Alright i got a couple sets of 193 heads. and Due to time and budget they are probably all im going to have to work with. I know the swirl ports are junk, and dont flow well, but i do have a few good machinists in town i can take these too.

Im not looking for a set of race heads, but with some o/s valves and some porting can 193s be a good head to use?

 

Bigger valves won't help.

The same port/bowl clean-up applies to them that applies to all other heads. The swirl wall can be reshaped to help flow a little. Exhaust is slightly better than some other heads, anyway.

Paying someone to work on them is counter-productive. Either do the clean-up work yourself, and have a shop do the final valve/assembly work, or just get a set of Vortecs.

Keep the lift and duration reasonable, and they'll perform reasonably.

 

How's the chamber design on swirl ports? I mean, it wouldn't be the end of the world to simply hold your carbide burr against the swirl ramp until it's GONE. Then wouldn't you end up with something very very similar to 083's then?

 

They seem to flow OK when cleaned up. Not ported vortec or AFR territory, but ok. Dont know if Id remove the entire ramp due to how large the port would become.

 

Hmm, now you got me thinking Dimented... I wonder how large they'd actually be?
And the increase in volume would be just in the bowl area, the "turn" part. Larger volume there is a good thing (according to my reading from Sir Vizard). Maybe if I ever stumble upon a set of these at the JY i'll take 'em home to find out...

 

It is HIGHLY counter-productive to grind out the swirl ramp. Grinding out the swirl ramp will only decrease the power you can make. Trimming the swirl ramp is a more productive option.

 

Why's that?
Have you ever tried it?

I'd think it'd slow down the air mixture right at the turn, and help keep it mixed.

Has anyone ever actually done this? Hard to judge without someone trying it eh?

 

if we get enough replies for it, ill be glad to do it and let you guys know how it turns out lol.

 

the swirls have been removed before just search im pretty sure at least a couple members did it and responded how it was after which i dont remember youll have to find it.

 

I didn't remove it
Numbers:
198 intake
187 Exhaust
Max

 

Fast355 didn't remove it either. He got 224 intake, 196 exh (both cfm). Hot Rod Magazine got numbers (on a 4.3 v6 build) between what Fast355 got and what Dyno Don got, and they didn't remove the ramp either.

The ramp gets the mixture swirling, and that gets the mixture to burn faster when it's in the chamber. A faster burn means less ignition advance is needed to get a full burn, so you get smaller increase in cylinder pressure while the piston rises to TDC and therefore a greater increase in cylinder pressure during the downstroke after TDC. Think about what this means and you'll understand why there is a net increase in torque and power.

 

Well that's all fine and good that some people have done fine by not removing it, but that's not enough reason to discount something. In order to prove the effectiveness (or lack of effectiveness, whatever the case may be) of the modification of removing the swirl ramp, you need to remove it.

The swirl ports seem to be great at making lower RPM torque and whatnot, but run out of port volume (and the ramp getting in the way) for high RPM flow. So, to get around that, i'd say enlarge the ports, particularly in the bowl, ie remove the ramp. I still want to see what exactly happens when someone removes it.

 

If you remove the swirl ramp from a 193, you get an 083. No need to remove the ramp to prove it.

 

The volume of the port is not the problem. Its plenty big. the problem is the shape of the intake ports.
The ramp in the bowl and bump at the intake flange create a lot of swirl and turbulance at lower valve lifts and part throttle use. (helps low rpm airfeul mix quality and efficientcy. At full throttle and higher rpms there is plenty of air swirl into the chamber without a flow robbing swirl vane.
You may get 224cfm on the flow bench after porting but the airflow will be very turbulant at high(er) +.400" valve lift and WOT.
These heads work well for their intended low rpm part throttle application purpose but at WOT have very limited power potential even with porting, even without the swirl vane. Takes a lot of epoxy/welding to correct the bowl shape for high airflow. Might as well start with a 081-083 TPI head and put your porting effort to much better use. They work very well with full porting and bigger valves.
here is a pic of a very nice fully ported 083 head (not mine) can't get near this bowl shape or airflow with a swirl port head.
removing the swirl vane wil not get you the same thing as a 081-083 head. (without a lot of epoxy in the bowl)

if you want 14-15second quarter mile performance use swirl port heads.
if you want 12's or even 11's on the street for low $$$s (if you're sharp)
the 081-083-113 TPI heads are much much better for the same money and effort. These are the junk yard jewels.

