Thread End vs Dome End Bypass?

[UNC017]

Originally Posted By: Jim Allen

Continue to stick. It's a good theory. Good chance it's fact, I think. It's probably not an absolute, though ... but then few things are.


I agree, its not an absolute, and thread-end bypass is probably *pretty* close to an absolute guarantee that stuff in the filter won't get swept into the system. But is the probability of a slug of grit happening to be lying in just the right spot at just the right instant during engine start (so that it doesn't have time to get shoved against the media) and then going through a dome-end system higher than my chance of getting struck by lightning? Probably not.

I'm still curious as to which type is really more common. I admit I haven't really looked closely, and I only have looked at the 4 filter types that work in my little fleet, but base-end still *seems* more common to me. Maybe not though.

One advantage to dome-end which I haven't seen mentioned is that there is room in the dome for a somewhat more precise (at least it looks that way to me) relief valve mechanism. I've always thought that bypass valves where the whole filter cartridge has to lift slightly were a bit neanderthal. But not all filters bypass that way, some have dedicated valves in the thread-end.

 

[Jim Allen]

Not sure if you read my followup when you wrote you reply, but I forgot to mention that he estimated dome end bypass was "at least 90 percent of the market." He could be off but I'll take a WAG from somebody in the biz over mine, your or BITOG's

 

[JOD]

Thanks for the post, Jim. Ever since Amsoil published their efficiency ratings, I've found less need to buy the Ford Racing 820S. I can live with 94% @ 20u of the 820S, particularly when I can walk to O'Reillys and pick it up for $4.00.

It doesn't surprise me that cost is a big factor in bypass location. Your friend's response gives me enough reason to stick with the base-end bypass, even if it's a marginal difference.

 

[UNC017]

Originally Posted By: Jim Allen
Not sure if you read my followup when you wrote you reply, but I forgot to mention that he estimated dome end bypass was "at least 90 percent of the market." He could be off but I'll take a WAG from somebody in the biz over mine, your or BITOG's


I didn't... that followup wasn't there when I started typing my reply ;-)

Very interesting and informative post, thanks much!

 

[UNC017]

Well, I thought I might get an informal survey of dome-end vs. thread-end bypass by searching the "cut open" filter threads with pictures. But VERY few people photograph the dome end of the media cartridge, so its hard to determine. Of the ones I could see, it was 50/50. But that was only about 4 filters!

 

[RF Overlord]

Jim, please forgive my question, but I'm old and confuse easily.

I just want to clarify my understanding of the following:
Originally Posted By: Jim Allen

2- He said that "generally" a threaded end bypass is slightly better in most applications BUT he also said that there have been a lot of functional problems with the dome end valves on the market sticking open. He says it comes down to cost. The example he used is that it takes a $1.50 to make a threaded end valve that will equal the reliability of a $0.50 dome end valve. From there, you do the math.
Did you mean to say that there have been "a lot of functional problem with the threaded end valves"? It's your next statement about the cost difference that's causing my confusion...

 

[Joenpb]

I believe Wix & Puralator are the only manufacturers who use threaded end bypass valves. I do prefer those, but I'm using a Royal Purple synthetic filter from Champion labs, and I know it has a dome bypass......

PS - Thanks to all for all the interesting information.

 

[ZeeOSix]

I don't think I've seen one Purolator that uses a base end bypass valve. They might have a few filters with them, but most of the Purolators have a dome end bypass.

 

[ltslimjim]

@Jim Allen, Love the contribution and effort.

A++

I also think it's a wash regarding horizontally mounted oil filters, no pun intended.

The biggest point of interest from that to me was higher efficiency oil filtration in FF oil filters, at least in the US. Sounds accurate.

It's almost as though something like the Bosch D+; at least in my app which only states '40mc' filtration from a couple of sources, would be a great find for 'not THAT efficient' and can hold a lot. Of course, some of that is marketing, but it is a stout filter. Cleaver. I'm using one now and have 3 others from the rebates they had over a year ago.

