Done the research and have differnet opinions about this. Granted the current one that I have could be a whole bunch better (if thats a word) needless to say have a 90 2.2 TBI that is boosted running aroudn 5lbs of boost and 9psi at the track, question is this. looking at the venom intake manifold that provide better flow ect. and read up on a few posts that were dated back in the day that its decent for forced induction applications, but when you get into the newer 2.2/2200 cars they are a wast of money. granted they are around 500 bucks the last time I checked, but regardless of the looks (which is a plus) but the functionabliity is what I'm in question. any advise would be great.


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ive never even seen nor heard of a 2.2/2200 OHV venom intake....

u sure they make em?

z yaaaa wrote:ive never even seen nor heard of a 2.2/2200 OHV venom intake....

u sure they make em?

x2



PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

before the venom-perfomance.com reconstruct of thier website, they had a PDF file that lists out all of the applications that they are in tune with. and believe it or not the 88-92 TBI was infact listed. (as shocked as I was) I called summit racing (which is a distributor for them) and they infact make em.


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Well... everything N/A sort of falls apart when you have boost. It's true that an airflow increase is an airflow increase, but when you add a turbo to a mild street engine it suddenly makes hours and hours of work looking for the smallest gains worth less. As far as airflow increases with TBI, if you could find a 2.0 / 2.2 TBI which used the old model 300 TB those have a significantly larger throttle blade. I believe the TB you're using now is called a model 700. There's also a model 500 which is like the 300. I'm not sure, but maybe some of the early S-10's came with the 300??

pictures of model 300 and 700 TB

I never would have guessed that, so what your saying is ( and yes your right I have the older model of 700 which is a winchester TBI). So what your saying is I can replace my TBI from this is what I currently have



to.....




which basicly adds 1 more injector and a bigger blade?


**changes are here**

You are correct, Slow! The '88-up Iron-Duke'd S-trucks came with the TBI at-top in the last posting. As for the dual-throat, there were two different types used: One for the 60* V-6 engines (Exclusively) & one for the 90* V-6 "Vortec" engines (Basically a small-block Chevy V-8 with two cylinders loped-off). The second design was also shared with the TBI V-8s in the time TBI was used in GM trucks & vans ('87-'95) and each unit got correspondingly larger throttle-bores for the size of engine it installed on (4.3L-7.4L. Yeah, you heard me right: 7.4L!). And IIRC, STS (Street Truck Specialties) Performance sells over-sized bore versions of the the 1-bbl unit.


Go beyond the "bolt-on".

I'm not talking about using the dual unit. There's a single bore TB with a larger bore than yours. If it were available on a 2.0 intake, it would have been from the early 80's. I'm fairly certain that the early 2.5 manifold is different, so you'd need to find a 2.0 manifold.

The single TB I'm talking about shares a throttle bore diameter with the TB's for the 4.3, 5.0, and 5.7l engine. A version of it was used in a dual-single TB setup on the 82 - 84 Crossfire injected Camaro and Corvettes. The 2.8 dual bore TB is smaller and the 7.4 dual bore TB has a larger bore. The dual 2.8 TB might be cool, but it's nowhere near a bolt on part.

-->Slow

True. And from what I've seen the pre-'88 2.5s used the same design TBI unit as the pre-'87 OHV 2.0. The only difference I can figure (From what I know) is that the ones used on the smaller engines had a different injector. Heck, Holley even made an aftermarket one that was a bolt-on for all the different GM engines that used that model design. But the real problem is that the earlier & later units won't interchange because of different mounting (IIRC). As for the Cross-Fire units, good-luck in finding one of them. Cross-Fire Injection was such a failure (Not to mention rarely-ordered option) that many of those whom ever got a car with it (Outside of the purists) ripped it off & replaced it with a fully-mechanical carb setup.

BTW: I figured you weren't talking about using the dual-bore unit. That's just crazy outside of full-race.


Go beyond the "bolt-on".

For many years the Holley units created more problems than they solved. Poor quality control combined with Holley made injectors caused them to be inconsistent even as a stock replacement. Later years saw some improvements with Holley finally switching to Delco TBI injectors similar to what's used in the model 700.

