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[Datsun 1200 encyclopedia]

AY12 engine

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Categories: Engine Modifications | Engine Swaps | Nissan Engines | Racing

Revision as of 03:18, 8 April 2010
ddgonzal (Talk | contribs)

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-The AY12 is so rare it has been dubbed the Nissan Mystery Motor. It was used in [[Works|works]] [[wikipedia:Datsun_Cherry|Datsun Cherry]] racing cars.+{{Nissan A Engine}}
-[http://datsun1200.com/modules/myalbum/photo.php?lid=449 http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://datsun1200.com/modules/myalbum/photos/449.jpg]+Perhaps the most interesting variety of A series engines was the AY12 engine. This was a special race-only Nissan factory (works) racing version with a crossflow cylinder head. The AY12 is so rare it has been dubbed the Nissan Mystery Motor. It was used in [[Works|works]] [[wikipedia:Datsun_Cherry|Datsun Cherry]] racing cars.
 + 
 +{{Album|449}}
 + 
 += Video footage of the engine in question =
 +{{YouTube|A6Hue-1gCKk|TS Sunny A12}}
= Overview = = Overview =
Cross-flow Double-Ignition AY12 OHV 160ps @ 8,800 rpm Cross-flow Double-Ignition AY12 OHV 160ps @ 8,800 rpm
-A12 cross flow engine in a Cherry X1-R raced in the Fuji speedway Victory 200 race in 1973.+AY12 was used in under-1300cc class racing with 76 to 76.8mm pistons. Intake valve was 40-41mm and exhaust valves that have been used are 33mm and 34mm. The piston was also special design. Because of the hemi combustion chamber, the pushrod-activated valve rocker system was different from the regular A12.
-[http://datsun1200.com/modules/myalbum/photo.php?lid=2521 http://datsun1200.com/modules/myalbum/photos/thumbs/2521.jpg]+A12 cross flow engine in a Cherry X1-R raced in the Fuji speedway Victory 200 race in 1973.
 +<br>{{Album|2521}}
It is rare as. Probably the rarest Datsun engine of all. Almost no one has ever seen one, but they exist in photos and old magazines. It is rare as. Probably the rarest Datsun engine of all. Almost no one has ever seen one, but they exist in photos and old magazines.
-[http://i11.photobucket.com/albums/a164/KB10/45feeceb.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://i11.photobucket.com/albums/a164/KB10/45feeceb.jpg]+{{Album|28752|was=Photo\45feeceb.jpg}}
Nissan Part Number 11041-M0820. See the FIA homologation papers for the PE10/A12GX E10 Datsun Cherry. Nissan Part Number 11041-M0820. See the FIA homologation papers for the PE10/A12GX E10 Datsun Cherry.
- 
LTR was planning to create a new head casting: [http://datsun1200.com/modules/newbb/viewtopic.php?topic_id=28058&forum=2 Remake of the Crossflow]. LTR was planning to create a new head casting: [http://datsun1200.com/modules/newbb/viewtopic.php?topic_id=28058&forum=2 Remake of the Crossflow].
Line 21: Line 26:
It used a large right-angle distributor lying horizontally along the block. It served eight spark plugs, so these engines used two plugs per cylinder. The original design & prototype head used only one plug per cylinder but the racing heads used two. It used a large right-angle distributor lying horizontally along the block. It served eight spark plugs, so these engines used two plugs per cylinder. The original design & prototype head used only one plug per cylinder but the racing heads used two.
- += Benefits =
-=Benefits=+Using a stock A12 engine block, here are some benefits of the racing-only A12Y cylinder head:
-Using a stock A12 engine block, here are some benefits of the racing-only A12Y cylinder hear:+