I can't see there being a problem with high efficiency filtration and OCI unless something such as sludge/cold weather, etc as contributing factors would make it ill advised to perform an extended OCI without changing a super-duper filter.

One indication may be 'elevated' insols for a few OCIs. If you are performing extended OCIs and it doesn't come down, try changing the filter sooner and topping off; among other things.

Probably more of a concern with smaller filters, like the revision on 'recommended' service use Amsoil made with their smaller EaO filters. Folks using these tiny filters and loading up, even sludge prone engines.

As most users here are ware of the kreen threads, gunk can clog a filter in a hurry with good cleansing action. I'd hope Amsoil 'is' clear in helping all of their customers realize the need for a 'starting' OCI on their products or any synthetic oil for that matter, with a used oil analysis if possible to gather more data, before the customer chooses to do something stupid.

IMO, the other side of that is real world people jump on a sales pitch and go 100-miles with it, not even asking questions or listening to reason.

Anyway, that co-relation between higher efficiency FF oil filters in street car vehicles/apps and shorter OCI in America vs the OCI in Europe leaves one wondering. How many top-tier oil filters are getting filtered to max in real world use today?

 

[Jim Allen]

Originally Posted By: RF Overlord
Jim, please forgive my question, but I'm old and confuse easily.

I just want to clarify my understanding of the following:
Originally Posted By: Jim Allen

2- He said that "generally" a threaded end bypass is slightly better in most applications BUT he also said that there have been a lot of functional problems with the dome end valves on the market sticking open. He says it comes down to cost. The example he used is that it takes a $1.50 to make a threaded end valve that will equal the reliability of a $0.50 dome end valve. From there, you do the math.
Did you mean to say that there have been "a lot of functional problem with the threaded end valves"? It's your next statement about the cost difference that's causing my confusion...


Dang it! My bad. YES. Functional problems of the THREADED END bypass. Isn't it great to have good info completely butchered by brain flatulence? Sorry to all.

 

[UNC017]

Originally Posted By: ZeeOSix
I don't think I've seen one Purolator that uses a base end bypass valve. They might have a few filters with them, but most of the Purolators have a dome end bypass.


See my earlier post. About half of the Purolator types I buy are threaded-end bypass.

 

[UNC017]

Originally Posted By: Jim Allen

Dang it! My bad. YES. Functional problems of the THREADED END bypass. Isn't it great to have good info completely butchered by brain flatulence? Sorry to all.


Which goes back to the comment I made earlier. Just looking at most dome-end valves, you can see that it would be easy to make the valves consistent under mass production, and also very reliable. The springs can be stamped out of sheet stock by precise cutters, and the valve disks are very lightweight and can also be cut precisely. They're just very simplistic. But the threaded-end valves require more engineering, or else work by letting the whole filter media lift and I still think that's pretty much a sledge-hammer solution.

 

[Jim Allen]

I agree. Sometimes the simpler, more reliable solutionis better, but as my source said, threaded end can be made reliable, but not cheaply. It's all about the dollars.

BTW, I see you have a '69 Coronet R/T. I had a '68 back in '74. 440 6-Pack, CR 4-speed, Dana 60 rear. Would you hate my guts to hear that I bought it to part out? I used the 6-Pack on my 413 (bored to a 426 with a NOS hemi forged crank) for a while and sold the main parts to various interested parties. Would I love to have that car back now? Youbetcha! It was just a tired old car then that I got really cheap ($500) with a pretty wasted engine and made some money on parting it out.

 

[KCJeep]

Originally Posted By: Joenpb
I believe Wix & Puralator are the only manufacturers who use threaded end bypass valves. I do prefer those, but I'm using a Royal Purple synthetic filter from Champion labs, and I know it has a dome bypass......

PS - Thanks to all for all the interesting information.


My current favorite, Baldwins, have the thread end bypass, at least in my size (FL-1A equivalent).

