TCTA

So, me and my step dad are finally getting fed up with this TPI crap, and we're just gonna carburate the motor.
It's a 350 Chevy, any tips on what kind of intake we should get?
Or any other kinds of tips would be appreciated, thanks!

whitedevilTA

iTrader: (8)

Is it a stock 350 TPI? Any reason you want to switch to carbed? If it's not running right currently, just slapping on a carb may not fix it. Just curious.

88 5.7 Iroc-Z

if you do decide to get rid of the TPI stuff, I have a buddy wanting to run TPI on his 1980 Z28 who would be very interested in the intake

fireturd350

iTrader: (8)

You'll need to wire the fuel pump to run if you plan on keeping the electric in tank pump.

You'll also need a return style regulator to keep pressures down. I used a Mallory 4309 return regulator. Carbs don't like 40+ PSI.

You will lose converter lockup unless you install a kit or make your own. Without converter lockup the transmission will generate more heat and lockup just makes the car more friendly for highway speeds (4th gear).

travis401

iTrader: (1)

you also need to sell me the TPI setup including wiring harness and computer . youll need to remove the passenger side wire harness (since its all for the tpi) but keep the one on the driver side. theres gonna be a few wires that cross over behind the engine, but you can just fish those out and seperate them. o and the biggest thing is none of this is federally legal at all.

thafaz

DO IT!!! I had all sorts of issues with TPI; just finished the swap and realized why....26 year old wiring is no longer reliable. That, and the hack and slash job of previous owner(s) didn't help matters at all.

Here's my Jegs laundry list:

1 1 350-2101 INTAKE PERFORMER SBC 129.99 129.99
1 1 555-210002 Int Gasket-SBC-No HC 14.99 14.99
1 1 555-28030 BLUE RTV SILCONE 3-OUNCE 4.99 4.99
1 1 555-83200 INTAKE BOLTS SBC/MPR/AMC 8.99 8.99
1 1 555-15840 CARB STUD KIT 1.5" LONG 5.99 5.99
1 1 720-56 CARB GASKET Q-JET 4-HOLE 2.99 2.99
1 1 650-4309 RET REG 3-PORT GAS 3-12 89.99 89.99
1 1 510-0-80457S CARB 600 CFM E/CHOKE ZNC 269.99 269.99
1 1 555-40002 HEI DIST & COIL, SB&BBCHV 89.99 89.99
1 1 555-40200 IGN WIRES CHEV UNIV/MULTI 34.99 34.99

Notes from swap:

1) I have swirl port 187 heads that were slightly reworked.....the intake center bolt holes had to be hogged out. It was a PITA. Get the intake to match your heads.

2) They sent me the wrong gasket for the carb.

3) Distributor needed to be recurved even with my mild set up (comp 260h, no lope whatsoever)

I finished it literally a month ago....really not that bad if you sit for a night and understand the wiring diagrams in the Chilton's guide. Shoot me an email if you need some pointers.

Faz

one92rs

iTrader: (5)

im not sure why you are doing this. a 350 tpi motor will run circles around a arbed 350 of the same. the only thing a carb does is maybe in some instances make more power up top and that is it. the driveability of fuel injection will be gone.

whitedevilTA

iTrader: (8)

Well....I love fuel injection myself and like TPI for a driver. A carb will run circles around TPI for power though with the right set up. However TPI is great for a street car and if the OP is leaving the motor pretty much stock, I would never swap to carbed.

one92rs

iTrader: (5)

the key words are right set up. it will have to be tuned near perfect. then they need to know that tuning will continue when how and again when cold. i have had both carbed and fuel injected engines. to me the injected engines will always win out. if you took the money that you would spend to carb it then it could be repaired properly. as for a daily driver i have never seen a carb outdo a fuel injected engine.

now if you are a die hard gear head and dont mind the carb burps and tendencies then i say go for it.

thafaz

Oh yeah, forgot the other PITA....connections to the 3 port....had to scour a bunch of plumbing places to get the right bits. I think they sell them right from Mallory....highly worth the investment.

In terms of drivability, there are some drawbacks...can't just hop in a drive away like my Volvo or Civic, has to be warmed up or it will stall. I have flooded it trying to get it to restart after stalling it out as well......really difficult to flood with FI. That being said, there are so many variables with FI that I gave up. Again, I now know it was the wiring.

For me, it's a weekend driver....does not have to be reliable or fuel efficient. It's simple to work on, easily upgradable, and cheap to maintain....TPI is none of these.

In hindsite, I would do it again...for $800 in parts and a few nights work, she's running again.

fireturd350

iTrader: (8)

Like anything if it's tuned properly it shouldn't be a problem. A properly tuned carb and FI setup should run about the same. It just comes down to what you want. I agree fixing the TPI would be cheaper by the time you get intake, carb, linkage, regulator, lockup kit, etc.

