jconrad

Hey Fast, it looks like when you are editing a post, it just keeps adding another post to the original one. Maybe it is your 'back' key that is causing the problem...
Maybe you could edit those other posts to say like maybe "." ?

BTW, I am very interested in what all it took to get those flow numbers from those heads, being as though mine are the same. Pics, or otherwise would be most helpful

kdrolt

To get anything close to those numbers on Cartest (as mentioned somewhere above), I needed to raise the engine output to (gasp!) 365 fwhp and 440 fwftlbs. The 1/8th mile came in at 9.96 sec @ 74.5 mph. 0-60 mph was 6.6 seconds. I still used a Cd=0.4, so you might be right that the Cd is actually smaller, because my trap speed was slower by 1.6 mph but the ET was close.

OBTW the 9.96 @ 74.5 mph continued, on Cartest, to a 14.9 sec @ 92.7 mph run in the full quarter mile. Taking the same engine and virtually planting it into a 3500 lbs Fcar, the timeslip would be 13.4 @ 106 mph. That's slightly better than what Dyno Don obtained, but still in the ballpark.



267 rwhp is 314 fwhp using a 15% loss, and 314 fwhp is roughly where the stock-sized dual 42.6mm-diam TBI bores really start to impede the airflow. So you might be able to use a larger TBI and pump more air through tyhe engine. The other tell-tale that you might be air-starved is that the rpm for peak power came at 4600 rpm. The Fcar LT1 cam pumping thru LT1 heads peaked at around 5200 rpm if I recall right (with approx 275-285 fwhp) so you seem to be making a lot more power at a much lower rpm with the same cam and with heads that have been presumed to be airflow-challenged. Your head flow data suggests the heads are not the problem, so I think the TBI bore size is limiting your output.

Also, the torque output is HUGE, 335 ftlbs @ 3200 rpm, which is excellent and at a nice low rpm. Imagine what the torque output would have been if you had used a TPI intake manifold.

The discrepancy between the track data (and the backed out 360+ fwhp) and the dyno-measured then extrapolated 314 fwhp is a mystery... unless the CTS was ok during the track runs and not ok during the dyno session. If the loss term was 20%, then 267 rwhp would be 334 fwhp, so the loss in the drivetrain still isn't enough to account for the difference. I'm not doubting what you posted, just trying to close the loop.



What kind of ignition timing are you using, base (by the distributor location) and electronic (in the EPROM)? The L31 Vortecs are often set at 29 to 32 deg total advance by way of comparo, and your heads seem to be doing as well as the best L31 Vortec heads on any TBI here.

kevm14

Fast355,

Those 1/8th mile results and the dyno pull - was that with a STOCK TBI intake??

Fast355

iTrader: (2)

That was with the stock TBI intake from a 1992 TBI van. I could imagine that the edelbrock would have given me a substantially better high rpm horsepower. Actually I am sending back the edelbrock because of the sealing issues (heads are not milled nor is the block but yet it is not sealing? Humm.) I am going to the cheaper projection one and using a TBI spacer to make room for the EGR valve.

The check engine light for the CTS sensor came on, coming back from the track. It could have had some effect on the track times in particular the slower MPH on the quicker run.

I know I am air starved because I have a vacuum gauge connected the the port on the intake. At WOT I am seeing 1.5 in/hg @ 4,000 and it only climbs from there.

I am sorry that I didn't think to take/post pics until after I put them on when it was too late. Looking down the intake ports won't tell you much as they look nearly stock. The real work was at the bottom of the port and the bowl. On the exhaust side I really worked them. The port is huge compared to stock. The area around the guide was trimmed down substantially as with the intake. I treated the swirl port as just another head. On the outside edge of the port leading into the swirl vane both of my heads had a rather large protrusion. I completely smoothed that out and made a near straight shot into the outer wall. My heads also had a ridge in the bowl with what looked like casting flash. I removed all of that. Finally I used a set of performance intake and exhaust valves. I almost wonder if those heads would flow better with 2.02 and 1.60 valves in them or if the swirl vane would impede flow.

