leak proof mechanical fuel pump gasket

[xctasy]

Modern fuels are a lot more aggressive to rubber...and I plan to boost my engine. Anyone got any ideas for a sump to mechanical fuel pump seal ?


Is there a way of permanently leak proofing a mechanical fuel pump from dropping gasoline into the sump when the diaphram fails?




I've had two six cylinder fuel pumps fail this way over the last 20 years, they drop fuel into the sump.

First was in 1996 when high aromatic 96 octane fuel was introduced as an Unleaded replacement for Leaded 97 in New Zealand. My 1984 Falcon 250 Carter fuel pump failed.

After a six month lay up, in 2014, my Carter fuel pump failed the same way in a 3.3 Fox.


I know the seal is cheap to fix, or the pump is easy and cheap to replace, but what if I'm pushing 8.5 psi like most 5.0 pumps do and the diaphram fails. The gasoline always goes into the sump then.

[Ethyl Cat]

A block off plate and electric pump if you are going to bring the boost.

[xctasy]

Yeah, block off plate and electric fuel pump is not an option. And not because it isn't a great idea, either. Any kind of fuel delivery system changes from stock 1983 and earlier Fox isn't an option. Too many problems with running dry fuel issues, since my car will be run dry. I don't want a stillage pot, EFI, or any kind of fuel delivery change except a return line.


Basically $650 ping plus container charges from B/C or Crompton gets me a Mercury XR7 Cougar.


With that I can make a turbo charged Ak Miller style XR7 as shown in Jay Stroers Propane Performance book. With 255, a blow through DGAS 38 Weber running on gasoline , and resleeved bores to 4.1 liters. This won't be LPG. Trip Minder, Digital Dash, AOD, vapor return line as per VV7200, MCU fuel and idel control, but with





non VV carb like this or a mixture between the 350 Holley and the unstaged ratchet 38 DGAS Weber


and the carb boost referenced carb like this



Basically like the AMA Banned Supercharged Mercury and Ford F code 340hp superchardged 312's below.




For fuel control, there is a potential membrane system like the French Solex 2-bbls used in the front drive Le Car R5 Turbo and the non EFI Solex 2-bbl carbed JDM and 1983-1984 NZ/United Kingom Colt Mirage/Cordia/Tredia Turbo.




Only thing is the membrane seals, if they are in gasoline, can rupture due to the amount of benzine and alcohol base in the fuel. Kind of like the old CDS 175 Zenith Strombergs. .

I turbocharged my Cologne V6 Cortina with a propane Impco CA 300A5 and a Ford Probe IHI RB6 turbocharger, and the viton seal kept blowing.


I can manage the carb side of thngs, that's easy. Its making a boost referenced Carter M4891 Super Strip pump for 350 Chev reworked to suit. Its got a cast in line to boost reference.


Its just safegarding a flow through rupture. Surely someones put a secondary seal in to prevent it happening in race cars that have to use mechnical pumps?

[Walking-Tall]

What about a sheet disk, a virtual 2nd diaphragm, loose enough in there to account for the strokes, a barrier of alcohol-spec GLFT (like the light blue/green components like Holley accelerator pump diaphragms for alcohol use... must be able to get that stuff in bulk sheeting someplace...) or equivalent alcohol-resistant (polyurethane?) material in there above the diaphragm, isolating it from the "gasoline", and putting an end to the rubber diaphragm failures due to the chemistry?...

[grabbergreen84]

Why the aversion to an electric pump?

If you're worried about a visual inspection or something like that, just gut the mechanical pump and mount it over a block-off plate. (Plus a line inside of it to connect the input and output.) Then add an electric pump, and plumb it through the now just-for-looks mechanical pump, and there you go.

And then you can lose the cam eccentric, and take that little bit of rotating weight off of your valve-train!

[xctasy]

Nah, totally respect the general view point you all offer. Its just the the fact that I'd like to offer a kit, and fuel control systems have improved so much that its possiable to get a better result with a boost referenced fuel pump and old carb FoMoCo systems than all the 1983 2.3/ 1986 5.0 sequential port add ons.

