aki11ez

2 stroke oil and paper-type pickup screens and filters do not work well together at all.

I've learned the hard way once, almost twice. First replaced my stock fuel filter when i upgraded my lines to stainless, to a aeromotive cannister, with paper-type filter. After about 3000 miles, the motor blew after a good safe tune for seemly no good reason. Well when I removed the paper-type filter to change it, I tried to blow through it, and it was almost completely clogged. Barely flowed air, much less fuel. Before anyone suggests contamination of the tank, corroson in the tank, or varnish build up due to the fuel sitting, I checked and rechecked, and that was not the case. The fuel did not set for any length of time, and the tank looked like new.

Then the intank fuel pump was converted to a sump type setup for a aeromotive external fuel pump, and the paper screen from stock, was adapted to fit the pickup. Well for some reason when you started the car the pump was fine, but after about 10-15 minutes, it started making all kinds of racket like it wasn't getting any fuel at all. I immediatley thought to ditch the paper pickup because of the last motor (r.i.p.) but my mechanic buddy thought i was crazy and there could not be that much restriction out of a simple screen.

Well weeks later after I had beatin my pump into submission I convince him to modify the pickup to take a stainless type 100 micron filter element to the pickup, and low and behold, the aeromotive pump is now only 1 step louder than the walbro I had in there prior. And it sounds very happy. (as a side note, the mechanic said that the sides of the screen (it was the larger box type) were starting to cave in on themselves)

This was also validated by a customer of the mechanics that had the same issue when premixing. Car started fine, then fuel pump started getting louder, and louder until eventally the car wouldn't even build rpm. Replaced paper filter element, and paper pickup, and he has not had another issue since then.

I can only assume as to the 2 stroke oil coating is soaking the paper, leaving a thin coating of oil on it that constricts the holes even further and blocks flow. Or maybe it's even the properties of the 2 stroke that make the paper swell.

I have remedy'd this by using a 100 micron stainless element for the pickup, and also a 100 micron stainless element for the after pump filter, and have had zero problems out of the fuel pump or fuel system in general ever since. Same setup for the second car with the problem, and also no further issues.

Some people will say that 100 micron isn't enough filtration, but it's going to take one hell of a lot of sub 100 micron particles to do any damage to a rotary motor, but a lean spike will take car of it in just a couple seconds.

Just wanted to spread the knowledge.

BDC

What ratio of oil to gasoline were you running?

B

aki11ez

4-5 oz of amsoil synthetic per fillup. They recommend you run it a little leaner than your typical 40:1 2 stroke oil.

In that time frame I also used a cheapie from wal-mart with the same results.

I'm not sure what the second car was using, I believe he frequents here, maybe he will chime in.

misterstyx69

iTrader: (142)

stated in threads ...1oz per gallon ..seems your puttin aside the fact you changed your fuel system ..shoud of checked component materials...paper in a system with this amount of pressure ?,,MOLLEY HATCHET>>FLIRTIN WITH DISASTER..ah screw it..just an observation..i care too much ..premix..safety measure...good lube ..paper..toilet paper...shitty!!!..out a here..****'s on hhhhaarddd to type..ah ****..later

lb_300

Since we are on the subject of premixing, do you guys premix your fuel for any of your other vehicles?

Maxthe7man

Its not so much the filters with the oil, its mixing different brands and types of oil that causes the gelling and gunking of the fuel system.. Some 2 stroke oils have to much wax and the bases are different, when you mix them, they turn into a slime if you let them sit for a bit.. after learning that, I run one brand of oil with the fuel only..max

aki11ez

lay off the smack

aki11ez

like i said, it was all amsoil pre-mix and it wasn't flowing well enough, THEN i tried another pre-mix to see if that helped. And it did not.

And if that was the case, then the gelling effect wouldn't have stopped when I switched to stainless elements, it would have continued to gum up the filters and fuel system.

aki11ez

My other vehicle right now is a diesel and I always have some type of additive that I use, whether it be marvel mystery oil, or slick diesel fuel additive.

Back when I had an n/a and a turbo it premixed both tho

RETed

Why don't you change from Amsoil?
We've had BAD experiences with Amsoil crap.


-Ted

peejay

So, pre-mix oil is magically falling out of dissolution in the gasoline and clogging the fuel filters.

Right.

I guess that's why I have low oil pressure, the oil is clogging the oil filter!

rmriggin

I premixed with MMO with great results and I used a paper type filter with a stock pump to boot. Never had any ill effects. Of course I am carburetted also. It would be nice if you could post pics of just how you used your 100 micron SS screen on you fuel pump.

aki11ez

thought had crossed my mind more than once, but the problem is fixed now. Amsoil is a premier brand in the 2 cycle industry so if those guys use it I belive that it lubricates well. It may just be a little to dense for paper filters tho.

aki11ez

never said dissolution, never said clogging. two stroke oil, along with all oils, are designed to coat surfaces, and that's just what it was doing, maybe it's possible that the amsoil has a thicker mil coating than other 2 strokes, but like I said, I did try another to the same effect.

oil filters are designed for oil, pickup screens are designed for gasoline, that's why there's an issue. if you have any more HUA comments i'd be glad to address those as well.

aki11ez

i also had considered mmo for a premix, but it seems as it's sole purpose is not to lubricate in the combustion process I just don't trust it as much as a authentic 2 stroke oil. I've considered mixing some mmo with the amsoil so I get a good amount of detergents in there as well. Might still try that.