I have dropped to 0* base and have around 30* total timing at WOT, 3,200 rpm and no vacuum. I have the adder set very low like 1* 1000 rpm, ending at 5,800.

kdrolt

Good catch Kevin... I thought Fast355 was using an aftermarket intake.




I think an aftermarket unit would flow better, but who knows by how much.... and it's still revealing to see that you are making 267 rwhp even with the factory TBI intake. That factory intake is often called "junk" on this board (aside: I never called it that but I had my doubts); if the intake were that bad on your truck, it would have been the weak link in the chain. As it is, it looks now like the TBI is the weak link in the airflow chain due to the small bores.



That's also good to know.

Wow. It makes you wonder what the ceiling on the engine power really is. You still have a fairly mild cam (though in a heavy truck, I don't think a bigger cam is desired), you did have a CTS problem, and the TB unit seems to be too small (now that you are maxing out out). You still have the factory (unported?) intake manifold. If you accept that you have somewhere in the 310 to 330 fwhp range, or even as high as 360 hp based matching a simulated track run to the real data, then how much power can you really make?

That's great info. Thanks.

kevm14

Hot damn that's impressive. Now how come Paul Doe's car is so slow? Are those World heads so bad? Maybe it's the cam. Or is 40hp hiding in the calibration? His car has less than 267hp at the flywheel. Probably more like 240. Or 230.

I'd like to dyno mine. It's been a long time. I'd probably pull 180rwhp.

PaulD

Ouch, that hurts. But it's a good question. I don't think it's the heads. I think it's in calibration. Then again, Kd has been after me to upgrade the fuel pump .

There, think that ties my record for smilies.

kevm14

As long as you can monitor fuel pressure while driving the car, and you confirm no drop at the highest fuel demand, then you don't need to upgrade your fuel pump for performance reasons. It's a good idea "for the future," but it's not The Problem (provided what I said above is true).

That said, what you probably should buy is that LM1 WB kit. It's either fuel, spark or both and the fuel can be dialed in relatively easily with a WB. After that, it's just careful tuning playing with SA, making sure we don't grenade the engine.

All of this assumes your engine is an adequate airpump for the horsepower levels we think you should be around. As for that, I'd say at least 260 flywheel, but probably no more than 275.

kdrolt

My 94 9C1 Caprice (with a stock 260 fwhp LT1) ran 9.74 secs @ 74 mph in the 1/8th mile, enroute to a 15.0 @ 92 mph timeslip. That's exactly what it should run with a stock engine. Fast355 is running roughly 0.1 sec longer duration but +2 mph faster trap speed in a aerodynamic brick of a van that weighs (by his numbers) 1000 lbs more than the Caprice. He rw dyno'd 267 hp. He's making a lot more than 275 fwhp.

kdrolt

...

kdrolt

Or the driver?

Fast355

iTrader: (2)

Alot is in the setup too. I am crossing the traps as I shift into 3rd gear. That helps boost MPH but hurts times a little. My transmission is set to shift at 5,500 rpm when matted which is perfect. Some people refuse to work on their shift point and keep the stock 4,200-4,500 rpm shift point. When your engine is making peak power at 5,500 or so that is going to hurt you bad by upshifting early and putting you out of your power band. I like letting the transmission upshift on its own at a predetermined speed so that I am consistent.

kevm14

Sorry if I was unclear, but I was referring to Paul's 9C1. I was also referring to where it should be for power, not where it is currently.

kevm14

Actually - he could probably eek more trap speed out of it with manual shift control. The stock governor is gonna upshift too early. But even holding it into the 5000 range, it didn't feel like 260fwhp.

PaulD

I was waiting for you to buy it! and then drive up here!!

You really don't want help with the Trans-go, do you?

Ahem, I'll not dignify that with a response.

My usual is to start in 2nd, allow the automatic 1-2 shift @4500, then to 2-3 manually at 5000. I've tried fully automatic with and without OD. THere is very little difference in results.

kevm14

That probably won't be happening for a little while (my buying the kit).

