Engine/Transmission (1998.5 - 2002) RASP as the primary - Fass as the backup?

[PRout]

Didn't want to hijack other threads, so started this one trying to not interrupt some already good discussion.

I already have a FASS 150 lift pump, normally mounted, with 1/2 inch lines throughout, and utilizing the OEM filter at the engine.

Just wondering if adding a mechanical RASP system directly inline and using that as the primary lift pump and using the fass as the initial pusher/primer pump until the engine fires would work out ok without issues.

Not very familiar with the complete RASP startup & failover to oem theory, but since the FASS supposedly has a BYPASS valve built in, wouldn't it make a good primer pump for the rasp, and then turn off after the rasp takes over still allowing flow through its bypass valve, or would it just become a restriction in the line for the rasp?

Just thinking if the rasp were to throw a belt, or fail, you could manually throw a switch to turn on the fass as a backup pump.

Would this be a good all around setup (quiet both to the ears, and to the CB'ers/Hams that don't want additional electrical noise affecting their receivers)? Would it effectively provide both a high quality primary and backup pump solution, without sacrificing quality of normal fuel flow?

Thanks.

Got the idea from this thread:
FINALLY!!!! Some one puts an end to Carter!! - TDR Roundtable

 

[PRout]

More thoughts to this:

Yes, it may be overkill. (Depending on your situation when it fails :-laf)

How does the RASP usually fail? Seems so far I've only read of belt failure, or the bearings failing sometimes causing a leak. Seems like if you get the leak, the fass backup isn't going to help much unless you have a way of bypassing the RASP.

 

[rweis]

That is what I do, except I use a Walbro backup on a cab switch.



The only failure that you are not going to know in advance is a belt break, or the belt running off the pulleys. Neither likely, but is a chance however small.



I do not think bearing failure is a problem because ther are no bearings in the classical sense of the word. The "bearings" are the fitment of the pump axle shafts in the body of the pump. Then there are seals to keep any leakage to a minimum.



I would think to have "bearing" leakage to the extent it would be detrimental you would be spewing diesel everywhere for several months / years and would "notice" a leak.



For belt breakage, running off the pulleys (that do have shoulders on them probably for this purpose) then turn on the Walbro in my case, FASS in your case.



There are pleanty of bypass valves (Kinsler JetCans) that you can devise ways to isolate the two systems. The nature of external (internal) gear pumps is when they stop they do not allow fuel to pass, so fuel going through the failed RASP in probably not a problem.



However to test that statement (probably) I will take the belt off my RASP and run on the Walbro only for a week or so to see what really happens.



Bob Weis



Oh, BTW, I have learned that I do not need the Walbro to prime the RASP / VP44 prior to engine start. I have not run my Walbro since 01/02 and have engine start just fine. Truck sat a full weekend and it started by just the RASP just fine.



At this rate the Walbro will last decades

 

[JR2]

OVERKILL

I have an idea, you send me the the $$ for the RASP and I will send you a stock carter pump to use as a backup to your FASS. Seems like a good deal for both of us.

 

[PRout]

OVERKILL

I have an idea, you send me the the $$ for the RASP and I will send you a stock carter pump to use as a backup to your FASS. Seems like a good deal for both of us.

Oo.



Get a job. .

Just looking at all the options. As far as overkill goes, beauty is in the eyes of the beholder. 500 HP could be considered overkill. Or we "uses what we gots".

Yes, I was looking at rweis's system as an example. Also like the idea of having an extra bypass type regulator valve up close to the VP for last second regulation and also purging air from the system after maintenance, etc. I have a (normally closed) valve there now to return air/fuel to the auxiliary tank for purging air, transferring & mixing fuel etc. Seems Bob & Gary's regulators are probably more reliable than having a valve that could fail and leak return fuel to the aux tank. Their way, bypassed fuel goes where it should, back to the main tank as designed and the filter's condition has little affect on their final pressure to the VP.

The RASP/Mechanical idea comes from wanting to install a ham radio in the truck. Am a little concerned about the noise emitted from electric pumps. My last truck (a gasser) emitted all kinds of spark plug & pump noise, so now the RASP is looking like a better option for a primary lift pump all the time, especially after reading rweis's post above.

Wondering how much of a restriction the FASS would be if it were turned off most of the time. Tnx.

 

[rweis]

The RASP does work well.



Just in case that for some weird reason the RASP or Fuel Boss were to not be available because whom ever did not want to provide them any longer, go out of business, or just get tired of messing with the Dodge. I have an alternate secondary external gear pump plan.