Usually people just compare the cars in there area and use that as examples. One guy in my class thought it would be a good idea to put a tunnel ram and 2 650 DPs on a 305 Camaro, it washed the rings and filled the pan with gas. That shouldn't mean tunnel rams or DP carbs are useless. Another guy had a 305 TPI Camaro in high school it ran like crap. He put a lumpy Comp Cams camshaft in it that wasn't ecm compatiable, but that shouldn't mean all camshafts are junk compared to stock peanut camshaft.

To get an excellent tune you basically need a wideband and that's one of the downfalls. Your o2 sensor does that work for you currently. After the swap you're going to have to make the float, idle screw, mixture screw, and jet adjustments.

Some dyno shops will setup a carb for you on there dyno and wideband. You can get close with a vacuum gauge but it will not be dialed in 100%. I my idle screws within 1/8 turn or so correct off the vacuum gauge, but on the wideband they found a huge flat spot coming in around 3000 RPMs and up and that's when we found the demon carb was leaking vacuum.

86Z

iTrader: (4)

coming from a carb to TPI swap. My tip, don't do it.

face215

im the middle of a carb swap and im pissed that the fuel pump runs thru the ecm which is no longer, so what is the best way to get power to the fuel pump with out buying anything!! i need a starting point like maybe wiring in a 12v toggle switch strait to the relay somehow? and where the best place is to tap into ?

whitedevilTA

iTrader: (8)

Does your year car have the oil pressure sensor that acts like a fuel pump safety switch too? (the big one by the oil filter). If so, just crank the car over. All the ECM does is give it that initial 2 seconds of pump activation with the key on accesory, then it shuts off. After this, it returns to on when it senses oil pressure as your cranking it over. Technically it should start just fine by cranking it over. Give it a try if you havn't already. You shouldn't have to change anything.

92z28camarokid

iTrader: (4)

Blah Blah Blah same crap different person. I dealt with the "Nah Sayers" when I posted up a similar post a year ago before I did my TPI to carb swap. I had a lot of trouble with my TPI setup up and there are pros and cons to doing the swap. Truth is each person goes a different way when doing this swap. Im a paint and body guy so this engine stuff is a bit over my head but by doing this swap I learned so much. Do your research, keep askin questions, dont forget that there are actual tech articles on the home page, and good luck.

Here is a couple things off the top of my head:
You will need a Fuel Pressure regulator with guage, IT MUST BE A RETURN STYLE, If its an auto then you will need a TC Lockup kit, as for intake I got an eldebrock performer RPM intake lookalike off of ebay saved some money and the polished aluminum looks great, you most likely wont need a carb over 650cfm. I went ahead and had a motor built for my car so somethings were different with mine. I found out that using a TBI throttle cable worked great, the TPI cable is way to long. The TV cable on my 700R4 gave me a lot of trouble, make sure that the geometry is correct on it or it will throw it off. While you are at it you might want to think about putting a fan controller in the car so the fans turn on at a lower temp, I wired mine up so when my key is turned its on.

As for everyone that has been posting on here, lets try to keep the chatter on whether he should do it or not and focus more on the OP question. He is lookin for expirienced gear heads like you all to help make this easier on him not tell him whether or not he should do it. Im not pointing any people out or trying to offend anyone, and Im sorry if you took it that way. I have had to deal with it and it just makes things more difficult when you can't get an answer because people are continusouly discouraging what youre doing.

GOOD LUCK WITH THE SWAP and dont forget to post up a build thread when you are done

whitedevilTA

iTrader: (8)

Well he said him and his father couldn't figure out the TPI to save thier lives so I was curious what was wrong in the first place. TPI is a simple system and not too hard to figure out. Carbs are NOT good for daily drivers. Don't even try to argue that point because I have owned carbed cars and they are annoyingly finicky. They don't run worth a damn when cold and they will run more rich or lean with a 10 degree weather change. My brothers 350 in his TA is carbed. It's a PITA, but his is only a once a week cruising car so it's tollerable.

I had a TPI car. Fired up every time I turned the key, got 18 mpg with a bigger than stock cam, and had excellent street manners. If the OP has never had a carbed car, then we want him to know that it will NOT be as driver freindly as an FI car. As long as he knows that then he can do what he pleases. In all honesty, he hasn't posted in here since his original post so I doubt he's coming back.

And as far as your fan wiring, I wouldn't recommend to someone to wire a fan so that it's on non stop....especially someone like me that lives in new england. If you need your heat to function, good luck with the fans on all the time. Plus, carbed motors like to run around 180 or so degrees and keeping the fans on will hurt that. My brothers car barely gets to 150 degrees and his fan is on a switch. It only just starts to go up from 150 while idling for a while. Wire the fans properly with a temp activation switch and you will be much better off. The less things to worry about while driving, the better.