# It is crossflow, the inlet and exhaust are on opposite sides of the head. # It is crossflow, the inlet and exhaust are on opposite sides of the head.
-# Using a [[hemi]] cylinder head design, the valves are in better position than in the normal model. Racing trim was reportedly 220 gross horespower+# Using a [[wikipedia:Hemi engine|hemi]] cylinder head design, the valves are in better position than in the normal model. Racing trim was reportedly 220 gross horespower
# The is no heat problem with twin carbs, because they are on diffent side than the exhaust manifold. # The is no heat problem with twin carbs, because they are on diffent side than the exhaust manifold.
#The chamber is hemi, it can take more compression without unintended pre-detonation (knocking or pinking/pinging) #The chamber is hemi, it can take more compression without unintended pre-detonation (knocking or pinking/pinging)
Line 33: Line 37:
Full-page article on the AY12 in [[Magazines|Auto Technic Magazine]] 1982 volume 14 no.164. Full-page article on the AY12 in [[Magazines|Auto Technic Magazine]] 1982 volume 14 no.164.
-[http://i238.photobucket.com/albums/ff99/ianey89/Auto%20Technic/E64F0430-1.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://i238.photobucket.com/albums/ff99/ianey89/Auto%20Technic/E64F0430-1.jpg]+Top:AY12 OHV engine (single-cam)
 +<br>Bottom: DOHC [[AZ12 engine]] design similar to the Nissan LZ Engine
 +<br>{{UploadPost|174_63da0f1011268.jpg|497468|was=Photo\E64F0468.jpg}}
-[http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0463.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0463.jpg]+Crossflow OHV AY12 (pushrod head)
 +<br>{{UploadPost|174_63da159038437.jpg|497468|was=Photo\E64F0430-1.jpg}}
-[http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0464.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0464.jpg]+{{UploadPost|174_63da15e3201fb.jpg|497468|was=Photo\E64F0464.jpg}}
-[http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0465.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0465.jpg]+{{UploadPost|174_63da16048e0cc.jpg|497468|was=Photo\E64F0465.jpg}}
-[http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0467.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0467.jpg] 
-Bottom: AZ12 DOHC Engine similar to the [[Nissan LZ Engine]]+{{translate|AY12 engine. The shape and size of the head cover are completely related|AY12&#12456;&#12531;&#12472;&#12531;&#65294;&#12288;&#12504;&#12483;&#12489;&#12459;&#12496;&#12540;&#12398;&#22411;&#29366;&#12289;&#12288;&#22823;&#12365;&#12373;&#12364;&#20840;&#12367;&#36899;&#12358;}}
-<br>[http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0468.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://i238.photobucket.com/albums/ff99/ianey89/AY%20Head/E64F0468.jpg]+<br>{{UploadPost|174_63da14f829ef8.jpg|497468|was=Photo\E64F0467.jpg}}
-<br>This is just a diagram. It seems no AZ12 was actually produced.+
- +
-[http://i238.photobucket.com/albums/ff99/ianey89/Auto%20Technic/E64F0394-1.jpg http://i238.photobucket.com/albums/ff99/ianey89/Auto%20Technic/th_E64F0394-1.jpg]+
Oil Pump with upright filter boss for Cherry FF (FWD) race car Oil Pump with upright filter boss for Cherry FF (FWD) race car
-<br>[http://datsun1200.com/uploads/photos/21714.jpg http://ddgonzal.members.winisp.net/getThumb.aspx?width=400&uri=http://datsun1200.com/uploads/photos/21714.jpg]+<br>{{Album|21714}}
-=Swap Notes=+= Swap Notes =
