sf4018 Posted May 28, 2021 Share Posted May 28, 2021 (edited) I’m working to get my 420R eligible to race in the HSR series, they have all the usual safeties as a requirement to enter, all of which I already have with the exception of the fuel cell. It’s taken almost a year to get the cell and parts due to the supply chain disruptions in the UK plus not knowing whether to keep the internal fuel pump vs getting an external one and a bunch of other stuff that I really have no business trying to make decisions on. I couldn’t find any fuel cell installation posts anywhere (maybe someone knows of a place?) so I figured I’d document this attempt. Here’s the shipment from Caterham of parts and the certificate from ATL... I have no clue right now what the pumps mount to and how the lines are plumbed. Definitely not the straight swap I was hoping for, but it’ll be a fun challenge. Gonna start the install after a VIR track day next week. This is the parts list... Stock code Quantity per Description 1221310053 2.000000 BRACKET COIL & ROVER FUEL 30T043A 2.000000 ADAPTOR-FUEL FILTER TO 380T0001A 1.000000 FUEL HOSE - PUMP/FILTER TO FUEL RAIL 5249970000 1.000000 FUEL PUMP-REMOTE VX RACE 73013 1.000000 BOOT BOARD-99>DD(H/COMB)- 73014/55 1.000000 55 LITRE FUEL BAG TANK-UN 73015/55 1.000000 55 LITRE BOX FOR BAG TANK 73052R 2.000000 BOLT-FUEL TANK RETAINING- 73055R 1.000000 BRAIDED FUELLINE-TANK/PUM 73213 1.000000 FUEL PIPE-INJECTION ROVER 76151 1.000000 EXTENSION-FUEL PUMP-ROVER 79714 1.000000 BOOT BOARD-90> DE DION EDP9976 2.000000 O-RING-FUEL FILTER ADAPTE GFE7020 1.000000 FUEL FILTER-RACE INJECTION (+ROVER) HEF7-6-5 1.000000 FUEL UNION-FOR BAG TANK WG17 1.000000 GROMMET-H'BRAKE CABLE IN WKB100250 1.000000 FUEL PIPE ASSY-FILTER TO ZFT04K 1.000000 HARDWARE FUEL SYSTEM Note from the future: a lot of plumbing parts in the list above ended up being unused or not needed, consider your own solution. Boot board was also not needed. Also there is a new GT bag tank that is a virtual straight swap and a lot simpler to install (with the exception of mounting if you have an SV). Edited August 25, 2021 by sf4018 Link to comment Share on other sites More sharing options...
bball7754 Posted May 28, 2021 Share Posted May 28, 2021 I’m no help with fuel cell install, but curious what class you will run in with HSR? Link to comment Share on other sites More sharing options...
sf4018 Posted May 29, 2021 Author Share Posted May 29, 2021 Group 11X I think, some of the cars in that group are 10 seconds a lap faster, the 420R is not really going to be competitive, it’s just an excuse to hang out with some neat folks and amazing cars at iconic tracks. Link to comment Share on other sites More sharing options...
Croc Posted May 29, 2021 Share Posted May 29, 2021 Definitely there are Caterhams around the US with fuel cells. No one ever documented the installation to my knowledge. If you feel uncertain about doing it yourself, a good race shop could help. If you are still in existing 420 engine spec then why not reuse the in tank fuel pump? Its a solution that works and saves you money of buying something extra. Link to comment Share on other sites More sharing options...
MoBoost Posted May 29, 2021 Share Posted May 29, 2021 There is this: http://lotusowners.com/RepairsUpgrades/Stock Tank Conversion/index.htm Kind of sparse. Tony V. would know more. Link to comment Share on other sites More sharing options...
Kitcat Posted May 29, 2021 Share Posted May 29, 2021 Bruce Beachman (Beachman Racing) installed the fuel cell on my Caterham, so may be a useful resource. I recently had it rebuilt. All customized as it is a 21 gallon tank. Not cheap. For instance, the top of the tank alone, with the filler cap was $1,800. I think the total cost, including installation (2x as there were glitches), was around $8K. That included a new tank, liner and foam. It does not include the cost of redoing the fuel system which was a separate adventure ($$$$) Off the shelf parts would have helped. Link to comment Share on other sites More sharing options...
