I was thinking about swapping to TPI but I really don't have the money yet.(I'm investing in higher learning) I have a 305 TBI and want to swap to a 350. What will I need? Is there any good web-sites out there? My biggest worry is will I have to change the ECM? I was thinking about a LM1, it's a caprice 350. Any help will be greatly appreciated.

Also anybody want to buy some TPI stuff?

Thanks

Dave

 

If you wana keep the 305, then get a TPI unit, but if you want a 350, keep the TBI, its much less hassel.

 

Care to explain why???

Kat

 

Unless you've worked on both TBI and TPI systems, you won't appreciate the absolute simplicity of TBI vs TPI. I've worked on all 3 carb, TPI and TBI and although to my friends when I recommend a Camaro I always say get TPI at the least for more power, I keep the TBI setup due to its simplicity. People would argue the carb would be the best of 3, but I don't have the time it takes anymore to keep a carb going, let alone the costs in fuel mileage. TPI by design alone has much more things that can go wrong with it. The 8 injectors in stock form are known to be crap and don't last long. My dad went through 3 sets in 6 years while my TBI still has the same injectors from 14 years ago. I have a friend who's learning about the high maintenance cost mechanics will charge to work on TPI too and that's all he bitches about, but for everything there is a tradeoff. Just go with what suits you. If you know how to work with a TPI setup and are not intimitaded by it, the gains on a 305 are good as the stock TPI was designed for the flow of a 305. Just make sure you get the appropriate year TPI parts as valve angles changed in 86 or 87, can't remember but is reported to have a whole 5% torque/HP boost over previous years. If you find TBI to be a good system, why drop a good thing? Same with carb, why swap if its already reliable?

Its your car, and its your skills that determine what you want to use, personally I recommend doing the 350 upgrade with TBI, its a good base to work with when building a performance block.

 

Hrmmm So I guess a q-jet cant get 25-30 mpg then for a carb and I also guess the the holly stealth ram is an expensive alternitive to TBI....

Hrmmmm

Kat

 

Since nobody has actually answered the questions that you asked I'll give it a go:

I did a swap from an L03 to an L98. 95% of the stuff off of the 305 will bolt back onto the 350. And you won't have any clearance issues to deal with when dropping in the new engine. The knock sensors for the 305 and the 350 were different so you will need an new knock sensor which is approx. $35 from an Autozone or something like it. Just ask for a knock sensor for a 1990 Camaro Z28 w/ 350 and they'll get you just what you need. That's about it in terms of parts that you HAVE to have except for the obvious gaskets and such. Everything else will bolt right back up provided you get an 87 or later roller cam block.

After I did the swap I took my car down to one of my friends who has PROM burning equipment and we richened up the mix and did a few other things. Car runs really great now. Good luck!

 

If you notice he already has a TBI and its fully functional, so yes buying a new fuel system would be more expensive from that perspective. Don't forget he also has to adapt his distribution setup to vacuum advance while he's at it. All that in the name of a 305 engine when he was asking whether for a TPI 305 or 350 TBI in which I recommended the 350 TBI since a) he has a good fuel system he has depended on and is used to using b) changing a fuel pump on a f-body is hell since with a TPI he has to go to a higher flow/pressure pump let alone the massive tweaking needed to get a TPI running from a TBI setup c)The switch to a 350 is probably the best bang for buck thing he can do, no replacement for displacement is key and save for knock sensor, gaskets and minor ECM tweaking is probably the easiest to do in all difficulty for someone new to engine building.

Since he is going for a more powerful setup may as well go 350 as a start.

I understand how much you swear by carbs and I know you could probably get one that is fuel efficient too, but can't you do that with a TPI or a TBI as well? For all the work that you can put into a carb, the same can be done to a TBI or TPI and with a TBI I can get on average during summer months 25-35 city mpg and in winter/cold temps upto 40 mpg. Like I said, this is a daily driver for my car and I aim for efficiency until I get the money to support my project car.

 

I like my setup. It's your money.
It's expensive no matter how you look at it.

 

I dont care how much you try to say you tuned it and how slow you drive there is no way in hell that you are getting 35-40 mpg. And this doesnt stem from being anti-tbi this stems from being anti bull****.

 

As for you swap over to a 350 , dont bother with a crate engine , buy a good shortblock and get the best set of heads you can afford. Use you TBI setup until you get enough money to do the induction swap.

 

Okay, I'm going to stay with the TBI and I'm going to pick up a 350. My question now is what about the ECM? Also where can I get a prom burned (if I need it) for a TBI? It just seems easier to stay with TBI until I get out of College and get a real job.

Mo Speed = Mo $$$

 

Shade1 I tak it you envoked highway mode int he chip huh?

Kat

 

Wait a minute... If you don't have the money for the TPI swap $500-700, then how are you going to afford a 350?

 

stock TPIs choke 350s as it is and they are EXPENSIVE to modify. Go see how much runners, base, injectors, TBs are and get back to me. If you want a hot 350 TBI your cost is $100 carb intake, $12 TBI to carb intake adapter, and some 350 injectors.

 

You CAN get away with the stock chip unless your cam in your new engine is radically different than the one that came with your stock 305.... You can find TBI compatible cams that will work with the stock system and eventually get a custom chip or burn your own.

If you are going with a 350 look into cams that won't throw your computer way out of whack. Find a computer-compatible camshaft and get what works for you.

I do have the Crane 2030 Flat Tappet cam in my engine and it works relatively well with my stock chip. The ECM/Chip will work fine with it. You can always get custom chips afterward.

 

My car runs fine on the stock chip without an AFPR unit or Ultimate throttle body mods.

 

Kragen has a 4 bolt main 350 shortblock for $482 plus a $250 core built by recon speced for a '92 1500 series truck. Years from now if it dies it's only $482 to get a fresh short block if you turn in the original block for a core.

R

 

Talking about the engines, I want to know what could happen if I get the block (bare) and pistons (newer than 87) from a truck and put everything else of my LO3 in place (heads, cam, tbi, etc) I will only need the knock sensor for a 350?

Wich trucks have those engines?

Thanks.

Also I will try to find a whole engine out of a truck (Blazer).

 

I don't think your crank would balance right with the 350 pistons and your compression ratio would be too high, your heads, cam and intake would choke the engine not to mention the stock TBI being small but it's the same size as a 350 TBI just with smaller injectors but I'd get a bigger throttle body if you want power.

My plan is for my LO3 '92 bird is L98 heads or some other decent head for a 350, L98 exhaust manifolds, a smog legal carb intake with an adapter for a 2" TBI, LT1 cam and a 3" exhaust all bolted to a recon built 4 bolt main short block for a '92 350ci 1500 series truck.

R

 

Just one note TAS - i've got a friend with a 383 El Camino that is putting a 305 TPI system on it because he's sick of the carb non-economy. My point is this - he's done a LOT of research (not bench racing like happens on here) and he knows his small blocks (he could embarass any one of us) and all signs he's encountered point to the fact that a 305 TPI setup can support up to a 400 without more than fuel-pressure modifications. And he raced Indy for some time - c'mon, i'm waiting for the snickers. Just you guys wait and see...

Tyler

 

400 what? Cubic inches? Or are you saying 400 HP?

If you are saying 400 HP, I guess it could be obtainable with the right pistons, heads, intake manifold, fuel pressure, camshaft that IS compatible with the engine and ecm......

But 400 HP and keeping it street legal and emissions legal? Hmmm. With a 305? Possibly with enough money I suppose you can do anything!

 

Naw, i meant 400cid small block - but he's working off a 383 that ran initially with a carb. I'm curious to see how it works... time will tell.

Tyler