Zion,

did you ever check the block casting numbers ???

 

Yeah i have the centerbolt.

WHY DONT YOU LIVE IN CANADA!


Yeah i figured it would be more around the $200 range. Thats alright though. Cam swap sounds easier then i thought...



EDIT: I havent checked the casting numbers yet. This is Iroc22's old engine, so ill ask him what it was.

 

If you have a TPI engine you already have a superior cam to the TBI cam. I would save the cam swap for when you take the engine apart and do heads etc. Exhaust, intake, gears and posi then you can practice some prom tuning on it. If you can't hit 14's on this combo something's dead wrong.

 

sweet!

what kind of 14's?

low? *crosses fingers*

 

I would have to say yes. Better intake, headers and 3in exhaust, 3.73 gears and a posi, I would put money on it I could get this combo deep into the 14's without much effort. After that I would buy a nitrous kit for the carb intake I swapped on and spray the thing into the low 13's or 12's until it exploded dramatically

 

dramatically? i like the sounds of this...

lol


seriously though, i think this will be my plan of action. Should i start a new thread now to find the best setup of those parts and installation?

 

Why don't ya do a

 

there is to much information on these boards!!!


besides, everyone kept telling me to start one...

 

does anyone know if my engine could handle a 50 wet shot mulitple times after all the other mods that have been mentioned are on?

 

Dyno Don ported 193 the (350) casting lightly and briefly, and posted the results on TGO before anyone else did. He obtained 196/183 cfm. Stock was 178/146 cfm.

On the same head type, Fast355 got 224/216 cfm with more porting effort.

HRM (via Westech porting) got 208/190 cfm on 4.3 v6 heads. Stock was 135 cfm on the intake side. A 4.3 is 3/4 of a 350, so the results are applicable to the comparison with the two above (both 350s).

That's three different tests by three different people on the same basic GM head design. The results are not identical, but then again the porting level/effort on each was not done identically so no surprise there. The trend, however, is clear in a peer review sense. The results have been reproduced and they are more than remotely close. And they're close to par with ported iron TPI heads.

 

Problem with porting swirl-port heads is, you gotta grind about a half-pound of metal out of each intake port, to get rid of the swirl-port ramp. Then once you do that, the rest of the head isn't too much different from any other head.

Where you run into trouble, is that porting costs money. Time, lots of it; and if you want those big numbers, it needs to be time from somebody that knows what they're doing.... and those people aren't cheap. So you pay for lots and lots of hours, and they're mighty expensive hours. Except just for the "thrill" of getting swirlies to run good, you're money ahead - LOTS of it - to get better castings to start with. Junk stock castings are cheaper than flow bench time.

 

Really? You must know this from experience then, with your scientific background. You've claimed ramp removal and a half pound of metal. Applying science to your claims:

A half pound is approx 226.8 grams.
Iron density is roughly 7.8 g/cc

So you're talking about removing 29 cc from each intake port (226.8/7.8). Stock ports are approx 168 cc, so by your "argument" the port size would go up from 168 to 197 (168+29) cc.

That's a big jump in port volume, which is a problem because no one that's ported them has removed the swirl ramp. It makes no sense to do that (they'd become the functional equivalent of iron TPI heads, which you could have started with had you bought them) and you lose the benefit of the swirl in combustion speed.

So ramp removal is overstated by you (no one has done that), and you also overstated the mass or volume of the metal removal.

Example as proof:
Dyno Don, who actually ported a set of 193s, said he removed about 7 cc worth of iron in this thread. 7 cc is a lot less than 29 cc.



Sorry but it's no trouble, and the cost isn't large if it's DIY porting. Most people, especially people that own budget 20-year-old 3rdgen Fcars instead of new Corvettes, wouldn't spend the money to have someone else port them.



Porting any heads, incl 416/081/083 iron heads, will also take time. There are threads on TGO that already prove it. And again, people on TGO with ported heads have them mostly because they ported the heads themselves. So the porting=money argument is, like your other points, a weak one.

 

Do most people actually <b>totally</b> remove the ramp in the stock swirl intake ports ?




Zion,
strip some pounds of the car. I would actually try to do some "body work" i.e. actually chassis work, so you can end up with a finished weight of the car.

Ever since I removed my entire backseat assembly I've noticed more body flex sound. Roll cage and subframe connectors will add weight.

