A14 Engine Possible Upgrades

[Sierra]

My A14 engine completely died on me a couple of months ago, so I found another one from a yard and going to sent it to the machinist to get it strip and rebuilt.

Since the engine will be rebuilt, is there any upgrades that I can do to it, that will provide me with a little more pep.

Not looking for a racer, just a little more kick.

I would love to hear your ideas and suggestions.

Thanks in advance

 

[Stoffregen Motorsports]

Is it going in a car that needs to be emissions tested? If so, there's not much you can do, except add displacement. Bore it to .040" and add a couple HP.

 

If it's old enough that it doesn't have to pass emissions, then I might consider a mild cam and a Weber DGV.

[Sierra]

It will go on a 1978 B210 in Cali, so it does need to pass emissions.

I was actually thinking of during the mild cam on it.

Stoffregen Motorsports do you think that will affect the emissions system?

[Stoffregen Motorsports]

There are ways to grind a cam and keep it smog legal. You could call a cam grinder and ask.

 

Anything more than a warmed over "blueprinted" cam profile would probably not pass testing.

[Sierra]

What if emissions is not part of the equation? What kind of mods can you do to this little engine?

[Tom1200]

As previously mentioned you can up on the bore to .040 / 77mm if you can find them once upon a time there were .080 / 78mm pistons. What you are looking is 50 and 100cc more displacement.

 

Next if you go with a thinner head gasket; the standard Fel-Pro ones are 1.2MM thick, the GX head gasket is .8 and you can get from Japan a .6 mm thick gasket. This will up the compression to between 9 and 9.5 dependent on what cylinder head is on the motor.

 

Next is porting; as you are having the motor rebuilt this may not be up your alley. I'm not talking about enlarging ports etc. but cleaning up what's there. The standard valve seats protrude into the port by almost 1mm simply using a dremel and low grit bit to grind back the seat so it is flush with the port opens it up nearly 2MM. You can also make sure the the intake manifold gasket isn't blocking the port. This is known as gasket matching. You can also clean up the area around the valve guide (look on Datsun1200.com for pictures)

 

Last up is a larger exhaust pipe; no need for a blat muffler but by going to an 1.75 - 2.00 exhaust tubing will help (you may have to go up on jet size or you may be able to use the A15 carb. Sorry I can't be more clear but I race my car so I'm not 100% on stock parts interchange.

 

Doing all of the above will net you around 10-15hp not going to be sucking the paint off Porsche Turbos but it will shave a second or so off the 0-60 time.

 

If you want to make the car more fun put on some decent dampers/shocks and a set of sway bars, then throw in better brake pads and drive the death out of it.

[datzenmike]

I might add that you should check the intake against the gasket as well. Place the gasket on carefully and use some cheap spray paint. Take the gasket off and grind away anything with paint on it. Smooth it away from the gasket an inch or two into the port. You can do this on the head surface also.

 

You can always run a hotter cam and then change it for the emissions test. Cake... and eat it too. Hell, for that matter build an engine but keep the stock one for emissions testing.

[Sierra]

Thank you Tom1200 your input was exactly what I was looking for.

datzenmike Your feedback is always welcome.

Since I now have two A14 engines, I might just have my cake and eat it too.

One emission ready engine and the other one for fun.

We will see...

Thanks again everyone for your comments.

[Stoffregen Motorsports]

One mod that I have made to A motors, is to the intake manifold.

 

Do you guys remember the Weber DGV downdraft conversions for the 240Z's L24? I have taken those adapters, cut them apart, then cut apart the stock A series manifold and then fit and weld the pieces together. Two benefits here. It just about doubles the plenum size under the carburetor for great atomization of the air/fuel mixture. It also allows a DGV to bolt on without any funky adapters.

 

If you can find a GX head, that would be a great improvement, but then you'd have to find the manifold that goes with it too. Probably a long shot.

[pdp8]

Blueprinting can help a fair bit:  A good 3-angle valve job, undercut the stems for better flow while you're at it and balance the c**p out of it... pistons, big end and small ends of rods, etc.  It will run smoother and make more power, with some better valve springs you can rev it higher to get more power yet.
Even if you don't do a real port job, cutting down the valve guides can make some nice room.  Especially if you have a swirl-intake head, porting can help improve power without hurting emissions much.

Fancy coatings in the exhaust stream will aid in scavenging and flow.

If you have the original catalytic converter, change it out for a new one, they will flow better and help you pass smog with your other modifications.

I found some joy with mild flow work on the Hitachi carbs, a dremel and time will allow you to re-contour the venturis and smooth the throttle shaft.  It's no Webber but every little bit, right?