 

I figured it would have a much bigger bowl area compared to an 083, which would be a good thing.... But hey, lets say for arguments sake you're dead on correct. You trip over 193 heads in the JY because they're so plentiful, but 083 heads are practically like hens teeth, not a lot of TPI 350's collecting dust in the scrap yards eh? But if you can turn 193 castings into something similar to 083's, then boom, you're work is done

 

IIRC they are 185 cc stock unported for the 193 and 191 (swirl port) casting numbers. The 187 swirl port are probably similar. That volume is fine for street use in 305 and 350s, so long as you don't need big power (well over 400 hp). If you need big power, the port volume is too small.

IIRC turbulence helps the chamber burn occur quickly (fast burn). Turbulence isn't helpful for airflow.... but then again all WOT airflow (in swirl or non-swirl heads) will be turbulent when viewed from Reynold's number for airflow past the valve.

If you define limited power potential as mid-400 hp, then I'll agree. Fast355 and HRM have already proven that porting will go 400+ hp.

That's a gross under estimate.

Lo-tec went 13.6 on a Caddy LO5 longblock in his 3rdgen, using stock 193 heads, aftmkt exh, and a 214 deg cam. Dyno Don did much the same thing using nearly the same setup. Ported heads would have gone faster. Ported heads + hotter cam would have gone much faster.

Fast355's engine builds would be substantially better than these (bigger cams, more porting, arguably better tuned).

Ported SP heads would probably run longer ET's, if similarly ported, than the 11s and 12s you mention and that makes the 081-083-113 superior. OTOH the part throttle street manners and fuel economy gain of the SP heads might be a worthwhile tradeoff. FWIW.

 

Why not just scoop up a set of vortecs?

 

well if i grab a set of o/s valves and find someone to port these i should be good? What size cam would be recommended for street use on these heads? Im not looking for a 11 second street car, 400+ is way over what im looking for.

mid or low 13's will be fine, and if thats achievable with 193 heads and a cam with some porting and o/s valves im happy, the car will be street driven

i dont want to go spend more money on a set of vortecs when i have a set of heads that can be used right now, id have to spend more buying the vortecs and then more money working them.

 

If you define limited power potential as mid-400 hp, then I'll agree. Fast355 and HRM have already proven that porting will go 400+ hp.


Show me a motor, any motor that has 191-193 TBI heads on it in any form that makes "mid 400 hp" Show me a dyno test of any motor that has 191-193 TBI heads on it in any form that makes 350 dyno tested hp.

224cfm from a port that is highly turbulant and has a volume of over 180cc will not make 400+hp on any real SBC motor with a useable pump gas cr.
You're confusing a little turbulance created by a bump in the port wall and a bit of swirl created by the swirl ramp that aids mixture quality at low low rpm and throttle opening with what happens on a hi performance port and chamber at WOT. At wOT the turbulance in a TBI port with the vane removed
is so severe that the port chokes at hi lift. At its port volume {++180cc with the vance removed} it should be flowing 245-250cfm @500" lift (typical hi perf cam) but it only flows 224cfm (cause the excessive turbulance is blocking the flow) it won't make power.

There is a big difference between a hole on a cylinder head with a valve on the end that you call a port and a real port with proper shape that actually works. (actually does make power)

 

My personal build put 279 RWHP down with a Production LT1 roller cam and 9.5:1 compression, using the 193 heads in question. I further backed it up with a 15.2 @ 94 mph 1/4 mile run in a 5,500# G-Van with 3.08 gears and a 2,000 rpm stalled 700r4.

On a different engine build with the same heads and a bigger crane roller cam, I got nearly 300 RWHP from a 350 TBI in a Tahoe.

HRM made 308 FWHP from a 4.3, that is over 400 FWHP from a 350 using the same HP a cylinder 4.3 being 3/4 of a 350, using ported swirl ports.

EDIT- Just found the dyno sheet for the run on the Tahoe. The lower numbers are with swirl ports, the greater numbers are with 49cc Dart Iron Eagle 180 heads and 10.5:1 compression. Keep in mind that the Tahoe had crappy shorty headers and the factory Y-pipe at the time. It really needed Tri-Y headers and a decent exhaust system, which showed further gains.



The Tahoe was totaled by a red-light runner while my little brother was driving it. We yanked the engine and replaced the 305 that I had swapped into my 1983 G20 Van with it. It ran a 14.7 @ 95 mph in the Van, with the Darts on it.

 

My personal build put 279 RWHP down with a Production LT1 roller cam and 9.5:1 compression, using the 193 heads in question. I further backed it up with a 15.2 @ 94 mph 1/4 mile run in a 5,500# G-Van with 3.08 gears and a 2,000 rpm stalled 700r4. Your engine was makeing not more than 353 gross flywheel BHP not 400hp.

