need a little help on a tpi swap

[jaros44sr]

Originally Posted by birdman8711

this is my fuel pump and filter combo im using my stock tank will upload a pic of my sending unit once its done. its a walbro inline pump 60psi max($112 from summit) and a stock replacement filter for my camaro which is a 10 micron($15 from autozone)

Just a heads up, i THINK the threads in your fuel filter are ORS and not NPT. If im right, you will have leakage. Hope im wrong, but check it out

[birdman8711]

is anyone here using the vapor canister with their swap and if not what did you do instead

[birdman8711]

okay guys i need some input im trying to prime the fuel pump but so far not having any luck any help is greatly appreciated

[Bigdav160]

Which is the inlet and which is the outlet? The filter should be on the outlet side not the inlet. Is you pump mounted below the tank?

[Andy4639]

I don't care what anyone says about baffeled tanks. U are in for trouble with out them. Once U run down the gas level it will slosh it all over the place. The fuel gauge will read all kinds of levels after U used about a 1/4 of tank of gas. On top of that U will pull air into the pump and cause it to faill once your down towards the bottom of the tank. I know from past experience and I've had mine in the 71 since 1989.

I have one of the first Street & Performance wiring harnesses in my truck. I run a v-6 Ferieo computer with a modified v-8 chip.

[birdman8711]

i have the filter before the pump to prolong the pump life as the pump is $90 and the filter is only $15 and yes its below the tank mounted on the frame as close as possible to the tank and im using the stock sending unit which i added a return line to so the pick up is only a 1/2 inch from the bottom of the tank and last i checked i had 7 gallons in it so it should be close to half full

[Andy4639]

Are U sure the pump is coming on? It may take it a little bit to prime it since it's a inline pump pulling the fuel up the sendor then to the pump.
This is beeen a problem with in line pumps since the beginning.

[Z10]

Or.....you could use a surge tank. I'm building a TPI system also. This will be mounted between the fender and battery.


Follow along on my build.http://67-72chevytrucks.com/vboard/s...=1#post6356218

[Andy4639]

Originally Posted by Z10

Or.....you could use a surge tank. I'm building a TPI system also. This will be mounted between the fender and battery.


Follow along on my build.http://67-72chevytrucks.com/vboard/s...=1#post6356218

That was one of my first suggestions long ago about using a gravity feed line to a tank under the truck with the electric pump and return line built into it. We did this years ago on a TPI install. Carolina Rod shop use to keep these in stock just for this.

[Z10]

Few more pics of what's going on inside the surge tank.
http://67-72chevytrucks.com/vboard/s...=1#post6356218

[birdman8711]

okay guys got the fuel system primed i ended up just using a multi use transfer pump from harbor freight to pull the fuel through and it only took about 2 minutes to do

[jaros44sr]

Heres the answer to your PM, the adapter to the fuel filter is ORS, i can give you thread and pitch if needed. The other end of the adapter is AN barrel nut and sleeve, your choice on how you want to terminate
The filter is not NPT


20131203_110123 by jarosaj, on Flickr

[MARKDTN]

You will have a hard time with a filter in front of that pump. It is not made to pull and you will burn it up in short order. Suggest a surge tank approach or sounds like you have a low pressure pusher pump that is pushing fuel through the filter to the high pressure pump. That will work too, but I would just make a sending unit that has an over-the-counter GM TPI pump on it. Simple, quiet, and effective.

[68c10airstream]

hey z10, I see you are building a surge tank. I was going to make a fuel injection cleaning tank that i was going to fill with cleaner fluid and pressurize it with air and feed it to injectors. My tank size and style was a lot like your surge tank. I discussed this with my brother ( a mechanical engineer) and he said "you must have domed ends, they look like bell ends. If not and the ends are sharp 90 degree transitions, these areas are stress risers, create flexing, and eventually crack". This would lead to pressurized fuel spray in a hot engine compartment with spark generators (coils, alternator, etc). My brother also said to look at any ASME (american society of mechanical engineers) tank and you will notice rounded ends. I work at a power plant with compressed air everywhere with surge tanks, etc, etc, and all holding tanks have rounded ends with an ASME id tag listing working pressure, burst pressure etc. I think the quality of your work looks great as i don't wont to rain on anyones parade, but when i switched careers from dealer mechanic to power plant work it was an eye opener. Keep up the good work, good luck Brian F.

[Z10]

Originally Posted by 68c10airstream

hey z10, I see you are building a surge tank. I was going to make a fuel injection cleaning tank that i was going to fill with cleaner fluid and pressurize it with air and feed it to injectors. My tank size and style was a lot like your surge tank. I discussed this with my brother ( a mechanical engineer) and he said "you must have domed ends, they look like bell ends. If not and the ends are sharp 90 degree transitions, these areas are stress risers, create flexing, and eventually crack". This would lead to pressurized fuel spray in a hot engine compartment with spark generators (coils, alternator, etc). My brother also said to look at any ASME (american society of mechanical engineers) tank and you will notice rounded ends. I work at a power plant with compressed air everywhere with surge tanks, etc, etc, and all holding tanks have rounded ends with an ASME id tag listing working pressure, burst pressure etc. I think the quality of your work looks great as i don't wont to rain on anyones parade, but when i switched careers from dealer mechanic to power plant work it was an eye opener. Keep up the good work, good luck Brian F.

