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Old 08-26-2002   #1
Dj92GTA
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Angry Track Times

Only got four runs in...

It was like +30C/80-90F out and pretty humid...

First run was a 15.04 @ 91mph

Second was a 15.02 @ 90mph

Third was a 15.0x @ 91mph

About this time running with no air conditioning and the staging lines miles long i stopped and waited for a couple hours and watched for a bit until it got cooler..

Got one more run in... with a chick ridding along I finally got a

14.9 @ 90mph with the best 60' of 2.1...

The damn daytime headlights wouldnt go down so that might be worth something

Of our little group (99 WS6, 99 SS, 97 WS6) that went out I got the best 60'... even better then a couple AWD talons... im just losing patience with the stock TPI and its death after the 1/8th..
i dont want to lose the low end kick but its time to wake it up...
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Old 08-27-2002   #2
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you car is a l98 right??...how the hell is it possible that my lb9 t-5 is quicker....can u post your full time slip so we can campare our 330ft 1/8 and 1000 ftr

there has to be somethin up for your ride to only run a 14.9

did u ice the plenum?
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Old 08-27-2002   #3
Brent87LT1
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A 5.7 auto will run about the same times as a 5.0 5-speed.

The 700R4 tranny robs the HP difference between the two and make them virtually equal. There will probably be some responses to this statement b/c I'm not using book knowlege or stats. This is what I've personally seen time and time again where the truth is: at the track.
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Old 08-27-2002   #4
Dj92GTA
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you are right on the money brent there is only about 15hp difference and about 30lb-ft of torque... they chocked the 350 out with the shitty cam and restrictive top end TPI...

our track doesnt give you the 330,1/8th, or 1000 ft though

in respect the LS1s which have some bolt ons ran about 13.7... and the 97 ws6 was running around 14.5... so we dont have the best track in the world... and it was hot out that day, 2000 ft elevation here as well.... ive ran 14.6 on the g-tech but thats just a testing aid
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Old 08-27-2002   #5
rich88gta
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Dj,
If you want a less restrictive top end you will have to sacrifice at least a little low end torque. There is just no getting around it. I have had great results with a LT1 intake. You lose about 20-30 lbs in the low end but the gain is about 40hp and a much better top end. Its about the same as bolting on a TPIS mini-ram. I was very pleased with my results.

Over all the price for everything cost me about $700. Thats intake, gaskets, injectors, remote thermostat housing, and fuel lines. You will see a huge wake-up after about 3000 RPM's. If your interested and want to know more go to www.lt1intake.com and e-mail the guy that runs the site....he was very helpful and did all the work needed for the swap. It was mostly painless.
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Old 08-28-2002   #6
f-crazy
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im going with a lt1 intake pretty soon...i wanna go through the traps in 3rd and with tpi its dead...i tried that my first run and it was a 15.2
i shifted into 4th at 4800 and ran a 14.8...almost a hlf second by goin to 4th...theres another half second shiftin to 4th...so if i keep it in 3rd and go thorugh the traps at 6000 it will be close to a 14.4 maybe i hope..
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Old 08-28-2002   #7
Krazzycowgirl
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Re: Track Times

Quote:
Originally posted by Dj92GTA
Only got four runs in...

It was like +30C/80-90F out and pretty humid...

First run was a 15.04 @ 91mph

Second was a 15.02 @ 90mph

Third was a 15.0x @ 91mph

About this time running with no air conditioning and the staging lines miles long i stopped and waited for a couple hours and watched for a bit until it got cooler..

Got one more run in... with a chick ridding along I finally got a

14.9 @ 90mph with the best 60' of 2.1...