On a different engine build with the same heads and a bigger crane roller cam, I got nearly 300 RWHP from a 350 TBI in a Tahoe. 300RWHP is about 350-to 370 gross flywheel HP on a real engine dyno.

HRM made 308 FWHP from a 4.3, that is over 400 FWHP, using ported swirl ports.
The amount of power made from a 4.3 V6 with 4.3 vortec heads has nothing to do with how much power you can make on a 350 with any 350TBI head
the heads are not the same. they are not even close to comparable.

EDIT- Just found the dyno sheet for the run on the Tahoe. The lower numbers are with swirl ports, the greater numbers are with 49cc Dart Iron Eagle 180 heads and 10.5:1 compression.

dart 180's stink too they flow 208cfm from a 180cc port "out of the box"
i have a set here.

None of this stuff actually proves or would even lead someone with a bit of knowledge and experience to believe that you can get 400+ real dyno hp from TBI heads on a real 350sb. Like I said show me a real engine dyno test of a 350SB with a TBI head on it that actualy makes 350 real dyno hp.

The power you get from a road/chassis dyno is highly variable unless you qualify ALL the factors that went into testing and calculating the result, the numberes you get are very typically meaningless and not repeatable down the street on the next guys chassis dyno.
I appreciate all your hard work in trying to improve the TBI heads, I do simular hard earned efforts with the 305HO heads, but lets keep our power claims reasonable and quote real actual performance tests of our actual engines not someone elses V6 as they are and not compare apples to telephones.
I may have been born at night, but not last night.

If you're so sure of the amount of real horsepower your TBI headed 350 is making, yank it out and dyno test it on a real engine dyno under real. repeatable SAE test conditions. Let the chips fall where they may.

Someday when I get the chance/time and the $$$'s I will do mine.

 

I hope you realize on the Tahoe, you have a Transfer case and a GM 14 bolt rear end with a 9.5" ring gear. It also has an emissions air pump, monster 7 blade clutch fan, and a 140 amp alternator. Your FWHP estimates are a little low.

I also beg to differ on the 4.3 build, HRM USED TBI HEADS, NOT VORTECS, TBI HEADS, WITH THE SWIRL RAMP. The 4.3 TBI heads are IDENTICAL to the 350 heads in every aspect, except they have 1 cylinder chopped off of each. Their build only had 9:1 compression and a 224/224 @ .050 cam, along with 1 1/2" primary tube headers.





My out of the box Dart 180s were also considerably better flowing than yours. 238 I and 175 E @ .500" lift and 28 in/h20 pressure drop.

 

Again show me a real dyno test from a a 350SBC V8 with TBI heads on it that makes more than 350BHP. Not ,a HRM V6 engine made 308 hp under unknown test conditions and parameters therefore my 350 will make X amount of horsepower. yank your motor out and dyno it.
----------
Again show me a real dyno test from a a 350SBC V8 with TBI heads on it that makes more than 350BHP. Not ,a HRM V6 engine made 308 hp under unknown test conditions and parameters therefore my 350 will make X amount of horsepower. yank your motor out of your van and dyno it.

 

Well we test both heads of the pair and could not get over 208cfm @28". Was barely able to get 238cfm after extensive hand porting and retesting.
My test results agree with others that have flow tested these heads.
My ported 305 heads flowed 232cfm@28' immeadiatly after the darts were tested in out of the box form Dart only claims 221cfm in their litature, how do you get 238cfm from a "out of the box" un tweeked dart 180 that no one else (me, pros or Dart Machine) them selves seems to be able to do.????
credibility gap there.

 

I'm getting 279hp and 318 hp respectivly thru engine simulation with your two configurations
TBI head 9.5:1 AND DART 180'S @10.5:1 CR "shorty headers and Y pipe"

 

HRM engine dyno'd a 4.3 engine (262 cid, bored to 270 during freshening) that made 301 fwhp. The heads were 4.3 v6 versions of the 191/193 swirl casting. Fast355 posted the pix from the HRM article above --- the swirl ramp tip has been clipped off so as not to interfere with the intake flow as viewed from the intake manifold port. The cam HRM used was not intended to make huge power; instead it was chosen so that a blower could be installed after the engine build/test. So the cam did not optimize the output power of the engine.

The 301 fwhp made from 262 cid // 4.3 liter v6 (3/4 of a 350) is the equivalent of nearly 390 fwhp for a 350/5.7... and when using a blower-type cam. A GM HOT cam (or the v6 equivalent) would have made more power, and the 208 cfm intake flow was still enough to support 416+ (350 equivalent) fwhp using the Vizard rule-of-thumb of intake cfm * 2.0.