Sure I do! Mike O'D drove my car last night and officially blessed it with "that thing shifts damn slow, dude" syndrome. But at least it doesn't feel that much slower than a stock LT1 9C1.

Have you tried bringing it to 5500 (or slightly more) in each gear?

PaulD

It just doesn't seem to want to keep pulling very well up there.

Fast355

iTrader: (2)

Last week I was into this engine again. Dang valve cover gaskets were leaking. I did a running adjustments on the lifters and eliminated a couple of clicking lifters due to, too loose an adjustment. I also fixed the CTS issue by adding a new connector that actually would stay plugged in. I also changed the weights on the governor for a 4,800 rpm upshift to get me back into my power band. I have also been working on the tuning some more too. I have also added the CFM tech TBI spacer, stuck my powercharger back on it, along with a factory van air cleaner, and my K&N.

Friday night I went to the 1/4 and ran the following into a stiff 20 MPH head wind.

60' = 2.55s
1/8 ET= 9.853
1/8 MPH= 77
1/4 ET= 15.6s
1/4 MPH 87.6

This is the only run I got to do, due to the crowd there.

Fast355

iTrader: (2)

In case you'll never heard I broke the crank in the 355 and it is becoming a 383. The 383 is going into a S10 with a six speed behind it. I have now gone to a 312 still TBI in the G20. I broke the crank less than 1,000 miles after the last dyno pull. The final numbers for the 355 were 279 RWHP @ 4,900 and 342 ft/lbs @ 3,400. That is roughly 340 horsepower and 417 ft/lbs at the flywheel. The torque curve was near dead flat from the lowest rpm of 2,500 all the way to over 4,500. The horsepower remained above 270 rwhp all the way to 5,700. It then fell of to 265 RWHP at a max of 6,300 rpm.

My TBI 383 is going to have even more torque.

kdrolt

It's amazing that you could manage 279 rwhp and approx 340 fw ftlbs from those "junk" heads that can't flow well at high rpm. 340 fwhp and 390 fw ftlbs (342/0.88) is much higher than the factory rating on the Fcar LT1 (275-285 fwhp and 330 fw ftlbs). IIRC both the Bcar and Fcar LT1s also had really flat torque torque curves so it shows just how well the ported 193s can mimic, and exceed the LT1/L31 factory heads.

The Fcar LT1 cam usually peaks hp well above 5000 rpm (it does on the Fcars), so me thinks you were really getting airflow limited from the TBI since your hp peaked at 4900 with that cam. Was it a stock sbc 2-bore TBI, i.e. had you done any mods to it?

You'll probably could use a larger TBI, either a bored unit or the big block unit. It might be interesting (if you have the time & resources) to test the 383 using the TBI you have, and then re-test with a larger TBI. That would also help more-firmly answer the ever popular question about how much airflow (and hp) can the sbc and bbc TBI support.

BTW were you still using 30 deg total ignition advance, and will you still be using the ported 193s on the 383? TIA.

Fast355

iTrader: (2)

Yeah I was still running the stock TBI and stock 350 TBI intake manifold.

My next build is going to be with a Weiand 7525 single plane with EGR, a carb-TBI adapter, and a 454 TBI. I am keeping the 68 lb/hr injectors though. The LT1 cam is staying as well as the 193s. I am even going to port them more, hopefully I don't hit water. I am also raising the compression ratio as well as going to the 1.6:1 LT4 style rocker arms. This is going to be a torque monster TBI. Now if I could only find a LO3 car to put it in. Yeah it still the stock 305, he he. But chances are it is going into a S10 like I said earlier, due to money.

JPrevost

Don't get trapped into the numbers game. Deriving fwhp from rwhp, comparing this dyno to that dyno. When it comes down to it numbers mean jack squat to me unless you got a baseline ON THAT DYNO. I'm in this field and can tell you now that dyno operators sway towards a dynojet because it reports a higher number. When it comes down to it, the only thing important is the 1/4 mile data. X weight (not guessed), goes X mph at this elevation would be a very good indicator of average horsepower being put to the wheels. Infact that's the best indicator of how much horsepower you're putting down.
Now if you want to limit the gains and get rid of variables then use an engine dyno, or baseline your vehicle on the dyno BEFORE ripping into it.

