So was planning to make my own top feed fuel system, so having a spare lower & upper plenum I made a start with some standard top feed Injectors I had loaned from my tuner, It didn't take me long to realise all the mods that would be required. Then suddenly I had a brain fart and thought wouldn't it be good if you could keep the fuel rail under the plenum. So I went to see my tuner (top bloke may I add) and he loaned my some short series injectors. Well after some playing around I think I may be on to something. See what you think. First Photo Injector fitted into Lower Plenum. Next Photo I had some 16mm hose to see how the rail would fit, looks like it will work, Under side photo Top Feed Under side photo of Side feed as a comparison What are your thoughts do you think this will work?? I am starting to think I can pull this one off, so am going to buy some 16mm tube and then start making the rail. fingers crossed.
Looks good! Fiddly but could be worth it to get rid of those unsightly top feed rails. What's the range like for short top feeds?
The ones I plan on using are 1350CC Dual Fual. Not sure if they go bigger than that and plenty of chose from Bosh to Injector dynamics I believe most of the brands make a short series. Bosch Top Feeds
Update It's slowly coming along still need to find out if the 16mm tube will be big enough to feed the 1200CC E85's was thinking running dual feed with a single return line. Any thought's suggestions?
Update So the Stainless steel seamless tube and pipe turned up today, only problem was I could only buy 6m lengths, so if this works I might be able to make around 8 sets. Anyway went to my brothers tonight to use his milling machine and Lathe, here are some picks. Will start welding some bits tomorrow with the Tig welder. 16mm Slot Drilling for the boss that fits to the fuel rail Fuel Rail being drilled to the Injector centres. Boss being machined using a Slot Drill spot on 13.8mm for the Oring of the injector. All 6 Injectors fitted to the lower Plenum.
Anothe r Update Well I will be hog washed and blown away, After many hours of hard work! I do believe I have done it. So to make sure it will fit I pulled out my spare motor from under the work bench and for a few minutes I had a O F--- moment the injector plug section is going to hit the valve cover, but after actually trying to fit it I realised that it does fit and the only problem will be plugging the wires in. No big deal 2 options make a tail and solder the wires directly to the injector and then fill with epoxy or silicon so no water gets in, or option two, not the preferred method is to remove the outer shroud of the plug which means it won't lock into place and moisture can get in. But her are some Photo's So now to buy some AN fittings and runs the lines to the Fuel Reg's
Would it be possible to make the fuel rail in a single 1 piece U shape? Using a tail would work. But would make troubleshooting slightly harder. Not a big deal tho.
U Shape Yes it could be done, I was going to use some 90deg AN fittings with just a short piece of hose linking the 2 rails.
you don't want that - ideally the fuel feed split in two and go to one end of both rails and be bridged back together before the FPR. it's called twin feed and it supposedly distributes fuel pressure more evenly.
dual feed I will do some more research before proceeding and will talk to the boys at Independent Motor sports but sounds like the best option.
so one has to ask... especially when one is considering such a thing... something something fluid dynamics something something is it really as simple as it looks?
Not sure if there's anyone on the forum that could answer that with authority. Anybody know if you need extra head volume above the injectors? 16mm is -10 which is plenty for 90% of VG builds as a feed line but no idea about rail design.
I admire your ingenuity; two things though 1. Heat soak? 2. Is the injector "pinned" down by the rail? As in is the injector body part of the assy or is it fee to "float"? Interested in your thoughts
flow 16mm tube with a 13.5mm ID length 350mm will roughly flow at low pressure at 75deg around .07 litres per second or 4.2 litres per minute x 2 rails, so 8.4 litres a minute for both rails. So a 1000cc injector will push out 1 litre a minute x 3 injectors = 3 litres at 100% duty cycle. It is more about keeping the flow rate up to the Rail in my opinion
Heat soak - would be the same as the side feed rail I would assume, but I will need to mod the rail hold down brackets with some insulators as per the stock rails. So good point thanks 2. the injector is held down by the fuel rail, the fuel rail is bolted back to the lower plenum same as stock rail.(less the insulators at the moment) the boss is machined so as the injector can not travel up any higher
Update So due to the rain today I decided to work on the Rail today here is the update. Twin Return Lines done used 3/8" SS tubing. With the Plenum fitted and nothing touching.
Progress Update OK had this on the back burner for a little bit, but have now started again. Received the 1150CC E85 injectors and here is the photo update. With fuel rail insulators fitted Regulator and lines connected With Top Plenum on