We haven't seen, yet, anyone install a cam that will completely use the full airflow in ported TBI heads, but we have seen many examples for similarly modified non-SP head engines in F and Ycars. So it's easy to "prove" what ported non-SP heads will do, but less easy to show the same for SP heads because of the lack of data.

Not true.

Iron LT1 heads (B and D car) that flow 215 to 227 cfm (stock unported) on the intake and use 10.0 cr on 87 octane pump gas; the port volume is ~180 cc. A GM HOT cam + 1.6 rocker arms and exhaust will run well over 400 fwhp. HRM did that exact build on a Buick Roadmaster engine and made 422 fwhp on pump gas. The rocker/cam/exhaust swap on the 94-96 Caprice/Impala LT1 is one of the most common swaps and results in high 13 sec quarter times.

The LT1 chamber promotes swirl from it's shape; the 191/193 heads do it from the swirl ramp. Fast355's ported example (224 cfm intake) flows the same as the stock LT1 intake, and both heads obviously have good swirl because both need only 30 to 32 degs total ignition advance to optimize power. So the comparison is a good one.


The vane is never removed -- only the tip of the vane. The remainder of the bowl / port is ported much the same as a non swirl head.

As for the port tubulence in a TBI head --- if you have removed the swirl vane (ramp) and have data to shows the choking of the airflow vs lift profile, please post it. If you don't have that data, then I'm inclined to think you are repeating hearsay about SP heads.

Vizard has said that there is more to making power from an engine than airflow cfm numbers alone. Do you know why he has said that? Because of the burn characteristic of each head. So it isn't enough to say that a ported 180 cc SP head should be flowing 245-250 cfm. It's a 20+ year old head with a big pushrod bulge impeding airflow. If it can be ported to flow over 200 cfm on the intake, and still need only 30 deg ignition advance, then it can make 400 hp in a 350.... if suitably modded with cam/exh and tuned. It will still make good part throttle low speed torque, and it will still have decent fuel economy.

It will also trade off maximal airflow (in cfm) because part of the ramp is still there, so it might never make the 245-250 cfm you mention. That doesn't mean it's not useful --- it just might now be useful to you at the strip. You might not accept that compromise, losing 10% peak airflow at the track, in favor of a better engine on the street. Others might.

Right. Like an LT1 head or an even newer LSx head. The TPI and TBI heads don't fit that category. Neither are performance heads.

If TPI and TBI heads are ported, they both improve. The TPI heads will always have more maximum airflow potential (because they lack the ramp) but that doesn't guarantee substantially more output.

 

But wait, that's an LT1 head - not a swirl port head. Much less turbulent at higher flow levels. That's why they can get the big HP.

Now.... Why is that, that no one has used a "proper" cam to maximize the output of a TBI headed engine in a sports car type of application (not a truck with a 5000RPM redline, but a camaro or the like..) ? They are stock in Camaros in some years, but no one (ever?) has fully used the output, to satisfy the naysers on here? I think that question somewhat answers itself doesn't it?

 

You need to take a good look at the flaw in the evidence you present (LT1 heads cc size, flow and performance. to support your claims of what a Swirl port heads will do. A swirl port head is not a LT1 head. It has a big friggin hunk of steel right in the bowl that blocks high airflow. And creates excessive air motion ( swirl) at WOT high rpm that further blocks airflow.
A Lt1 head does not have a swirl vane because the vane becomes a big restriction to further power (airflow at WOT).
The intake airflow = x amount of horsepower "guideline rule" is just a guide line.
it assumes a perfectly tuned motor and very high compression ratio.
a head that flows 224cfm has no guarantee of making x amount of power.
My ported 305 heads flow 232 cfm. According to the rule, they should make 477hp. Well i can tell you for sure they won't. Not on any motor you and I can build. I have found that if you take the result that the flow rule suggests and correct it with a .85 to .9 factor for a streetable cr and realistic power based on a imperfect engine design, you end up with a power prediction that fits the real world a lot closer. Now you can start to predict the power you'll really get from X amount of airflow on a SBC like you can I build. that would suggest that my ported 305 heads at 232 cfm should be good for 406 to 429hp at a realistic usable cr and a good (big) camshaft, induction system and headers. Previous experimentation with these heads on a 12.65:1 motor and a few 9.5-10:1 motors seems to fit the power prediction pretty good, once you include my "reality factor". (.85 to .9) My "reality factor" is based on a head that does not have a big friggin hunk of metal right in the middle of the bowl and a huge, but modest flowing 180+++cc port. that would lower the factor a good bit. You build the motor with your ported TBI heads and dyno it and see.

