Tpi

[First c10]

Was think of putting tpi in my truck. Did it help with fuel economy in your trucks. Basically a stock motor with the tpi. Can anyone let me know!
Thanks

[First c10]

Anyone?
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[BlackedOut67shorty]

Well a couple people have done the swap, but if your after fuel economy you might want to think about going a step further and going with an ls motor and modern transmission. Even with that the mileage isn't gonna be spectacular, hard to accomplish with a truck with the aerodynamic characteristics of a brick.
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[Andy4639]

I've had my TPI setup since 1989 and I love the fact it starts when I want to. The MPG aren't that great but I do have a 4:10 gear. I can get 18MPG if I drive it right...Yea right, like that ever happens.
I like it though.

[MARKDTN]

Here is a real-world example. I have had an '83 K20 pickup since '91. I bought it with 42k miles. It has 3.42 gears an a 700R4 transmission. It always got 14-15 city and 17-18 highway MPG. To maintain highway speeds with any kind of load, you were always on the gas. At about 150k a cam lobe went down. I swapped the original 180HP 350 4bbl for a bone stock '91 Corvette L98 TPI engine. My mileage is now around 17 city and 21 highway. It maintains speed effortlessly. Low end torque is noticably better. I gathered parts and did the swap in a day.

[First c10]

I have a chance to get a complete TPI setup out of a camero for Free. i wa thinking of pullin the motor, freshen it up a little and install the TPI. The truck has a 700R4 and 3.07 gears I will probably put a little larger cam and swap in some vortex heads that I already have. This truck is for my son so speed is not what I want, sound and drivability is what I am after and the TPI for free well thats a plus(I think).

So basiclly if I install the TPI is should give me better fuel economy and drivability as long as I dont get crazy on mods?
thanks

[ChevyCruizer]

You cant beat free...

I have a couple of stock IROC camaro's with TPI and the system is very good (drivability, maintenance, power, etc). Like others have said the MPG's wont go way up, but these are great torque motors and there is plenty available as far as aftermarket upgrades.

I will say that there are differances between the 305 and 350 TPI units injector size [but can use smaller injectors on a 350 with an increase in fuel pressure], also there was a change in 1989 (F-body at least) where the earlier units use a cold start injector and the later do not. There were 4 different knock sensors, and then there is the MAF or speed density motors. Then there is the theft deterrant (VATS)

I just read your plans for the motor...There is also two different base manifolds, the older one has all of the intake bolts at the same angle while the newer manifold as the 2 on each side near the center (4 total) bolts more vertical for the center bold cylinder heads. I know you can use either manifold on either head but you have to "wallow" out the holes and doesnt look very pretty. I think the vortec heads have the bolts at a completely vertical mounting position and I also thought that the bolt pattern if different.

If you are using the entire motor just use everything, but if you are swapping the injection onto your longblock do some research. Easy to do with the proper information.

Originally Posted by First c10

I have a chance to get a complete TPI setup out of a camero for Free. i wa thinking of pullin the motor, freshen it up a little and install the TPI. The truck has a 700R4 and 3.07 gears I will probably put a little larger cam and swap in some vortex heads that I already have. This truck is for my son so speed is not what I want, sound and drivability is what I am after and the TPI for free well thats a plus(I think).

So basiclly if I install the TPI is should give me better fuel economy and drivability as long as I dont get crazy on mods?
thanks

[First c10]

The plan was to use my longblock and install the TPI on it, the original is a 305 but I was thinking that a mello 350 would be ok. I dont want to go through the work to install a 305.

[MARKDTN]

You might be surprised by that 305. The IROC 305 roller cam motors were not bad at all. The TPI system was really designed around a 305. If you do put it on a 350 you must get a 350 knock sensor as they are different. Here is a little TPI history/interchangability.