The damn daytime headlights wouldnt go down so that might be worth something

Of our little group (99 WS6, 99 SS, 97 WS6) that went out I got the best 60'... even better then a couple AWD talons... im just losing patience with the stock TPI and its death after the 1/8th..
i dont want to lose the low end kick but its time to wake it up...
THats not bad at all for a 350 firebird lol

My camaro thats totally stock runs 14.6s (well I went out & got a new chip in her & K&Ns so shes not totally stock lol)
OH by the way shes a 87 Iroc z with the 700r4 tranny
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Old 08-28-2002   #8
Dj92GTA
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Talking

you cant have my low end lol.. i dont know if youd lose that much if you woke it up with a good cam/heads

i just dont know if its sacreligious (sp?) to go ahead and rip off the TPI and put on the LT1 intake..

if I was I would rather go with a stealth ram as its a bit more fitting and I dont know if it would leak as much, my LT1 intake was horrible on my 97 (probably due to the EGR though)...

i still think there is some hope with the tpi... i plan on getting some SLP runners and then gutting the inside of the manifold/plenum...
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Old 08-28-2002   #9
Krazzycowgirl
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Quote:
Originally posted by Dj92GTA
you cant have my low end lol.. i dont know if youd lose that much if you woke it up with a good cam/heads

i just dont know if its sacreligious (sp?) to go ahead and rip off the TPI and put on the LT1 intake..

if I was I would rather go with a stealth ram as its a bit more fitting and I dont know if it would leak as much, my LT1 intake was horrible on my 97 (probably due to the EGR though)...

i still think there is some hope with the tpi... i plan on getting some SLP runners and then gutting the inside of the manifold/plenum...
you can get better Runners like the SLP, Larger Fuel injectors, also go with a ram air system that Comes out where your fog lamps are at.

little changes like that will get you a faster ET
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Silver 2000 GP Daytona Pace car
Newest is a 67 C10 Step side short bed pick up.

2003 South area Rep: Pacific Northwest Camaro Club
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Old 08-28-2002   #10
rich88gta
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I guess the point that I am trying to make is that the TPI system in its stock form is restrictive. That it is the bottle neck of the whole engine. Changing just minor details can result in poor performance and slower times. Especially in your case with a MAP system. Which is super sensitive to change. Adding an aftermarket camshaft is a good way to make more power, but can result in really poor performance for people who are not familiar with what they are doing, or not using the TPI to its maximum by poor cam selection. It has to work with all the other parts of the valvetrain to get maximum results. Here is what I mean. The stock TPI "architecture" reguardless of aftermarket parts/porting, is really...I mean really sensitive to valve event timing. This is due to the TPI design using pulse tuning for that lovable and ungodly torque curve. You could really wake your engine up with a head and cam swap. Just be sure that before you do major work like that you are matching all other components to the ones you will install. As well as have an idea of how to tune the car after the install.
To quote Dj "i dont want to lose the low end kick but its time to wake it up..." So the whole point of this is just how much you want to "wake it up" All the suggestions that have been made are good valid suggestions. Some will move your RPM range up the scale a little while you can see dramatic increases in trap speeds with others. And if you are worried about keeping the car looking original with the TPI and all, expect to pay outrageous prices. That is the only reason that I suggested an LT1 intake. It is super cheap and performs outstanding in comparison to more popular aftermarket TPI setups costing $3500 or more for the entire kit.
On a different note, if you do plan on doing a head swap consider what you will be swapping. If you decide to go with an aluminum head you will change the thermodynamics of your engine. So to counteract that you will have to ensure a higher compression ratio. Just thought I would mention that

Whew....sorry for bieng so long winded. I just love talking about the TPI in general.
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Old 08-28-2002   #11
f-crazy
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the myth that low end torque will suffer with a lt1 intake is false....the lt1's made there peak torque at 2400 so the low end is there and stronger then tpi...however, between 3000-3500 you will loose a little bit not much maybe 20 ft pounds.and it will scream about 4 grand and pull like a raped ape to 6 grand....
along with rich said a fully optioned tpi will run ya biiiigggg bucks...although you can run mid 12's with it....(ive seen a guy with a 305 running mid 12's on a n/a tpi) so it can be done..but it will cost you...400 for the base 350 for runners the cam heads and you over $2000...and if your goin with a set of heads....have your l98's ported...they WILL rival the afr's 190 and they will support 565 horse...take un to a machiene shop and in 10 hours and 400 bucks later youll have the same heads for $1000 less then the afr's....put a healty cam in it and a lt1 intake and youll be knee deep in the 11's...for the price of a lt1 intake a cam the macheine shop bill and headers.....figure 1500 bucks....
with the stealth ram hood mads are required for it to fit correctly....and its more money for that over the lt1...of course its up to you cuz its your ride but what ever you decide...dont buy heads! port your l98's and youll never have to buy a set of heads again...with the setup ive just described youll be in the 450-500 horsey range...now are u gonna miss that 20 ft pounds? lol

