A modern, simple way to install a spin on oil filter for Dodge flatheads. By 1rifleman

[B1B Keven]

I am still wading through corrective actions on the 52 Dodge truck that was purchased recently.  Primary among these concerns was the complete lack of the oil filter.  I am still not sure why anyone would remove these parts.  Neither is there a way to determine how long the engine has been without oil filtration.  

Another piece of equipment I use is a 51 Ford 8N tractor.  It is powered with a four-cylinder flathead engine originally designed for the model A.  Some enterprising individual must have been thinking about modernizing the typical flathead version of the canister-style oil filter which would allow the use of a modern spin-on filter.  Once installed, it allows an oil filter change in about one minute without any spill or mess.  Best of all – that same oil filter set up is a direct fit for my 52 Dodge truck without modifications or adapters.  The oil line from the #3 oil passage needs to be plumbed under the new oil filter housing and connected to the filter inlet on the right side.  Filtered oil is then routed back to the original port designed by Dodge.  

The original oil filter studs must be removed since they are not long enough to attach the new filter housing.

The buy list is:

1) oil filter housing available from: MSFparts.com, Cost: $41.88
Website: https://msfparts.com Also available on eBay.  
This system uses a spin-on oil filter (#1084) made by Wix.  

2) two stainless 3/8-16 x 13/4 long bolts

3) two stainless 3/8 flat washers

 

Edited February 1, 2023 by B1B Keven

[Merle Coggins]

Oil filters were an option for these trucks and many left the factory without one. My truck didn't have a filter when I got it. I found one on ebay to put on it as I was building it. There have been many that have plumbed in modern spin-on filters. They're probably better than nothing, but most filter elements used are made for full flow applications and don't have the fine filter media typically used in bypass filters. Also, a bypass filter needs to have a restriction built in to limit the amount of oil flow going through the filter. This prioritizes the oil feed to the critical engine components. The Chrysler flat head engines have this build into the oil pressure regulator, to restrict the return flow from the bypass filter if the oil pressure drops. But I would still use a restricted fitting in the system to limit the flow if you end up using a full flow type filter element. 

 

Amsoil has bypass filter kits for several applications, including a 'Universal' kit. https://www.amsoil.com/p/universal-single-remote-bypass-system-bmk21/ It's not cheap, but I know Amsoil sells quality stuff. 

[kencombs]

Just be aware that most modern spin-on filters are not nearly as good at catching smaller particles compared to the bypass cartridges.

 

But, there are spin on filters designed for bypass filtering.  Most are found on diesels.  80s Mitsubishi Fuso trucks are one source for such.  They have two filters, one for the full flow circuit and a second that filters the bypassed oil before returning it to the oil pan.

[billschwindt]

Mopar flathead engines were not designed  for full flow filters only used bypass systems  .                                                                          

[kencombs]

48 minutes ago, billschwindt said:

Mopar flathead engines were not designed  for full flow filters only used bypass systems  .                                                                          

True of 218/230 and some long blocks.  But some 251 and 265 had factory full flow systems.

 

And my 230 will be full flow if I ever get it installed.   Retrofit of course, installed by me but copied from another member's design.

[bones44]

I used a Wix bypass filter head part #24755 on my 37 D5 coupe.

[LeRoy]

My 50 b2b has a sticker on the filter housing that says "Chrysler full flow filter", I'd guess it's not a bypass/side stream filter?

Edited February 9, 2023 by LeRoy

[Merle Coggins]

13 hours ago, LeRoy said:

My 50 b2b has a filter that says "Chrysler full flow filter" on the sticker, I'd guess it's not a bypass/sidestream filter?

 

You’ll need to inspect the filter to see how it’s plumbed. I’ve seen those “Chrysler Full Flow Filter” decals for sale and someone may have stuck it on a bypass filter housing if you weren’t the one to restore your truck. What engine is in your truck? 23” engines, which would have been original in your truck, were never equipped with full flow filters. 

