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blue68deville
04-28-2014, 10:29 PM
Hey,
I've got the caddy up and running with an external pump drawing thru the sender. It works ok until I get close to half a tank then I start having cavitation problems when the car isn't level. I figured this might happen.
My tank is huge but really shallow, 5 3/8" tall at the center and about 3ft square. I've seen the generic weld on sumps and that looks like a simple solution but will it work well?

http://www.jegs.com/i/Competition+Engineering/247/4040/10002/-1?CAWELAID=1710616506&CAGPSPN=pla&catargetid=230006180000514884&cadevice=c&gclid=CISL68D4g74CFU9p7AodqBIAEw

Running a newer module with a siphon jet would be nice also but I don't know of one that short.
Ive also thought about making some baffles and running the ac delco tbi in tank pump.
Any suggestions? I'd prefer simple/cheap but I'll go elaborate if its going to make a big difference.
Thanks in advance, this site has been immensely helpful

EagleMark
04-29-2014, 06:22 AM
Your sump part/link may be half the solution, still going to need some baffle on top.

I don't think you'll have much luck fitting anything that short? I just looked at my old 74 IH 345 TBI conversion thread and it says 7-8 inches deep pan (?) but I'm not sure it was that deep, maybe less. It was about 2 feet wide and four foot long that came with a factory baffle! But not even the shortest bucket pump known of, modified to be even shorter would fit...

Ended up removing the 5/16th feed line from sending unit and welding in 3/8th, then used a AN fitting with a drilled hole in tank for a return as there was no room for return. But I did get it close enough to drain into baffled sump area of tank.

Then a external inline Carter Pump (noisy but good) very close to tank with EFI line to pick-up so it would not collapse, did not use the in tank sock, but did use a 3/8th clear inline filter before pump.

It ran well and no signs of running out of fuel, common when done like this. But the IH motor is not a high rev engine and even built up a little like this one was under 300 HP. During inspection you can sometimes see the filter in clear fuel filter twist! This is a sign of cheap clear filter collapsing! Also ran the tank very low and no signs of cavitation around corners, but this was never an issue as factory tank had baffles... in a 1974 carb truck!

HTH with some ideas for external pump... :rolleye:

delcowizzid
04-29-2014, 07:43 AM
this is why i fit surge tanks to every efi build then you only ever run out when going up hill for an extremely long amount of time LOL

blue68deville
04-29-2014, 08:45 AM
I thought about making something like this, just tilt the pump 45deg to make it shorter.

http://www.tanksinc.com/index.cfm/page/ptype=product/product_id=84/category_id=61/mode=prod/prd84.htm

There's a home made version here, half way down the page;

http://www.britishv8.org/mg/curtisjacobson.htm

EagleMark
04-29-2014, 10:05 AM
Great options! Just way more then I was going to do with the project I had. They fit your project much better...

lionelhutz
04-29-2014, 05:14 PM
The sump you linked is what I used. I just welded it to the bottom of the tank at the lowest area (to the front on my tank) with a couple of 3/4" holes in the bottom of the tank at the front of the sump to let fuel into it. It works great with no stumbling around corners or accelerating even with the tank quite low. The instructions say to weld at the back of the tank but the back is higher so placing it there wouldn't let my tank empty. By my quick calculations that sump would hold over 0.4 gallons so I figured it would hold lots of fuel when the tank was sloshing for my application.

The instructions say to put it at the back of the tank with a bunch of big holes in the tank but I felt that applied more to a drag-car only application.

Actually, my neighbor is a professional welder so I had him TIG weld it in place. I'd highly recommend you find someone to TIG weld and tank work. It makes for a very clean and neat weld.

blue68deville
04-29-2014, 06:12 PM
@lionelhutz;
I'm going to go that route too thanks. I've also got a friend that's an excellent welder, me not so much on something as important as a fuel tank.
@eaglemark;
My family has had several IH's and I was always impressed by their engineering, lots of little things that were pretty well thought out. I'd love to do a scout project, maybe a 392 & nv4500... Someday

blue68deville
06-24-2014, 07:44 AM
Figured this might help someone else, here's my setup. It's working well for a couple hundred miles, I can drive around with well under 1/4 tank and no cavitation. The deep end faces the rear of the car.

The high-tech pre-filter is window screen with a small soldered tab of copper wire strand for a retainer, can't see it in the pic. I used a strand of screen to sew it closed at the end.

The brass fittings are PEX push on stuff. They seemed to have the largest ID.

EagleMark
06-24-2014, 08:34 AM
Nice work! I had the idea of mounting to the tank once but since I had so many issues with noise I never tried. I finally found some isolated mounts that stoped the fuel pump whine from echoing from front to back of frame it worked well.

How is the fuel pump noise mounted on the tank?

blue68deville
06-24-2014, 05:50 PM
I don't hear it with the engine running, during prime in my garage I notice it but nothing annoying.
I used some extra filler neck hose between the pump and clamps, it just happened to be the right ID to slip on. If that didn't work I was going to use the rubber isolators. No need.

lionelhutz
06-24-2014, 07:33 PM
It looks good. Nice home made screen. I actually don't have anything between the tank and the pump on my car.

blue68deville
06-24-2014, 07:39 PM
My first go-round I had a clear prefilter on the suction side and it ended up with some debris in it. Figure I would rather err on the side of caution. My luck would put me in the middle of the mountains if the fuel pump took a dive because of some drilling bits I missed.