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Electric fuel pumps

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Some BMW's, before intake pumps became the thing,, have the fuel pump mounted in a rubber container.  The rubber container/bottle thing is the part that get bolted to the car.  I'll post a picture if I find one.  80's cars seems like the range, if I remember.  The container is about the size of an aftermarket Airtex EFI pump.

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I am using a carter pump do not remember the model #. but is in the post by me as I installed it last year. I can tell you it  is as quiet as a mouse. the most pressure I can get out of it is 3.47 lbs with a pressure regulator and  the 3.47lbs is more than enough for the su carbs.

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57 minutes ago, kully 560 said:

just check the posts it is a carter p60430

Thanks for that info, that pump was on my list to try. I'm sure Capt. O will wait to hear it on my car :)  

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I shot some pictures of the fuel delivery setup on my race Z with the stoopit phone the other day.

The rules require a flame retardant bulkhead between the fuel cell and the passenger compartment, so I built one with aluminum sheet picked up at Boeing Surplus in Kent, Washington (now closed and only available online - I used to go there a couple times a year, and bought lots of materials and abrasive supplies there). It also makes a great place for the dash plaques from the races I have competed in.

The supply lines start in the rear corners of the fuel cell, there is a sump about 4” square to ensure an ample supply of fuel under acceleration and cornering. Passing through the access plate the lines then go through 10 micron screens, the Carter fuel pumps, check valves, then are joined up, passed through the floor bulkhead and connected to the steel tubing going to the engine bay. There a short flex line connects to a red Holley fuel pressure regulator with a gauge. The regulator has two outlets, so I ran one to each carb.

The engine is prepped to ICSCC Production Car rules. Cylinder head to to manifold port matching, and necessary blending is allowed. Although never on a dyno, the guy that ported and flowed the head, manifolds and carbs estimated a theoretical 230 horsepower. Notice I mentioned the entire intake and exhaust path was on a flow bench. We realized huge gains with some creative work, including altering the length of the intake runners by using two isolators between the carbs and manifolds (gasket type and thickness is free by the rules).

More important was with the the increase in airflow over a “stock” setup, with my “stock” setup, along with the increased demand for fuel. This dual pump and pickup configuration supplied fuel adequately for the rigors of racing, so it would certainly be a decent setup for a street driven Z, especially one that has been breathed on a bit.

3349A88A-EF3E-42DF-B6EF-1144622ED7F9.jpeg

544E8E93-403D-453A-B14D-8704BE66336D.jpeg

Edited by Racer X
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Double stack carb spacers? Never heard that but I'm no racer.

2 x these with longer bolts will add power? With a mechanical pump or would you need the electric like you have?

I'm thinking of switching to SUs on my EFI '77 2.8 that's been "breathed" on a little bit. Opened up the ports to a trumpet looking match. 

It's either play with what I have or get another motorcycle, my Mom's still alive but another bike and she would drop dead. " I'm coming Elizabeth!! the dummy bought another motorcycle".

I'd have to go electric for my N42 head. I have a high lift cam kit sitting on a shelf, MSA calls it a stage 3. I think it's a schneider 274? Yep, .480.  http://schneidercams.com/274FL6.aspx

Carburetor Insulator Spacer and Gasket OEM 240Z 260Z | Z Car Depot Inc

Edited by siteunseen
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20 hours ago, siteunseen said:

Double stack carb spacers? Never heard that but I'm no racer.

2 x these with longer bolts will add power? With a mechanical pump or would you need the electric like you have?

 

Well it is more complicated that simply adding a couple of spacers and longer studs.

The extra 12 or 14 millimeters the added spacer give is only part of the whole package. As I mentioned, the entire intake and exhaust stream was included in the flow bench testing, before and after the work. Port matching, smoothing everything along the way, work done around the valve guide bosses, three angle valve seat cutting, etc.

Also note the short exhaust system after the exhaust manifold. There is a relationship between the length of the intake runners and the exhaust, including the headpipes and muffler. The rules require the exhaust exits aft of the steering wheel hub, and meets the maximum decibel limits. I used the largest primary pipes, joined at the elbow just before it exits from under the car, and the muffler is a Lowbak used in circle track racing. Looks like a glasspack, but it isn't. A 3/4" length of tubing runs down the middle, wrapped with a piece of flat stock wrapped in a spiral around it, inserted into the larger tubing, welded in, and then the ends are swedged down to create what looks like a glasspack. There is no fiberglass packing in the muffler. It works very well, and my car never even came close to the decibel limits.

So, yes, it does add some power, and it is measurable on a flowbench. The carbs have had extensive work done too, to increase and enhance airflow through them, resulting in more fuel being drawn from the float chambers.

I also cheat the cam lift some by running tighter valve lash, which gives another couple of thousandths of an inch of valve lift, and effectively more duration.

A comprehensive package that results in more power output.

 

Oh, and I don;t run a mechanical fuel pump. I have never been a fan of them. When the diaphragm fails, fuel gets dumped into the crankcase, diluting the engine oil, which is not a good thing.

Edited by Racer X
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So I assume the OE airbox wouldn't be viable? LOL

Hell it's a pain to get it off there now with the one insulator.

Thank you Racer X. I love learning stuff. Maybe I can figure out something useful from your info.

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7 minutes ago, siteunseen said:

So I assume the OE airbox wouldn't be viable? LOL

Hell it's a pain to get it off there now with the one insulator.

Thank you Racer X. I love learning stuff. Maybe I can figure out something useful from your info.

I removed the velocity stacks from the airbox and mounted them to the carbs, and use a pair of Uni foam motorcycle air filter socks. No trouble fussing with a bulky airbox.

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