in a couple months im gonna pull my 305 rebuild it put a juciy cam in it have my heads ported and put a lt1 intake on it....and i bet ill be eatin ls1's breakfast...imagine the look when i tell um they just got smoked by a 305 lol....then ill put a snort of happy gas into it and go huntin for z06's
god i love 305's lol...so underrated just the way i like it....expect the unexpected
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Old 08-28-2002   #12
rich88gta
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Just to touch on what you said f-crazy....where did you see numbers that even heavily ported l98's will flow as good as AFR 190's? Dont get me wrong....I agree that l98 heads will flow plenty for a stock or even slightly modified TPI setup. Properly ported that is. But the stock heads intake runner volume before any porting is aprox. 165cc. whereas stock AFR's are at 190cc's. That would take an extreem amount of porting for the stock heads to reach those numbers. I am not sure its even possible without grinding into a water jacket or somthing. I have seen flow bench numbers on stock heads flow up to 235CFM but thats after being heavily ported. AFR's reach into the 260CFM catagory out of the box. It doesnt seem like much but when you talk about a stock TPI flows at around 200CFM the stock heads wont flow well for a well modified TPI aplication. You just dont have the room to grow.

To go further with this..... Stock runners flow at 200CFM aprox.
A set of accel runners flow at 242CFM. The stock base w/runners flow at about 198CFM and the stock base with accel runners flow at 213CFM. We can go further with this... but buying just off-the-shelf TPI equipment you can see how easily it would be to start flowing at the Super Ram or LT1 levels of 280CFMs. All we looked at was runners and you saw an increase of 13CFM. That is no joke. Being that the major bottle neck is at the base. Slap a accel base for a gain of up to 230-40ish or go further with a tpis big mouth.

Ok Ill shut up now......
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Old 08-29-2002   #13
f-crazy
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dont shut up you know what your talking about...i didnt beleive it either untill i read tha article...theres a guy on thirdgen.org that ported them out and he got right around 250 cfm and the port sizes were heavily ported i beleive to the likes of 185 or so...he had them flow tested at right around 250 with 2.02 intake valves and 1.9X exhaust....he figured it out using afr's charts that will support 565 horse..and the thing with the lt1 intak is that youll never have to buy another intake again unless you want to run 10 seconds....

so what your saying is even if you have a fully optioned tpi base runners and plenum you still wont get the flow of an lt1 intake?..thats when the heads become the bottleneck?..even afr 190's wont outflow the lt1 intake then....ill look for the link and post it so u can see for yourself, i was quite amazed...
so as u see dj there is plenty of power for the tpi just how much money u want to spend....the lt1 intake will be the last youll ever buy though
i have a questoin for u rich....when i rebuild my 305 with a comp cams XR258 headers and the lt1 intake and my ported heads..what size injector should i use?....i dont think my 19# will be enough what about the l98 injectors there 22# right
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Old 08-29-2002   #14
Dj92GTA
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ok.. what if I get a set of SLP runners, port them out a bit... match the plenum and gut the hell outta the base, what would that flow in comparison??

i drove my roommates WS6 LT1 and I forgot the way the cars just dont die at like 5 grand i think i should stop caring about the TPI image... i could just lie to people and say it was a special edition that came with a prototype LT1

so with the LT1 intake should I then follow the LT1 modification guidelines... bigger cam, headers, and ported heads... i would just get an extra set of L98 heads and port them to ~250cfm

i just bought all the stuff to do the chips so tuning is not a worry here... id like to see 12s
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Old 08-29-2002   #15
rich88gta
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Quote:
Originally posted by f-crazy

so what your saying is even if you have a fully optioned tpi base runners and plenum you still wont get the flow of an lt1 intake?..



i have a questoin for u rich....when i rebuild my 305 with a comp cams XR258 headers and the lt1 intake and my ported heads..what size injector should i use?....i dont think my 19# will be enough what about the l98 injectors there 22# right
What I am saying is yes you can get the flow numbers of a LT1(remember all those parts are still unported) just that the characteristics change between intakes. The TPI an LT1 intake design are good ones. It just a matter of where you want the most power and how much you are willing to spend and sacrifice.