JPrevost

You'll be making the same horsepower only at a lower RPM if all you do is increase the displacement. If you want a torque monster I'd use a dual plane that doesn't have a cross-over passage. 2 4 cylinders resonate at a lower RPM and will make more torque as a result... then the "mid range" will suffer up to about 8000rpm.
Why stay with the Lt1 cam? Is this a stock Lt1 cam? If so, you'll make more low end AND top end with a larger cam. It's a misnomer that a larger cam automatically makes less torque down low. The only thing the smaller cam does is create more vacuum at idle and more torque at idle . Just off idle a hot cam like the Lt4 hot or zz4 would make more torque, even with crappy heads . j/k

kdrolt

Not trapped. Maybe you didn't read the rest of the thread.

There is:

1. flow data
2. dyno data
3. track data

all by different people, at different times, and in different places... all focused on swirl-port type heads. I think you study science/engr so I'll put it to you --- how can you use these disparate pieces of information that are each "noisy" by virtue of the different test locations/conditions? Can you use the track data to sanity check either the dyno data or the flow data or both?

You previously dissed the flow data as having not been tested on a real flow bench... but you never told us what flow bench we should be using. We already know what your feelings are on dyno tests per the above (I think Fast355 used a Mustang dyno, and not as you suggested, a Dynojet). But we do know that you like track data. Fine, so use the track data.

Dyno Don ran his Fcar at the track, while Fast355's track runs were in a Gvan (G20?). One lives in CA, the other in TX. The data/timeslips have been repeatedly posted. Use your engineering judgement to back out the torque and power for each, and try using both Fast355's claimed measured weight of 5300 lbs... or you can try your own engineering guess for van weight. There must be data on the web for that. Hell my Caprice weighed 4240 lbs, and the Roadmaster wagon weighs over 4600 lbs with all that glass and no riders, so I don't think it's a stretch to allow the Gvan to weigh over 5000 lbs. But it's your call.

Then sanity check whether the power and torque numbers from the track make sense give the cams they used, the dyno measurements they took, and the flow numbers they measured. It's engineering JP so the numbers are supposed to work, or be close to matching, so long as you get the rest of it right. And that way you don't have to complain about before/after dyno testing even though most would agree that ideally it's what you would like to have.

It's easy to armchair how someone else should have done their testing, but it's another matter when it's your time/energy/money sunk into it, and the rest of us have the (free) benefit of learning from it afterwards (like me). Please deal with the data you have on hand, draw your own conclusions, and then post them with the analysis to back it up.

Fast355

iTrader: (2)

If running a 15.6 @ 87 into a 20 mph headwind isn't enough in a G20 that has the aerodynamics of a brick and weighs 2 1/2 tons with crummy swirl ports what is. . You can tell on the last pass that I got to make on that engine that the last 1/8 mile I only gained 10 mph. I would have probably been running low 15s without the headwind. The quickest pass was run at over 5 mph slower trap speed than some of my slower ones.

All the dynos were run on the same Mustang dyno which is stingier than the Dynojet.

In case you have forgotten the numbers we simulated were just to back up the dyno proven power. The track numbers are real, then there are also the predicted numbers that verify the power output.