*****************
Following is information on TPI swap in a 68-82 Corvette, however much of it is applicable to a 67-72 truck. The big difference is the fuel tank. If you don't mind the tank behind the seat, you can use a stock tank and the Ford external pump. The truck I did ('72) was a short bed and he wanted the tank out of the cab. I looked into a 87 truck TBI tank and I think it had clearance issues with the rear suspension (might work on a long bed). I used an '86 S10 Blazer tank from a 2.8TBI vehicle. I even used the fuel lines from this Blazer up to the engine compartment with some re-bending, but they worked pretty well. This put the filler rear and right. He swapped to a stepside bed from a 88-99 pickup and had the body shop swap the filler around. It did require a bit of frame cutting and boxing, but it was all behind the axle mounts. I just swapped the TBI pump to a TPI pump from an IROC Camaro. The TBI tanks work nicely because they use barbs on the hose insead of screwed firttings. Be sure to swap to FI hose and FI clamps, there is a difference and it is important. On the truck, he wanted headers. I despise headers, on my own truck I would use stock manifolds and weld a bung into the exhaust for the oxygen sensor. I mounted the ECM behind the glove box which took up a lot of room. If I ever did another, I would buy a C4 Corvette weatherproof ECM and mount it in the engine compartment instead. This requires a more expensive harness and ECM, but it would help in the cab. On the swap I did, I used C4 Corvette serpentine accessories, which forces you into electric fans because the aluminum water pump cannot stand up to mounting a fan. If you go this route and have A/C, it will require a custom hose. Also, you will want to upgrade to a CS144 alternator, the CS130 is not very reliable. A better (less expensive) alternative is probably 88-95 TBI truck acessories, which would allow a pump mounted fan. If you have any other questions, please ask. This was written almost 10 years ago, so finding good used low-mileage TPI engines is probably not possible now, and the prices are not correct anymore. Just look at the technical info below and ignore those details.
*****************
You have a unit
First you have to determine whether you want mass air flow or speed density. The C3 is more conducive to speed-density due to space issues. Mass-air flow is easier to make engine changes without PROM changes. If you are technically proficient enough to make a Camaro harness work they can be bought for $100 or less. I have been told that you can also use a 3.1 Corsica or Cavailier harness with a little work, it uses the same 7730 Speed-Density ECM. Aftermarket harnesses range from about $300 for Painless to $500 for Howell to $700 for Street and Performance. Howell makes a great harness, but for a Tuned Port they do not make one that will control the converter lockup on a 200R4/700R4/4L60 transmission. If you are running a manual or non-overdrive-automatic transmission I highly recommend them. I have heard great things about Street and Performance harness, but do not have first hand experience with them. I also have a Fuel Injection Specialties (FIS) harness and it is OK. The ECM can be had used for $10-50. A good external fuel pump will cost at least $100. I use an 88 Ford Truck external pump, $114 from CarQuest, made in Texas by Airtech (also available at O'Reileys). If you have a 78-82 you can use your fuel tank with an 82 sending unit and a TPI pump. 68-77 can also use a modified tank or Rock Valley makes a tank for these cars with a baffle and a GM internal fuel pump. Stock 82 tanks do not have a baffle contrary to popular belief. An aftermarket PROM with VATS and Emissions codes removed will be $100-200 depending on source and complexity. You will have to add an oxygen sensor to your exhaust, $20 for the sensor, $5 for the weld-in bung, and say $25 for an exhaust shop to weld it in if you can’t. Some harnesses use VSS and some do not. An auxiliary VSS sensor is around $75. I recommend using VSS to get better drivability. To install a TPI I say figure at least $800 plus the TPI unit and whatever repairs are necessary to bring it up to useable status. I have TPI/700R4 in my 69 Corvette (Howell harness) and an 83 Pickup (FIS harness) and I love it. Starts good, great torque, good fuel mileage, easy to swap onto stock engines (although both of mine are complete engines out of 90/91 ‘Vettes).

Differences in years
All Corvette TPI intake manifolds work with the older (through 86) iron heads and the factory aluminum heads through 91. F-body TPI intakes use the upright center bolts on 87-92 and thus fit all 87-95 iron heads (non LT1). Either can be swapped to fit the other with some drilling. F-body has the fuel lines come out on the drivers side and has a central port for EGR. Corvette has fuel lines that come out on the passenger side and has an external port for EGR. Corvette fuel rails fit F-body intakes and vise-versa. The runners are all the same through the years, but the LH runner has a hole for a 9th injector in the 85-88 runners. This can be plugged off if you get a nice LH runner and don’t want the 9th injector or decide to run speed-density. The plenums all physically interchange, but 90-92 have an extra vacuum port for the MAP sensor used with the speed-density computers and wiring. 89 is an odd year, it is mass-air flow but without the 9th injector. 89 up throttle bodies can be used on all years, but a 85-88 throttle body requires a ½” hole be drilled in the front of a 89-92 Plenum for idle air. 89-92 Throttle bodies have a more desirable cable attachment. The cable attaches around a circular linkage which has a smoother actuation than the straight linkage on the 85-88. The Corvettes have an aluminum plenum extension over the distributor, the F-body extensions are plastic. The Corvettes use an HEI coil-in-cap distributor for 85-91 (Delco 1103680). 85-86 F-body also used a big-cap distributor. 87-92 F-Body used a small cap distributor with an external coil (Delco 1103479). This same distributor is used in the 87-95 5.0/5.7/7.4 TBI injected trucks and pre-LT1 B-body. The F-body intake gets it's exhaust for EGR from the center passages in the heads like most SB Chevys. A Corvette intake gets it's EGR exhaust from the RH exhaust manifold/header through a flex-tube to an opening near the distributor-no center passages in the intake. If you are required to keep EGR and you have a Corvette intake, I recommend getting the C4 exhaust manifolds. They are like mini-headers, and have a 2 1/2" outlet. I have them on my 69 and like them.