Ford wisely decided advancement in design would be via its 4 and 8 cyl cars going EFI early on, and the sixes were just there for making production inventoris when they couldn't get 4's and 8's. They never made a true first generation turbo with mechanical systems.

When making cars, you don't really care how much more complicated an EFI Fox is over a carbed one....the massive amount of engineeering to bring a car up to EFI spec doesn't bother Ford. The issue is that a heack of a lot of stuff has to be done just so for safety's sake, and 90% of the time, homemade retro fits have short cuts made. I'm not interested in short cuts, I'm interseted in pushing the old pre OBDII carb Foxes as hard as they can be.


Most of you guys won't remember the Ford Six and Classic Inlines guys who did the 10 second 1963 Falcons and 13.5 second 1984 Mustangs with the 1969 250 and 1983 LTD 3.3 engines. Just adding boost took the cars from 20 second 1/4 miles to 10 and 13.5 second quarters, and although they did blow up, I'm certain I could have done the same thing via a V8 Carter mechanical pump and some 60's Hugh McInnes tech on a small V8 and gotten a better result.


The Japs, French and English made there Turbo cars carbed and boosted cars work really well with just basic fuel pumps.

[xctasy]

I've got an In line six solution. Not SBF

I worked it out a few months ago, although I had the info way before that.


They always say"Never run a turbo out of fuel".

I'm a luddite, I don't like submersible electric fuel pumps, they are a stupid idea, and create in service reliabity problems becasue fuel isn't ever clean, and none of the parts can last the same 50 years my old AC fuel pumps could. I spent 2 years working with Grunfos staged submersiable pumps when Gold Mining...we had constant particulate problems, and had to do rutine praventative maintenace to get them working. We just decided to use an air lift pump, and an Ingersol at surface pressure system in the end.

I feel that suppliers to the industry aren't focused on long term solutions, becasue the working life of a car is really 7 years, not 17 as it used to be. Or 37 if its a Fox, or 57 if its a 1960 Falcon....

The problem I have is my CFi Toyota 1.8 Corona does 32 mpg, and its never had its eectric fuel pump replaced.


Going back to leak proof Mechanical Fuel Pump gaskets, and thinking boost, I got this:-

The best bet , the Rolls Royce mechanical fuel pump for a Ford I6, is the 120 gph Carter M4891 Super Strip pump for 350 Chevs It's a little X'y regards dollar purchase but it works.




Then you boost refrence it. For sub 9 psi boost, thats about it


https://www.theturboforums.com/image.../engine8-1.jpg[


https://www.theturboforums.com/attac...mp-jpg.459271/


For 12 psi and more, people need to see where the C***y boys have headed.


General sub 9 psi boost level rules are:-

Dave Emanuel--Super Tuning and Modifying Holley Carburetors:

In blow-through systems using a mechanical fuel pump, the upper chamber must be referenced to boost so that the pump will develop sufficient pressure to deliver fuel to the carb float bowls. A sealed operating rod is also required so boost pressure does not escape into the crankcase.

The area above the pump diaphragm must be sealed off from the crankcase. By connecting this chamber to boost pressure with an external line, the pump will always be supplying fuel at its normal pressure above boost pressure.

.... you can see the modifications necessary to the mechanical fuel pump. Basically a fitting is threaded or epoxied in this case to the atmospheric vent on the side of the pump. I added two in this case to ensure adequate pump operation at high RPM. The other end of the hose is connected to the bonnet, BEFORE THE CARB, this is required. With this modification fuel pressure to the carb is increased 1 psi for each psi of boost to maintain fuel flow into the carb under boost. This can also be done with a high pressure electric fuel pump and a boost referenced regulator. Also seen here are the turbo oil supplys from the oil sending unit location in the engine block.

Long time turbo 200 Ford Sixers

hasa68mustang
&
kirkallen143

are two guys who have found the mechanical pump idea wanting...like everyone who tries to run over 9 pounds finds...they weighed in on the thread above. They towed the Ak Miller Ford party line, that above 9 psi boost is a bad idea with any mechanical pump.