JPrevost

kdrolt; what isn't working for me is you deriving horsepower at the flywheel from performance and a dyno. That doesn't work in reality. The mustang dyno is definatly a better dyno, I'm impressed with the numbers but here's where I'm not impressed; excuses. You guys are coming up with excuses why the truck is still relatively slow. Head wind, weight, stock TBI, stock intake, small cam, blah blah blah. Then you take those excuses and like ricers with their stickers, add on horsepower. So far I see dyno results but can't recall the conditions or if the numbers were corrected. If they were, fine, it just doesn't stick in my head as being posted and I'm usually intune with technical details.
87mph with a 6000lb vehicle using a crude calculation says 300hp max flywheel horsepower. WTF good is that? You've totally guessed on the true vehicle weight and nobody has compared it to what it ran stock and in good running condition. Excuse my sceptisizm but last time I checked results were MEASURED against something stable, like a baseline, NOT by some crazy fill in the blanks where most of the influential variables exist.
I'm by no means saying the engine isn't producing some great power but your insistance that these heads are some kind of gift to TBI performance is just getting out of hand. I can't stand idly by while you tant peoples minds with "slight" port work on swirl ports as this better than x_ heads. Want to compare heads, then compare the exact same motor with just different heads. What to compare TBI's, do a direct swap and post results.
It's just crazy how bent you are on taking these heads and comparing them to other STOCK heads. I wish you would compare them to aftermarket, or various other ported heads because then it would be on equal grounds.
Example; Look, my ported vortec heads make more horsepower (derived number from flying barn door into head wind and then a dyno session) than a stock Lt1! wa wa WHAT, lol. It's just crazy because when I originally said those heads need to go I was talking completely stock. Stock for stock they are bottom of the barrel. With enough port work I could make my vortec heads look like the expensive fastburns... but I wouldn't sit here and tell you my vortec heads are better than the larger aluminum fastburns because I compare things by removing the variables... not adding them.
So please, for the record, remember that I think his performance is great but that I don't like how you all are comparing things and deriving conclusions. Last time I checked there wasn't a van with a 350 TBI and vortec heads tested in the 1/4 mile . So I'll leave you with that. I know it's personal and please don't take it too personally. I'm just playing devils advicate since nobody else wanted to play the role.

kdrolt

A two minute web search revealed:

http://www.stancy.ehc.hu/Crash.htm

NHTSA Crash Test Results For 1997 US NCAP

year........vehicle......................... lbs weight
1994-95 Chevrolet G20 Sport Van-- 5031
1987--- Chevrolet G20 Van-- 5456
1988--- Chevrolet G20 Van-- 4872
1992--- Chevrolet G20 Van-- 4826

The driver + interior stuff adds weight. So Fast355s claim of 5300 lbs measured weight is in the correct range. It's not difficult to do a sensitivity analysis by running several different weights to see how it affects the outcome, in this case, of acceleration runs modeled by computer.... as a way of verifying both the track run and the engine output. And a 5000+ lb brick-like truck will be slow with only a mild cammed 350 pushing it. It's not an excuse -- it's just a fact. Blah blah blah.

If you don't like the flow tests, or the dyno tests, then deal with the track data. If you don't like, or know how to deal with, a 355 with TBI running 15.7 in a 5000+ lbs van (or use the 1/8th mile data, he posted that too), to extrapolate engine out put or for comparison with a 3rdgen Fcar then use Dyno Don's tests of his 3rdgen Fcar. He ran 14.1 @ 9x mph before porting, and 13.7 @ 101 after porting. You should be able to estimate a reasonable weight for him + car and then use +/- 100 lbs to get the spread. His runs were using stock TPI, stock/ported 193 heads, LT1 cam, and a slightly improved exhaust he had laying around. This is just computer modelling, via Newton --- as a way of sanity-checking dyno AND track data, and your skills at ECM work show you know how to use the computer. QuarterJr or CarTest or any equivalent sim tool will work, so you don't need to code-up the force-and-drag balance yourself. So this should be a snap for you.

Finally I never said the 193 heads were a gift to TGO performance, as you have implied, so you should either get help with your reading skills or skip the snotty know-it-all remarks. I have steadily maintained that they were better than the junk you/others claimed they were; I claimed that they are on-par with the iron L98 heads if no porting is done to either. I claimed that they are, after adequate porting, on par with the L31 Vortecs and probably better than ported L98 iron heads. Period. Re-read the thread and tell me where I said anything different.

