The Ford Barn

51504bat · 05-13-2014, 05:21 PM

Barners,

I've got what I think is a 99T flathead that came out of my 1940 1 1/2 ton
that I replaced with an 8ba. I'm trying to clean out the shop and want to sell the motor but want to make sure what I have so as not to mislead anyone. The motor has 99 stamped on the front of the manifold surface on the passenger side. The heads have 9T cast on the top of the heads and 99t cast on the side of the head. It also has a bolt on cam gear. The trans ID beginning with 99T matches the frame ID number. There are 4 core plugs on the pan rails. The center water holes are round. Based on my research (from the Van Pelt site and others) it sounds like an early '41 Mercury (based on the round center water holes). BUT it does not have a raised manifold deck which I understood the 99T motors had. The motor has been apart since it has a 10/10 crank and its bore .060 over. Any insight would be greatly appreciated.

Tim

flatjack9 · 05-13-2014, 05:32 PM

That would have been introduced in 1939 and is a Mercury engine. The serial # after the 99T will tell you what year it is, or at least the transmission.

Ken/Alabama · 05-13-2014, 05:34 PM

99 is the designation for 39 Mercury. Should be 3 3/16 bore vs the 3 1/16 bore ford. Those blocks can bring a premium if it's good.

rotorwrench · 05-13-2014, 06:22 PM

1939 up to beginning of the 19A for 1941 which differs from your description. These were the block to get before the war and still are for the hot rod crowd. They are 9 for 1939 and 9 for 239 cid in the 99A V8 world. First of the 95 horsepower for Mercury cars and big trucks. They were optional for about any truck in that time frame as being the heavy duty engine but most went into big trucks. These are known to have the thickest cylinder walls of the flathead era.

In 41 they did away with the core plugs on the pan rails and the boss for the intake manifold was narrowed giving it a raised appearance above the rest of the cast surface there. They carried on this configuration to some time in the war years. The 59A series doesn't have as thick a cylinder wall as the old prewar version of the 239 V8 so the change was in the war years somewhere.

51504bat · 05-13-2014, 06:34 PM

Thanks flatjack9 and Ken/Alabama for your lightning fast response. I checked the bore with my trusty HF calipers and it measures 3.2475 which seems to confirm a .060 over 3 3/16 (3.185) bore. So I should be safe to advertise the motor as a 39 to early 41 Merc. As usual the Barn comes through.

Tim

51504bat · 05-13-2014, 06:39 PM

Sponsored Links (Register now to hide all advertisements)

More good info, thanks rotorwrench

Ol' Ron · 05-13-2014, 06:41 PM

The 99A was Mercury and the 99T was truck, Both blocks were the same, trucks had lower CR. I think.

rotorwrench · 05-13-2014, 06:50 PM

The Merc started out with the 81A heads but the trucks all had the 99T heads. Many of the 81A heads just had an "A" casting mark and trucks had the 9T or just a T with the larger chambers and lower compression ratio. The Mercury started using the truck heads somewhere in 1940 if I remember correctly. There was likely an issue with spark advance under heavier load so they fixed the problem that way.

38 coupe · 05-13-2014, 08:40 PM

You have a 1939 / 1940 Mercury engine with truck heads. We put together a thread that discusses the identifiable differences in each year block here: https://www.fordbarn.com/forum/showth...5301&showall=1

Lawrie · 05-13-2014, 10:48 PM

I picked a few of the 99a engines the other month, all came out of trucks as my mates family owned them from new.they have the relieved block,thick walls,( I sonic tested them) and two were std bore.all had the plus in the pan rail.
Lawrie

51504bat · 05-13-2014, 11:05 PM

Quote:

Originally Posted by 38 coupe

You have a 1939 / 1940 Mercury engine with truck heads. We put together a thread that discusses the identifiable differences in each year block here: https://www.fordbarn.com/forum/showth...5301&showall=1

Great link. Thanks.

Graeme / New Zealand · 05-13-2014, 11:47 PM

I've got a 99A block sitting under a tarp at my sisters place. The heads are off so I filled the bores with Marine grease. One of the heads has a T cast into the outter face.

GB

scooder · 05-14-2014, 02:46 AM

Quote:

Originally Posted by Lawrie

I picked a few of the 99a engines the other month, all came out of trucks as my mates family owned them from new.they have the relieved block,thick walls,( I sonic tested them) and two were std bore.all had the plus in the pan rail.
Lawrie

Lawrie, it'd be interesting to know how thick the cylinder walls are on the ones you sonic measured.
Thanks
Martin.