# In a right drive, rear drive car, the rear carb is likely to cause interference problems with the brake cylinder. Solution: use a [[Brake_Swaps#Remote_Brake_Cylinder|remote brake master cylinder]]. # In a right drive, rear drive car, the rear carb is likely to cause interference problems with the brake cylinder. Solution: use a [[Brake_Swaps#Remote_Brake_Cylinder|remote brake master cylinder]].
#* Left side drivers, however will immediately see the advantages #* Left side drivers, however will immediately see the advantages
Line 58: Line 61:
# The induction on this one precludes the use of a conventional distributor # The induction on this one precludes the use of a conventional distributor
#* One could use a right angle drive to lay the distributor down alongside the block, but it makes it hard to service. #* One could use a right angle drive to lay the distributor down alongside the block, but it makes it hard to service.
-#*: [http://i11.photobucket.com/albums/a164/KB10/69c391dd.jpg http://i11.photobucket.com/albums/a164/KB10/th_69c391dd.jpg] 
#* Or use an [[EDIS]] crank trigger ignition #* Or use an [[EDIS]] crank trigger ignition
# In RHD, the carbs in the picture are causing a problem with the routing of the clutch cable. Again, LHD cars will have no problem # In RHD, the carbs in the picture are causing a problem with the routing of the clutch cable. Again, LHD cars will have no problem
 +
 +Right-angle distributor
 +<br>{{Album|28753|was=Photo\69c391dd.jpg}}
The head was originally designed for a transversely mounted engine in the Cherry range of cars & some of the clearance problems simply did not arise because of this transverse mounting. The head was originally designed for a transversely mounted engine in the Cherry range of cars & some of the clearance problems simply did not arise because of this transverse mounting.
Line 66: Line 71:
The cure for some of these problems might just be a custom EFI induction with a crank angle sensor made from a modified distributor & let the computor sort out the spark problem. Even a simple Pertronix conversion would very likely serve this purpose quite well for many aftermarket computers. Just make a flat[ish] cover for the distributor to replace the distributor cap, & run two coils in a wasted spark configuration. The cure for some of these problems might just be a custom EFI induction with a crank angle sensor made from a modified distributor & let the computor sort out the spark problem. Even a simple Pertronix conversion would very likely serve this purpose quite well for many aftermarket computers. Just make a flat[ish] cover for the distributor to replace the distributor cap, & run two coils in a wasted spark configuration.
-[[Category:Engine Modifications]]+= Discussion =
 +Forum: [http://datsun1200.com/modules/newbb/viewtopic.php?topic_id=28058 Remake of the Crosslow, pushrod a-series "ay12" 11041-M0820 head]
 + 
 +OLD TIMER Magazine, February 2005
 + 
 +The FIRST version of the AY Crossflow was a 'Single Ignition' version, and this was soon modified to the SECOND 'Double Ignition' version - which was more efficient. As the FIA homologation papers show the FIRST version, it is possible that the JAF homologation papers ( covering domestic racing in Japan ) may also cover the SECOND version, or it was being used prior to proper homologation and the then-current homologation was going to be retrospectively updated ( which is not an unprecedented situation ).
 + 
 +{{Album|28754|was=Photo\ayartnov062kb0.jpg}}
 + 
 +http://img518.imageshack.us/img518/8845/aycrossflowfront1ld9.jpg
 + 
 +{{Album|28755|was=Photo\aycrossflowhemipiston1qo1.jpg}}
 + 
 +[[Category:Engine Modifications]] [[Category:Engine Swaps]] [[Category:Nissan Engines]] [[Category:Racing]]{{End}}

