building a head for power? a14

[PinoyDat210]

i want to do as much diy and tuning to get hp out of my head. i have ported out the head to the nismo gx size, quench heart chamber, im going to do a 3 angle valve job and fit stiffer valve springs? what other options are out their lets hear everything and focus soley on the cylinder head alone, because isnt it the where all the true power making capabilites lies? dual vs. single spring?, is the gains made from bigger valves worth it? quenched vs. open combustion chambers? roller rockers and rocker ratios? thnks amigos looking forward to some educated response!

[ggzilla]

What gain from big valves?

 

If you are planning maximum HP at 6800 rpm, you will need dual valve springs and a camshaft with more duration than the stock 6000 rpm cam. All A14 heads are 3-angle, so no gain there.

[Kirden]

Just note, the 1200 site will have a huge wealth of information on the topic.

 

That being said, are you planning on forced induction or NA? Realisticly you aren't going to make huge power out of the A14 NA. 100 can be attained pretty easily with the setup you described not including larger valves, roller rockers, ect. Then the cost goes up to approx $500 for every 10hp over that mark. You also end up moving the RPM band higher making streetability lower.

 

An interesting note, the A14 pistons and heads were designed together for the different chamber types. The quench heads had deeper dished pistons to retain driveable compression ratios. Here is some info on my closed chamber head from the 1200 site, note the piston statement:

 

H89

Oval-port Closed-Chamber was fitted to A14-powered B310 Coupe and Sedan in the JDM market (but not to Van (wagon). C120 came with A15 engine and H89 head. Closed-chamber is a non-emissions controlled head (no EGR). It is sometimes called "High Compression", but the compression is about the same as the open chamber (H72) head -- the compression is controlled by the piston dish, not the head.

 

That said, you can contact Peter Zerkert for some quality high CR pistons or figure out which flat tops/dome pistons will work. Mr. Zerkert offers used race pistons as well.

 

http://www.peterzekert.com/for-sale/engine/engine-components/138-used-datsun-a-series-race-pistons

 

I believe max potential power is around 140 for NA, but you are going to spend a lot to get there. Even with forced induction I'm only shooting for the 110-120whp mark.

 

Did you raise your ports like the GX had as well? The GX has raised ports for better flow into the chamber. Mostly this is a mod racers use because of their high RPM band, but it may be worth looking in to for max power.

 

http://datsun1200.com/modules/mediawiki/index.php?title=Cylinder_Head_Modifications

[Dime Dave]

To get 120WHP out of an A14 NA you are no longer in street engine world.

 

My good A15 race engine that I ran in my 1200 put out 156whp at like 8400rpm 

 

That had huge compression in the area of 15:1. The dome on the pistons were so big the valve reliefs weren't notches, they were round circles plunged into the top of the piston and they had to cut out a pocket for the spark plug electrode.

 

Here is the dyno chart with 3 pulls. AFR trace is all screwed up from the leaded 112 octane race gas.

 

 

 

 

[PinoyDat210]

im not shooting for alot of hp, im doing an n/a build i just want to have a solid powerblock before doing my suspension build for lots of handling. so valve springs are on the list. any info on the 5 angle?? would i benefit from knife edging the crank, lightened pushrods?? thanks for the input

[Dime Dave]

If you are looking to build a solid bottom end I would start with an A15 crank and some Subaru Justy pistons. Get the displacement up first. That will help make for more reliable power.

 

Here is an article on the Datsun 1200 site with details on building a 1608cc A series engine.

http://datsun1200.com/modules/mediawiki/index.php?title=Justy_Piston_Swap

[Dime Dave]

When modifying an engine, it is usually an all or nothing kind of deal.

 

Increase displacement and you need more air/fuel. Porting will get you more, but if the intake is choked with a small carb you'll have little if any gains. Put on a bigger carb and then the exhaust may become the restriction. Change the exhaust and then you need more cam to match the larger intake and exhaust capacities. Change the cam and then you need more static compression to increase your effective compression.

 

It is kind of a vicious cycle. One area helps but it doesn't usually amount to a significant gain unless you match the others to it.

[ggzilla]

The A14 comes with a solid block right from the factory. A good used short block can easily make 100hp and rev occasionally to 8500 rpm.

 

To make 100 HP naturally aspirated can be done for under $5000. As DD said, its in all the other things.

 

If you want more power, there is no replacement for displacement. Adding 200cc will make more power than 1000 ARP rod bolts.

 

im not shooting for alot of hp, im doing an n/a build i just want to have a solid powerblock

[PinoyDat210]

so ncreasing displacement is necessary for major hp gains.. couldn't you just bore an a14 block to increase? i only ask because i have been looking for an a15 to no avail, but have two a14 blocks to use. and doesn't knife edging the crank increase stroke??

[ggzilla]

Yes, you can overbore an A14. A15 uses the newer A14 block, they are identical.

