The Ford Barn

old guy rich · 11-20-2018, 09:42 PM

Hi guys, I haven't posted in a long time, just driving my 50 Merc every day and loving it. My question is about a late 51 Merc engine. I think it has the trans that has 4 bolts holding it to the bell-housing. My 50 has the completely round bell that is part of the trans. Is there any way to put the later 51 Merc engine in my 50 and bolt my overdrive trans to it? Thanks guys. old guy rich.

19Fordy · 11-20-2018, 10:03 PM

You can if you use the 50 Merc stamped steel bellhousing. My 51 Merc had an OEM 51 Merc engine with the OEM 51 Merc stamped steel bellhousing and OEM 3 speed trans. with OD. See first photo. 49-51 merc stamped steel bellhousings are all the same.

old guy rich · 11-21-2018, 07:57 AM

Quote:

Originally Posted by 19Fordy

You can if you use the 50 Merc stamped steel bellhousing. My 51 Merc had an OEM 51 Merc engine with the OEM 51 Merc stamped steel bellhousing and OEM 3 speed trans. with OD. See first photo. 49-51 merc stamped steel bellhousings are all the same.

Thank you 19Fordy. old guy.

rotorwrench · 11-21-2018, 10:16 AM

Both of my 51 Mercs are early models (Nov 1950). They still have the old trans used in 49 & 50. I think it was Feb of 1951 when the new style transmission and cast iron bell housing became the norm. The equalizer for the clutch should work fine on the earlier stamped half bell same as 50 & early 51. You may also need to find the earlier rear trans mount that uses the round rubber biscuit type mounts. The late 51 transmission has the smaller diameter input shaft so you will need to change back the the 49 thru E51 Borg & Beck clutch set up to use the 1 3/8" 10-spline trans input.

old guy rich · 11-21-2018, 12:26 PM

Quote:

Originally Posted by rotorwrench

Both of my 51 Mercs are early models (Nov 1950). They still have the old trans used in 49 & 50. I think it was Feb of 1951 when the new style transmission and cast iron bell housing became the norm. The equalizer for the clutch should work fine on the earlier stamped half bell same as 50 & early 51. You may also need to find the earlier rear trans mount that uses the round rubber biscuit type mounts. The late 51 transmission has the smaller diameter input shaft so you will need to change back the the 49 thru E51 Borg & Beck clutch set up to use the 1 3/8" 10-spline trans input.

Thanks rotowrench, I have not seen the late 51 Merc engine yet, it is for sale not far from me. What I want to do is just install the late 255 engine into my stock drivetrain and want to make sure my 50 trans and bell housings will fit the later engine with no problems. My engine uses a little oil and the engine for sale was rebuilt is what I'm told. Thanks rotowrench. old guy rich.

rotorwrench · 11-21-2018, 02:19 PM

Sponsored Links (Register now to hide all advertisements)

If it is a late 51 and comes with all the trans stuff. You should be able to separate the trans, bell and clutch then use the motor as is. If it's a later 1951 engine, it may have some upgrades for use of automatic trans (larger bore in rear of crankshaft) and it may have the rotator type valves. The intake might also be different in the type of automatic choke. The oil pan may or may not have the three studs for the stamped half bell brace. I've seen them both ways.

It would still be a bolt up deal though. Just use all your OEM 8CM stuff you need off the original motor in the 50. The cast iron type bell housing is a very good bell for converting transmissions on all the old flatheads so it's worth a fair bit in trading stock if you have no plans for it. The 4 bolt pattern overdrive transmissions were used clear up till the end of the flathead era in Fords and Mercury cars. It has a good value to it if still in fair shape. The T85 type transmission sort of took over in the Y-block era.

old guy rich · 11-21-2018, 04:06 PM

Quote:

Originally Posted by rotorwrench

If it is a late 51 and comes with all the trans stuff. You should be able to separate the trans, bell and clutch then use the motor as is. If it's a later 1951 engine, it may have some upgrades for use of automatic trans (larger bore in rear of crankshaft) and it may have the rotator type valves. The intake might also be different in the type of automatic choke. The oil pan may or may not have the three studs for the stamped half bell brace. I've seen them both ways.

It would still be a bolt up deal though. Just use all your OEM 8CM stuff you need off the original motor in the 50. The cast iron type bell housing is a very good bell for converting transmissions on all the old flatheads so it's worth a fair bit in trading stock if you have no plans for it. The 4 bolt pattern overdrive transmissions were used clear up till the end of the flathead era in Fords and Mercury cars. It has a good value to it if still in fair shape. The T85 type transmission sort of took over in the Y-block era.