None of those claims existed on this forum one year ago. I used Thirdgen-measured data to back up my claims. I used math-based engineering analysis to further make the case. There are better heads (but more expensive heads) that you can buy, that flow better off-the-shelf with zero porting involved. I already knew this, so did you. Those heads might be overkill if the rest of the TBI chain (TB airflow, 2 injectors) limits the engine output, so it might not make any sense to buy expensive aftermarket heads. That's an OLD reason used by many people who criticize TBI in the first place, because there will be a ceiling on performance that 2 injectors and 2 small diameter air bores will impose. That's not even including the lack of port injection.

Let's agree to disagree, or take this offline.

So long as the data keeps coming, I will be interested to see if it agrees or refutes the info that appears above in this thread.... and I'll post on it either way. You have many objections to what's been written here -- fine. Then instead of linking us/me to the "stickers and excuse" people, why not spend your time here doing analysis of the data. You wanted baselined track data, you have it. Dyno Don is still around, you can PM him for the details. Use your education and post something useful, prove or disprove (using Dyno Don's baselined testing) my claims as I stated above.

EDIT: You like baselined data: on the flow bench, on the dyno or on the track. I agree that it's great stuff if you can get it. So you could compare Dyno Don's results to yours, i.e. his car to your car. Both cars were 3rdgen Fcars, so no worries about 5000+ lb mystery weight Gvans. Both use(d) LT1 cams IIRC, both had modified exhaust, and both used skillfully retuned ECM (his, yours). Both have track data! He ran stock TPI atop ported 193 heads. You ran TBI atop stock L31 Vortec head + manifold. You both ran the quarter mile. Sure the tracks are different, but no need to pump excuses into the mix --- there's enough similarity to sensibly discuss it.

TPI gives a big fat torque boost (approx 10% extra over TBI) somewhere near 3000 rpm but it's also restrictive at high rpm; you've posted on that very subject before and I agree with what you wrote. I doubt your TBI is that restrictive, knowing you, especially after your L31 swap. We also know DD baselined his car on the unported stock 193 heads and ran 0.4 sec slower (he also posted the mph but I don't recall what it was. It's on TGO somewhere). So you can directly compare estimated power output via baselined track mph trap speed, his and yours. We also have his rwhp dyno tests, also baselined (210 rwhp unported to 250 rwhp ported).

It's easy enough to sanity check among all those pieces of baselined data to see if they are consistent, and to compare with a similarly equipped L31 car (yours). So it's still a good comparison, especially using your metric of trap speed in the quarter as an indicator of peak power.

Fast355

iTrader: (2)

I am afraid it takes more than 300 hp to pull me to a 15.6 quarter mile and even more torque considering 3.08 gears. Need proof here you go. I was running a full 1/2 second faster than a new dodge truck with the 345 net HP Hemi, that truck weighs 5,300 lbs as well and has the advantage of a 5spd automatic. I am 1.4 seconds faster in the 1/4 than a Silverado with the 295 net HP 5.3 and it weighs 5,200 lbs. I practically tie the newer Nissan Titan in performace.

By the way a stock TBI 350 G20 w/ 3.42 will make the 1/4 sprint in roughly 18.5 seconds @ 68 mph.