 

[ZeeOSix]

Originally Posted By: 440Magnum
Originally Posted By: ZeeOSix
I don't think I've seen one Purolator that uses a base end bypass valve. They might have a few filters with them, but most of the Purolators have a dome end bypass.


See my earlier post. About half of the Purolator types I buy are threaded-end bypass.


Are they Purolator "types" (ie, other brands made by Purolator) or actually Purolator branded filters? For instance, Purolator makes all the Motorcraft brand filters, but I don't consider them Purolator filters because they are designed/specified by Motorcraft.

Looking at their total filter line-up, I really don't think very many Purolator branded filters have a base end bypass valve.

 

[UNC017]

Originally Posted By: Jim Allen
I agree. Sometimes the simpler, more reliable solutionis better, but as my source said, threaded end can be made reliable, but not cheaply. It's all about the dollars.

BTW, I see you have a '69 Coronet R/T. I had a '68 back in '74. 440 6-Pack, CR 4-speed, Dana 60 rear. Would you hate my guts to hear that I bought it to part out? I used the 6-Pack on my 413 (bored to a 426 with a NOS hemi forged crank) for a while and sold the main parts to various interested parties. Would I love to have that car back now? Youbetcha! It was just a tired old car then that I got really cheap ($500) with a pretty wasted engine and made some money on parting it out.


Hate your guts? Nah. Would you hate my guts to know I once sold a Chrysler 300L knowing the same would happen to it? There was a time when those cars were worn out, expensive to run, and cheap to buy. LOTS of people parted them out for other projects. They were only made to last a few years anyway. And now that just makes them rarer ;-)

 

[UNC017]

Originally Posted By: ZeeOSix
Originally Posted By: 440Magnum
Originally Posted By: ZeeOSix
I don't think I've seen one Purolator that uses a base end bypass valve. They might have a few filters with them, but most of the Purolators have a dome end bypass.


See my earlier post. About half of the Purolator types I buy are threaded-end bypass.


Are they Purolator "types" (ie, other brands made by Purolator) or actually Purolator branded filters? For instance, Purolator makes all the Motorcraft brand filters, but I don't consider them Purolator filters because they are designed/specified by Motorcraft.

Looking at their total filter line-up, I really don't think very many Purolator branded filters have a base end bypass valve.


These are all Purolator branded (Pure One line) Probably most of their line has moved to dome-end, but not all of them.

 

[ltslimjim]

Isn't the thread-end bypass valve set up something that was designed/engineered for mass production 'after' dome-end types?

 

[Sayjac]

Quote:
These are all Purolator branded (Pure One line) Probably most of their line has moved to dome-end, but not all of them.

Interesting, I've never seen a P1 or Classic/Prem Plus with a thread end bypass. A recent post showed a 90's-ish model PowerFlo with thread end bypass, but not a Purolator branded filter. Like to check one out with a filter application number. Of course, I have seen the Purolator made for Motorcraft and Mopars with thread end bypass.

As for the topic, every time it comes up I think of the late Gary Allan (rip) on the topic, and I suppose that's where I formed my opinion. GA used to say (paraphrase) that Ford was rather 'anal' when it came to bypass placement, using thread end. But, that overall big picture, it wasn't a critical factor either way in his opinion. Obviously I'm not using the detailed explanation Gary did, but that is the main idea I gleaned from his posts on the subject. If I owned a Ford though, I'd feel very comfortable using a Motorcraft filter, for it's design, construction and value price.

And Jim, thanks for the detailed post from your friend, good info. I especially found interesting his comment that it's really unknown how often the bypass opens. Seems to dispute somewhat one of the lastest Fram info videos posted here which mentioned some very high number. I was/am skeptical of that figure.

 

[Gene K]

Purolator built Mopar Mo-090 (Std) and Mo-899 (Metric) Filters used on the 5.7L Hemi and 4.7L OHC are thread end end bypass as well.

Interestingly despite the Mopar Mo-899 being interchangeable with the Motorcraft FL820S they are different with the Mopar having jelly bean style holes in the base plate instead of the round holes.