March 79V Fuel Cell & Installation

[ianashdown]

The fuel cell in my March 79V completely filled the LH side of the chassis side member, something like 55" long. I believe it held 18 gallons! Way more than is needed for anything I'll be racing in for the foreseeable future.

I'm going to be ordering a new cell that will be roughly half the length of the space available. If this were designed this way there would be an aluminum diaphragm built in to the monocoque, but I really don't want to alter the chassis in any non-original way. I'm thinking I could cut a section of semi-rigid foam to fill the extra space which is forward of the cell on the LH side, and the whole RH side.

Has anyone done this? What type of foam would be appropriate? I'm thinking this could add a little to the safety of the car in a side impact situation, in addition to filling an empty space, so the selection of the right foam is important. I feel it should be closed cell, non-flammable, and also offer some impact resistance. Does such a thing exist?

As a side note, I'll be ordering two LH cells, most likely from AeroTech Services as I think they build the best cell and are local to me. If anyone would like to add to my order we should be able to get a slightly better price. Please contact me and we'll see if something can be worked out.

Ian
SoCal

PS. Oh yes! It should also be light.

[racerdad2]

qualityfoam.com has several fire retardant foams to choose from

[Charles Warner]

If you are going to have to order another cell anyway I would suggest you order one that is identical to the original one. Why alter the original specs and, at the same time, impose an un-necessary limitation on either yourself or the next owner? Keeping these cars as original as possible is (IMO) a responsibility of owning them.

[ianashdown]

The cell in either car was not the original cell. They were also not made to the correct size for an SV. The original drawing shows them as being made to the Atlantic dimensions. Way more capacity than will ever be needed for any SV race these days. There is the option to run another tank in the RHS too, so the maximum capacity is potentially something like 36 gallons!

The scary thing with the cells in both cars, which are of the coated fabric style, is that they both basically fell apart! One is coming out in a pile of almost crystallized resin and the other had the feed tube fall of. The interesting part of that one is that there was no fabric in the feed tube, it was 100% resin. The thing I like about the AeroTech tanks is that they use the bonded and vulcanized neoprene style of construction. My Lola FF which sat in the CA desert for 10-12 years had a similarly built tank made by Marston in the UK and it looked quite good after all the exposure etc. I think I'll trust this style even if it costs a little less!

My intention is to make a tank more or less to the same dimensions as the original March drawing.

Ian

[Charles Warner]

Ian,

Relilze the car was probably originally designed as an F3 car which could require longer races. As for the old cell failing, I am amazed at how many expect their cells to last decades. IMO if you get 10 years use out of it you are lucky. Replacing the cell every 8 - 10 years costs les than a set of tires (usually) yet racers are loathe to spend this money on safety.

I would suggest there were cells on both sides for a reason - such as using all of the fuel. The original system would have had a relatively large cross-over line from the bottom of one side to the bottom of the other so the fuel woud naturally divide into an equal amount in each side, thereby protecting fuel starvation due to lateral loads as much as possible. Not the safest of situations but, never-the-less, common. I still suggest keeping the car as close to original as possible. You never know when that might become a selling feature.

[ianashdown]

Hi,

The March Drawing has the length, they are all the same cross section, for all the options. FSV, F3, FAtl, F2 etc.

FSV cars did indeed have a cell both sies, but the races were long enough that it made sense, plus they used to race on ovals. These days 9-10 gallons will be more than enough and that is about the size of one tank. There is a central collector and it will be very easy to fit the other side tank at a later point if required. No modifications are required to run a single tank and the panel to fit the other can be removed with the car completely assembled.

At this point I'm not going to pay double jusy for the originallity of having two tanks.

Ian

[dereklola]

Ian

Are you sure just one cell (one side) holds 18gals - I think 10 or 12 gals is more like it but I don't have my notes with me right now.

You spoke about just using a LH cell - are you going oval racing? If not I'd use just the RH cell. I believe all 79B Atlantics just used the RH cell.

Derek

[ianashdown]

According to the March drawing its 18.5 US gallons and my CAD model supports that figure.

You make a good point about RH Vs LH. I'll have to think about that. . . .

Ian

[ianashdown]

Correction.
The FAtl spec tank is 16.5 US Gallons not 18.5 as I'd previously stated. There is also another spec for the 782 which gives 14.25 US Gallons.

Charles - I'm not in anyway upset that the cells need replacing, I think that's part of almost any 'proper' restoration. What I'm surprised at is the way they are failing. The resin, which appears to be just painted over the fabric, is breaking up and coming away in pieces. It seems to me that the neoprene cells which are fabricated from fabric reinforced neoprene and then bonded together offer a more durable solution. These cell are way part their 'use-by' date and have probably been left with fuel in for years. There is no way to empty the cell completely. Might be something to think about adding . .

Ian

[ianashdown]

I pulled the cell from the LH pod of the other 79V tonight. It was a bit of a struggle, but it basically came out as a cloth bag and a pile of crystallized resin! See attached pictures. It appears to be full length also, and I'm not sure if this car has ever had a cell in the RH side at all as there is no evidence to suggest one was ever fitted.

