Fuel/water separator, can I drill and tap?
03-21-2015, 06:31 PM
#1
Charter Member #927
Charter MemberThread Starter
Fuel/water separator, can I drill and tap?
I've got a stock fuel water separator for a 454 mag engine. That is the only part in my fuel system that is 1/4' NPT fitting. everything else even my Holley fuel pumps are 3/8 NPT. Is there any reason I can't drill and tap them to 3/8"? Looks like there is plenty of material to do it. I am moving from 525 or so hp to 650.
03-21-2015, 08:06 PM
#3
Banned
iTrader: (9)
the stock filter mount still has the cork in it. take the mount off and turn it upside down - then look where that fuel comes thru where the inlet you are going to drill - it still is about the size you can only stick a Q -tip in. very small diameter. Total waste of time drilling the stock mount to fit a 3/8 barb fitting into, the cork is after that.
move on and buy a billet one or an one that still does not have a cork in the system meaning the portion where the incoming fuel is going into the filter that has a bigger diameter than what the stock mount offers..
move on and buy a billet one or an one that still does not have a cork in the system meaning the portion where the incoming fuel is going into the filter that has a bigger diameter than what the stock mount offers..
Last edited by BUP; 03-21-2015 at 08:08 PM.
03-21-2015, 08:09 PM
#4
Registered
03-21-2015, 08:14 PM
#6
Banned
iTrader: (9)
forgot the other cork in the fuel system is the L fuel fitting sitting on top of your gas tank that your fuel line attaches to. One it has a restrictive anti siphon valve in, plus make sure your fuel pick up is clean and not cracked or bent and then the fitting is L shape - L shape fitting are not the best flowing of liquids nor is the anti valve. Just saying if your app still has all the stock fuel configuration.
03-21-2015, 08:16 PM
#7
Registered
Hey Guys, nothing wrong with doing that but I know that a lot of filter mfgs. have different flow rates passing through the filters, has something to do with how many microns the filter will flow......You have to be very careful to get the right flow rate or you will starve that big engine .......Don't buy junk and check the flow rates ..
03-21-2015, 08:47 PM
#8
Banned
iTrader: (9)
don't forget you still need a enough meat for a TRUE 3/8 drill bit on the outlet side of the mount drilled all the way thru as well. Some of the OEM mounts had more meat internally in certain years that could be drilled & tapped but some years not enough especially mostly on the outlet side to be drilled all the way thru and tapped far enough without cracking.
As for the inlet side drilling a 3 / 8 bit all the thru could be very hard without getting into the base of the filter mount.. I am telling you for a fact. Been there, seen it & measure it & replaced with new
I do sell an aftermarket mount thats even slightly a tad bigger than 3/8's hole internally all the way thru both inlet sides and outlet sides, exact replacement of the stock app. Externally looks the same. Its works for V- 6 all the way up to whatever. I do not recommend it for 1/2 inch fuel apps because their not enough meat to drill that size out.
Let me know how yours works out with the 3 / 8 drill bit internally NOT going into the filter base itself on the inlet side because that hole is not centered in that portion, it is almost drilled into the base as it sits. plus the bigger hole & tapped with enough depth. I am talking about the 1/4 size here and the internal portion of that tiny hole on the inlet side plus for the portion for the bigger hole to fit a 3/8 barb depth then tapped correctly ..
. The new filter mounts that I have and even slightly bigger than 3/8 holes both inlet & outlet sides all the way thru are no more than 50 bucks.
As for the inlet side drilling a 3 / 8 bit all the thru could be very hard without getting into the base of the filter mount.. I am telling you for a fact. Been there, seen it & measure it & replaced with new
I do sell an aftermarket mount thats even slightly a tad bigger than 3/8's hole internally all the way thru both inlet sides and outlet sides, exact replacement of the stock app. Externally looks the same. Its works for V- 6 all the way up to whatever. I do not recommend it for 1/2 inch fuel apps because their not enough meat to drill that size out.
Let me know how yours works out with the 3 / 8 drill bit internally NOT going into the filter base itself on the inlet side because that hole is not centered in that portion, it is almost drilled into the base as it sits. plus the bigger hole & tapped with enough depth. I am talking about the 1/4 size here and the internal portion of that tiny hole on the inlet side plus for the portion for the bigger hole to fit a 3/8 barb depth then tapped correctly ..
. The new filter mounts that I have and even slightly bigger than 3/8 holes both inlet & outlet sides all the way thru are no more than 50 bucks.
Last edited by BUP; 03-21-2015 at 10:19 PM.
03-21-2015, 10:27 PM
#9
Registered
While you can drill and tap the stock 1/4" mount that you have. Sierra offers both a SS and an aluminum version that is already 3/8". It looks identical to the one you have and will mount up exactly the same. I don't have the numbers in front of me but I think the SS version is #18-7776. It is around $50.
Eddie
Eddie