Quote:

Cross-Fire is a failure, it can't be found, etcetera

.

Is this the same mentality that says "can't make power with TBI" ?


The blue truck has a crossfire equipped 302. Starts and drives, will run across the country (and has). Generally sees 16-18 mpg @ 60-70 mph running 3.90 gears without benefit of OD. There's another setup upstairs in the parts box. Can get more if needed. X-fire is nice system for making usable torque on small displacement engines.

-->Slow

Uh, lemme see if I've got this right... You have a Cross-Fire Injection system on a 302? IIRC the Chevy 302 had a cross-flow ram dual-quad system, so are you saying that you or whomever bu8ilt that truck put a Cross-Fire Injection system on that engine? If it works well for the operator (Although I'm not sure as to what was done to make it do so) then my hat's-off to 'em!

But from what I recall from all the textbooks & builders whom ever dealt with it, it was a failure in that it couldn't really deliver fuel that well (Puddling in manifold), and if it were tuned to keep that to a minimum, it held more promise for power than it could really deliver. "A brilliant idea that was flawed in result." is what was said.

The problems had by it is what pushed GM to develop the TPI (Tuned Port Injection), which was designed to make use of the same operating principles as the Cross-Fire held, but located the injectors individually aimed down the intake ports of the cylinder heads. The result was it made torque like a cross-ram, delivered fuel more precisely (No puddling!) than either a cross-ram or cross-fire system could, and was way more compact. Not to mention how because of first two reasons I listed it made way better fuel economy to boot!

I'm not saying TBI can't be used to make power, because I've seen too-much respectfully to go saying that. I'm just saying that if I were looking to make power with a TBI system, the Cross-Fire wouldn't be my choice. Unless I was going for looks, then I'd have it fitted for MPI and just use the injector-less throttle-bodies as air-valves & air-cleaner supports.

And BTW: The aftermarket Holley Pro-Jection system units, like the ones supplied to Chrysler for use on the TBI-equiped Super Commando (Pre-Magnum) truck engines, used Bendix-made injectors... Like the first (Pre-'82) GM EFI systems used. Just puttin' that out there.


Go beyond the "bolt-on".

Wet flow crossram intakes all have distribution problems at low engine speeds. High plenum volume requires large amounts of acceleration enrichment to prevent leaning. Add large carb(s) to the mix and the problem gets even worse. Those intakes were virtually impossible to make "right" on the street and they could almost never have been cleaned up for emissions.

The Crossfire bridged a gap between carburetors which GM techs were plenty familiar with and the forthcoming PFI systems. The fact that the Crossfire and the TPI were developed almost concurrently can be seen in the 1980 and 1981 EPA certification dates for the first TPI calibrations used in the '85 Vette. The Crossfire intake was designed to provide emissions compliant improvements in torque on a small displacement engine. It was never designed for a 350 although Chevrolet decided to use it on the 82 and 84 Vette engines. It was designed to do a job and it did that job well. To say it failed because technology allowed better designs is no different than saying the Geo Metro failed because the Prius gets better mileage.

Crossfire has small port cross-sections and a fairly small volume plenum. The EGR passage is a raised casting which virtually cuts the plenum in half, a generally bad thing. The lid is so close to the tops of the runners that incoming fuel doesn't like to turn the corner into the port. Without the factory mixture distribution plates the cylinder to cylinder AFR varies almost too much. The Crossfire system will not support over 300hp without some real work, and it's rare to see dyno results in the 400+ range from anything X-fire equipped. It was never intended to be a high performance manifold and comparing with a performance part only demonstrates this.

Crossfire is not a brilliant idea. It's an old idea quickly adapted to fill a need. And it's not flawed in result. It distributes fuel well enough to pass emissions, it provides more torque and hp than the carbureted engines of similar displacement from the same era. In fact, GM likes the crossram so much they used it again when building the L30 and L31 engines. But like the Crossfire of 16 years prior, the newer system is designed to achieve hp and torque with very little room to grow. So I suppose that one will be a failure, too.