 

I too took those courses and had the same outlook as you. About a year and a half ago I couldn't have agreed more. I may have been the biggest skeptic of them all at one point. Then people like Fast355, kdrolt, dyno don, Dewey316 started developing trends and started to produce flow, track, and dyno data to validate their claims. Then they backed it up with Fast355 running 15.5's in a 5500lb van and Dewey making almost 300hp on untouched 187 heads with a full exhaust, mild cam and tuning (ran 13.9 with same combo). They went into great detail about their combo's, theories, flow data, track data, and dyno data. The hearsay that I previously took at face value didn't have any hard data to contradict them. I had a hard time accepting it because to many people for so many years had bashed these heads. It was easy to hop on their wagon. I am not saying these heads are great by any means, and they are limited for all out performance, but the data produced thus far does not indicate that a TPI or stock untouched vortec head is that much better for a budget build. I realize that vortec heads have great flow out of the box but they come at some cost ($300 to $500 + intake). Our peer review has concluded that chip tuning is the bottleneck for all TBI modders. It has plagued the TBI crowd for two decades because people never truly took the time to understand it and learn it. They would throw miss matched parts at these motors and fail to do the necessary tuning. It was easy to blame the heads after you replace everything but them. There is a some great new stuff in the DIY PROM world which makes tuning these cars easier. More and more trends are starting to be seen as the afore mentioned people educate us on tuning and swirl port porting. This is an exciting time for budget LO3/LO5 builds.

That was a bad typo on my behalf and I did mean '88. There are a few original owners of '88 LO3 cars with 416's and one or two '92 cars with 081's. I have no reason to doubt them and they are here somewhere in the archives of TGO.

 

I would have to agree on the tuning side with these cars. I didn't tune my 91 RS but I did up the fuel pressure and manually advance the timing, this made a literal WORLD of difference with my other mods (exhaust and no air cleaner, no I didn't run it this way just played with it). The fuel pressure and timing mods were basically a "band aid" fix for good tuning. There's also a bunch of stuff you can do to those TBI units to get them flowing alot better (grinding off the big walls in front of the bores, grinding down the throttle shaft, putting in 3 or so injector spacers). I have 2 or 3 of them hanging around just in case I ever get a hankering to mod on one. BTW I sold the adjustable fuel pressure regulator I made for one to a kid in an 88 Firebird with a TBI and it made a huge difference in his car. In Zions case however we must keep in mind he DOES NOT have the swirl port heads anymore, he now has the 305 TPI heads, cam, and block. This is going to make his car respond much better to the smaller mods he can do and I'm sure it's in need of a chip tune.
PS This thread is massively long and has changed topics like it has ADHD. I hate to admit it but I keep coming back to it like it's crack I'm surprised one of the mods hasn't closed it yet.

 

No!

I already said it above --- no one that I have ever seen, or heard of, has removed the ramp entirely. No one. It would be a massive undertaking that even I would not attempt to justify.

Anyone that hard-over on ramp removal should just get rampless ordinary iron heads to begin with (contemporary example: 083 casting from an iron head L98)

Most of the owners on TGO that have ported heads, any heads, have not paid others to do the porting work. They've done it themselves.

 

That's why I asked, because I have an extra LO3 in the garage and I was going to port the heads.

 

what should i advance the timing too on this new block?

also, is there anyone that has already tuned this engine/injection that i could get a chip burned from? Becuase i have a seriously ran out of time for that sort of thing.

Im getting really excited about the possibilities i have now, i cant wait to start adding parts!


will i need this fuel pressure regulator if im tuning the prom ? or does the computer take over instead?

 

Correct me if I'm wrong:

1) Adjustable fuel pressure regulator will be needed.

2) Learn to burn chips, very unlikely someone else will have the very same EXACT engine, including induction system, engine block, heads, cam .. similar yes.. exactly same .. no way

Advance it to probably anywhere between 4 and 8

 

i put it to 6.
is it normal that when i start the car it revs erratically for a few seconds then stabilizes?

 

The weird revving is due to the larger cam, mine did it when I ran the 110 LSA cam, I had to bump the idle up to get it to not die when it was warmed up, you WONT have to do this you have a fuel injection friendly cam, it's just not the same as the TBI cam. You need to do the adjustable regulator it's free and you'll know you did something. Did you ever start a new thread on this? You should start the thread "TBI on a TPI long block" and tell us what all you have done already (I know it's in your sig somewhere but have you done anything new etc.). Do you have exhaust yet? Bumping the timing and fuel pressure regulator are free so you should do those asap and tell us how it reacts to this. Also did you get the prom burning stuff yet? With the TBI you can pull your chip directly out, this will help alot; but remember you need a UV eraser to erase those proms and DEFINETLY get a spare in case you mess one up (I have one here with a broken off leg, junk now).

 

FINE!


i made a new topic
https://www.thirdgen.org/techbb2/sho...hreadid=343158