Revision as of 18:22, 8 February 2023

Nissan A Engines: Overview | A10 | A12 | A12A | A13, old | A13, new | A14 | A15

Perhaps the most interesting variety of A series engines was the AY12 engine. This was a special race-only Nissan factory (works) racing version with a crossflow cylinder head. The AY12 is so rare it has been dubbed the Nissan Mystery Motor. It was used in works Datsun Cherry racing cars.

449.jpgAlbum 449

Contents

Video footage of the engine in question

 V I D E O  TS Sunny A12 (click to view)
hqdefault.jpg

Overview

Cross-flow Double-Ignition AY12 OHV 160ps @ 8,800 rpm

AY12 was used in under-1300cc class racing with 76 to 76.8mm pistons. Intake valve was 40-41mm and exhaust valves that have been used are 33mm and 34mm. The piston was also special design. Because of the hemi combustion chamber, the pushrod-activated valve rocker system was different from the regular A12.

A12 cross flow engine in a Cherry X1-R raced in the Fuji speedway Victory 200 race in 1973.
2521.jpgAlbum 2521

It is rare as. Probably the rarest Datsun engine of all. Almost no one has ever seen one, but they exist in photos and old magazines.

28752.jpgAlbum 28752

Nissan Part Number 11041-M0820. See the FIA homologation papers for the PE10/A12GX E10 Datsun Cherry.

LTR was planning to create a new head casting: Remake of the Crossflow.

It used a large right-angle distributor lying horizontally along the block. It served eight spark plugs, so these engines used two plugs per cylinder. The original design & prototype head used only one plug per cylinder but the racing heads used two.

Benefits

Using a stock A12 engine block, here are some benefits of the racing-only A12Y cylinder head:

  1. It is crossflow, the inlet and exhaust are on opposite sides of the head.
  2. Using a hemi cylinder head design, the valves are in better position than in the normal model. Racing trim was reportedly 220 gross horespower
  3. The is no heat problem with twin carbs, because they are on diffent side than the exhaust manifold.
  4. The chamber is hemi, it can take more compression without unintended pre-detonation (knocking or pinking/pinging)
  5. The exhaust side is the same as normal head. The ports are not in same place but one can use standard A12GX exhaust manifold

Documentation

Full-page article on the AY12 in Auto Technic Magazine 1982 volume 14 no.164.

Top:AY12 OHV engine (single-cam)
Bottom: DOHC AZ12 engine design similar to the Nissan LZ Engine
174_63da0f1011268.jpgPost 497468

Crossflow OHV AY12 (pushrod head)
174_63da159038437.jpgPost 497468

174_63da15e3201fb.jpgPost 497468

174_63da16048e0cc.jpgPost 497468


AY12 engine. The shape and size of the head cover are completely related AY12エンジン. ヘッドカバーの型状、 大きさが全く連う

174_63da14f829ef8.jpgPost 497468

Oil Pump with upright filter boss for Cherry FF (FWD) race car
21714.jpgAlbum 21714

Swap Notes

  1. In a right drive, rear drive car, the rear carb is likely to cause interference problems with the brake cylinder. Solution: use a remote brake master cylinder.
    • Left side drivers, however will immediately see the advantages
  2. The exhaust can quite obviously be made in a more conventional style to allow a lot more room in there
  3. The induction on this one precludes the use of a conventional distributor
    • One could use a right angle drive to lay the distributor down alongside the block, but it makes it hard to service.
    • Or use an EDIS crank trigger ignition
  4. In RHD, the carbs in the picture are causing a problem with the routing of the clutch cable. Again, LHD cars will have no problem

Right-angle distributor
28753.jpgAlbum 28753

The head was originally designed for a transversely mounted engine in the Cherry range of cars & some of the clearance problems simply did not arise because of this transverse mounting.

The cure for some of these problems might just be a custom EFI induction with a crank angle sensor made from a modified distributor & let the computor sort out the spark problem. Even a simple Pertronix conversion would very likely serve this purpose quite well for many aftermarket computers. Just make a flat[ish] cover for the distributor to replace the distributor cap, & run two coils in a wasted spark configuration.

Discussion

Forum: Remake of the Crosslow, pushrod a-series "ay12" 11041-M0820 head

OLD TIMER Magazine, February 2005

The FIRST version of the AY Crossflow was a 'Single Ignition' version, and this was soon modified to the SECOND 'Double Ignition' version - which was more efficient. As the FIA homologation papers show the FIRST version, it is possible that the JAF homologation papers ( covering domestic racing in Japan ) may also cover the SECOND version, or it was being used prior to proper homologation and the then-current homologation was going to be retrospectively updated ( which is not an unprecedented situation ).

28754.jpgAlbum 28754

aycrossflowfront1ld9.jpg

28755.jpgAlbum 28755 

¤