The truck above is mine. The engine was built 14 years ago and the Crossfire was installed 5 months after the engine was finished. It's never failed or let me down. The engine was built to achieve a goal and the crossfire is part of the package. If I make any changes it will be to swap out the 2X1 Chevy manifold for a 1X2 Edelbrock SY-1 and a BBC throttle body. But that's in the future...

-->Slow

I'm not saying it was a failure because of technology developments, I'm just saying it's flawed for the same reason you listed in the first sentence in yor last post^. I don't like the idea of fuel puddling since it effects the smoothness on engine operation, especially with any EFI system since part of the idea behind the development of it is to prevent the problems like that were had with carbs.

I may seem a little extreme in that view, and maybe I'm setting my standards too high for such an early piece because of the results had with latter ones, but after so much effort is made to improve over what was (Carburetors), can you blame me? And I agree, comparing Cross-Fire with TPI is like comparing a Cutlass fighter-jet with an A-6 Intruder. But if overall performance is the issue, I'd prefer the better of the two. Wouldn't you?

I agree with your findings about the runner size being too small for the 350, as I've seen a friend try the bold (But foolish) idea of running Ford 260 heads on a 351W(?). Even though he ported them they were still too restrictive & hurt performance more than the compression yielded from the tiny chambers could make. And you are correct... The Cross-fire won't support over 300hp without some work, as I've seen in a Corvette mag that did an article about improving the output of a Cross-Fire while retaining a stock apperance.

True, it was a steppin'-stone for GM in it's days of desperation (Late-'70s thru early-'80s), much like the Olds 260 V-8/THM350C with 4-pin ALDL connector CCC management of fuel mixture dwell control & ESTC that was in my mom's late-'80 (Not late-'80s) Cutlass LS. I could deck the saleman who told my dad "Yeah, it's got a towing package. And this is it!". Ask me how much hair I pulled-out trying to find someone that had a Scantron with a connector that worked with it, just so I could do more than pull code with a paperclip!

Hey... When you do swap to the CFI-style setup, feel free to send me the Cross-Fire pieces. I'd love to have them as a conversation piece to show at local cruise-ins.


Go beyond the "bolt-on".

I'll sell the Crossfire. There's still plenty of demand. I never said runners are too small for a 350 engine. System works good on 350 where high torque and power below 4500 rpm is desired.

If you don't like fuel puddling you should sell off the S10. Injectors fire 2X per cam revolution but valves only open once. Guess that means fuel puddles in intake port on backside of valve. And TPI was even worse since all 8 injectors fire 8X per cam revolution. So much for advances in manifold design. Oh, and did I mention the TPI was designed and certified by 1980? Just because it was put into production after the Crossfire does not indicate it was designed after the Crossfire.

You might want to consider what your idea of performance is. The TPI intakes are lousy for high rpm power production. Long runners and small ports combine to make power drop off after about 4500 rpm on a 350. Spending gobs of cash on aftermarket replacement runners, TB's, and bases brings peak power point up 500 - 700 rpm. Big deal. Throw the intake on a 383 and you lower the max rpm even more. The TPI equipped engine was the greatest smallblock truck engine that GM ever built. Too bad they didn't put it where it belonged.

Carby systems have some exceptional qualities which should never be ignored. Wet flow system with high velocity air and proper atomization can allow lean operation without negative performance. Small ports, small valves, and high vacuum signals all part of the package. Tough to play the same game with injectors spraying fuel at the back of a closed intake valve and delivering a mixture of warm liquid and vapor to the combustion chamber as soon as the valve opens.

I hold the crossram design is not a failure and it is not flawed. It has a purpose and place, and it's generally not on the street. It's similar to a tunnel ram or a 1000 cfm carb. By your measure would a Sprint Cup car or a top fuel dragster would qualify as flawed if someone were to drive it on the street? Poor mileage, fuel puddling, hard to work with... definitely seems like a flawed design to me.

