I know it's been done a million times but I've just finished an A15 into a B110 sdn and I thought i might do a quick write-up before I forget it all.

I've had a JTS built A15 sitting quietly in the corner for 5-6 years now wrapped in plastic but temptation got too great so I pulled the fairly warm A12 with 32/36 out and dropped the A15 in. Luckily I had some custom engine mounts lying around from when I bought some A series motors so I had the right mounts to bolt it straight in. It saved time (obviously) but as is well documented elsewhere on this site, mounts are hardly hard to fabricate.

Now is when the smooth sailing stopped.

First issue the mechanical fuel pump now hit on the drives-side mount, straight onto the rubber mount bolt. I made a small plate from some 3mm aluminium (10 mins with a hacksaw and drill) and, using two gaskets and the plastic spacer off the standard pump, and some gasket paste, blocked off the fuel-pump hole into the block. Then I mounted an electric pump low on the firewall and wired it to a switch on the dash. Not the best setup I know, but sufficient for the run-in period....

Second the Alternator mount was now on the other side of the engine bay. I looked at re-mounting it back to the passenger side (to match the existing wiring), but decided to simply strip back some wrapping off the wiring loom and traced the alt. wires back to the battery mount. I re-wrapped the loom with electrical tape and shortened the alt. wires to suit. Alternator sorted.

I had an Electronic Dizzy on the A12 so I removed that and installed it into the A15. I'm sure it's detailed elsewhere on the site how to install a dizzy and no doubt there a many here who know the procedure backwards, but i will detail this a little in case someone is perusing the thread looking for that detail...
1) Take all the spark plugs out of the eng. Mine where all brand new on a brand new engine so i didn't worry about keeping them in order.
2) I used a socket on the crank bolt (22mm i think) and, putting my finger over the spark plug hole on number 1 piston, turned the motor over until i felt pressure blowing out the hole. Looking down the Plug hole, I could watch the piston come up while I turned it over.
3) Once it got to the top of the stroke (TDC) I installed the new Dizzy. As long as the Rotor Button is pointing at the number 1 Spark Plug Lead on the Dizzy Cap and the motor is at TDC on the compression stroke, you can just put it straight in. Easy.

The last issue I had was where to run the crank case vent(?). The pipe that comes out the rear pass. side of the block below and behind the exhaust manifold. On the A12 this vent re-circulated back to the inlet manifold through a PCV(?) valve. Not sure if that was right but the GX manifold I'm now using doesn't have provisions for the same setup so I had to run it somewhere else. I had an oil catch can from another project lying around so I mounted that to the radiator support panel and connected that to the crank case vent with rubber hose. The rocker cover vent I ran to another inlet on the catch can with the filter now at the top.

Re-connected the starter motor wires, filled the water up,(i'm pretty sure the radiator hoses were different but by this stage all the bits I had were mixed in together so I was picking bits that fit), turned the motor over for a while on the starter without the plugs in to build some oil pressure (Jeff built the motor, if that's how he wants me to do it then that's what i'll do), put the plugs back in and started it up. A quick 2 minute drive down to the beach and back to check everything was running ok. Found out the water temp sensor was being female so i took the one from the A12 and put it in. Works fine.

A quick call to Jeff this afternoon to check timing position and run-in procedure, 15 degrees advance at idle for interests sake, and now I start the boring process of running the motor in.

I had a quick 10 min drive this arvo and gave it a little squirt up to about 4000rpm. I can report it certainly will have more pull than the A12, but I guess most the people on here will groan at the obviousness of that statement....

Thanks for your time, sorry if I wasted it.

crank bolt is size 27

Sound great,Timing sould be 7 degrees BTDC.Pics will help out to see how cool it sounds.

Obviosly you have twin carbs on the engine. The only place to run the breather pipe is into a catch tank, just like you have.Another thing you can do, as they used to do on all the L series rally engines, is to remove the pipe & blank the hole off with a welch plug. As for the timing, did Jeff Taylor suggest you leave the timing at 15 degree once it's run in? I've always used between 10 & 12 degrees even with Avgas, so 15 degrees seems a lot. Can you remember what the compression ratio is on that motor?

As for running the motor in, try & keep some load on it to bed the rings in. I always try & find a bit of a drive on old twisty roads to get this happening, like going from Sydnry to Wollongong down the coast road, out through Macquarie pass then over to Goulburn, then west towards Bathurst on the Taralga/Oberon Rd, & back to Sydney down the Bells Line. If you need more running you can then go up the Putty Rd to Singleton, & back down the New England Hwy to Newcastle, then down what is left of the old Pacific Hwy to Sydney. This would probably be a weekends driving, but the engine would be run in over a variety of roads with load, instead of expressway driving where there's no load. A couple of weeks driving to & from work in normal traffic is an option as well. I haven't tried the Goulburn to Bathurst part yet, but have done everything else. The drive on the Putty Rd from Windsor to Singleton is particularly good with lots of corners & elevation changes to load the engine. This is where you use half to three quarter throttle at medium revs, without letting it rev out.

@bakat - Thanks.

@mrwilson - No offence intended, but the engine builder said to run 15 degrees so that is what I am running. Pics are a bit awkward for me to organise but if people really want to see another B110 engine bay with an A15 i'll get some sorted.

@b310gx Tapping a thread into the GX manifold was never an option so that only left the catch can. If the breather hole is welsh plugged, that only leaves the Rocker Cover breather. Can the crank pressure bleed through the head or would it just blow out the dip stick?

And your commitment to running in motors is commendable. I know most the roads you mentioned very well but now i'm mid north coast so a drive to Armidale over Walcha mountain and back would be sufficient, though nowhere near as long... And last time I went along The Putty Rd there were waaay too many Coppers for my liking.

All factory GX manifolds have boss for the breather.

The GX engine has a reverse flow block ventilation system, compared with the standard A12 engine. In the GX, the block breather hose goes to the air cleaner, while the rocker cover hose goes to the manifold.

Not sure if it's a genuine Datsun GX manifold, and it's hard to tell from your pics, but it has a big GX cast into it hence why I called it a "GX".

That 'GX' manifold is a twin weber pattern one that's been made for years here in Australia. Was originally made by John Taylor, who had his name cast into it. He then sold the molds to somebody else, who changed the name to GX.

It was Jeff who supplied the manifold many, many years ago and I can safely say it has never caused me any problems or issues.......




.......EXCEPT that the runners are cast very close to the studs so I had to move the manifold in as I tightened the nuts. If I had the manifold against the head the runners were way too close to fit the nuts on the end of the thread.
Also the flat area cast around the stud hole to allow for the washer/nut to sit flush when tightened didn't really exist. The runner side of the bolt hole is too close so a spring washer sits on a slight angle and if I did the nuts up flush, it would bend the stud away from the runner slightly.


Edit: And thanks for the Manifold info....

Just wanted to say thanks for the detailed post, sometimes people like me (or maybe only me) feel too noobish to ask questions like where the crank case vent hose should go (cause its a simple thing but im still learning about these smaller things) to as my a12 engine had it run to the air filter but Im upgrading to an a15 in my datsun soon so just yea thanks for extra info, little things like that help people like me to think about problems im probably gonna run into. Aleo the distributor thingy. Nice job