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jonpotvin
jon potvin

(8 posts)

Registered:
10/11/2017 09:49AM

Main British Car:


Early 215 crankshaft dimension
Posted by: jonpotvin
Date: October 11, 2017 10:08AM

I need to know the diameter of the flywheel mounting flange on the early 3.5 V8 that used the rope seal. I am trying to determine if later motors with the one piece seals have a larger flange diameter.


MGBV8
Carl Floyd
Kingsport, TN
(3210 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Early 215 crankshaft dimension
Posted by: MGBV8
Date: October 11, 2017 11:20AM

To what end?


jonpotvin
jon potvin

(8 posts)

Registered:
10/11/2017 09:49AM

Main British Car:


Re: Early 215 crankshaft dimension
Posted by: jonpotvin
Date: October 11, 2017 04:45PM

Because I have a modified 4.6 Rover crank to go into an early 215. If the flange is the same size as the 215, then the rear main seal for a rope seal 215 will work.If the 4.6 flange has a larger diameter, then the easy solution is to turn the 4.6 flange down to the 215 dimension.


MGBV8
Carl Floyd
Kingsport, TN
(3210 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Early 215 crankshaft dimension
Posted by: MGBV8
Date: October 12, 2017 12:12PM

Unfortunately, the only 215 crank I have, is installed in my MGB. I can't seem to find a pic of a 215 crank for comparison, either. I was thinking that when they went to the one piece seal that the the crank was machined a bit different in that area.

Maybe someone will come along with some pics.


jonpotvin
jon potvin

(8 posts)

Registered:
10/11/2017 09:49AM

Main British Car:


Re: Early 215 crankshaft dimension
Posted by: jonpotvin
Date: October 12, 2017 07:41PM

The real visible difference at the rear of the 4.6 crank is the lack of the oil slinger ring. Apparently the one piece seal would make the slinger ring unnecessary. This motor has defeated me. After 3 tear downs , 2 rubber seals from D&D and a new rope seal, the thing is still leaking. The rubber seals on both tries lasted about 15 minutes and then started leaving a puddle. The rope seal began leaking immediately but no where as bad as the 2-piece rubber seals. I thought maybe the 4.6 crank seal surface was of a greater diameter and therefore putting too much pressure on the seal.
The only thing I know to do is machine the back of the block and install a Rover one piece seal.


MG four six eight
Bill Jacobson
Wa state
(269 posts)

Registered:
10/23/2007 02:15AM

Main British Car:
73 MGB Buick 215, Eaton/GM supercharger

Re: Early 215 crankshaft dimension
Posted by: MG four six eight
Date: October 12, 2017 11:39PM

Jon,

I have an extra 215 crankshaft out in the shop and I'll try to remember to bring a micrometer home from work to measure it with.

In the mean time the block in my car was originally machined by Phil Baker and he machined the rear for a one piece crank seal. The seal part # is a National 417433 with dimensions of 3.250" ID x 4.003" OD x .375" deep. So I'm guessing that the crank would be around 3.250".
Not sure what the original application is for the seal, but I seem to remember Phil telling me that it was for a tractor of some sort. (It was a long time ago)!

Bill


MGBV8
Carl Floyd
Kingsport, TN
(3210 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Early 215 crankshaft dimension
Posted by: MGBV8
Date: October 13, 2017 11:03AM

Tractor?! Maybe a Triumph. ;)

Actually, it seems to be a multi-purpose seal that works in many applications.



jonpotvin
jon potvin

(8 posts)

Registered:
10/11/2017 09:49AM

Main British Car:


Re: Early 215 crankshaft dimension
Posted by: jonpotvin
Date: October 13, 2017 06:13PM

No need for a tractor seal. All late model Rovers use a one-piece seal that is readily available.Since my 215 has a 4.6 Rover crank, the Rover seal would be right for this rear flange. This answers my original question regarding the diameter of the 215 crank flange. If the 215 crank is 3.25, it is the same as the 4.6 I measured it at 3.243 after a small clean up cut , So the seal failure is not due to an oversize seal journal surface.The Rover seal measures 3.15".
Now, WHERE IS PHIL BAKER???

Just now got a call, found some rope seals gathering dust in the back of an old auto parts store. Owner, thinks they are asbestos.
Maybe this is worth a try. Back in the day,( please excuse the cliche) rope seals were removed without removing the crank with a tiny cork screw type device and the new seal was pulled thru using the same tool. However, the 1961 factory manual says to beat the seal into the groove.


MG four six eight
Bill Jacobson
Wa state
(269 posts)

Registered:
10/23/2007 02:15AM

Main British Car:
73 MGB Buick 215, Eaton/GM supercharger

Re: Early 215 crankshaft dimension
Posted by: MG four six eight
Date: October 14, 2017 12:48AM

I just measured it and it's 3.246" at the sealing area. It does have a slinger on it.
I have seen other engines with a 1 piece seal and a slinger as well. If your 4.6 crank doesn't have one, it's possible that maybe a 4.6 block used some other type of "shield" incorporated into the main cap.

Sadly I believe that Phil Baker passed away a number of years ago. He had a machine shop in the Seattle area and was the 215 guru back in the day!
IMG_3206.JPG


ex-tyke
Graham Creswick
Chatham, Ontario, Canada
(971 posts)

Registered:
10/25/2007 11:17AM

Main British Car:
1976 MGB Ford 302

authors avatar
Re: Early 215 crankshaft dimension
Posted by: ex-tyke
Date: October 14, 2017 08:37AM

As another possibility to your leakage problem, Is it possible that the crankcase ventilation system isn't doing it's job?


jonpotvin
jon potvin

(8 posts)

Registered:
10/11/2017 09:49AM

Main British Car:


Re: Early 215 crankshaft dimension
Posted by: jonpotvin
Date: October 14, 2017 01:57PM

Thanks for the pic and measurement.

Adding a slinger has been discussed. Tack weld an .060" ring to the crank, either mig or tig, which ever puts the least heat into the crank, however, there are other cranks without slingers but they have one piece seals.
Put my first motor together in the 70's, and NEVER had a rear main seal leaker.

Crankcase venting is good. PCV hooked up and flowing. This motor has only 45 minutes on it after a crank re-grind to reduce clearances and show decent oil pressure. Cured the oil pressure problem. Total rebuild only 500 miles ago. Third time assembling.

Will post new thread requesting name of experienced machinist to machine the block for a one piece seal.


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