Clark Solutions (Valves, pumps, dataloggers, and instruments to monitor and control)

Pumps on the left verticle list

Gear on the list of types of pumps

S Series on the list of types of gear pumps



S Series Model 1S

Order 713-10-2 ((713) S Series Model 1 with (10) foot mount and with (2) clockwise rotation without relief valve)

The internals of the pump are field rebuildable with several different level kits

$271



Clark Solutions is a national manufacturer of external and internal gear pumps for commercial industry. They will sell 1 at a time to anyone using a cc and you do not have to set up an account. Which means these guys are NOT going out of business any time soon, and have been building this pump for industry for a very long time. Just an alternate backup option. Minor change in Gilmer pulleys would need to be done.



Bob Weis

 

[PRout]

Wow, you guyz really do your homework. . Great info.

 

[PRout]

Ok, JR2 you're right. It is OVERKILL. . What was I thinkin??

 

[rweis]

I trust overkill way more than underkill. Underkill is generally what we end up try to fix. Can you say "fuel system"?, "APPS"? "VP44"?



ARRRRRRRRRGH



Bob Weis

 

[Stefan Kondolay]

rweis, You haven't needed to use the electric to prime you system? If you could get away with not running the electric system you could build this system real affordable.

 

[rweis]

Once I got the system primed, I have not turned the electric system on.



I did use the electric to prime, but also found that it was hard for the Walbro to purge air through the JetCan bypass valves. I am going to put a manual bypass around the JetCans so the air is pushed through the system much better. Maybe a manual prime system?



As far as cost there are a couple of points that might be worth looking at:



1. With a internal gear pump as the backup pump instead of the vane pump you do not need the brass bypass valve at the backup electric pump since fuel will not go through a internal gear pump backwards. Cost saving



2. Use a manual switch instead of the Hobbs switch. Cost saving / inproved control



3. Use Kinsler JetCans to set VP44 inlet pressure so the user can order any combination of shims and springs they want, instead of DTT working each individual request. Labor savings



I really do admire your pump choice though. I have looked through several (6 - 8) pump manufacturers and have dozens (50 different pumps) of gear pump specifications in a spreedsheet to be able to compare all the different gear pumps (internal gear & external gear).



Some have too high a GPM at higher RPM,

some have too low a GPM at low RPM,

some have too high a psi at high RPM,

some do not tolerate any particualtes,

some do not have enough pump frame toward the pulley to ensure stable leak free operation,

some do not have subatancial enough mounting frames,

some have ports that are way too big,

some have so much weight in them to make them impractical to mount,

some do not have high enough maximum rpm capability to handle the entire rpm range of the engine even after the pulley gearing,

some have to have their packing system adjusted frequently,

some state that the packing will intentionally leak 1 drop per minute and that is correct for that packing system.



The RASP matches the engine range, doesn't leak, pumps little enough at low rpm to satify the VP44 without over taxing the fuel return bypass, pumps enough at high rpm to satisfy the VP44 demands, tolerates particulates, easy size ports, great mounting system, great drive system.



I would be really interested to know who the manufacturer is (PM me?)



My congratulations to DTT,



Bob Weis

 

[PRout]

The RASP/Walbro is sounding like a pretty good setup. . hmmmm. Yeah, since I already have the fass, would probably use that as the backup/pusher. But the RASP mechanical pump sounds hard to beat, unless you have an aftermarket cam with the pump lobe.

 

[Turbo Terry]

I have a RASP and you will need a backup (electric pump) to reprime the system after a fuel filter change. I,m using the stock lp for this. How could you do this without a electric pump ? I would like to know?

 

[Stefan Kondolay]

Drop the pump down and use a 1/2 inch drill.

 

[PRout]

De-Walt ; )

 

[Turbo Terry]

Thats a great idea. Why didn,t I think of that. Thanks

 

[PRout]

Now someone needs to come up with a lowering kit and we'll be in biz.

 

[Stefan Kondolay]

All you do is un-bolt the 2 brackets from each other to prime the systems. We actually got a new pump set-up, I just working on getting the price down so that it's comparable to the electric pumps on the market in price.

 

[rweis]

Backward compatiability upgradable?



Will current RASP users be able to upgrade to the improved mount if they want to? The "old" mount was pretty nice though. Trouble free since '03 (75k miles). I did get the "improved" pump frame with the longer front shaft support. VERY NICE.



Bob Weis

 

[PRout]

Thinking it may be time for a RASP system. Just wondering if you need special tools for adding the new pulley for the belt drive. . And did I understand correctly, that you can push fuel though the RASP if the belt goes away? Will the VP pull through it? Is a regulator mandatory at the VP44? Would go with the Jet cans soon, but just looking at getting a system up and running for now and looking at options. Thanks.