1970 Perkins 4108 w/fuel system issues

[cmesiam]

All Concerned,

First, I'd like to thank all for their valuable input. The wife and I got it going on Sunday. I completely rebuilt the fuel lines from the tank to the motor. I added a WALBRO Fuel low preasure diaphram fuel pump then a RACOR 10 Micron Filter then used the origianal RACOR filter/water seperator, (both filter now have a valve and by-pass added) and then the lines go to the engine where, of course there is another filter. I put the DC Pump on a lighted switch, this way I know when I have it on. After I got the engine started, I was able to turn it off (engine still ran). Old mechanical pump still works fine.

I

[cmesiam]

Does anyone know of a problem with the electric pump and filters, if I keep the dc pump on all of the time. WIll the fuel go through the filters then go the the filter on the motor and come back to the tank via the overflow? Can I use this as a fuel polishing system. Or should I devote another 'tee' to allow the (unused) fuel to return to the tank prior to the motor?

[S/V Elusive]

Cmesiam - the only problem with the system you described is that you are running it through your PRIMARY and SECONDARY filters - which will, as designed, clog up. Then you get to go through the replacement and repriming all over again. What some of us do is to use a second filter (or system) and run it through THAT, so that our normal fuel path is not screwed up.

But, you are right, that would polish your fuel ... at the expense of lots of filters (depending on how dirty your fuel is) and time spent replacing and repriming.

As to the air pressure back flush - yes. It did dislodge whatever was in there. Since it worked for me, I figured it might help you.

Good luck.

[DeepFrz]

cmesiam, there is a current thread on fuel polishing. I would suggest you read that.

[sailalfin]

Although I have had a 4-236 for 20 years, these issues are pretty much same for most engines.
Yes, the secondary filter is a pain-There is a conversion kit that turns it around.
Water lift observation-very important.
To me the greatest thing I did was to install a "booster" pump downstream from the 2 Racors and straight to the engine. This helps me on two fields, changing filters is a cinch, just vacuum them full, and, bleeding is a second cinch: start the booster pump, bleed the upper screw on the pump, close it; bleed the lower screw, close it; turn loose the upper bolt holding the secondary filter (or whatever means to bleed this filter); then turn loose all the injector nuts, finally, start cranking with throttle WOT, when it starts firing, pull throttle back and start tightening injector nuts. It has never failed, but the secret is the 65psi booster pump. Look in the Yellow "Boats and Harbors", there is a regular page add with this little pump that sells for 39.50 (be sure to ask them to send the little electric connector cap, without which you'll have problem wiring it)
Good luck
I also built my own Fuel Polishing system with a used Racor 1000 and a 2 micron filter. I turn-over my two tanks daily with a 15 minute timer I have on the pump. If any one wants drawings, ask.
Sailalfin

[Cheechako]

sailafin, what pump do you use for your polishing system?

[sailalfin]

I use an ITT- Jabsco pump specially for oil changes and fuel transfer. You may order it at DEPCO in Clearwater, FL
It is reversible and a work-horse, good luck, sailalfin

[roberttigar]

I'd appreciate a sketch of the polishing system. Bob Tigar

[sailalfin]

I may have spoken too soon, now I can't find the drawing I made. If I can't find it, I'll do a new one but may take a few days. Sorry.

[sailalfin]

Need some help. I have the drawings requested for fuel polishing and the fuel filtering systems but do not know how to attach drawings, control size, etc. Any help here? thanks
Sailalfin

[sailalfin]

I have attached a sketch of my fuel polishing system I made for my Brewer 44
I hope I have done this right and the attachment icon is visible somewhere.
If negative, please write, and I'll send via e-mail. Sailalfin

[sailalfin]

The attached sketch shows how I have my fuel filtering system ahead of the engine's secondary filter. There was a question posted about the fuel pump I use. It is described in the sketch. Notice how with this system you can do the following:
Run the fuel through filter A
Run the fuel through filter B
Change either while running engine
Run both filters in series
Run both filters in parallel
Fill the Racors when you change filters
Force-Bleed the system without cranking engine (most of it, except injectors)
Thanks, Sailalfin