As far as a throttle cable to use, on my Vette, I used a TPI Corvette cable, 1990 I think (now discontinued from GM) but you have to cut the end off inside the car and use a hood-release-cable end (Corvette Central 342138 "cable stop") to get it the correct cable length (the housing is OK). You must use a cable from the type car your throttle body came from if you want to have a chance of not cutting it. Again, 85-88 use a straight pull, while 89-92 have a circular attachment for more smooth actuation and so the inner cable is longer. On my 83 truck I used a TPI F-Body cable and it was OK, but I had to coil it up into a loop in the engine compartment because the housing was so long. I also TPI'd a 72 Chevy truck and used a 90 350 TBI truck cable for it. It was 1/2" short outside if anything, but I was pretty pleased with it all told-I didn't have to shorten it. In a Vette it might be about right. In all vehicles I've done you need a die grinder to square the firewall hole off a bit. All vehicles I've done used the late throttle-body.

I would look into a TPI. They start immediately in winter, have great vacuum, and will get great mileage. It will bolt up to everything in your car, use stock accessories, use your transmission, and the visual appeal is awesome. Don't be afraid of fuel injection, it really works.

As far as websites see:
www.corvettefaq.com for conversions or more TPI info at www.fuelinjection.com also www.jagsthatrun.com for misc hard to find conversion parts and info.

LT1
Not to get too deep into the differences in LT1s, there are basically 3 variations. There is the C4 ('92-96) and an F-body ('93-97) version which are 5.7L and have aluminum heads. There is a B-body ('94-96) which is 5.7L with iron heads that actually flow better than stock aluminum heads. There is also a 4.3L B-body (L99) version that you want to stay away from. There is an LT4 in '96 that is an upgraded LT1. All are dimensionally the same as far as bolt-ons. Corvette engines have 4-bolt mains, all others have 2-bolt. All are cast iron blocks. An LT1 is a very similar installation to a TPI. As far as the mechanical installation, the 700R4 and 4L60E transmissions are the same (same length, same basic dimension, mounting, yoke, etc.). You have to have a computer to run a 4L60E which you will have for the engine anyway. As far as the engine, an LT1 will bolt in and can use the same exhaust although you may want to use C4 LT1 manifolds to get true 2 1/2" outlets. The biggest difference between a TPI and an LT1 installation is accessories. TPI can use stock C3 accessories. LT1 has to use LT1 accessories and really needs C4 LT1 accessories. Both F-body and B-body put the a/c compressor low on the passenger side. This interferes with the frame and the right motor mount. You have to use electric fans on an LT1, there are no provisions for a mechanical fan (B-body has an optional one, but it is offset and won't work in a C3). The other difference is in air intake, most LT1s are mass air flow. Again, it is difficult to locate the MAF sensor in a C3. You are better to have it set up for speed-density. In a '78-'82 C3 you could still use an '82 sending unit but an LT1 fuel pump instead. You will want to stay with programming for an OBD1 (pre-'96) style setup, without multiple oxygen sensors. '96-'97 OBD2 engines are fine, you just don't use all the sensors. LT1 requires a custom radiator because of how the hoses run. There are differences in the Optispark, later is better and if you swap to a later cam you can add the later vented Optispark setup. The water pumps are bad to fail and wet the Optispark, so always replace the water pump when you do a swap. LT1s have better top end power that TPIs, but all things considered I'd rather stay with TPI for a cruiser or mild build-I just like the look and the low end torque. If you want more power, LT1 is better; or just step up to an LSx.