sf4018 Posted May 29, 2021 Author Share Posted May 29, 2021 6 hours ago, Croc said: Definitely there are Caterhams around the US with fuel cells. No one ever documented the installation to my knowledge. If you feel uncertain about doing it yourself, a good race shop could help. If you are still in existing 420 engine spec then why not reuse the in tank fuel pump? Its a solution that works and saves you money of buying something extra. Caterham said the internal fuel pump cannot be used with the fuel cell, so I got a new external one that they use for their race spec 420R. I took a peek inside the new tank and it’s full of this sponge material so maybe that’s why, dunno. The parts list doesn’t seem complete, I can’t see how the pump and filter connect right now, plus the new tank is much larger than the existing, so the aluminum honeycomb is going to have to come out, which means the roll cage has to come out, which means the rear dampers have to come out lol. ThIs is not going to be quick or easy. Link to comment Share on other sites More sharing options...
sf4018 Posted May 29, 2021 Author Share Posted May 29, 2021 4 hours ago, Kitcat said: Bruce Beachman (Beachman Racing) installed the fuel cell on my Caterham, so may be a useful resource. I recently had it rebuilt. All customized as it is a 21 gallon tank. Not cheap. For instance, the top of the tank alone, with the filler cap was $1,800. I think the total cost, including installation (2x as there were glitches), was around $8K. That included a new tank, liner and foam. It does not include the cost of redoing the fuel system which was a separate adventure ($$$$) Off the shelf parts would have helped. Yikes! Yeah I’m trying to replicate the Caterham factory installation with as much of their parts as possible, I think I’m most of the way there with the materials with the exception of odds and ends like off the shelf mounting hardware and maybe fuel hose. Link to comment Share on other sites More sharing options...
Croc Posted May 29, 2021 Share Posted May 29, 2021 Eeek! That is more involved than I thought it would be. Bit surprised to hear the honeycomb has to come out - interesting. The sponge is fire retardent foam. So yes that would stop an in-tank pump from working. Edited to add: Kitcat has a very different installation from the Caterham fuel cell. Far more bespoke and professional than the average Caterham given it was originally built for a 24 hour race. Link to comment Share on other sites More sharing options...
Edger Posted June 10, 2021 Share Posted June 10, 2021 On 5/29/2021 at 9:23 PM, Kitcat said: Bruce Beachman (Beachman Racing) installed the fuel cell on my Caterham, so may be a useful resource. I recently had it rebuilt. All customized as it is a 21 gallon tank. Not cheap. For instance, the top of the tank alone, with the filler cap was $1,800. I think the total cost, including installation (2x as there were glitches), was around $8K. That included a new tank, liner and foam. It does not include the cost of redoing the fuel system which was a separate adventure ($$$$) Off the shelf parts would have helped. Sounds a bit expensive job. Link to comment Share on other sites More sharing options...
sf4018 Posted June 11, 2021 Author Share Posted June 11, 2021 Started the disassembly…straight forward so far though the aluminum honeycomb doesn’t come out of the top, hopefully it drops down after the tank is removed. Anyone know how to remove the fuel line shown in the pic below?? Link to comment Share on other sites More sharing options...
sf4018 Posted June 14, 2021 Author Share Posted June 14, 2021 The old tank is removed. There aren't many technical points to note for disassembly except that the tank is lifted out not lowered, so the roll cage and dampers needed to be removed to allow aluminum honeycomb and then tank removal. One item that is unknown right now is whether the drivetrain needs to be removed to allow fuel pipe installation. The existing fuel pipe is mounted under the topside of the tunnel so it's pretty much inaccessible without removing the drivetrain. The hope right now is the new pipe can be installed without having to do this. Cross fingers! For the installation I'm waiting on 3 bits of info from Caterham to move forward... 1. New tank mounting: The old fuel tank was 91cm wide, the new bag tank container is 80cm wide. So the lower black tank brackets on the car are too wide for the new tank (55mm gap each side), see picture below. I've asked what the correct mount method for the underside is. 2. Electrical Wiring: The original tank had a ford/rover pump and tank level sensor which was connected with a 6 pin connector with 4 wires to the tank. The new tank has a Bosch external pump and no tank level, and 2 wires for the pump only. See pics below. The questions to Caterham are: a. Do I keep relay AU5A-9D370-FC and existing wiring intact? (I believe yes) b. Which of the 4 wires connect to the 2 pump wires? (I think pink and yellow). Original 6 pin connector with 4 wires: •Pink/White •Black •Green/Black •Yellow/White 3. Pump and Filter Mount Location, plumbing: I've asked Caterham for info about where they normally mount the pump and filter, plus pics of the plumbing. I really have no clue about this part. Link to comment Share on other sites More sharing options...