I will agree with you on one thing in your last statement: It is a shame they didn't put the TPI in truck & vans. Many is a time I wished they did (Father had two late-'80s G-series vans at one time, both saw towing duties), and even thought it would be quite a complement to a stroker 305 with the "K"-code '87-'95 truck & van 5.7L engine camshaft in light of what I would be trying to acheive with such a build-up. Otherwise, it seems I didn't receive enough information on it. That's the problem with many of the traditionalists of motorsports-hobbists I encounter: They'll build a carb-system on anything but shy away from dealing with EFI in any nature, including what's-up with their daily driver.

As for my truck, yeah right! If I could afford to sell it I wouldn't be screwing around gathering ideas on how to improve mileage & driveability on a 4-cyl. And a V-8 is totally out of the question. I could never afford an aluminum block, and an iron assembly will make it too nose-heavy to handle well. In fact, I wish I could duplicate Smokey Yunick's Hot-Vapor system on it (Ever hear of it?). If it got 50mpg & produced 250hp in a Iron-Duke (4.00" bore/3.00"-stroke, just like the 302!)/Fiero w/5-speed combo, 30mpg in a 2nd-gen automatic S-truck don't seem unrealistic. The only difference (Change) I would do is to use a TBI-unit instead of a carb for better metering control during warm-up & full-temp operation, just to see if I could eek-out perhaps just a lil' more mileage from it.

Well, I think we've detour'd this thread long enough. I'll leave you now a lil' wiser (Although you some things you mentioned I already knew, just didn't mention I did) and in hopes we can share more at a later date. 'Bye now & best-wishes!



Go beyond the "bolt-on".

Between patents, the 'net, and Smokey's autobiography there's enough info to duplicate Smokey's efforts. I've told you before how to get better mileage with the truck but you don't seem to believe it.

Your AFR is, for the most part, fixed at 14.7:1. Regardless of the tricks you think will magically imporove combustion you'll find only minimal improvements await along that highway, especially without reconfiguring the internals of your engine. With the amount of fuel per part of air already determined, the simplest and most effective approach is to reduce the amount of air consumed per mile travelled. To ensure you have the ability to move the loads the truck is intended to carry, increase the torque output of your powerplant.

As an excercise, try comparing EPA highway mileage for vehicles which exemplify the two approaches to motivating vehicles, i.e. the Honda (high rpm power) and Chevrolet (low rpm torque). For similar displacements, the GM cars win more often than not.

http://www.fueleconomy.gov/feg/2008car2tablef.jsp?column=2&id=15906

Ryan, if you happen to find an intake that uses the throttle body I mentioned, I may be able to supply the actual TB and I can probably come up with some injectors.

-->Slow

slowolej wrote:Between patents, the 'net, and Smokey's autobiography there's enough info to duplicate Smokey's efforts. I've told you before how to get better mileage with the truck but you don't seem to believe it.

Your AFR is, for the most part, fixed at 14.7:1. Regardless of the tricks you think will magically imporove combustion you'll find only minimal improvements await along that highway, especially without reconfiguring the internals of your engine. With the amount of fuel per part of air already determined, the simplest and most effective approach is to reduce the amount of air consumed per mile travelled. To ensure you have the ability to move the loads the truck is intended to carry, increase the torque output of your powerplant.

As an excercise, try comparing EPA highway mileage for vehicles which exemplify the two approaches to motivating vehicles, i.e. the Honda (high rpm power) and Chevrolet (low rpm torque). For similar displacements, the GM cars win more often than not.

http://www.fueleconomy.gov/feg/2008car2tablef.jsp?column=2&id=15906

Ryan, if you happen to find an intake that uses the throttle body I mentioned, I may be able to supply the actual TB and I can probably come up with some injectors.

-->Slow

ok, ever since you made the previous post I've called a few places diligently and can't quite locate one, but I'm still trying.. thanks for your help in advance too!


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I think Nickelin Dimer is right about the intake being found on the 86 and older engines, which means the intake ports are probably very different. And I don't have a manifold like yours here to see how hard it is to adapt the larger TB to it. Hmmm.... I wonder if there was ever a marine 2.0 or 2.2 GM engine.

-->Slow

Yes. The later TBI's used only two bolts to mount, while the earlier 300- & 500-series units used three.

P.S.: Please excuse the tardiness of this response, as I ran-out of postings.


Go beyond the "bolt-on".