who have 305s to try that combo, and they really like it. Has a nice lumpy sound, makes good power and it isn't that boggy on the bottom-end.

You will need to do some eprom tuning, but that's not too hard either.

bmfIROC-Z

iTrader: (1)

i understand what you r saying like i said ive never had it on a dyno so i dont really know how much it pulls in terms of numbers, i just know that ive rode in probably ten different lb9s in my lifetime and mine pulls noticeably harder than all of them, just my experience though,and i will keep my 305 i like being the underdog i would much rather say i have a 305 that runs with the 350s than to say i switched over to a 350 like everybody else, so what heads would u suggest for my application?wouldnt the ported vette heads pretty much put me at the same compression ratio as i have now?