sf4018 Posted June 22, 2021 Author Share Posted June 22, 2021 Caterham sent 3 pics of a bag tank installation that's in for service right now.... The first pic shows a pressure regulator (yellow part) with return to tank and presumably line to rail but cannot be seen. The metallic part before that looks like a sampling device (I guess they have that in the UK). I don't believe that'll be needed in the US unless someone thinks otherwise. Caterham did not include either of these parts in the original shipment so this has spawned more questions. This is the mount location for the pump, which is very helpful. No filter though, another question. Bottom up view of pump installation. It mounts to the tank box. Link to comment Share on other sites More sharing options...
sf4018 Posted June 25, 2021 Author Share Posted June 25, 2021 (edited) Electrical Wiring: Nothing from Caterham yet despite pleas, so I've gone into reverse engineering mode. Here's a diagram I made of the existing pump module/fuel tank harness wiring. Everything is known except for a mystery GY wire that goes to the pump module. My hope is GY is some kind of engine running signal but I won't know until the job is done (it's not ignition it didn't switch on when I cranked the engine). .... Based on some testing I did the current system energizes YW for about 1 second after turning the key to the 2 position (YG154 energizes), which pressurizes the fuel lines in preparation for cranking and starting the engine. Then presumably the mystery GY wire will switch the pump on full time. The system I'm building will have a pressure regulator with a return to tank so this pulse is probably not needed and can just stay on full time with the key in the 2 position. I'll be cocking about with this once the system is ready to startup as I don't know whether the control module should/can be eliminated yet, but in terms of electrical wiring it's a pretty simple change. At least there's a plan, hopefully it's correct! Note from the future: GY wire was a pump run command from the ECU. Plan A is best if you have an unlocked ECU. Plan B also works but stays on even if the engine is stopped so is not quite as safe. Edited September 29, 2021 by sf4018 Link to comment Share on other sites More sharing options...
sf4018 Posted July 25, 2021 Author Share Posted July 25, 2021 Missing parts came in finally so I’ve got this weekend to do as much as possible before vacation or otherwise out of pocket for the next month. Added 2 strips of angle for the new tank to sit on, which is bolted on the old tank brackets. It’s a tight fit but it does fit. Glued on rubber cushions and then added some stoppers on the strips to stop any lateral movement of the tank… Note this is only needed for SV width. Next is mounting the pump. I removed the bag from the container, then placed the container, tank to pump pipe and pump in mounting bracket and mocked up to position it correctly then marked off where the holes should be drilled. Bolts face out and the bolt heads taped up to prevent chaffing of the bag… Link to comment Share on other sites More sharing options...
Kitcat Posted July 25, 2021 Share Posted July 25, 2021 Here are a couple of shots of my fuel cell setup. Not sure it helps. It is a return system. All built by my mechanic, I have no info on the details or setup. The fuelline hose that runs up along the rollover bar is the overflow line, not pressured. Tom Carlin runs these thru the hollow bar, which is much more elegant/tidy, on his Birkins. There is a catch can by the drivers’ side rear suspension. The red switch on the rear bulkhead is a separate off/on for the pump. Link to comment Share on other sites More sharing options...
sf4018 Posted July 25, 2021 Author Share Posted July 25, 2021 Thanks for the pics, the switch is a good idea, I’ll add that. Do you have a fuel filter in the system? They sent me one but their pics didn’t show one. Link to comment Share on other sites More sharing options...
Kitcat Posted July 25, 2021 Share Posted July 25, 2021 I will take a pic of the filter tomorrow. It’s just past the fuel pump. I also have a swirl tank. Engine kept sputtering at 1/4 tank, so added that while we were at it. Link to comment Share on other sites More sharing options...
sf4018 Posted July 25, 2021 Author Share Posted July 25, 2021 Bag tank completed prior to insertion… tank installed and braced… Link to comment Share on other sites More sharing options...
sf4018 Posted July 26, 2021 Author Share Posted July 26, 2021 This is the plumbing concept, hopefully it’s correct…input welcome! Link to comment Share on other sites More sharing options...
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