I don't, tt350 chevelle's system really works, For Fords, we don't have the C**** pocketed fuel pump arrangment. You can use the same scheme if you use a shortened C**** pushrod, and hold it to the cam with a honed intermediate plate.

Here's tt350 chevelle's decription of his SBC carb turbo with Carter Super Strip fuel pump. It allows the pump to be mounted with the diaphram downwards, although if you want to, you can run the pumps either way.

This mod closes off the the drain area and allows proper boost pressure to be seen at the diaphram, the "leaking" boost from the pump seal has no place to go.This worked as I expected but the fuel pressure would rise at a greater rate than 1:1, it was easy to get 20+ psi of fuel pressure (running about 8psi boost)

The solution to boosting well past the 12 psi level safely is to seal and pressurise the fuel pump with a SB Chevy method.

Run the pump off a shortened C**** pushrod, and drive the Carter Super Strip pump via the C**** rocker arm.

They have a 1/2" rod 5.75 or 5.95" long, which operates off a 0.337" max lobe lift.



https://www.theturboforums.com/threa...l-pump.314799/



https://www.theturboforums.com/attac...le-jpg.459272/



Fords I6 era pumps had Eccentric total lift of 0.290-0.310 inches. Basically, you add an additional steel plate with a 0.505" hole, and seal the fuel pump off, and use tt350 chevelle's presurised chamber method. Splash lubrication works for the times of lower speed, lower pressure.

The SBC pushrod operated pump has an intermediate plate covering a vented to the crankcase pocket.
http://i1207.photobucket.com/albums/...ps7347c8d5.jpg


Inside, the pushrod moves in the cast iron machined bore, with the drain hole below...
http://www.chevydiy.com/wp-content/u...014/01/162.jpg

All the FE era onwards Ford V8 stuff traditionaly had 2.5" eccentrics, with strokes of 0.581 to 0.700 via a pushrod, so they don't work. Nor does the old 0.200" stroke Flathead Ford system.

I haven't worked with them yet, but the SBC Billet Piston fuel pump is pushrod operated, and it looks like the ideal solution




https://www.summitracing.com/int/par...1500/overview/
http://www.competitionplus.com/drag-...ston-fuel-pump







I'm not a Nancy, love EFi, but I've seen nothing but in service trouble with Port EFi and retrofit 4bbl EFi systems, both here in New Zealand and, um, here

http://vb.foureyedpride.com/showthre...51#post1720151


I'm a pretty good techie after a lot of work with computer systems, but the modern era is a lot more ropey...if I'm selling a 12 to 14 pound boost turbo engine, I don't want to be dealing with the same faults we have with aged EECIV wiring, or a system laying idle because its unable to have get a fall back system on line to solve a problem. Those earthing faults, wiring, and system degradations can be spread over the entire car, and its fuel delivery system.

I consider all my carb Fords to have been supperior with respect to carefree day to day running, the newer may rank well within there pears, but definetly not in comparison with there forbears.

The in tank EFi fuel pump, well I can't afford to be Found On/off the Road with a Dead engine, and already its happened with my Nissan, my 98 Explorer XLT, yet my carb 1981 Stang scavanged down to 11.4 gallons of gas with prewarning, my EFi gasoline and Diesel cars are down right dangerous in a one in 5 shoulder just idling. How can modern fuel injection units be so bad at stranding people on gradients and in terms of year to year reliabity, I just don't know...Well I do...its the lack of stillage pots, long life non aerating return lines, and understanding that in an automatic 4 x 4 car on a gradient, running out of gas due to sub-par tank design is just not an option for me, and shouldn't be for anyone else.

I'm just lucky I carry fuel to top up.

Never mind. The engine bay and engine mounted Billet Piston fuel pump is hope for the safety and simplicity conscious like me, I hope.


For the Winsdor and Cleveland and Lima and FE's, I don't really know if there is a boost able mechanical, non electric fuel pump option unless I spend some time transferring the pushrod system over to those engines.