Airstream, please go over to my build and copy and paste your comment.
http://67-72chevytrucks.com/vboard/s...=1#post6356218
My surge tank was created by diceman50, I'm sure he'll respond. The tank was actually created by utilizing two DOT calibration gas cylinders which were originally rated at 500psi. As far as the domed ends, I'll default to your brother. On second thought I'll copy and paste your comment, just monitor it for his reply.

[68c10airstream]

Hi Z10, Most times i hesitate to comment on issues, but we get pounded on with safety related potential issues at the power plant, so excuse my spill over on these forums. Some items raise the hair on my neck, like 120 volt incandescent trouble lights working around fuel repairs, using compressed air to blow debris off of your skin, but i'll stop now. Those cal gas aluminum tanks i suspect being rounded on one end only is ok because they are a single use item. Hence pressure cycles up and down won't happen, leading to cracking. I wish all of you could see my brothers work. he uses a program called solidworks, and has designed testing systems for people i can't mention. The wild off the wall stuff he gets into is amazing. I guess i would rather suggest something and possibly be chastized for it, than do nothing and then hear of an accident. A friend used a 120 volt incandescent trouble light during a gas tank removal job, explosion ensued, nova a total loss, 3rd degree burns, firemen saved the detached house. i warned him in advance, but to no avail. Enough of my rant, good luck, Brian

[Z10]

Originally Posted by 68c10airstream

Hi Z10, Most times i hesitate to comment on issues, but we get pounded on with safety related potential issues at the power plant, so excuse my spill over on these forums. Some items raise the hair on my neck, like 120 volt incandescent trouble lights working around fuel repairs, using compressed air to blow debris off of your skin, but i'll stop now. Those cal gas aluminum tanks i suspect being rounded on one end only is ok because they are a single use item. Hence pressure cycles up and down won't happen, leading to cracking. I wish all of you could see my brothers work. he uses a program called solidworks, and has designed testing systems for people i can't mention. The wild off the wall stuff he gets into is amazing. I guess i would rather suggest something and possibly be chastized for it, than do nothing and then hear of an accident. A friend used a 120 volt incandescent trouble light during a gas tank removal job, explosion ensued, nova a total loss, 3rd degree burns, firemen saved the detached house. i warned him in advance, but to no avail. Enough of my rant, good luck, Brian

Airstream, no worries. I've been in the Safety business for over 30 years and actually managed a certified DOT cylinder recertification service for several years.
Not sure if you jumped over to my thread. http://67-72chevytrucks.com/vboard/s...=603726&page=3

I'll repost Diceman50's answer to your questions. Post 65, page 3

"Diceman here,

The gas sample canisters we used are rated at 500 PSI and although they are flat bottom on the outside they have a very large radius on the inside which in effect makes them domed on the inside. However, the point is mute since in our application there is ZERO pressure on the surge tank. We are using the mechanical pump on the engine to fill the surge tank with a return line to the main tank. The high pressure pump is inside the surge tank. It pumps fuel to the fuel rails after which excess fuel is returned to the pressure regulator which is mounted on the outside of the tank. Therefore no pressure is introduced to the tank. The pressure testing I did was for the fittings."

[diceman50]

Originally Posted by Zeke's Garage

I heard all sorts of warnings and blatherings about how using an in-tank pump wouldn't work in an unbaffled, unsumped tank. How it will suck air and cause no end of drivability issues. Well, I've got about 3k miles on this setup with the MegaSquirt ECU, and other than a cracked head on my inline 250 (not the fault of the pump I assure you), The drivability has been great, and I've never noticed any issues at a nearly empty tank. So if you're on a budget, I would not hesitate to try this option.

Good luck!

Shawn

I'm not sure your cracked head was not caused by the lack of baffling in your tank. Lack of baffling in an EFI system can and will result in a lean condition in your engine even if drive ability issues are not detected. An overly lean situation as you know can cause detonation and overheating. Which could have contributed to your cracked head problem. If baffling is not required the OEM bean counters would definitely do away with it. Besides who wants to worry about always keeping the tank at a certain level. I did my first EFI conversion in 1991 and I have done 3 more since, so I speak with some authority. The vehicle is a 1986 SWB 4 x 4 Silverado that I put a 350 TPI into. I drove that truck over 50,000 miles before I sold it in 1998. It is still running as far as I know.

[birdman8711]

okay guys im picking up another tank with the eec and im thinking of either doing a sump box on bottom of the tank and having the fuel line come out of it into the fuel pump mounted on the rail or pulling the camaros fuel pump and mounting it in the tank which do you guys think would be better

[birdman8711]

okay guys i got the wiring harness all hooked up but the engine wont crank i think some of the connections to the fuse box got messed up so im trying to figure out a way to get this done as i have 6 weeks to have it running and road ready i was thinking of trying to supply power to the fuses during run and start but any suggestions are welcome

[birdman8711]

okay guys i got it to crank i found the problem which was 2 loose wires so what i need now is what wires are what on the ignition switch