There was a shipping label on the cell from Wilbur Bunce to March Cars so it appears that this is the original cell, which is likely as this car has only 6 races from new as far as we can tell. Interesting stuff!

[Charles Warner]

It's interesting that the shipping would have been FROM Wilbur TO March Cars. I would imagine it should have been the opposite. I don't think Wilbur was in the bidness of making fuel cells. That may have been the standard sort of fuel cell from the late 70s for some manufacturers in the UK. I know that by 1980 Marston was making aviation style cells for the Ralts.

[dereklola]

I know that by 1980 Marston was making aviation style cells for the Ralts.

Charlie - not sure what you mean by aviation style, probably because I'm not a fuel cell expert, but what I can add is that the various cars from that era that I've stripped and renovated all had similar Marston cells. All seemed to me to be "impregnated woven fabric" rather than anything applied afterwards to a "cloth" cell. Ian's pics were incredible to me!

The cars I refer to have been - 1974? Lola T340, 1976 Lola T460, your 1980 Ralts RT2 and RT4, 1979 March 79B and 1991 Lola T9150. And to repeat - all had Marston fabric cells which, visually, appeared in good physical shape although no way was I ever going to use them to hold fuel at that age. As I wrote earlier the last two needed much pulling and heaving to extract from the tub and in both cases the fabric ripped - but even then there was no sign of any "coating" flaking off. Nor on the earlier ones.

edit: - just remembered that I actually kept various 'squares' of the material from the last two for possible future use as "anti-scuff" padding - they still look in great shape. It really bothered me that they ripped so easily when extracting.

[SEComposites]

Ian, can we have some pics of your car please : )

[ianashdown]

Charlie - I was a little confused at first as to why the fuel cell would be shipped from Wilbur to March, but then I remember that the March drawing shows "Supplied by customer" for the US SV's.

Ian

[ianashdown]

Here are the shipping stickers from Wilbur Bunce to Marc c/o Rapid Movements that were stuck to the outside of the cell. I think they were just stuck on the outside of the cell, it wasn't boxed or anything! Also, the Kit List for the 79V Fuel System showing the North American SV Cells were 'Customer Supply' and lastly the panel from the Fuel Cell Drawing showing the various lengths for the different cars.

What is interesting, however, is that the cell I just pulled out, which I believe is the original cell, was not made to the length specific on the drawing. My guess is that maybe the 27" was a supplemental cell for European SV where they possibly ran the F3 RH cell and the LH 27" cell. Given that US SV's raced on ovals Wilbur may have decided that LH only was the best solution but that it would need the full 16.5 gallon capacity.

Ian

[ianashdown]

Ian, can we have some pics of your car please : )

Anything in particular?

Ian

[Rick Kirchner]

Vince Tjmeland has a beautiful March FSV he recently restored and he's not too far from you (Sabina preparation). Might give you some ideas about the fuel system.

[ianashdown]

Yes, Vince and I have been chatting about this.

Thanks,

Ian

[Bob Coury]

Kind of like what mine looked like after 7 years.

http://www.apexspeed.com/forums/showthread.php?t=62928

[ianashdown]

As part of the rebuild of my March 79V's and fitting of new tanks etc I'm going through the whole system but I have a little confusion. I'm hoping someone has knowledge of how these cars go together and can help.

It seems the RH side of the chassis was never used for a fuel tank and it was never intended to be used as the holes that are in the inner monocoque skin are in the LH side only. I have the fuel plumbing schematic figured out with one exception.

The fuel is supplied from the fuel cell to the central collector via a 1" dia tube, you can see it in the picture (RH is blocked off) and there is another small tube that is attached to that 1" tube (also blocked off on the RHS). I'm trying to figure out what connect to that tube. The breather goes from the top of the fuel cell to the filler neck - seems right - and the fuel supply comes out of the front of the collector, so I can't figure out what should collect to this small tube (indicated in the picture) unless it is a return from the fuel injection. I didn't think these cars ran a rail system, but I could be wrong.

If anyone has any insight I'd be very happy if you could enlighten me!

Thanks,

Ian

[Charles Warner]

Probably as you suspect, a return - either from the fuel pump/regulator or the rail.

[ianashdown]

The new Fuel cells have arrived and are up to Aero Tech Services high standard in every way. They are really very nice indeed. I think these are the nicest cells I've seen in over 30 years of messing around with race cars and that includes F1 an CART!

In the pictures you can see the difference in length between the original cell and the new ones. I've also added an additional 1/2" tube in the lower LH corner for a drain. I don't think it's good to leave fuel sitting in the cell for long periods. Hopefully I got the size right and it's not too much of a wrestling match to get them in!

I have some 8" wide helicopter tape I was going to use over the rivets etc, cut down to 2" wide. Anyone se any issue with that?

Ian
SoCal

[dereklola]

Ian - those cells certainly look great (ie. high quality).

Any particular reason for the large access hole/plate?
Is that plate bolted to the tub inner - or is it just "loose" inside the tub?