http://truckworld.tenmagazines.com/T...-4way-num.html

JPrevost

There you go again with the comparisons. Did it ever orrur to you that the 5 speed automatic might be sucking up more horsepower than your 4 speed? Or that they're running with cat-over temp protections which = not the rated net horsepower. Or that the drivers were really crappy... or that they've got traction control, etc. Stop comparing marketing numbers. Now if there was a 345hp hemi in your van and it ran a 15.6 then it would be more creditable... more being the key word. All I'm saying is don't get caught in the numbers game and then comparing it to engines in an f-body... see where it gets crazy? I used to come up with excuses for my times but that's all they are, and I never EVER said I was making x horsepower because I was turning x mph. All anybody needs to know is my car is about 3550lbs and the 1/4 mile performance. Obviously I'm making more than stock... and I got a baseline with my motor. You could go to the dyno and pick up 10hp just from tuning, then go to the track and run slower ET and lower mph... why? Because dyno tuning isn't the same as actual tuning. It's just that crazy here in reality. Too many variables to start coming up with horsepower numbers.
Also, your weight is reasonable but from an online calculator 5300lbs and 87mph is saying 269fwhp! And so yeah, the gears and aero might be hurting the van but that's the calculator, lol.
I like the comparisons between the other trucks, it gives you a good idea as to how much average power you're putting down. I'd definatly say you're upwards of 300hp but that's with at least a 15% error either way! Oh, barn door aero as if the other trucks don't have the same problem . Truely you are probably putting down more power than an LT1 but I wouldn't state it as fact... until you've swapped in an LT1
Good luck with the engine build and if you need help with the chip side just let me know, I'm here to help.

kdrolt

If you were a mechanical engineer, or a physics major, and if had a better understanding of forces and dynamics, you would know that it's a completely legit way to compare performance across different vehicles... especially when the engines are the same size (350) or close to being the same size. You are stuck in comparing the track trap speed (or track data) of only 3500 lb Fcars having a L31 head 5.7, by your own argument. That doesn't mean anyone else here has to be similarly stuck.

Which suggests that EVERONE who doesn't use YOUR methods is making EXCUSES. Hummm... that must mean YOUR WAY is always the RIGHT way. Yes, I can see where it gets crazy.

YOU don't have to work with numbers (of any kind) if YOU don't want to. That doesn't mean I can't, or that Fast355 can't or that anyone else here can't. When I work with "the numbers" I always qualify my comparisons with the assumptions I made, or cite the software I used, or both to back-out the torque and power. That's what you do when you do engineering analysis, in the real world, and that's btw the SAME thing they do in any firm that designs a car before it gets built. That goes for handling, braking, thermal analysis, acceleration, fuel economy, vibration, noise etc.

Dyno tuning isn't the same as track tuning because the inertial forces aren't present on the dyno. It affects carbs and TBI more than port FI. I already posted that 1-2 years ago in another long thread. I explained why it was so because no one here had done so. That argument isn't a valid reason here though.

Maybe your numbers get crazy for you in your reality, but I don't have that problem. You can do a lot with the numbers "game", so long as you know what you are doing and if your assumptions are reasonable, and it also helps to run several different scenarios (e.g. slightly different vehicle weights, as mentioned above) to cover the contingencies.

Here in the real world it's called system modeling and it gets done all the time. This just happens to be system modeling, with Newton's law as the framework, on different vehicles. System modeling of that type, using Newton, was good enough with antique computers to get men to the moon, and back, in 1969 so it's certainly good enough here for performance comparisons of cars/trucks.

Hey, you don't use the excuse that ECM work is crazy because of the numbers in DIY ECM-land, and that's an area you know a lot about -- so I'm likewise not letting you off the hook here by suggesting the same thing.

Oh great, you actually agreed with his reasonable (vehicle) weight though you didn't acknowledge why (because of my post replying to your assertion that his weight isn't valid.) You're talking out of both sides of your mouth.

LOL !!! Excellent, you chose a calculator that's a one-line equation calculator that uses trap speed, vehicle weight, and fixed constants within it. Did you know that those fixed constants apply correctly to only one type of vehicle, and that they are a poor approximation for any arbitrary vehicle? Picking that one is tantamount to a hack job... but you already know that.

Why not post the URL for the one you used so we can all sanity check it ourselves? I know I'm making you look bad, but I am trying to be polite about it.

You sure know how to nail the math: JP's answer is somewhere between 255 and 345 hp. That's what I call damning someone with faint praise.

No, we know you wouldn't.

And you are doing a fine job.

xlwhellraiser

iTrader: (1)

I think its the end of the world.
Here is all the bickering and crap.