[First c10]

Thanks Mark
I guess I didnt think going from a 305 to a 350 was going to be that much of a change but looks like I am wrong. I will see what I get and than go from there on if I actually want to install it. I will let you all know
Thanks
Scott

[cjohnson6772]

Originally Posted by First c10

Thanks Mark
I guess I didnt think going from a 305 to a 350 was going to be that much of a change but looks like I am wrong. I will see what I get and than go from there on if I actually want to install it. I will let you all know
Thanks
Scott

I put a tpi on my truck years ago. Stock truck 350. 85 tpi unit. Simple unbolt rebolt as far as the intake. No need for a knock sensor. I am running speed density set up. Th350 trans and 3.07 gears gets me 14-15 mpgs. I am going LS this month though happy to help if i can. Great little running engine as is though.
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[First c10]

14-15 with a 350? so since I have 700r4 do you think it will get 18 MPH?

[cjohnson6772]

Originally Posted by First c10

14-15 with a 350? so since I have 700r4 do you think it will get 18 MPH?

Tpi. Modest cam. 3.07s. 700r4. Light foo

Get all that and get 15 town and 17 highwaII don't see anything over 18 in these bricks. Aero stinks on these trucks.
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[Andy4639]

I installed mine in 1989 and used Street & Performance wiring harness. No knock senor are egr valve. I have the ecu inside the glove box and use a V-6 Fiero ECU with a special chip burned for it from Street and Performance. I use the map senor and it does great on the interstate. I also have the 700 R4 with lock up by B&M shifter with a toggle switch hooked up to unlock if I pull my trailer. The truck has a 305HO TPI cast iron heads no roller's and will run 70-80 MPH all day and only turning 2300 RPM's with a 4:10 gear. Mine has the cold start injectors but they are not hooked up and it starts with no problems.
When I did my truck S&P were the only company doing these swaps. I used a 93 Suburban gas tank. 42 gallon in the bed with a custom filler made into the fiberglass bed cover.

[Street Smart]

I took an `89 305 with 700r4 out of crashed camaro put it in my `70 panel about 12 years ago. It`s the most reliable vehicle i have ever owned. I did the whole swap with only buying new headers, fuel pump and a painless engine harness. Great throttle response and decent mileage, long highway run maybe 18-19, but local about 15 mpg.

[red71cheyenne]

I have never gotten the MPG gains I thought I would with the TPI and 700R4 swap. I am however in love with the instant starting and low end torque that I gained on just an old bone stock 350 bored to .030 over. At some point I'm going to swap rear end gears to see if that nets my MPG gains, but I would still do it all over again.

[Katrina/10]

[QUOTE=MARKDTN;5940213]You might be surprised by that 305. The IROC 305 roller cam motors were not bad at all. The TPI system was really designed around a 305. If you do put it on a 350 you must get a 350 knock sensor as they are different. Here is a little TPI history/interchangability.

*****************
Following is information on TPI swap in a 68-82 Corvette, however much of it is applicable to a 67-72 truck. The big difference is the fuel tank. If you don't mind the tank behind the seat, you can use a stock tank and the Ford external pump. The truck I did ('72) was a short bed and he wanted the tank out of the cab. I looked into a 87 truck TBI tank and I think it had clearance issues with the rear suspension (might work on a long bed). I used an '86 S10 Blazer tank from a 2.8TBI vehicle. I even used the fuel lines from this Blazer up to the engine compartment with some re-bending, but they worked pretty well. This put the filler rear and right. He swapped to a stepside bed from a 88-99 pickup and had the body shop swap the filler around. It did require a bit of frame cutting and boxing, but it was all behind the axle mounts. I just swapped the TBI pump to a TPI pump from an IROC Camaro. The TBI tanks work nicely because they use barbs on the hose insead of screwed firttings. Be sure to swap to FI hose and FI clamps, there is a difference and it is important. On the truck, he wanted headers. I despise headers, on my own truck I would use stock manifolds and weld a bung into the exhaust for the oxygen sensor. I mounted the ECM behind the glove box which took up a lot of room. If I ever did another, I would buy a C4 Corvette weatherproof ECM and mount it in the engine compartment instead. This requires a more expensive harness and ECM, but it would help in the cab. On the swap I did, I used C4 Corvette serpentine accessories, which forces you into electric fans because the aluminum water pump cannot stand up to mounting a fan. If you go this route and have A/C, it will require a custom hose. Also, you will want to upgrade to a CS144 alternator, the CS130 is not very reliable. A better (less expensive) alternative is probably 88-95 TBI truck acessories, which would allow a pump mounted fan. If you have any other questions, please ask. This was written almost 10 years ago, so finding good used low-mileage TPI engines is probably not possible now, and the prices are not correct anymore. Just look at the technical info below and ignore those details.
*****************
Thanks for the TPI lesson! Always good to read about the diffences in those units, and how they relate to other EFI systems. Have you ever used an external fuel pump on a 67-72 truck with a stock in cab tank?