 

A15 is already 100cc more than A14 due to the longer-stroke crank. Using 79mm Subaru pistons gains another 100cc

 

More displacement is not the only way to get major HP gains. For double the cost you can build a non-streetable 150hp full race engine. Or the other choice a $1500 turbo system can give even more power e.g. 160hp with a stock A14 block if very carefully done. But if you have to pay someone to install new turbo parts it will be closer to $5000

 

Knife-edge crank does not change the stroke. Instead it reduces windage i.e. needed for 10,000 rpm use.

[maddjack]

i used an a15 crank with a14 rods. a14 block with 91-94 nissan ga16 pistion 1mm over (77mm) only had deck .040 to get the piston to zero deck. do not have to mod the small end of the rod, ga 16 pins are 19mm

[ggzilla]

You can also use factory pistons w/o milling the deck. 77mm pistons for A15 are sold by Nissan. Use A15 crank & rods and the late A14/A15 block (which are the same, but if using the early A14 block then grind crank throw reliefs)

[PinoyDat210]

I was thinking of using the a15 crankshaft and oil pan, a14 rods, and over-bore out the block for next size up pistons. Bored and stroked a14! :) with a quench head stiffer valve springs and a port and polish.

[ggzilla]

A15 crankshaft and a14 rods?

[Dime Dave]

A15 crankshaft and a14 rods?

 

A14 & A15 are the same 133mm center to center. Same length as the CA16, just the CA is a slight bit narrower on the big end and the bushings need to be resized.

[ggzilla]

Yes, and A15 uses the A14 block. No difference. So just start with an A15 and its much easier.

[PinoyDat210]

if i can find one, i have found crankshafts though and i already have two a14's. so it really depends on which way would be cheapest for me. and hey, i'm all 4 building unique, the better challenge the more fun and faster hah

[Datsun210Deluxe]

I currently have my 81 Datsun 210 Deluxe wagon with the A15 motor 5spd from California, It was taken cared of pretty good 210,000 miles.... Time to replace the engine... I recently acquired an A14 out of a 310 off of ebay... should i just plop the A14 from the salvage yard in there.... Got a quote from a shop that labor would be $350. does this sound reasonable, The A15 motor currently in it has worn out piston rings, I recently replaced the head at a shop within a year ago, so its no burnt valve. Any ideas to do to the A14 I have before taking it to the shop, Any comments would be apppreciated... I live in Indiana, so everyone loves the car cause its not a rust bucket,

[datzenmike]

I would start an introduction post in the 1200 section http://community.ratsun.net/forum/13-1200/ as your 210 is the grand son of the 1200 or in the Project section http://community.ratsun.net/forum/6-project-datto/ to have your own personal space to devote to your car.

 

This is PintoDat210's thread of modifying his A series head. It's ok just start again in the correct place and I can move your post over to it.

[Johan-Datsun]

I have a 1975 Datsun 1200 pickup .  I love these little pushrod  engines. I am unfortunately  a Normal Aspirated fan. Modified an A15 with 1200 GX head, flowed, ported and fitted larger  valves with Cat springs. Kent 264 cam (310 degrees), Opel pistons 79mm on std A14 rods, and 2 x 40 side draft  webers., lightened flywheel  and bigger clutch  plate. All added up 1608cc with a 13.8 compression ratio. It was pretty fast but kept  braking  the gearbox . Then fitted a Toyota 1800 Corolla 5 speed box. 

 

I never stop trying  to go bigger. Now busy with an A14 block, bored 80mm but with offset . By the way, the A14S block casted in South Africa, has thicker sleeves  than Japanese A15. I tried 80mm bore on A15, but the sleeves were too thin. Then took the A14 & A15 and cut them in half over the length . That is how I know about the sleeve  thickness . I will use the Opel pistons again but in 040 (1mm) oversize . Using an A15 crank, but stroked to 86.25 mm. A Custom cam was designed by a good friend and cam specialist from Camshaft Dynamics. 330 degrees duration with 9.2mm lift on cam, giving 13.8mm valve lift. Head modified and inlet  & outlet ports made bigger to match cc`s.  TD23 stainless steel valves fitted. Compression ratio will be 15.8 and will use methanol. Total cc = 1734. Now using 45mm Throttles with 1000cc injectors. Dictator management  with MSD Sports  compact  ignition. A copper gasket , 2mm thick was custom made to fit offset  bore. The offset  bore created extra space for larger exhaust  valves, which was always a problem on high revving  and long duration  cams. Electric pump replaced the std water pump and crank pulley  size  reduced equal  to alternators  pulley size. Roller rockers on the way and I consider running dry sump.

 

That`s it, any suggestions for improvement ? Email me direct if you want to, I can get A14 & A15 blocks, heads and crackshafts. johan.umusa@gmail.com.