@clyons8...great job man
can some one explain how much Max. hp can be produced from a A12 engine?

awesome work chris, great to see
are those arms all good on the carbys?
have to pop round and have a look soonish
sorry been flat out
cheers

i love your close up photography, wish i had a camera that could do it that well (not camera phone)

nice work on the shims, hope the holymar doesnt blow with combustion pressures.

any benefit of just using 2 head gaskets over this method?

That head shim looks great, love your work.

Sorry Mik, hadn’t read that. Video soon?

I finally managed to use one of my own head shims had to open up a galley that I found to be a little restrictive, just used a dremel tool to open it up to a slot shape. The installation was fairly straight forward but I just made sure everything was clean as clean can be. I also sanded down the shim using 800 & 1000 grit and then sprayed with methylated spirits to clean. I made sure I didn’t touch any of the surfaces. All those little bits of material in the bores are just bits of fibre from tissue paper, I blew all that off when I put the head on.

The hylomar was put on two different surfaces and left for the solvent to evaporate, it flashed off fairly quick even in the cold. I think I may have put too much on but I’m not sure. I let the head sit bolted for about 15 minutes then tightened again and again about four more times. I let it sit for about two days while I worked on everything else.

Dropped the gearbox and replaced the noisy thrust bearing, sorted out the rattley exhaust and tightened it up so it wasn’t hanging down so obvious at the back. Almost got round to lowering it even more but decided to leave it.

Also made up a catch can setup that looks as factory as possible, just an old overflow bottle from a pintara (keepin’ it Nissan). I can afford all that shiny eBay #OOPS# anyway, so I settled for an $8.00 second hand dirty as all buggery overflow bottle. Need to sort out the hose on top of the rocker cover, looking at putting in some bent pieces.

GX race head is on and there is an obvious increase in power and the exhaust note has a bit more of a bark to it. Gave the engine a flogging and it all went well, lotsa power to be had out of this little A12.

Speedo cable got replaced but it still doesn’t work…..not sure what’s happened there.

Also got some new linkage sockets which have a clip on the inside then a second clip to make sure it doesn’t detach from the ball, another Nissan part.

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  Engine Bay.JPG (127.05 KB)


  Shim Discrepancy.JPG (116.11 KB)


  Shim On Test Fit.JPG (178.93 KB)


  Shim On with Hylomar.JPG (196.52 KB)


  New socket ends.JPG (165.75 KB)


  New socket ends 2.JPG (161.76 KB)


  New socket ends 3.JPG (151.36 KB)


  New socket ends 4.JPG (117.82 KB)


  Race head on.JPG (167.23 KB)


  Routing for catch can.JPG (139.96 KB)


  Catch can location.JPG (190.34 KB)

video of it running better please!!!!! i cant do the same- got nowhere to host anything

She's up and running finally.


Gylezy came around and synchronized them for me using a piece of fuel pipe (after I battled it out with a fancy balancer and couldn't get them right!), gotta give it up to this guy, he's a teenager who can tune carbs, lay a perfectly clean 'toothpaste' weld, and understand an engine like he designed it. F'in unbelievable, I was too busy trying to get myself completely inebriated when I was his age, wouldn't think twice about a car.

The engine pulls really cleanly from what I think is about 4 grand and it just goes and goes! Very, very tall camshaft (in that most of the power is in the high 5's and 6's) but it's good fun. I haven't even found the end where it stops producing power.




@ Armiee, Yeah I know your engine, the extended GX intake. Neat motor, crack it open and lets see what's inside. Shorter manifold? I want the revs nice and quick. The angle of the carbs also effect the length of the manifold, I have limited space between bonnet and engine so if I want a longer manifold, the carbs go closer to the bonnet.

hey chris great build thread, coming along nicely! just a quick one, how come you're going for a shorter manifold for the carbs? wouldn't a longer one allow more time for the air/fuel to mix before it eneters the engine? only asking cos the ex-rally A12 i've got has got extended manifolds, i asked why and he said they were for that reason. just curious is all ;)

All looks good bar the last pic is strange.

My only suggestion would be to make it cheaper and modular for other carbs
by looking at making it a thick flange with oval to round start finish and
then the owner can have the tubes welded in according to preferences.

Just have to say this is such a great looking car! Look forward to the rest of the build.