Hey everyone this is one of my first times posting although I've scouring through the forums for a few years because I've had a 305 TPI laying around for awhile and I finally have a use for it. I want to put it into my 91 XJ6 next summer along with a T-5. I posted earlier about which engine I have and I was told it was 1987 or earlier because the alternator and air pimp are on the passenger side of the engine. I want to make as much torque and power out of this engine as possible because my Jag weighs close to 4300 lbs. with me in it, preferably more torque if I must choose. But I want to burn my own proms because I loved the thread on it and it seems a lot of fun. The motor has an automatic on it so the only things I need for the engine as it sits is a computer and the T-5 (flywheel,clutch,shifter,etc.) Since you all have experience I want to know how to build this thing, the only thing I do not want to do is touch the short block(it has 40,000 miles on it) or switch to a 350 because this is what I have and I am not terribly rich. But besides that don't hold back, thanks in advance.

 

New Heads, Cam, Fuel Injectors, Headers/Full Exhaust, PROM.

 

I have got a set of 21lb/hr venom fuel injectors for sale if you are interested... $150 plus shipping - got about 1k miles on them, practically brand new... I just need a bigger set (like 26lb/hr) because I switched from a 305 to a 355.

-NBP

 

Let us take this one step at a time and hopefully we can walk you through what you want.

First, you indicated the TPI engine is mounted to an automatic; however, you would like to mount it to a T5. You also indicated you need a computer. Do you have a computer? Was it the computer that came with the engine and transmission set up? If so you will probably need a different PROM to use a manual transmission.

Second, take the valve covers off the engine and advise us which heads you have by indicating the casting numbers. The casting numbers should either end with the number 187 or 081.

On a very general level you will be considering things like an exhaust system, heads, cam, new fuel injectors, adjustable fuel pressure regulator, air foil, air filters and porting work. This is also much easier to do once the engine is out of the car and if you can do several things at once.

You may want to consider some new sensors such as TPS, IAC motor, MAF sensor, EGR valve, EGR thermostat, just to name a few. Some of these sensors can only be changed by spending a lot of labour to remove parts to get to them. So it may be worth spending a little bit of money to change them now rather than a year after you build this TPI set up having to pull it all apart again to change a faulty sensor.

Then there are cooling system up grades such as a 160 thermostat, high flow water pump and throttle body coolant bypass. All new hoses may be in order at this time.

You also need to check the entire TPI system for vacuum leaks. Do not forget all new gaskets.

Then there will be the ignition system to consider with things like a new distributor, coil, spark plug wires and spark plugs.

You say the short block has 40,000 miles on it. Is this how many miles the TPI system has on it? Do you know that for a fact?

Then there will be suppliers of these parts. You will be considering places like Hawks, TPI Parts, Summit Racing among others. Do know a good mechanic in your city.

Last but not least what is your budget for this project.

Over the last year I just completely overhauled my TPI system, sensors, computer, ignition system, cooling system, transmission and differential. There are a lot of people here that know these engines and the TPI system inside and out. However, first you need to form a plan before you go out a buy parts and hire mechanics. Also, what is more important to you torque or high end horsepower, recognizing the TPI system is a little torque biased.

 

Thanks for all the response Guys.

-I do not have a computer for the engine so I will find which ever one I need.
-I want to convert it to a serpentine drive because they are easier and I may eventually want to install a vortech on it.
-As far as the injectors go, I will keep those in mind but I think everyone is a little short on cash around Christmas time.
-Next time I am at the shop I will figure out what heads it has but I read that the Corvettes with TPIs had aluminum heads....and I have a port and polishing kit, I was planning on porting the upper intake at least and buying runners and porting the lower intake if there is enough meat in it, if not I can buy one.
-I want a good ignition, probably MSD and I will probably replace all those sensors.
-I do all the work myself, I've put more than a few motors together and I have every tool I could need.
-I do not know for a fact that the engine has 40,000 miles on it but it supposedly came out of a wrecked Firebird and the TPI is correct for that engine, it came with it.
-I am tearing the motor down to the shortblock to chech the cylinder walls so all gaskets will be new and I am probably putting a larger oil pan on. Is the factory oil pump enough to feed the eninge?
-I want as much torque as possible, RPM's don't matter. I just want big torque and low gears.
Thanks.

 

The fuel injectors of choice here are the Ford Motor Racing (FMR) EV-1 injectors. They are cheap and good. They have been discussed many times here. For a 305 you will need 19lbs/hr.

For an adjustable fuel pressure regulator several companies produce them. The Holley unit has been used here and is liked because of the large wheel on top to facilitate pressure adjustment.

There are not many options for a 305 heads to bolt up to a TPI set up. Basically you have two stock heads the 187 swirl port and the 081. Then you have the Corvette 113 aluminums head which are considered very good; however, they have EGR issues and they will not work with your TPI base I believe. Then you have some heads from World Products which are OK. Lastly, you have some aluminium heads from Trick Flow. I have been doing a lot of research on 305 heads which I will post here soon. Also, see my recent post about compression ratio and aluminium heads.

I have a MSD distributor, coil and wires. They are good. Another sensor (well not really a sensor I believe) is the Ignition Control Module (ICM) in the distributor. This will come with a new distributor.

On producing torque the 187 heads were designed to do that. They were considered the first vortec heads. They are generally not looked upon favourably here due to the large swirl ramp in the intake bowl which limits air/fuel flow for producing high RPM horsepower.

I would think the factory oil pump should be fine; however, I will defer to anyone else who posts contrary here.

There is porting work that needs to be done to the plenum and intake manifold and when the time comes there are about three articles you can be directed to which goes into than in detail. You should not need new runners.

On the throttle body the consensus here is that, especially for a 305, you do not need a twin 52mm or twin 58mm one. However, recently I found my stock twin 48mm throttle leaked vast amounts of vacuum from the throttle body shafts. To correct that I had new bushings installed which caused alignment issues with the butterfly valves. If I had to do it over again I would have just bought a new twin 52mm throttle body. Companies like Holley, Edelbrock, BBK and others make these.

Several companies make air foils such as Holley, BBK, Jet, TIPS and others. Their merits have been debated here but they do not cost much. If you end up getting an after market throttle body you will not need to consider an airfoil.

On cams you can search here and find many opinions on what to use. Once you have decided on heads, headers and other things I would contact Comp Cams or other big cam companies and ask their technicians what they would recommend based on what is important to you in terms of torque, horsepower, idle quality and fuel economy.
Headers. I suppose ground clearance may be an issue for this project. Heddman makes some good shorty headers; however, many other companies produce good headers.

On sensors I would generally stick with the stock GM units. TPI parts is a good supplier for these. There has been much posted here recently about mass air flow (MAF) sensors which you can search and read about. I would stay with the stock Bosch one and do not remove the screens.

The Third Gens suffered from cooling problems due to the design of how air was directed or pulled into the radiator. That will probably not be an issue with you. There is a technical article here about throttle body coolant bypass if you stay with the stock throttle body. Check out all the other technical articles while you are at it. A lot of people use a 160, 170 or 180 F thermostat. Edelbrock makes a good high flow water pump as do other companies. I am using a Mr. Gaskete 160 F high flow thermostat.

Last but not least is the K&N air filter.

 

Here is a good article to read.

http://www.fuelinjection.com/portinj.html