Street Lethal

iTrader: (16)

Oh my goodness, are you serious lol...?

TCTA

Holy crap, I didn't know I started this big of an argument.
I never really planned to get good gas mileage anyway, so thats no big deal.
I'm mainly just switching to carb, because my stepdad KNOWS he can get it running if we switch it.
I know alot of you guys have these cars as sunday drivers, or once a week cruisers or whatever,
but my mom bought two TA's for 3000 bucks, and we don't have any money to just blow on some Honda, so right now, this is all I have.
So in other words, I'm switching just for the sole fact of getting it running, so I can find a job and whatnot.

85z28kid

iTrader: (7)

I would say do it they're fine for a daily driver i'm19 and did the swap my self it was easy wouldn't change it for the world and if you decide to build a bigger motor then they are easy to adjust you can spend hundreds of dollars just getting a motor tuner by time you take it somewhere. But won't say they're better on gas tho. I did mine and love it but it's personal preference but I don't drive mine in the winter tho which wouldn't be friendly at all

85z28kid

iTrader: (7)

BTW I don't understand what people say by driveabilty personally I like carbs alot better fordriving especially mechanical secondary the the fuel and air is there when you w an t it. And no I don't needpeople saying i don't no anything about cars cuz of my statements cuz a carb is like anything else if you tune it then it will run good no troubles I have a Barry Grant750 double pumper wiith mechanical secondary and it starts up every time no troubles but I do no how to tune a carb really good tho. So its your preference do what you want it's your car and good luck with your car

rusty vango

your in for a host of problems ,all of which altho easy to deal with could be avoided by just repairing your car correctly

rusty vango

almost every third gen camaro that is brought in, is seriously "boogered up" by people that obviously couldnt fix a can of soup, let alone a fuel injection set up. and it is sad really.because TPI is pretty much trouble free.it dosent require you to do anything EXCEPT leave it alone.AND as mentioned by another poster it is ILLEAGLE to modify our cars in this fashion

rusty vango

and your wondering why most posters are against doing this??

Awesome-X

Blah blah blah, if you wanna do it, do it. Unless you live in a smog state. I had an edelbrock 1406 on my 355 and it ran great and got 27mpg highway. I have a CCC on my stock 305 now and I can't seem to get anywhere near that now. Personally if I had a TPI setup I would keep that and take it to a shop for their opinion then fix it myself but I always seem to fall into carbed cars...can't even get a TBI

travis401

iTrader: (1)

I had a TBI. not really worth trying to upgrade that system to run a healthy stroker. so I went carb and havent looked back.

chevymec

iTrader: (5)

I did this swap and didnt look back. I bought used parts like a carb and intake. I used a TBI fuel pump since it was a low psi pump and I had one on the work bench. I got a billet fuel psi regulator from Jegs since it can handle up to 20 psi inlet psi. I probably should of bought a Mallory regulator and used the same TPI pump. The way I looked at it was, spend $$$ upgrading the TPI runners, base, and upper or save a lot and buy what I did. I gained no TQ although the power band increased almost 2k rpm's and increased 30hp.

midias

Sorry I cannot help more but go for it just get a decent carb with mechanical secondaries and sell your tpi stuff to pay for it. If your dad knows and understands carbs I bet he can get it running right with decent mileage as long as you keep it off the second two barrels.

travis401

iTrader: (1)

with an auto, getting vac sec would be more eco freindly.

-AO-

I'm very happy with my setup. 600 Summit VS carb, low-pressure pump, Digital-6 ignition, and Painless TC lockup kit.

Car ran a 13.9 last year and should run low 13's now. 310 cid, Vortec heads, LO3 cam, 1.6 RR's, stock stall. It's my daily driver. Just hit 254k on the odo.

Guest

Well I for one am glad you asked this question, I am about to do the same thing, and to all those that gave you positive answers and suggestions, thank you. My problem is not the TPI, its the aftermarket computer to run the thing correctly. $1600 to be replaced and a conversion I am sure can be done right around $1000. I have not seen any additional comments from you, have you completed your project and if so could you send along any suggestions. One thing I have different is my engine is in a 1985 Jeep and sits in front of a Chrysler Trans, engine from a 1989 Camaro rollover.
Thanks any comments welcome, but please keep it constructive, I have given you the reasons, I am not looking for a debate, just good comments to get it done right.
Thank You

Guest

Well looks as if you did all the leg work on this job, I am about to tackle the same conversion in spite of all the negative comments posted, my question is did you complete the job and if so do you have any suggestions for someone about to start the same project?
Thanks,
Wayne

InfernalVortex

iTrader: (4)

TPI will beat a carbed L98 if the carbed L98 is COMPLETELY otherwise stock and poorly tuned. The Tuned in "Tuned Port INjection" completely cripples any kind of real horsepower potential of the L98. That's why the LT1's got such short runners. The TPI was setup to feel sorta fast and still get decent gas mileage. A properly tuned carb setup doesnt have the performance bottleneck that the TPI runners have from the factory. The minute you start trying to up the power level, the TPI becomes the biggest bottleneck on the whole engine.