I pick out injectors last. They are just too expensive to get wrong. So here are a couple of formulas that will help you decide once you come to that point.....

LBS./HR @ Fuel Pressure

F2=(P2/F1)0.5 x P1 EXAMPLE (40 psi/24 lbs. hr)0.5 x 30 psi= 25lbs hr

Where:
F2= New fuel flow rate
F1= Original fuel flow rate
P2= New fuel pressure
P1= Original fuel pressure

Estimated injector size

CFM x 0.44298/ # of cylinders

Hope these help.
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Old 08-29-2002   #16
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Dj, thats a tough question to answer.....just how much gain are you looking to get? There is no magic TPI combo. Its all on what you want and where you want it. You cant build a high flow TPI without losing some low end. It just wont happen. My suggestion is come up with a plan as to where you want to see your numbers at in your RPM range and decide from there what products/work will be required to accomplish that goal.

As for the l98 heads. That would be somthing I would have to see with my own eyes to believe. A stock head that flows 250cfm???? Even if it is possible(which I highly doubt) that would be just to worrysome for me. I like high flow numbers with a sense of security....I would hate to put $400 into some heads and not feeling safe as to whether or not they will last the next time I drop the hammer.

I know I am a little closed minded when it comes to cyl heads..... I am of a mind that you dont cheap out on the important things, and you cant get more important than cyl heads.
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Old 08-29-2002   #17
Dj92GTA
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seeing is beleiving

http://www.thirdgen.org/techbb2/show...t=porting+part

id like to see around 400+ HP/420+ TQ... id like to it rev under 6000rpm around the 5500 mark peak power

id love to get a set a AFR 195s but they are like 1250+.. by the time I get them up here im looking at over $2400 Canadian, canada sucks !!!

i can rip my stock heads off and I have all winter to make them flow like that... i will get one cylinder ported pro to where i want it then basically match the rest of them to that sample.. get better flowing valves, cut them for some better springs, get some screw in studs and im looking at like $300+ into my heads...

that leaves me cash for headers, a new cam, LT1 intake/ported TPI, subframes(which i plan to build myself), head studs, gaskets, modified TB, bandaids and some LCA and brackets... throw in a tranny cooler, shift kit, and stall in the spring and im done...
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Old 08-29-2002   #18
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ok i promised

i promised the flow numbers for heavily ported IRON L98 heads
theres 3 parts so ill post each part sepretly...these posts can be found on thirdgen.org on page number 17 under the heading "l98 head project"

heres part #1

L98 Iron head project Part 1 (long)
Ok, I promised flow numbers, stock and ported on these heads, I'm running a little behind but I've got the beginning for you. First of all the intake and exhaust ports have all kinds of wierd bumps in them that screw up flow. If I can get my digital camera going I'll post some pics. Second I flowed all the ports on the head and there was quite a bit of difference from port to port, like 10% in some cases. When I'm done they should all flow within a cfm or two of each other (hopefully ).
For those of you who pay someone else to flow their heads you need to make sure of a couple of things. 1 is that they use a radius inlet on the intake port, a lot of "professionals" i've seen don't (lazy b*&***ds) and I tested it on these heads just to see what the difference really was. 20 cfm less on the intake without it! It only takes a minute (I just use modeling clay) and is well worth it. 2 is on the exhaust port, make sure they block off or at leat restrict the exhaust crossover port if they use one of the two center ports. If you don't you'll see an extra 20-30 cfm on the exhaust as the air will blow right through that passage, which it doesn't do on an engine. Don't get me wrong exhaust flows through there, but not at a rate that will really affect anything.
Ok, now that we've said all that I forgot to bring the complete flow chart with me, but the peak numbers were 193 intake and 120 exhaust. I've seen better numbers posted, the intake's pretty close, but I've seen other people claim 20 more cfm on the exhaust. I've never seen it though, the most I've seen on a stock set of these heads is 130 on the exhaust and average seems to be around 118. With my numbers it works out to 62% exhaust to intake flow, which pretty much sucks. I'll try and remember to bring the complete numbers home and post them so we can compare later on. Oh btw the numbers are at 28" of water and .5 valve lift. I'm testing at 6 points from .1 to .6, but the stock heads peaked at .5.
Plans for the porting:
1. There is plenty of room to cut these heads for 2.02/1.6 valves.
I haven't decide whether I'm going to do it or not. Probably, but
I'm going to have to look at it some more.
2. Valve job. This would normally be number 1, but I have to
decide which valve size to use first. The stock valve job is
pretty ugly, so should see some good gains here
3. Clean out all the wierd bumps and crappy casting edges. These
heads are pretty bad so this should show a pretty good gain
4. We'll start into the serious port work now. Go into the pocket
radius the turns, teardrop the intake guide. I may fill the exhaust
crossover passage, once again haven't decided yet. Will open up
the intake port a bit. Should show the most gains from the
pocket work, these heads are reaaaallly ugly there.
5. Move into the chamber and smooth the edge between the seat
and the chamber. I'll blend and polish here, trying to remove as
little material as possible to keep the volume the same.
6. I'll polish the ports so we can see how much gain that is or
isn't worth.
My plan is to test the heads after each modifcation so that we can
see the progress and differences. I'm hoping to get 254 cfm intake and 180 on the exhaust. Get there and this would be one serious set of iron heads, capable of over 500 hp, and with smaller intake ports to keep the velocity up.
I'll also try and keep track of my hours so I can offer an estimated price on what a shop should charge you, or how long to do it yourself. Then we'll know if it's worth it or to just scrap 'em and buy aftermarket.
Feel free to offer advice, comments, and definitly wish me luck these heads will be going on the Iroc project, I've decided to see how much power I can get cheaply on that one.
John
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Old 08-29-2002   #19
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part #2