 

Fast 355? Did you get my email, and can you post it here? I did not know this discussion was going on here. Guys, I am currently porting a set of 193's to run in a Gasser Coupe. I want wheelies, and I want to do it on a stock converter with a 700R4. I also want to run faster than mid 12's in the quarter. I am using a stock dished piston 400 block with Comp Cams nitrous camshaft. This cam has lots of exhaust duration, will run well on gas on the street, but can evac the exhaust if i push the button. The swirls will get my wheels up, hopefully, but I don;t know if they will spin to 5500 in a 400, which takes more air than a 350. I am straight ining out the outside wall, removing the peak of the swirl, canting the bowl to the center, getting rid of anythin in the way, using a 1/2 inch football shaped bur on a 6 inch shaft to take back the guide and open the highway. Hay, frankly, I don't know squat, I am trying to open new territory. And remember all you nay sayers, nitrous doesnt care if the intake port is limited. One more comment on the power of low RPM torque. I see we all like to quote Vizard, but some of you would do well to read a little Jim Hand. He runs 11's in a station wagon.

 

No, I didn't seem to get the email.

This is how my ZZ4 cammed 350 TBI ran with stock 810 swirl port castings on it. LT4 springs/retainers. 0-60 MPH with my 3.08 geared fullsize Van running 30" tall tires.

http://youtube.com/watch?v=koWaPeAu3hg
Good luck on the project, 5,500 rpm might be a challenge on a 400.

I know of Jim Hands Lemans nosed wagon. Runs on premium pump gas, Turbo 400 shifts @ 5,500 rpm. His engine uses almost an entire makeup of factory Pontiac parts. Block, Heads, Cam, Intake to my knowledge is all modified stock pontiac. Last I saw he was even running a Q-Jet

Then again, I wouldn't laugh too hard at torque with the right setup. The old roller cammed TBI 350s in the B-bodies were pretty quick for what they were. 0-60 in about 8 seconds.

http://www.youtube.com/watch?v=1U7O-U4EF00&NR=1

 

F355
Jim was using a Wolverine cam with Rhodes lifters and sometimes an Edlebrock RPM intake, but otherwise almost all Pontiac parts. He races in drive and lets the trans shift at its predetermined rpm, just like you were doing. He set shift at 5600 rmp. He is feeding a 470 something CI engine with high velosity small ports that flow just over 250 CFM. 250cfm divided by 470ci gives us an air flow need of .53 CFM per CI. You got 225 CFM out of your 193's. 225cfm divided by my 400 ci engine is .56 CFM. Jim insists that all you need is what you need, and no more. So overporting, or even running high flow aftermarket heads is not necessary given the self imposed conditions of a stock automatic transmittion. I was lusting after some 195 AFR heads, and even a NASCAR shop crate engine but since the real estate market has tanked, I can only afford junk. The reason I am using 193's is I have them. I don't have some Darts, 083's, ARF's or what ever. I discovered your writeing in the process of deciding whether or not to use my ported smog era 493 400 heads with 76 cc chambers or bump it up to more modern 64 chamber and get some compression. anything you can tell me about porting these babys would be greatly appriciated. I have worked one intake chamber, and I took off the peak of the ramp down to the top of the guide boss. The theory there was that 'Vizard' says the flow changes from swirl to flowing across the valve at about .5 lift and above. The problem of course is that the high lift high speed air stream comes from the roof of the port, and that is limited to the outside wall on these heads. Your experiment suggests that it is not a problem. I did shave the guide down all the way around, and widened the ramp to 1/2 inch , and straightened out the outside wall where the head bolt bump is. I also removed the lip except on the outside wall. I figured the air stream can start hitting the valve as soon at it starts into the corner. I also left the center side of the bowl sloped slightly the way Vizard shows in his books. That way the air will hopefully pour into the cylinder on the center side of the valve. Do you think I am on the right track, and am I missing anything?
I took a turkey baster and CC'd the intake ports this afternoon. The stock ports cc'd +-188 and the more or less done port at 200. I have no idea how accurate a turkey baster is, and the smallest reading was 10 cc, but the idea is I took out about 12 cc.
I see by your air feul mixture guage, knowledge of computers, feul injection mods, auto trans shift points ect that you are light years ahead of me in TECH. I am still at keep it simple stupid. KISS. Thanks, the Appraiser