bobert94 38 #1 Posted November 13, 2011 Just purchased a 18 automatic and PO had converted it to a electric fuel pump. Does any one know of a suitable replacement for the original pulse pump as it is nla. :dunno: Share this post Link to post Share on other sites
DavidD 0 #2 Posted November 13, 2011 I did a little research on this a while back. Look up pulse type pumps on MG's with the old style SU carbs. There are varying flow rates, maybe some one here can elaborate on the flow required for the engine series that are on the D's. I will see if I can find my notes on this and get back to you. DavidD Share this post Link to post Share on other sites
DavidD 0 #3 Posted November 13, 2011 Here are some of the notes I found, they mostly deal with pressure and flow rates. Thease are from an su (Skinners Union) pumps site for mg's like the tc,td, tf, althe way up to midgets and mgbgt. They also produced the SU Carbs. They were low pressure carbs. (I owned a 1973 Midget for 4 years) From researching pressures and flow rates of the pumps on the d types, they are very low pressure and pretty low flow rates. Main point is to not overpower the float. SU pumps are not that cheap, but the presure and flow rates should help you narrow down pumps that can do the job. L Type (low pressure pumps). These are found on the T series (TA, TB, TC, TD and early TF) and earlier MGs. They develop up to 1.5psi and have a flow rate of 1.3 pints per minute (9.6 gallon per hour). L Type HP (high pressure pumps). These are found on late TF, MGA, Z Magnette and early MGBs. They are the same outline and size as the Low Pressure pumps or sometimes come with a longer coil housing (referred to as a High Pressure/Long Body pump). They develop up to 2.7psi and have a flow rate of 1.1 pints per minute (8.4 gallons per hour). These are the 2 in a range that I thought might work on a M12 on my 312-8. But I was able to purchase a mechanical replacement for mine. Anybody with more knowledge than me, feel free to jump in anytime, I would not want to mislead anybody. Hope this helps, Share this post Link to post Share on other sites
TT-(Moderator) 1,162 #4 Posted November 13, 2011 The main reason fuel pumps are used on these engines is to ensure a constant supply at any angle of operation. (The need for a pump on the models with under-seat tanks is self-explanatory.) If these engines can run off a gravity-feed tank, that proves that line pressure is irrelevant. The Briggs & Stratton / Kohler (Mikuni) pulse pumps are capable of supplying all the fuel these engines ever need ~ and they are relatively inexpensive. They can also be used on engines originally equipped with a mechanical fuel pump by fabricating a simple fuel pump block-off plate drilled & fitted with a nipple for the pulse hose to the pump. Briggs & Stratton 808656 for more info & pictures. :wh: Share this post Link to post Share on other sites
bobert94 38 #5 Posted November 13, 2011 Thanks David & TT. Found pulse pumps on line for less than 20.00 did'nt figure there was a big difference from the original as it was also a pulse pump. vacume hose is still there in the original location. just thought i would ask before buying. :dunno: Share this post Link to post Share on other sites
DavidD 0 #6 Posted November 13, 2011 Thanks, TT. I never did look at pulse pumps. Forgot about them. I started out looking for electric to replace my mechanical. I remembered reading about an electric pump on D series, so that is what i went looking for. That is good to know if my mechanical ever fails again. :dunno: Share this post Link to post Share on other sites