To start with I had a plan but it got changed around a bit. First I decided to hold off on the valve job. I also decided to do some porting first, get the numbers, then cut for the 2.02's, to see if they really make a difference, instead of cutting them first like I was going to.
So I did step 3 of my plan first, and part of step 4. This amounts to removing all the wierd bumps in the passages, a little bit of widening of the port at the pushrod pinch, some light pocket work, and a light radiusing of the short turn and valve guides. I also deburred the rest of the head, and radiused the oil drain back holes since I was going. I just left the ports rough cut and did absolutely no polishing. So here are the numbers, all taken on our superflow 300 at 28" of water.

Stock Stage One Port
Lift Intake Exhaust Intake Exhaust
.1 53.9 41.6 63.5 41.2
.2 111.2 95.2 115.2 87.7
.3 157.3 112.4 163.2 122.7
.4 182.0 116.6 198.2 151.6
.5 192.0 116.9 224.8 161.3
.6 193.6 117.6 228.6 170.7

As you can see, with just a little bit of work (about 2-2 1/2 hours for a complete set of heads, if you've got good tools, longer if your gonna use a dremel) we picked up 35 CFM on the intake, and a great gain of 53.1 on the exhaust, which takes our intake exhaust ratio to a much better 74%, instead of the stock 60%. And this is without touching the factory single angle valve job (which really sucks on these heads).

So far we've seen an 18% improvement on the intake and 45% on the exhaust with just basic work that anyone can do. Just take it easy with the grinder and don't remove too much metal. Air flow velocity is also up as well.

My posted goals were 254 on the intake and 180 on the exhaust. As you can see we're well on our way there, especially on the exhaust side.

Coming up I'll do some bowl work, get a little more serious in the pocket, and at the pushrod pinch. I've got a lot more meat to smooth out the short turn radius and do some more profiling of the valve guides. Also a valve job, which will really improve low lift flow especially. Match to the intake ports (I'm doing the LT1 intake conversion). And finally cutting for 2.02/1.6 valves and unshrouding them. Also if you look down the ports you'll see a bad area where the rocker studs come down. It's a pretty big dip and I'm sure is hurting flow, dunno what, if anything I'm going to do about that yet.

Theoretically our stock heads will support up to 400 hp with the right matched components. Our lightly ported heads will support up to 470 hp, now on a 350 you'd have to spin it to between 6200 and 6800 rpm to get that kind of power (once again theoretically). On a 400 it would be between 5500 and 6000. Desktop dyno shows an increase vs. stock l98 heads of 20 hp on a stock tpi with small tube headers. More than 40 on a 383 with lt4 hot cam and intake mods.

