I have a converterd PI TR-6 with an un-baffled tank. As long as I keep the tank
1/4 full I have no problems.
If I let it drop below 1/4 and a make a very hard corner then she'll sputter
for a moment until the fuel settles.
It serves as a 'slow down and get some gas' reminder. Someday I may go to the
trouble of baffling, but I
doubt it.
-Erik
At 09:20 AM 8/17/99 +1000, you wrote:
>
> Tony Gordon was thinking out loud about a PI conversion and mentioned
> that a pre-pump should fix the problem of an un-baffled fuel tank.
> This is not the case. The baffles in the tank prevent the fuel
> flowing away from the outlet, keeping a constant fuel supply available
> for the pump. In a carby car, this is overcome by the fuel bowls -
> they maintain enough fuel until fuel, once again, flows from the tank
> outlet. With the high pressure pumps, both Lucas and Bosch, you need
> constant fuel flow or you won't go! Even worse, if you suck air into
> the system, you're going to have to bleed it (main cause of problems
> with the PI system). I converted my '71 ex US carby car to PI and
> tried to do it without a baffled tank - it doesn't work! A cheaper
> and easier way to fix this problem is to fit a 'surge' tank of about a
> litre capacity, in the spare wheel area of the boot (opposite the
> filter is where I mounted mine). Run the tank outlet into the surge
> tank then from the surge tank to the main pump (you can run it through
> the filter on either side). My pre-pump is mounted before the surge
> tank which also runs a return line to the top of the fuel tank. I've
> crimped this line slightly so that I have positive pressure throughout
> the system (about 1-2 lbs). This way GUARANTEES positive fuel flow at
> all times to the main pump.
>
> When you're looking at making your throttle linkages, may I suggest
> that you look at running them from ABOVE the throttle bodies so that
> they PUSH the butterflies down. The standard system runs below and
> pulls on the butterflies. This, in itself is not a problem, but if
> you intend to fit extractors, then you do limit the space available.
> If you've got the chance, run them above and you don't ever have to
> worry about space to fit those big bore outlet pipes! (ask me why I
> know this.)
>
> All the best in your quest - it will prove very rewarding - nothing
> better than 6500 rpm and still going - can't do that with carbys!
>
> John Mc
> '71 TR6 PI
> '76 Dolomite 1850
> "Fast is First"
>
--
Erik Quackenbush, V.P. Operations, Midwest Filter Corporation
1-847-680-0566 fax: 1-847-680-0832 http://www.midwestfilter.com
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