The original cell I pulled out of my 79B (and all my other similar vintage cars) had no access hole - foam was inserted via the filler hole.

[TED K.]

As part of the rebuild of my March 79V's and fitting of new tanks etc I'm going through the whole system but I have a little confusion. I'm hoping someone has knowledge of how these cars go together and can help.

It seems the RH side of the chassis was never used for a fuel tank and it was never intended to be used as the holes that are in the inner monocoque skin are in the LH side only. I have the fuel plumbing schematic figured out with one exception.

The fuel is supplied from the fuel cell to the central collector via a 1" dia tube, you can see it in the picture (RH is blocked off) and there is another small tube that is attached to that 1" tube (also blocked off on the RHS). I'm trying to figure out what connect to that tube. The breather goes from the top of the fuel cell to the filler neck - seems right - and the fuel supply comes out of the front of the collector, so I can't figure out what should collect to this small tube (indicated in the picture) unless it is a return from the fuel injection. I didn't think these cars ran a rail system, but I could be wrong.

If anyone has any insight I'd be very happy if you could enlighten me!

Thanks,

Ian

Ian, for your info,
If your FSV originally ran a fuelinjected VW- like my '78 Wheeler there is a fuel return from the Bosch mechanical fuel injection pump-not the fuel pump- to the top of the fuel cell. I don't think the Lucas fuel injection was in use that early. When I first rebuilt my Wheeler in 1995 the Fuel Safe fuel cell looked just like yours-powdered resin and fabric. The original tank was 16 gal. and I replaced it -in1996- with another Fuel Safe 10 gal. cell apparently made from the same material. The 6 gal. empty space under the cockpit is filled with styrafoam blocks. The original cell was stored empty for 16 yrs.-1979 to 1995,hence the degradation. The new cell was kept full from 1998 till a crash in 2007 and then kept empty and vented -no foam or fuel-till 2014 when I rebuilt the car. The cell today, with no leaks, looks like it was in 1996. The foam shrank a little but is still usable.
My Caldwell D10 has been similar. I replaced the original ATL fiberglass coated cell in 1973 with a new version-glued rubberized fabric-ATL cell. That cell has also been kept full-except for a 1 yr. rebuild in 1977, in storeage from 1998 to 2012, and today still ,with no leaks, looks like the day I received it from ATL.

Luck with your project,

Ted K. greyeagles@msn.com

[marchsv]

Looks great Ian!!!

Best of luck with her

Tom

[ianashdown]

Derek,
The tank shown earlier in the thread was the original tank in one of my 79V's and it had an access plate in the middle. It doesn't attach to the tub, just sits unsupported. There was no foam in that one.

The only other openings are two 1/2" tubes and one 1" tube so the only way to get the forms out and the foam in via the access plate.

The quality of these cell is superb. I would, and do, recomend these guys to anyone!

Ian

[ianashdown]

Ted,

Great information!

I think the return must go to the small tube in to the collector. There was no return on the original cell, and this is the only place that makes any sense.

I have to say I think the Aero Tech material, and method of construction, is giving me peace of mind. It should outlast me!

Interesting that your tank was kept full for all that time. I know that is (was) the practice for aircraft, but I'm not sure I like that much gas sitting in my garage! I'd rather empty and vent the cell 'till the next time it's needed.

All the best,

Ian

[TED K.]

Ian,
Just to be sure, when I say vented , the coverplate was off and the foam was out.

Ted K.

[ianashdown]

That is truly, vented! I wasn't thinking it'd take that much but you may be correct . . .

Ian

[Lola_T360]

Charlie - I was a little confused at first as to why the fuel cell would be shipped from Wilbur to March, but then I remember that the March drawing shows "Supplied by customer" for the US SV's.

Ian

March always used Marston cells in their production, but I think that maybe there was a USAC rule for cars running the mini-Indy series to have a particular spec (and American made) cell. I've come across this on a Ralt RT1 that ran that series - and again, Ralt only ever used Marston.

[ianashdown]

If you look in the original Parts list for the 79V which is available online, you'll see it shows "Supplied by Customer" for the US Supervees. My cell had a shipping tag stuck to the outside showing it was shipped by Wilbur Bunce Via Rapid Movements (the freight forwarder that everyone in the UK used) to March Cars. This would support the "Supplied by Customer" note in the parts list. I had no idea that this may have been a USAC requirement but that seems totally feasible.

Ian

[Steve Demeter]

There was a USAC spec. I knew two guys who had to buy USAC cells to run their cars in the pro series circa 1980. The USAC cell was tougher than the tires as far as the bladder went.

Had to stand something silly like 100 psi.

[Snakedriver]

We always kept our fuel tanks topped off in the Army. But Jet fuel is a lot different than gasoline. However, I never remember changing out a cell because it was breaking down. In fact Im not even sure if they were on a calendar maintenance cycle.

During this time I was working on UH-1s that were as old as me...20 years or so.

So if they can resist gasoline, they should be serviceable for 15 to 20 years...If my memory serves correctly.

Leo