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Rope or Neoprene rear main XA 250?

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XAFalcon250
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Joined: Tue Jun 02, 2020 3:26 am

Rope or Neoprene rear main XA 250?

Post #1 by XAFalcon250 » Fri Jul 17, 2020 7:53 am

Replace rear main Rope Seal with two piece rubber seal?
I’m just in the process of re sealing the whole motor on my XA 250 2V (72 DA) and want to replace the rear main while I’m there. Im considering replacing the rope seal with the rubber type if possible. I think I have read that the 302 Windsor and the 250 share rear crank flangesizes. Is this only 250 Cross Flows? And do they have 3.75 / 95.25mm flange.

Anyway have measured my crank flange and it is 3.622inch / 92mm. So not sure what I need part no wise for a Neoprene.

Any experience and advice would be much appreciated. Thanks.
Last edited by XAFalcon250 on Sat Jul 18, 2020 5:27 am, edited 1 time in total.

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bubba22349
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Location: Flagstaff, Az. 86005 near the old Route 66

Re: Rope or Neoprene rear main XA 250?

Post #2 by bubba22349 » Fri Jul 17, 2020 1:47 pm

Hi XAFalcon250, using a neoprene rear main seal is a great benefit of less frictional HP reducing drag, if you can find the correct fitting one for your engine. Assuming that your in Australia, It was discovered that the seal parts listings for Ford small six'es over there in Austraila are wrong. The 302 Windsor seal won't work correctly and can't be modded to work, so if you can't get the correct fitting 250 neoprene rear main seal than your better off on using the Rope type seal. Below is a link to a group of posts going into detail on rear seals that should be of help to you in getting the right neoprene rear seals for both the 200's or the 250's Aussie blocks. Aussie site member XRWagon went through all this severial years ago when being sold this same wrong seal. I am surprised that this listing error still hasn't been corrected, in any case you can still get one from the US if you can't find one there. Best of luck :thumbup: :nod:

Neoprene Rear Main Seals for 200's & 250's
viewtopic.php?f=1&t=72398&p=556250#p556195
Even a bad day Drag Racing is still better than a good day at work!

Current project is a 1988 John Deere 420 Garden Tractor I need a few small parts to get it fixed, plus some cosmetic items, maybe a few attachments, if you happen to have or know of JD 420 parts would welcome the help!

My Ex-Inline 6 Fleet 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

XAFalcon250
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Posts: 5
Joined: Tue Jun 02, 2020 3:26 am

Re: Rope or Neoprene rear main XA 250?

Post #3 by XAFalcon250 » Fri Jul 17, 2020 7:53 pm

bubba22349 wrote:Hi XAFalcon250, using a neoprene rear main seal is a great benefit of less frictional HP reducing drag, if you can find the correct fitting one for your engine. Assuming that your in Australia, It was discovered that the seal parts listings for Ford small six'es over there in Austraila are wrong. The 302 Windsor seal won't work correctly and can't be modded to work, so if you can't get the correct fitting 250 neoprene rear main seal than your better off on using the Rope type seal. Below is a link to a group of posts going into detail on rear seals that should be of help to you in getting the right neoprene rear seals for both the 200's or the 250's Aussie blocks. Aussie site member XRWagon went through all this severial years ago when being sold this same wrong seal. I am surprised that this listing error still hasn't been corrected, in any case you can still get one from the US if you can't find one there. Best of luck :thumbup: :nod:

Neoprene Rear Main Seals for 200's & 250's
viewtopic.php?f=1&t=72398&p=556250#p556195


Thanks heaps! Digging through that thread lead to this thread /viewtopic.php?f=1&t=72342&p=555758#p555758 where xctasy listed the part numbers which confirms that here in Aus you need to be on your game and measure the crank flange to be sure.
I.e. I have an early one owner 1972 250 XA Falcon that has the smaller crank flange. Looks like as others have said Ford Australia mixed and matched parts to get cars out the door on the production line.

So I basically need the smaller seals as xctasy listed. I will see if any Aus parts suppliers stock theses otherwise will source direct from the US.

Love the forum. Thanks so much!

FEL-PRO BS30135
http://www.rockauto.com/catalog/moreinf ... cc=1333370

or Felpro P30135
http://www.ebay.com.au/itm/200-Ford-Six ... 1448123339

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bubba22349
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Posts: 10276
Joined: Sun Jan 03, 2010 4:46 pm
Location: Flagstaff, Az. 86005 near the old Route 66

Re: Rope or Neoprene rear main XA 250?

Post #4 by bubba22349 » Fri Jul 17, 2020 10:24 pm

Your very welcome glad those posts were of some help, yes "Xctasy" is very knowageable and is one of this sites top posters. Good luck :thumbup: :nod:
Even a bad day Drag Racing is still better than a good day at work!

Current project is a 1988 John Deere 420 Garden Tractor I need a few small parts to get it fixed, plus some cosmetic items, maybe a few attachments, if you happen to have or know of JD 420 parts would welcome the help!

My Ex-Inline 6 Fleet 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

XAFalcon250
Registered User
Posts: 5
Joined: Tue Jun 02, 2020 3:26 am

Re: Rope or Neoprene rear main XA 250?

Post #5 by XAFalcon250 » Wed Sep 02, 2020 3:15 am

This is just an update to this post so that anyone ever reading this in future gets the right info.
After some extensive reading on this forum and a post from xctasy https://fordsix.com//viewtopic.php?f=1& ... 58#p555758
I was just a little confused.

The post mentions that a crank flange of 3.625" and 2.75" pitch uses the smaller 200 6cyl neoprene seal ala the FELPRO BS30135. However it also states that there is a later XY/XA/XB non cross flow 200/250 item. The point of confusion stemmed from the fact that my Australian 250 72DA block actually has a crank flange measuring of 3.625 and 2.75" Hence I over thought this if that's a thing.

Cut a long story short I initially purchased the BS30135 to find its too small. I then purchased the Permaseal HN064 which was what was recommend from Bursons (Australian Parts Supplier) and its a perfect fit. I confirmed they listed this seal (Permaseal HN064) for my 1973 XA Falcon 250 6cyl. So at least they do have the right info.

Finally the suitability for the HN064 seal shows it applying to (assume Australian model engine installations) below. Therefore you could also infer that the FELPRO BS30136 also applies to the 71 onwards 250 6cyl.

Permaseal HN064 Cankshaft Rear Seal Rubber 2 Piece to suit;
200 6cyl; 1972-1978
221 V8; 1962-1963
250 6cyl; 1970-1978
260 V8; 1963-1965
289 V8; 1964-1968
302 V8; 1965-1972
3.3 6cyl; 7/1976-6/1984
4.1 6cyl; 1976-8/1984

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