Racor Filters Straight from their tech pages

[Turbine Doc]

Inqiuring about Racor filters yesterday for my 6.5TD; John Kennedy sent me to check out what you 6.6 folks were saying on the subject. I called around and since it was a crappy day decided to do some surfing at Racors site to see what they have to say. I now have a 85 page spec sheet on each and every filter they make.

www.parker.com/parkersql/default.asp?type=2&id=27

The above is their tech page link once again JK comes up with the right info. Both the 400 and 600 series filts in 2 micron size are for final filtration, if you have primary filts coming apart filtering the suction side of primary(tank side) won't help much there, but if you are putting it on after primary and they are coming apart you better have some sort of delta P indication across inside the cab; that filt as 2 micron secondary wil plug up real quick like and starve you of fuel.

As I was typing this a thought occurred to me, is it possible the filter bypasses arent working and the fine 2 micron which seems really small to me for everthing is plugging and the filters are being blown apart. We had simalar problems in the Navy on our gas turbine coalescer filts getting blown apart from repeated reset of high DP cause the guys were to lazy to change the elements, a 4 hour task. After a while we started failing fuel controls, equivalent sort of to a Diesels injector pump, upon teardown analysis they were finding in entire Navy fleet cellulose fibers in the internal control coarse element screens. The fibers weren't the problem, the problem was from dirty fuel going to the controls not being filtered by filter elements with holes in them. Now the primary filts were 25 micron rated filts, but the coalescing media after that was in the 2 micron range. Holes of that magnitude are not readily visible to naked eye.

Maybe we are looking in the wrong place this filt is doing its job per design, but we are maybe asking it to do too much, maybe we need a bigger primary to knock out the big stuff so the 2 micron isn't overwhelmed and coming apart.

Do our filts have a bypass, or a high DP alarm, anybody ever checked the DP asross one to see how long it lasts. I don't know but I'd like to know. I printed the long version on this topic but wanted to start another thread for a differenet thought track other than the filters are bad design.

[Turbine Doc]

Upon further reading of the volumes of matl in the 85 page download is something within quote" A simple rule about filtration, the finer the filt the more frequent the change, carry sparres"

"A 30 micron filter (or primary filter) is used to filter raw fuel (or poor quality fuel) before it can be filtered by finer medias such as 10 or 2 micron."

"A 10 micron filter (or secondary and even final) is used to filter fuel which is known to be of good quality."

"A 2 micron filter (or final filter) is the finest filtration available and is the last filter used prior to engine ingestion"

From above looks like GM needs to go back to the dwg board, Racors mounted by the tank should be 10 or 30 micron for raw fuel filtering, and the 2 micron is final fuel filtration before injectors. Or in our case post lift pump to increase longevity of Inj pump as well.

I'm leaning to my Navy story the filts are blowing apart on you guys, GM is asking too much of them to do everything with a 2 micron element.

John Kennedy on my 6.5 the filters there all seem to be made by Stanadyne regardless where I buy them, you got any idea what their micron rating is, if not I'll go ask them.

[CareyWeber]

tbogemirep,

The 6.5TD fuel filters are 5 microns, and they are all made by Stanadyne. I got this info from Stanadyne.

Carey

[ 02-09-2003: Message edited by: CareyWeber ]</p>

[Turbine Doc]

Thanks Carey,
Sort of makes me wonder though if 5 mic was okay for 6.5 why go to 2 mic even smaller for 6.6, I've heard of std engineering 2x minimum is requirement, but maybe a bit overboard here.

[CareyWeber]

"Thanks Carey,
Sort of makes me wonder though if 5 mic was okay for 6.5 why go to 2 mic even smaller for 6.6, I've heard of std engineering 2x minimum is requirement, but maybe a bit overboard here. "

I think if you look at most any heavy duty diesel you'll find that they are running two fuel filters (primary 25 - 35 microns and secoundary 2 - 10 microns). I think if you want to run 2 micron filters you'll need to run a primary filter to keep the 2 micron filter from plugging prematurely.

I think GM's bean counters kept them from running the 2 filter system like they should have.

I am adding a Racor 445 with a 30micron filter and a heater before my lift pump.

Carey

[wangotango]

A flow rate question:

First curious about the flow rate of fuel in the 6.6L.

As long as you had filtering capable of this flow rate you should ok wouldn't you?

Does adding a second filter decrease the flow rate? Must be a formula for this.

Or is it insignificant?

w/t

[TraceF]

There is a lot of info in the the now really long other filter thread about flow rate.

The consensus seems to be (and Stanadyne told me) that the filters we have been discussing, the Stan FM100 and Racor 645 and 660 should easily pass the fuel demand of the DMax without any significant drop.

It only makes sense that a bigger element would be better on this issue.

The clogging issue is yet to be resolved but Todd and I will keep all posted if and when it happens.

The fuel I am getting here in FL seems to be pretty clean judging by the filter bowl on visual inspection.

[Kennedy]

I've never seen a fuel filter with a bypass.

The extra fine filtration is needed due to increased operating pressure, AND expense of componentparts...