mgb fuel injection tank

rkas3882 · October 25, 2011, 12:41:49 AM

hey guys, i plan to fuel inject my mgb v8 conversion. how have you all done it? i am going to buy a new tank and modify it. did you use the late fuel sender unit to suck the fuel through or did you weld in a 3/8 line? pics would be great. thanks
Randy

kstevusa · October 25, 2011, 03:19:45 PM

There are several articles available if you enter "EFI Tank" in the SEARCH portion of the page. You can pick & choose what feautres you like from them.
SAFETY FASTER! BTY, The British V8 meet in next May In Palestine Tx. Stay tuned for Updates

Steve Mc · October 28, 2011, 01:25:29 PM

As Kelly notes above, there's amillion ways to do it.

I use the unmodified stock gas tank ('73). The stock SU pump feeds a surge tank, the surge tank gravity feeds a TR7 EFI high pressure punp. The return line from the fuel rail recirculates through the surge tank. The overflow from the surge tank is sent back to the gas tank through the no longer used carbon cannister return line. It's alot more complicated that it needs to be, but that's part of the fun.

AL WULF · October 28, 2011, 05:20:55 PM

I think running a in tank fuel pump is the way to go, eventhough that isn't what I did. When I put Rover Hotwire injection on my car in the summer of 2008, I plumbed in a 3/8 inch return line at the front of the tank and I hooked up a Airtex E8228 (125 PSI, 35 GPH according to the specs) with a fuel filter ahead of the fuel pump. It worked well with the Buick 215, except for being noisy and really obnoxious when driving all day. The next pump was a Airtex E8445 with less pressure, the same GPH and still noisy even when mounted on a rubber pad. Both external pumps had a tendency to scream which I think is a indication of cavitation. When I replaced the 215 V8 with a 3.9 Rover it seemed like it was sometimes fuel starved. When I took off E8445 to inspect the plumbing, I dropped it and broke it. I replaced it with a E8446 which worked OK, but started to fail on the way back from Townsend last May. About 50 miles east of Russell, Kansas the car would start surging, and finally stop until I let the pump cool. I limped into Russell, but soon found out that you can't buy a high pressure EFI pump at any of the local parts stores. Summit Racing, nor anyone else overnights anything into Russell. I did order a Accell 74701 which turned out to be 3/8" in and out eventhough the Summit parts guy told me it was 5/16 in and out. We didn't want to wait until Monday for it to arrive, so early Saturday morning we left, and made it all the way home by letting it rest whenever it would surge. I used the Accel pump for most of the year but still wanted one with 5/16 in and out, so I replaced it with a SUM G 3138 (45PSI and 43 GPH). It works as well as the 74701 but is nosier and still cavitates occasionally, but almost continuously if the ambient temperature is above 80.

All of the pumps except for the 74701 were 5/16" in and out because I wanted to use my original fuel line. I'm wondering if it would be better to switch to 3/8" lines, and maybe the extra fuel volume might cool the pump better. That said, I think installing a in tank pump like Kelly did is the way to go.

Al

kstevusa · October 28, 2011, 06:23:45 PM

Al, I run the GM in-tank out thru AN-6 but use the original 5/16" line and also use a 5/16" return. I have not fuel starvation on a full throttle dyno pull: therefore I suggest the 5/16" is adequate for my 5.0L engine. anything larger may require a 3/8" line. I do no think I could run any smaller line. Who cares if you run at Max capacity on a fuel line at WOT. Dyno was only time I ran WOT. Hope to see you in TX. in May

AL WULF · October 29, 2011, 10:04:04 AM

Kelly,

I'm looking forward to going to TX next May.

Al

BMC · November 19, 2011, 09:31:43 PM

Randy,

We sell a tank specifically built for MGBs with fuel injection. The stock pump holds up to most V8 and super/turbo charged applications. If your going beyond 350 BHP, then we can install a higher rated fuel pump.

You can see it here:
http://bmcautos.com/shop/index.php?main_page=product_info&products_id=153

If your planning to build your own and you have a good tank, there are plenty of little things to consider.

Personally, if we were not installing a tank with an internal pump, I will only use a single pump system. I see too much complication, too many chances for additional failures, added costs and more for a dual pump swirl pot system. The single pumps wil eventually wear out quicker but I have seen and read about more problems with the dual system than any single system.

-BMC.

david_mckay63 · March 30, 2012, 12:27:43 PM

Hello

can anyone advise how far to the left the fuel tank has to be moved in order to center it?

rficalora · March 30, 2012, 05:28:50 PM

Going from memory David, but seems like it was about 3" when I moved mine. But it's pretty easy to measure distance from the tank to the frame rails on each side. 1/2 of the difference is how much you need to move it to center... unless you don't have the car handy?

Are you doing an engine swap? I'm right up the road (290/Barker Cypress area).