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Doing some planning on engine bay layout and was looking at various threads on swirl pot and pump location when I picked up on the comment that some builders hadn't needed them because tank was baffled.
Mine isn't, but has anyone tried the baffle foam from Merlin Motorsports? Comes in chunks of a size you can feed in through filler hole. If it was on eBay I wouldn't have given it a second look, but these guys tend to know what they are about. Was think of trying it with a dip tube sender and single pump to save room in engine bay. Saving from swirl pot and second pump will cover foam and sender costs.
Note this will not be a track day car, road use only. Not interested in the really fast stuff since my stroke. If I was I would still have my nice red Ducati getting in the way of my build.
Thoughts?
Personally one of the mods I will be doing is getting rid of the low pressure fuel pump and swirl pot. I hate having the pot in the engine bay. And the noise of the lp pump does my head in. Either I will modify the fuel tank and add baffles and a sump, look at using the foam or a different type of in tank pump with internal swirlpot
The Sportster tank was never baffled as far as I know.
Adding a swirl pot is a pita and adds a lot to the complexity (I should know...).
Best option is what Patrick did. You have a small hole in the bottom of the tank at its lowest point. Under that you make a small sump like feature (I think Patrick used a cone shape) which feeds the fuel pump. The small hole in the bottom of the tank allows the fuel into the sump - but not back the other way (unless you drive upside down...). No need to cut into and baffle the tank so much, much simpler.
I am surprised the Sportster tank does not have baffles as standard - a Marlin "economy" measure?
I would suggest it is still a good idea to consider a pair of baffles in the tank to prevent 25kg of fuel (half a tank) sloshing from side to side under spirited driving?
An experienced fabricator could cut a pair of thin slits in the top, slide two baffles into place, and stitch weld them to the bottom, and then weld up the top slits quite quickly.
Simon Gregory's design is probably easier to copy!
I would suggest it is still worth considering a couple of baffles in your tank even with a sump - just to prevent around 25kg of fuel (half a tank) sloshing from side to side when driving quickly through bends.
A good fabricator could quickly cut two thin slits into the top of the tank, drop in a pair of thin aluminium baffle plates with holes in to divide the tank into three compartments, tack weld them to the bottom, and them weld up the top slits. This should not take too much time?
Here's the sump I had added to mine, oddly my tank came with baffles depsite them saying it didn't. The combo of the sump and the baffle work fine for road driving.
Thanks all. Will be going into fabricator next week, sump and baffles coming up.
One more question, what sort of size for feed hole into sump from tank?
Dropped tank off at local guy this morning, Rawles Classic Cars, and they are going to fit two baffles and a sump underneath the tank. Reckon I can get about 1.5L capacity and still keep it protected by the diff.
Won't be done until new year but no rush, really just needed to make the decision and agree the work so I could plan the other bits.
It’s been a long time but finally picked up reworked fuel tank this afternoon. A sump has been added to the bottom of the tank and two baffles put inside it. This should remove the need for swirl pot and second fuel pump in the engine bay. So a simpler install, more room in engine bay and all for about the same cost.
