Wacky idea! J13 with MGB head?

[1hr40minlate]

I read somewhere that the J series motor was a design that Datsun licensed from MGB. While Datsun of course made it better there are some parts that may swap.

 

The other day I saw a hi po aftermarket head from Moss motors. It is a crossflow design that bolts onto the MGB 1800 pushrod motor. Sounds like it would be the cool ticket for a bored out J-13.

 

I was going to start by comparing head gaskets. Then if it looked promising start to look for a used setup.

 

Then again I could just use the cash to buy a real nice 75 280z that has been in dry storage for the past 20 years.

 

Any thoughts?

[DanielC]

My opinion here. The Datsun L-series motors are light years ahead in design from the MGB motor. At least put a L-series motor in it. Just one example, the 4 cylinder L motor has 10 head bolts, and has four head bolts around each cylinder. The J-13, an MG copied motor has 11 head bolts, and cylinders 2. and 3 have only three head bolts around each cylinder. Guess where head gaskets commonly blow on on the MG/J-series motor. Never mind that the Datsun motor is OHC.

[1hr40minlate]

Hello DanielC,

 

For me it is kind of like hot rodding a flat head Ford. Sure there are better ways to go but there is something appealing to seeing how far I can go with the original design.

 

I do have an L20, 5 spd and rear from a 620 that I could put in the 520. I am not too interested in fabricating the motor mounts and would prefer to have any mods be bolt in so that later I can return the truck to bone stock.

 

I saw that someone else posted that these trucks aren't worth that much in stock form so you might as well go custom. I just have not come around to that way of thinking yet.

 

Later,

 

1hr40

[RacnJsn95]

I've also wondered how much potential the J engines have... I'd be interested to see what you learn about the head gasket comparison! I wonder if the J13 and the J15 use the same block? Then you know you could bore out the J13 quite a bit, and open up the piston possibilities!

[1hr40minlate]

I think that they are the same block. I also think that the same block was used in forklifts that went as large as 1800cc.

 

Maybe stroke it a bit too?

 

When I had a roadster there were some forklift parts that worked on the R series motors too.

 

As I figure it out I will post the findings.

 

The first thing I am going to do is an axle swap. I have to drop the RPMs. Seems like the motor has enough torque to pull a taller gear.

 

1hr40

[DanielC]

Fair enough, go for it. Kind of along the same lines, I get bored when I go to a car show, and everything has a small block Chevy motor

[datsunaholic]

Couple of things... MG people who know about it tend to run Datsun heads and cams on their MG blocks. The Datsun heads flow better, and the valve geometry dictates running the Datsun cam. I know one part that bbsolutely doesn't interchange Datsun-MG- the block itself has a different rear bolt pattern, and secondly the valve covers attach different.

 

The J13, J15, J16 all have different casting numbers. I haven't measured one though (I have one of each). The J13 and E1 are very, very close (same bore) but the J head and oil system is more advanced.

[RacnJsn95]

Seems like a nice idea, but that crossflow MG head is 1800 bucks! Way too much for a datsun owner to spend on a J motor ;) Are there different J series heads, like the L series? open/closed chamber?

[ppeters914]

I think someone did this or at least knows more about it on the EarlyDatsunClub Yahoo Group.

 

Hot roddin' a flathead? Kewl. :thumbup: Hot roddin' a J w/ MG parts? Dunno.:blink:

 

My two centavos....spend freely.

[datsunaholic]

J heads were all the same, at least J13, 15, 16. Any difference would have been for Forklift Propane service (but AFAIK they were all gasoline until much later).

 

 

 

Hot roddin' a flathead? Kewl. :thumbup: Hot roddin' a J w/ MG parts? Dunno.:blink:

.

 

So long as you avoid using the MG electrical components. Lucas, Prince of Darkness, y'know. MGBs had some pretty nice SU setups that fit the J, unfortunately they don't fit in the Datsun Truck engine compartment (steering is in the way).