[LeRoy]

47 minutes ago, Merle Coggins said:

 

You’ll need to inspect the filter to see how it’s plumbed. I’ve seen those “Chrysler Full Flow Filter” decals for sale and someone may have stuck it on a bypass filter housing if you weren’t the one to restore your truck. What engine is in your truck? 23” engines, which would have been original in your truck, were never equipped with full flow filters. 

Thanks Merle 

 

It is the original engine. The guy that restored the truck tried to make it as close to factory as possible, (purposely) putting the wrong sticker on it would surprise me. That said, the filter is plumbed just like my D24 so I'd guess it is a bypass. 

 

I should have started by saying I'm not at all familiar with this truck so I may ask a million really dumb questions about it. Maybe I should read the shop manual for it before I come here and start typing. I guess that's one benefit of starting with a car you got in cardboard boxes, you know every nut and bolt by the time you get done and you've had to read the manual closely several times. 

[tanda62]

I have been using this WIX filter 51050 for several years now.  It is by-pass only and seems to do a great job.

 

[Merle Coggins]

23 hours ago, LeRoy said:

Thanks Merle 

 

It is the original engine. The guy that restored the truck tried to make it as close to factory as possible, (purposely) putting the wrong sticker on it would surprise me. That said, the filter is plumbed just like my D24 so I'd guess it is a bypass. 

 

I should have started by saying I'm not at all familiar with this truck so I may ask a million really dumb questions about it. Maybe I should read the shop manual for it before I come here and start typing. I guess that's one benefit of starting with a car you got in cardboard boxes, you know every nut and bolt by the time you get done and you've had to read the manual closely several times. 

 

No worries, LeRoy. Ask away… That’s how we learn. 

[wallytoo]

On 2/6/2023 at 10:18 PM, billschwindt said:

Mopar flathead engines were not designed  for full flow filters only used bypass systems  .                                                                          

 

yes, they were, and no they didn't.

[Merle Coggins]

On 2/6/2023 at 9:18 PM, billschwindt said:

Mopar flathead engines were not designed  for full flow filters only used bypass systems  .                                                                          

 

On 2/10/2023 at 7:11 AM, wallytoo said:

yes, they were, and no they didn't.

 

Technically both statements could be flagged as “miss-information”.

@billschwindt is correct in regards to the 23” engines but not for the 25” blocks.

@wallytoo is correct in regards to the 25” engines only. I believe most, if not all, 25” blocks have the full flow filter mounting boss, but not all had them. Some were plumbed with by-pass filters. 

As for the larger 33” truck engines, we’d have to refer to @Dodgeb4ya

 

[wallytoo]

is the 25" family a mopar flathead?  since it is, it is incorrect to state that mopar flatheads were not designed for full flow (some clearly were), and that they only used bypass filters (some clearly used full flow filters).  my statement does not claim that all were designed for full flow or that none came with bypass, unlike the statement that i quoted.

[kencombs]

I'm surprised that the industrial line of 218/230 engines were never made with full flow filtering.  Especially since the 25" ind's were often found with them and the smaller ones were made up into the 70s.  

 

Has anyone ever encountered a forklift, aircraft tug etc with the shorter engine and full flow?   I never have for sure.  But my 230 will have one.

 

 

[Young Ed]

How will you modify the oiling system for full flow? 

[kencombs]

14 hours ago, Young Ed said:

How will you modify the oiling system for full flow? 

It is documented somewhere on this site, but I don't have a link handy.  Short description:  Drill and tap 2 holes for 1/4" pipe thread in the block .  These intersect the oil passage from the pump to the oil pipe that goes to the main galley.  then insert a plug into the passage to separate the two holes.  Now oil from the pump will go out the first hole to be piped to the filter and return to the second.  I've got mine drilled and tapped as well as having the filter base mounted on the lower rear of the block.  I used a base for a PH8 Fram filter, common to 60s/70s Fords.

I used  a couple of fittings  I had from old e218/230 engines.  They are 1/4" pipe but use an odd tube size, that seems to be 7/16".  3/8 and 1/2 are common, but I've yet to find  any tubing that matches the one Mopar used.   And I'd really like to keep the larger.  3/8 would be easy, 1/2 not so much.

 

 

 

 

 

 

 

 

 

 

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Edited February 14, 2023 by kencombs