Great info rotowrench, thank you very much. I'll see the "for-sale" engine this coming week.

oldskool · 11-21-2018, 06:20 PM

I have the 49/50 merc stamped steel bell and starter plate to match if you need it

Ol' Ron · 11-21-2018, 07:28 PM

Just use your bell housing flywheel and clutch. the engines are the same block.

old guy rich · 11-21-2018, 08:28 PM

Quote:

Originally Posted by oldskool

I have the 49/50 merc stamped steel bell and starter plate to match if you need it

Thanks oldskool, old guy rich.

old guy rich · 11-21-2018, 08:32 PM

Quote:

Originally Posted by Ol' Ron

Just use your bell housing flywheel and clutch. the engines are the same block.

Thanks OL' Ron, that was my worry, didn't know if the blocks were the same. old guy rich.

JSeery · 11-21-2018, 09:19 PM

The bolt pattern should be the same on all the 8ba blocks.

old guy rich · 11-22-2018, 04:10 PM

Quote:

Originally Posted by JSeery

The bolt pattern should be the same on all the 8ba blocks.

Thanks JSeery. old guy

rotorwrench · 11-23-2018, 10:58 AM

The only thing you have to be careful of is whether the engine is an actual Mercury 255 cid engine or not. I've heard plenty of tales about folks installing Mercury 8CM or later heads on a standard 239 engine and representing them as a "Mercury" engine which is fraud. All the 8BA family of engines used the came basic block design and they are interchangeable. The 4-inch stroke crankshaft is the main difference with the 239 being a 3 3/4-inch stroke. Mercury pistons are different with the wrist pin location being changed to compensate for the 1/4" longer stroke.

11-20-2018, 09:42 PM	#1
old guy rich Senior Member Join Date: Jun 2015 Posts: 186	Trans question Hi guys, I haven't posted in a long time, just driving my 50 Merc every day and loving it. My question is about a late 51 Merc engine. I think it has the trans that has 4 bolts holding it to the bell-housing. My 50 has the completely round bell that is part of the trans. Is there any way to put the later 51 Merc engine in my 50 and bolt my overdrive trans to it? Thanks guys. old guy rich.

11-21-2018, 10:16 AM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,426	Re: Trans question Both of my 51 Mercs are early models (Nov 1950). They still have the old trans used in 49 & 50. I think it was Feb of 1951 when the new style transmission and cast iron bell housing became the norm. The equalizer for the clutch should work fine on the earlier stamped half bell same as 50 & early 51. You may also need to find the earlier rear trans mount that uses the round rubber biscuit type mounts. The late 51 transmission has the smaller diameter input shaft so you will need to change back the the 49 thru E51 Borg & Beck clutch set up to use the 1 3/8" 10-spline trans input.

11-21-2018, 02:19 PM	#6
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,426	Re: Trans question Sponsored Links (Register now to hide all advertisements) If it is a late 51 and comes with all the trans stuff. You should be able to separate the trans, bell and clutch then use the motor as is. If it's a later 1951 engine, it may have some upgrades for use of automatic trans (larger bore in rear of crankshaft) and it may have the rotator type valves. The intake might also be different in the type of automatic choke. The oil pan may or may not have the three studs for the stamped half bell brace. I've seen them both ways. It would still be a bolt up deal though. Just use all your OEM 8CM stuff you need off the original motor in the 50. The cast iron type bell housing is a very good bell for converting transmissions on all the old flatheads so it's worth a fair bit in trading stock if you have no plans for it. The 4 bolt pattern overdrive transmissions were used clear up till the end of the flathead era in Fords and Mercury cars. It has a good value to it if still in fair shape. The T85 type transmission sort of took over in the Y-block era.

11-21-2018, 06:20 PM	#8
oldskool Senior Member Join Date: May 2010 Location: shirley ny Posts: 992	Re: Trans question I have the 49/50 merc stamped steel bell and starter plate to match if you need it

11-21-2018, 07:28 PM	#9
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,859	Re: Trans question Just use your bell housing flywheel and clutch. the engines are the same block.

11-21-2018, 09:19 PM	#12
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: Trans question The bolt pattern should be the same on all the 8ba blocks.

11-23-2018, 10:58 AM	#14
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,426	Re: Trans question The only thing you have to be careful of is whether the engine is an actual Mercury 255 cid engine or not. I've heard plenty of tales about folks installing Mercury 8CM or later heads on a standard 239 engine and representing them as a "Mercury" engine which is fraud. All the 8BA family of engines used the came basic block design and they are interchangeable. The 4-inch stroke crankshaft is the main difference with the 239 being a 3 3/4-inch stroke. Mercury pistons are different with the wrist pin location being changed to compensate for the 1/4" longer stroke.