Ol' Ron · 05-14-2014, 08:39 AM

I built one several years ago 3 3/8 X 3 3/4 270 ci 400jr, fantastic acceleration. These were very popular stock car engines.

05-13-2014, 05:32 PM	#2
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,527	Re: 99 t ? That would have been introduced in 1939 and is a Mercury engine. The serial # after the 99T will tell you what year it is, or at least the transmission.

05-13-2014, 05:34 PM	#3
Ken/Alabama Senior Member Join Date: May 2010 Location: Alabama Posts: 3,261	Re: 99 t ? 99 is the designation for 39 Mercury. Should be 3 3/16 bore vs the 3 1/16 bore ford. Those blocks can bring a premium if it's good.

05-13-2014, 06:22 PM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: 99 t ? 1939 up to beginning of the 19A for 1941 which differs from your description. These were the block to get before the war and still are for the hot rod crowd. They are 9 for 1939 and 9 for 239 cid in the 99A V8 world. First of the 95 horsepower for Mercury cars and big trucks. They were optional for about any truck in that time frame as being the heavy duty engine but most went into big trucks. These are known to have the thickest cylinder walls of the flathead era. In 41 they did away with the core plugs on the pan rails and the boss for the intake manifold was narrowed giving it a raised appearance above the rest of the cast surface there. They carried on this configuration to some time in the war years. The 59A series doesn't have as thick a cylinder wall as the old prewar version of the 239 V8 so the change was in the war years somewhere.

05-13-2014, 06:34 PM	#5
51504bat Senior Member Join Date: Sep 2013 Location: SoCal-Redlands Posts: 3,024	Re: 99 t ? Thanks flatjack9 and Ken/Alabama for your lightning fast response. I checked the bore with my trusty HF calipers and it measures 3.2475 which seems to confirm a .060 over 3 3/16 (3.185) bore. So I should be safe to advertise the motor as a 39 to early 41 Merc. As usual the Barn comes through. Tim __________________ Making the simple complicated for over 30 years.

05-13-2014, 06:39 PM	#6
51504bat Senior Member Join Date: Sep 2013 Location: SoCal-Redlands Posts: 3,024	Re: 99 t ? Sponsored Links (Register now to hide all advertisements) More good info, thanks rotorwrench __________________ Making the simple complicated for over 30 years.

05-13-2014, 06:41 PM	#7
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 99 t ? The 99A was Mercury and the 99T was truck, Both blocks were the same, trucks had lower CR. I think.

05-13-2014, 06:50 PM	#8
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: 99 t ? The Merc started out with the 81A heads but the trucks all had the 99T heads. Many of the 81A heads just had an "A" casting mark and trucks had the 9T or just a T with the larger chambers and lower compression ratio. The Mercury started using the truck heads somewhere in 1940 if I remember correctly. There was likely an issue with spark advance under heavier load so they fixed the problem that way. Last edited by rotorwrench; 05-14-2014 at 01:00 PM.

05-13-2014, 08:40 PM	#9
38 coupe Senior Member Join Date: May 2010 Location: South Texas Posts: 1,631	Re: 99 t ? You have a 1939 / 1940 Mercury engine with truck heads. We put together a thread that discusses the identifiable differences in each year block here: https://www.fordbarn.com/forum/showth...5301&showall=1

05-13-2014, 10:48 PM	#10
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,221	Re: 99 t ? I picked a few of the 99a engines the other month, all came out of trucks as my mates family owned them from new.they have the relieved block,thick walls,( I sonic tested them) and two were std bore.all had the plus in the pan rail. Lawrie

05-13-2014, 11:47 PM	#12
Graeme / New Zealand Senior Member Join Date: May 2010 Location: Lower Hutt , New Zealand Posts: 2,126	Re: 99 t ? I've got a 99A block sitting under a tarp at my sisters place. The heads are off so I filled the bores with Marine grease. One of the heads has a T cast into the outter face. GB __________________ "you can't make honey out of dog sh*t" "You're a long time looking at the lid"

05-14-2014, 08:39 AM	#14
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: 99 t ? I built one several years ago 3 3/8 X 3 3/4 270 ci 400jr, fantastic acceleration. These were very popular stock car engines.