[MARKDTN]

Originally Posted by Katrina/10

....Thanks for the TPI lesson! Always good to read about the diffences in those units, and how they relate to other EFI systems. Have you ever used an external fuel pump on a 67-72 truck with a stock in cab tank?

No, but I have done a few vehicles with that '88 Ford truck pump. (A '69 Corvette and a '50 Ford truck). It says to use a primary "kicker" pump with it, but I did not in either of those and both are still going 10+ years later. I prefer the intank pumps and if I did another it would also use that S-10 Blazer tank too. I would have to say that after seeing some wrecks with in cab tanks, I would prefer to get the tank outside.

The only real difference in a 350 and 305 setup is injectors and knock sensor. You may get away with the 305 injectors if you jack the pressure and/or don't rev it high. Another lesson I have learened in the last year is injectors. The GM Multec injectors do not like ethenol fuel. There is a guy in Atlanta that sells rebuilt Bosch injectors that fit that use stainless pintles and should last a long time with todays fuels. Before the carburetor guys jump on the bandwagon, remember that some Q-Jet floats and especially older accelerator pumps do not ethenol fuel either. Fuel quality and chemestry is a real problem whether you are carbed or injected.

[burnin oil]

Didn't read all of the long post of info but for anyone thinking of doing the swap this might help out. The Pontiacs didn't have VATS where the camaro did. Go figure the higher dollar ride didnt have the security system. I put a camaro 350 TPI in a 86 Firebird years ago and used a Pontiac PROM. All stock parts.

[Ackattack]

I put a TPI 350engine in my 72 GMC I had along with a 700R4. In all honesty I thought it was a turd. I read about the great torque these engines had and was disappointed with its performance (ran a 15.7 quarter mile, doing the math worked out to about the rated horsepower).

I put a 5.3L in my 68 and it is WAY WAY better. If you want to go fuel injection, I wouldn't waste my time with a TPI engine any more.

[Katrina/10]

Originally Posted by MARKDTN

No, but I have done a few vehicles with that '88 Ford truck pump. (A '69 Corvette and a '50 Ford truck). It says to use a primary "kicker" pump with it, but I did not in either of those and both are still going 10+ years later. I prefer the intank pumps and if I did another it would also use that S-10 Blazer tank too. I would have to say that after seeing some wrecks with in cab tanks, I would prefer to get the tank outside.

The only real difference in a 350 and 305 setup is injectors and knock sensor. You may get away with the 305 injectors if you jack the pressure and/or don't rev it high. Another lesson I have learened in the last year is injectors. The GM Multec injectors do not like ethenol fuel. There is a guy in Atlanta that sells rebuilt Bosch injectors that fit that use stainless pintles and should last a long time with todays fuels. Before the carburetor guys jump on the bandwagon, remember that some Q-Jet floats and especially older accelerator pumps do not ethenol fuel either. Fuel quality and chemestry is a real problem whether you are carbed or injected.

The reason I ask is that I installed the same Ford pump you mention on a 71 truck using the stock tank, and it failed in short order. I am assuming it did not like having to suck fuel up the long straw of the truck tank, so I am going to try to install a pump in the tank.

[MARKDTN]

Originally Posted by Katrina/10

The reason I ask is that I installed the same Ford pump you mention on a 71 truck using the stock tank, and it failed in short order. I am assuming it did not like having to suck fuel up the long straw of the truck tank, so I am going to try to install a pump in the tank.

You can use a low pressure pump that has suction to supply the high pressure one. That is how the Ford truck that pump is used on is set up. Did you install the pump lower than the tank? Both of my installations have put the pump lower than the tank.

[MARKDTN]

Originally Posted by Ackattack

...I put a 5.3L in my 68 and it is WAY WAY better. If you want to go fuel injection, I wouldn't waste my time with a TPI engine any more.

I would agree with you. However, the TPI can sit on top of the original engine which has it's advantages. If you don't have the location, skills, or resources to do an LS swap, the TPI can go on an engine already in the truck and parts are available at most any parts store. Some people would be more comfortable with an intake swap that might not attempt a full-on LS conversion.

One more thing. If you do put TPI on an existing engine and want to use it in closed loop, you need a cam that has vaccum. TBI, TPI, and LT1 all require cams that produce vaccum or they will not run right with a stock computer setup.