Well the mechanic buddy of mine is a magician with metal, so he made an adapter for the pickup. Like i said, it was a sump pickup with the original paper screen at first, now it has an adapter to take aeromotive's pre-filter.

banzaitoyota

Kris, I need to clairify some facts:
1. You modified a stock OEM Style pickup screen for the suction of an Aeromotive pump?

aki11ez

yes, if your familiar wit hthe n/a screens it's about 3" tall by 3" deep by about 3.5" wide, and the guts of the screen were taken out. The screen couldn't be anymore dense than 150-200 micron so I figured it would not be a restriction.

The pump actually would sound just fine at start up, so I don't think it's the density or the surface area of the pickup, it only starts to restrict when the pickup gets saturated with oil.

Marcel Burkett

If you look at some of the suggested fuel system schematics on Aeromotives site , you'll see that the smaller 10 micron filters are designed to be used on the discharge (high pressure) side of the pump and the larger micron (100I stainless ones are to be used onthe low pressure , suction end of the pump.

aki11ez

O trust me, I read the schematics, even talked to a tech guy from aeromotive. I might put one in later once I'm convinced there won't be any issues. But after losing a motor to a clogged filter, I'd rather pass a 99 micron particle, then pass nothing at all.

cmartinp28

how can you blame your filter for blowing up your motor, dont you have a fuel pressure gauge to let you know that you're running low fuel pressure? and wouldnt this be a gradual transition considering from free flowing to clogged? when fuel pressure drops, the car will run completely different, i've had several fuel delivery issues before and you can usually tell low fuel pressure is low by the delay in the throttle responose

i've been running amsoil dominator 1oz:1gal for the last 8000 miles, i have two walbros in the tank, with the strainers, and two inline fuel filters for each rail with a metallic filter, and actually still have the stock filter in the car also... lol and just recently i had a fuel pressure problem where i couldnt get the pressure down below 80psi, now i cant get it down below 45.... which means im still flowing fuel.

Marcel Burkett

I have a pair of high flow Bosch pumps ('044's) , they both have Aeromotive filters on their suctions (100micron) for a while now and I also premix , I never had a problem !!! , what I'm saying is that the filters element is soo fine that it cannot pass enough flow to satisfy the pump and it in itself becomes a restriction , by the way , what model pump do you have I had an A1000 with the same filter on it and had absolutely no problems with that too.,

aki11ez

im not saying im innocent in the matter, I just said that the filter clogged after 3000 miles (if that) causing the engine to lean out. I have a fuel pressure gauge on the regulator, and will have one inside once I convince myself to drop 150 bucks on an isolater setup, because I don't want high pressure fuel 6 inches from me.

And your probably not haveing issues because you running twice the screen and sucking half the fuel through each. which both walbro's combined do not push the fuel that an aeromotive external does, so you might be experiencing the problem, but it's not as major of an issue as your not moving as much fuel and/or you can't hear your fuel pumps starving because they're muffled by fuel.

I posted this topic so that the many other pre-mixers can be aware of this potential issue, and when building thousand dollar fuel systems for multiple thousand dollar motors, so that people will keep this in mind. Oil will saturate your filter and cause less fuel to pass, than pure gasoline alone. That's chemistry and physics, but you have saftley over calculated, then you should be fine. It's not up for debate that this was the cause of my problem, because I know it was the cause of my problem. So if your not having issues or (as most people) are not aware you are having this issue, then I'm happy for you. Ignorance is bliss.

Hopefully someone will take something positive from this thread.

aki11ez

I'f you will read again I switched to the 100 micron pre-filter and it fixed my problem. I was commenting to you about the 10 micron post-filter that I might try in the future.

I'm using a a1000 as well, with a 100 micron pre-filter and 100 micron post filter. Both stainless and they work like a dream.

cmartinp28

alright.... your intent is noted, and i appologize if i came off a little harsh.

here is a suggestion for you, which i have done myself, and helped me trouble shoot my fuel issues a lot faster.

a lot of different companies offer electronic fuel pressure gauges, where the sensor stays in your enginebay. they are pricy, but very very useful.

scathcart

I used to run the aeromotive 1200 hp pump mated to a 100 micron SS pre-pump filter, and a 10-micron paper post-pump filter.

I ran the car for about a year like that, and never had any problems. I later stripped the fuel system and sold the car to another person, who has been running it for 2-3 years now. I personally used royal purple synthetic premix, I believe he runs RP or redline, can't remember. Between the two of us, there are yet to be any problems at all with the system, and I would estimate logging 40K kms between the two of us on the system.

I don't think the filter is the problem itself.