The other issue is that any factory carbed engine you ever drove was a 70s dog of an engine. The TPI L98 was one of the first decently quick smallblocks chevy made since the 60s.

travis401

iTrader: (1)

a properly tuned carb with a light foot will get you decent gas milage. a properly tuned carb with a lead foot will get you performance. its possible to get both out of a carb, if you know how to tune one. 90% of people using a carb, bolt one on out of the box and go. itll work, but its not getting the best of either world.

Camarobuild18

my 2 cents are go for it. Then get in the back, pull your carpet up right over the sending unit and cut a hole. No grinding! This way you can get to the fuel tank. Then you take your fuel pump disconnect it and run a line of your own to the engine bay. Run one of those 60 $ carb elec pumps. Have a toggle switch. Then get you vacuum advance distrubutor. Vacuum can, Any will do. Manifold vacuum. Then have it tuned singing like a bird! Finely tuned carb and finely tuned timing will run an engine fine.

five7kid

iTrader: (14)

Cut & hack to your heart's content. It's your car, your money, your funeral.

midias

Not sure why people are ragging on going tpi to carb. I love my carb setup easy 300 hp and with vortec heads 400 is no prob. And if you know ehat your doing it can run great. After a very quick warm up in my driveway (I don't have a choke) I have no hesitation or throttle issues. Electrical problems are gone checklist includes 12V to the coil and nothing else I love it.

Awesome-X

Why would cutting an access hole for the fuel pump be funeral worthy? lol

-AO-

Cutting an access hole and hacking the fuel lines is a bad idea because you have to hook the fuel lines back up somehow. Do it right and drop the tank.

Camarobuild18

yea and youl have to drop the rear end just to do so! And not many have the time to do it. Youll have to have it on stands also which is very dangerous.

Camarobuild18

ok well what many do not know is my uncle did this on his 86 camaro, V6 swap, he put a monza spyder engine it with a 4 barrel and a TH350 behind it. Even welded his own drive shaft. he did everything himself, even built his own cherry picker himself. He's still alive. I got even more in expensive proposition and even more safer way to solve not having to drop the rear end, get you a 1/2 drill bit, drill a whole as center as you can on the part right behind the top of the back seat. Remember to pull the carpet back. When drilling have water fed, and dont go deeper then a 1/4 of an inch, and the eye ball it from there. Than you get the hack saw blade out. Dont even concider grinding. Just have patience and try to go around the lines. And if you like for s**ts and giggles just install a door there, primer and all that good stuff. Put carpet back down and then your done

-AO-

That sounds like more labor than dropping the tank. And you didn't even mention what to do with the fuel lines.

travis401

iTrader: (1)

here we go with the whole "dropping the rear" issue. I personally have removed my tank from my car more than once, and not any of those times did i drop the rear to do it. it takes me about half an hour to remove the tank from my car now.

whitedevilTA

iTrader: (8)

I've dropped a thirdgen tank probably 5 times. It's really not that bad guys. Quit being lazy and get on your back and roll in some dirt! As long as you tilt the tank forward while pulling it with the axle at full droop it'll slide right out.

five7kid

iTrader: (14)

I was referring to the whole process, not just the part about cutting an access hole.

Rather than going through all this work to downgrade your car just because someone you know knows something about carbs, why don't you educate yourself on EFI and go from there? Did you consider the simple reality that switching your car to carb will make it illegal for street operation in all 50 states?

travis401

iTrader: (1)

the only reason i went carbed is because i did a motor swap, and rather than try to get the stock tbi to run 400+ hp, i went with carb. Just swaping from TPI to carb on a stock engine isnt a good idea. if it were me, id get the tpi running correctly and not even think about carbing it

Awesome-X

Luckily for me I don't have a fuel pump in the tank, but unfortunately for me that means my car was carbed from the beginning. Honestly, I'd rather have TPI or even a TB just to have the upgrade from a carb. I'd rather have a TBI out of the two, though just because it's so simple.

Benlunsford3104

Hey I'm currently switching to carburetor. What do I do with all the extra wires. Please call me 9406139031

jwfirebird

iTrader: (2)

read the sticky "welcome to carb forum" lots of good reading there, and wouldnt put your telephone number on the internet you are just asking for trouble there

DonW

Just realized how old this thread is!

DonW

For dang sure DONT cut them. Just zip tie them back please in case I buy your car next time around...lol Would like to have a chat with my PO about cutting wires as it is