Couple of notes here:
All theoretical math is done with accepted formulas provide by superflow.
All flow numbers are corrected to standard atmospheric conditions. Not much of a difference (about 1%).
A valve job would help these numbers a lot, the reason I'm not doing it til later is 'cause most of you wouldn't be able to do one at home, and I don't want to have to do it twice, so I'm waiting til I get the heads cut for the bigger valves.
This level of porting would cost you around 150-200.
In part one I mentioned blocking or restricting the exhaust cross over port to make sure you got accurate flow #'s. I tested the difference on this so you could see it. My numbers are with it blocked, WITHOUT it blocked the exhaust flow at .6 on the stock heads was 150.6, a substantial difference that you wouldn't see on a running engine.
My damn camera still isn't working, soon as I can I'll get some pics up for ya.
A variable speed of some kind is imperative, a fixed speed setup just doesn't give you enough control. Car craft had a neat trick where they just hooked there single speed unit up to a dimmer switch if you don't have a variable speed unit.
Think that covers it for this installment. I'll keep you posted.
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Old 08-29-2002   #20
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part #3

Ok now for part 3, In this installment I have further ported both the intake and the exhaust ports, as well as done a valve job on the intake. Time did not allow a valve job for the exhaust so expect further gains there. The porting consisted of extensive bowl work, , substantial profiling of the valveguides, further opening up the pushrod pinch area, unshrouding the valves slightly, matching to a felpro 1205 intake gasket, thorogh polish of the exhaust, slight polish on the intake (need to keep the mixture stirred), raising the roof of the exhaust port .1 inches and opening it considerably, also some blending of the valve ridge. A lot of reshaping of the entire port was done here as well. The valve job consisted of a standard 3 angle valve job and a 10 degree backcut on the intake valves, exhaust valves were not touched. I also polished the chambers, though this won't affect flow, it will make the heads less detonation prone.
numbers are:
Lift Intake Exhaust
.1 63.8 41.4
.2 120.6 88.2
.3 178.9 124.1
.4 215.2 154.3
.5 240.1 171.8
.6 241 180

As you can see these numbers are substatially up from stock across the entrire lift range, and a significant improvent from stage 1 porting. we are still arunning a 74% intake/exhaust percentage, which is good, though not excellent. These nubmers put us up 47.4 cfm on the intake and 62.4 on the exhaust. The exhaust is right at what I set as a goal (with once again a bit more to come with a valve job) the intake is 13 cfm short of the goal. I ahve not cut for larger valves yet either. Also these are the stock valves, not the ones with a high flow design, so more gains could be found there. According to Superflow we are running over 90% of the flow potential of these heads with these valve sizes on the intake which is excellent and almost 100% on te exhaust which is incredible. For comparison I am attaching a flow chart from the afr 190 heads. As you can see the numbers are getting close. Right now these heads will support 490-500 hp NA.

Things yet to come:
Pictures!! Took some 35 mil shots, digital still screwed, soon as I can get them scanned I'll get them in.
Exhaust valve jnob, maybe the expensive valves.
Larger valve size (maybe, haven't decided yet) I'l probably do this, but only if time allows. It's also something you can't do your self if you don't work in a machine shop.
I might also be able to do some more short side work, not a whole lot though.
All in all maybe another 10-20 cfm depending on what i do.

Conclusions:
The often debated point is whether these heads are worthe working on, at this point I'd have to say the answer is a definite Hell yes, they now way outflow the aluminum L98 heads, performer and performer rpm heads and e-tec 170's, dart iron eagles(small version), vortec heads, well pretty much everything with an intake size of 180cc's ore less, and are right up there with most aftermarket aluminum heads in the 180-200cc range, compare at www.chevyhiperformance.com.
At this point though you better be prepared to do some work and/or spend some money, but you've got the bragging rights of being able to say you did it with stock heads and they're a hell of a lot cheaper than a set of AFR's. The flow velocity on these heads is excellent right now as well, so you'll still get good low end torque.
The down side is that now if you were to pay someone else for thsi porting work your into the $450-550 range. Add new valves and watch the price climb. BUT if you can do the work yourself you have a kick ass set of heads for chump change.

I may do a stage 4 on this series, I may just stop here, but either way I hope that it helped you all out. Good luck, and remember as always, drive fast and take chances
John

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