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Mech. fuel pump/rod

Posted: Thu Jan 08, 2004 7:33 pm
by Trike Rider
Looking for a good mech fuel pump and rod for a type 4.
Dennis

Re: Mech. fuel pump/rod

Posted: Fri Jan 09, 2004 6:28 am
by dstar5000
Trike Rider wrote:Looking for a good mech fuel pump and rod for a type 4.
Dennis
Get rid of it!

It is a potential (and usual) oil leak...

Don

Posted: Fri Jan 09, 2004 7:05 am
by MASSIVE TYPE IV
BUT THE pushrod guide MUST STAY IN PLACE if you get rid of it. Take it out and watch the oil pressure plummet

Posted: Fri Jan 09, 2004 7:13 am
by Wally
Damn this is good info! I did what Don said, but the oil warning light goes on at 800 rpm at idle, which it only is just off-choke anyway, but the signal is there!
Thanks,
Walter

Posted: Fri Jan 09, 2004 7:18 am
by MASSIVE TYPE IV
With that guide gone the oil dumps out of the cam galley and right into the sump. The guise is the only thing sealing that galley off.

Posted: Fri Jan 09, 2004 11:06 am
by IMPI
I even went as far as leaving a piece of rod in there suitably modified to not hit the cam as the bush is made from phosphor bronze and is permeable thus still allowing oil to pass We lost an engine when a friend removed this bush.
BTW the stock pump does not fit when installed in a bug chassis with ramehorns.
Armand

Posted: Sat Jan 10, 2004 9:27 pm
by Bobby74
Hey this is good info!! This guide is missing from my case because I had it drilled and tapped.

Can I drill and tap and use a shallow plug to plug it at the lifter galley?
It looks like I have a 1/4" until I reach the smaller galley opening... The larger one is a 3/8" NPT I believe

I dont' have a lathe but is there some tube stock that could be used as a plug?

Thank you!
-Bobby

Posted: Sat Jan 10, 2004 9:37 pm
by Bobby74
It actually looks like I could tap the whole deeper and drive the plug in. I'll have to check it and see if I can get a tap in that far wihout wiping out the lifter area.

Posted: Sat Jan 10, 2004 10:02 pm
by MASSIVE TYPE IV
yes, you can put a galley plug deep and one shallow.

Posted: Sun Jan 11, 2004 6:20 am
by Wally
IMPI wrote:I even went as far as leaving a piece of rod in there suitably modified to not hit the cam as the bush is made from phosphor bronze and is permeable thus still allowing oil to pass We lost an engine when a friend removed this bush.
BTW the stock pump does not fit when installed in a bug chassis with ramehorns.
Armand
Armand,
Your right: the bush is of a sort of a pressed-in phosfor-bronze alloy. I noticed it when I removed the lid I made to seal the absent mechanical fuel pump.
In my engine the guide was still there, but I had removed the rod.
Now I have re-installed the (shortened) rod and already have much better oil pressure! amazing. It would be better to do it like you mentioned: to modify the rod so it won't hit the cam. Plugging is not an option for me tho because my engine is used daily.

Thanks all,
Walter

Posted: Sun Jan 11, 2004 1:43 pm
by BluBus
I removed my fuel pump and just took the pump and the pushrod out. What is this guide and am I safe or do I have to put the pushrod back?

74 Rivera

Posted: Sun Jan 11, 2004 2:34 pm
by njv
hi
im about to go thru with the removal of my mech pump and my intention is to shorten the operating rod and then thread the end to hold it off the operating lobe on the cam with nuts between the bronze bush and the new cover plate.

my question is this should i at the same time block the small drain thats in the bottom of the operating rod plenum ? am i going to cause to much pressure within the plenum there?

Posted: Sun Jan 11, 2004 8:44 pm
by Bobby74
The bush is blocking the end of the lifter galley. As long as you have the bushing in there, it shouldn't have oil pressure loss. The oil could be leaking around the bushing?

I like the idea of threading the rod and putting locking nuts on it to sandwich it in a block off plate. That would be great in a daily driver.
I'm still building my engine so, I'm blocking off the actual lifter galley end, and running a larger plug to block off access on the case back. I'm runnnig an Al block off plate on the stock plastic fuel pump spacer. I'm not going to worry about the little galley that leads to the sump beacause any oil that gets up in there should be gravity fed back to the case as long as you don't have a lot of crankcase pressure (good PCV).
-Bobby

Posted: Sun Jan 11, 2004 11:18 pm
by Wally
Wally wrote:Now I have re-installed the (shortened) rod and already have much better oil pressure! amazing.
Well, it appeared that when the engine is well warmed up, the difference of only reinstalling the rod doesn't really make that much of a difference.
The real difference is probably only when you don't have the bronze guide fitted like Jake mentioned.

Plugging the oil return hole doesn't seem a good idea to me tho. The oil that comes up the rod for lubrication of the rod needs to return at one time...

Thanks,
Walter

Posted: Mon Jan 12, 2004 9:01 am
by njv
hi
now can somebody point out to me if there is an oil return in this location on a non mechanical fuel pump car?

my point being that plugging this drain will increase the pressure to the lifters and so on where it will return to the sump on its normal course .

i have decided that i am going to do this as it will help with keeping good oil pressure to the lifters and so on on the 1/2 cylinder side.
a possible week point in the carb cases compared to the injection engines that dont have this plenum at all.

now here is a very latteral thought the bronze bushing were it plugged at the plenum side then tapped on the case side could surely accept a oil tube that could then dissapear of to spray the bottoms of your pistons and such much easier than installing 4x ball valves .

i picture a short outlet where the operating pushrod normally protudes to run on the cam to a t peice with two oil rails one running along the inside of the left case half the other the right with small drillings placed at specific points to spray oil on the base of the pistons !!

must dissapear off and find the oiling post thats going on at the minute.