Do you know that ever since I got on this forum, its been hard to get the right information. Its easy to get the wiring diagrams or what this does, and what that does. But, engines have always been the problem. The numbers, the flow. No one trust eachother, and everyone has their own opinion.
Did it ever occur to you that there are soo many variables that you have to count in?? Did it ever occur that numbers from factory can be used to compare your numbers??? Its easy, dyno it and take it to the track. Now, thats the numbers that you are doing and thats it. If you think there is a problem than change it.
The world is ending people, no one likes eachother, everyone always disagreeing, no trust. Please, TGO get it together and lets make some f-bodies fast. Not like "your 193's are crap". Its easy to say that, but swirl ports were ment for something and they do what they were ment to do. If you port them, they will do what they were ment to do a bit better.

You can achieve anything that you want, just don't limit yourself.
193 are good heads, and they will be more than enough for street performance.
Now, if you have money than go for better ones. Do it.
There is always something better and faster outthere, a fact of life.

Do with what you have.

shaniac

hi 355 you seem to now alot about 193 heads . i race a stock car with a 350 with 193 heads 194/ 1.50 valves , .40 over K.B. pistons, 480/480 lift hyd cam,torqer 2 intake and headers. we are not aloud to port or polish or port match.the car comes off the corners really good but and the end is a dog. about 5800rpm. This year i am putting 2.02/1.60 valves 507/507 lift 247/247 dur. cam with 1 lb balancer. will this help ? thanks

89bowtiepastya

Hi, I bought an L05 out of a 90' K1500 and it has the 193's I was planning doing some garage porting to spruce them up for my Camaro. Do you have any pictures of the finished product or any tips for a newbie to porting?

Thanks,
Evan.

89bowtiepastya

Fast I'm impressed by those flow numbers I entered them in desktop dyno on the engine i was planning on builting and I got 384hp @ 5500 and 404tq. @4000. I was selling my 193's and I changed my mind now, I'm gonna take a wack at grinding them. I'm a newbie and I have some junk 293 heads laying around that I'm gonna practice on. Any tips would be really stoked.

morepowerjoe

What would happen if you completely grind out the swirls? Would they flow better up in the higher rpm range?

belaw

First, I'm sorry for dredging up an ancient thread, but its the only one I've been able to find discussing flow numbers for "193" heads. I've read that stock these heads outflow Vortecs at low lift. Is this correct?

Before anyone jumps in about how these heads are junk please understand that I'm looking to install them in a carbureated 327 SBC powered Toyota FJ40 (Jeep style 4x4) with 4:11 gearing and 33" tires. This engine will never see 5,000 RPM and I'm only interested in bottom-end torque. Vortec heads are also an option.

Does anyone have stock flow numbers for these heads? While Fast355's numbers are very impressive porting is outside my experience (and budget!).

Deweywolf

iTrader: (1)

I dont have hard #s for you, I just have my own limited personal experience. I am fighting with these heads im my car right now. Everything I read points out that these are not performance heads. This seems to be true, my car does not out run much. What it does do is smoke tires all day long. I got this great low end off the line instant torque. The suburban I pulled it out of was the same way. 88 suburban with 36" super swamper and you could smoke the tires on a whim. So for cheep easy low end torque I'd say go for it. The other thing is that most of the 87-94 blocks that these came on are factory roller blocks.

belaw

Smoking a set of 36" mud grips is no small feat!

Any idea how the swirl port heads compare to Vortec's for low/mid range torque? Personal impressions are probably more value to me than numbers anyway!

Deweywolf

iTrader: (1)

I know that everything I've read says the the easiest way to wake up a TBI is to put Vortec heads on it. I'm going to build a Vortec TBI, unfortunately I don't live in the country right now so I wont be able to build my engine for another 2 years.
Vortec is cheep good power. Swirl port heads are a dime a dozen (dirt cheep) and they are great for trucks for their low end torque as far as towing goes.

89-S-dime

iTrader: (3)

dont mean to bring up an old thread from the dead, those flow number on the exhaust side are insane! best I got with a set of 083's was 168.3 @ .500 on the exhaust, and I spent more then eight hours porting mine , good job fast355 I am impressed!