MA12 tuning

gtsnissanb

gtsnissanb

Official MSC Trader
hi chaps i just got myself an MA12 to drop in my k10 super, what can i do to it that isnt gonna cost me the earth before i drop it in?
once i remove it from my boot, i will do a bit of inlet port matching and exhaust port polishing but from there on cant really think of anything?
if anyone has any bits (cheap :grinning: im massively skint for now) i can fit, cams induction kit manifold ect then give me a shout.
back on topic is there anything i can tweak to scrounge a few more ponies from it?
 
if you can weld you could knock up a manifold and stick some cbr600 carbs on it. theres not really much out there for k10s these days unless you diy lol
 
I may try turbo it, modify the manifold to fit a t2 and bung on a r5gt carb? This is just top of my head stuff! Basically don't want to just bung it in stock want it a bit wild
 
i had a 100 thou (2,5mm) headskim on my old ma12, and a lightened fly too, it went pretty good :wasntme:
and autosprint would do the cam for about £80
 
100 thou off the head..christ...at 80 thou there will be valve to piston contack at hi rev's
frank said:
i had a 100 thou (2,5mm) headskim on my old ma12, and a lightened fly too, it went pretty good :wasntme:
and autosprint would do the cam for about £80
Click to expand...
 
Exhaust port two, the one that's an egg shape has a weird big bump in the opening can this be ground down to make it circular again
 
Exhaust manifold dude, get yourself a nice performance once. You could also get a super turbo inlet manifold (with injector holes) fit injectors and wire it all up to a k11 ecu, and whammo, fuel injected 1.2. Also lighten up the car a wee bit, and loose a few pounds yourself, it all helps. :laugh:

The egg-shape port is made that way for flow/pressure reasons. All in the name of keeping the cylinders at equal pressures.
 
Bet superturbo inlets are difficult to get hold of though
The egg shaped one inside the circular port has bump in it, looks like it would be restrictive as the circular port isn't circular like all the others. I need to wait for my polishing bits to come shouldn't really try to polish using silicon carbide bits lol
 
Just thinking wouldn't that set up be a bit more difficult than just fitting the bits and ecu? As I'd need some form of trigger cam/crank sensor wiring in?
 
gtsnissanb said:
Bet superturbo inlets are difficult to get hold of though
The egg shaped one inside the circular port has bump in it, looks like it would be restrictive as the circular port isn't circular like all the others. I need to wait for my polishing bits to come shouldn't really try to polish using silicon carbide bits lol
Click to expand...
Yes it is a "restrictor". It is used to slow the gasses down to pass into the tube which leds back to the inlet manifold.
 
So It's sort of an old fashioned egr device? If so I'll grind it off as that will be useless as I'm not going to run egr
 
The odd shaped port; it's a design #### up. Where there is a bump inside the port to allow something to fit elsewhere inside the head, i can't remember what that something is but the bump is there so that it fits. The bump reduces the ammount of "area" or space inside that port. That would cause that particular cylinder (no. 2) to have more back-pressure than the other cylinders which would restrict that particular cylinder. Basically the engine would not run evenly because of the difference in resistance between cylinder number 2 and the other three with "normal" round ports.
It's that shape because that's the way it needs to be, that extra little cut-out that gives it the oval shape is there to give that port the same internal area as the other three so just make the manifold work around it, i.e. make the manifold fit the engine not make the engine fit the manifold.

EGR has NOTHING the do with the block, the head, or anything other than the manifolds. So don't be grinding anything off the engine or it'll end up scrap.


Non EGR Engine;
38817_422453994871_839509871_4473761_7095533_n.jpg


EGR Engine;
20148_297539919871_839509871_3195409_679677_n.jpg


Both exactly the same, it's the manifolds and all the other #### that bolts onto the engines that makes them EGR or not.
 
Thought as much, didn't make sense how egr would work because of a bump i knew there was no egr pipe on the mani! luckily I have a very short attention span and started stripping an mr2 turbo to fix the HFH (hose from hell) as it's known what a nightmare spent the last 3 hours just stripping the #### still no closer
 
I noticed a nice difference, but I use a 298° camshaft so probably you will have a slight gain, but nothing really noticeable. I think the engine will rev up easier.
I have the problem, that I have the most torque in high revs, so I am building a new head at the moment with a nice skim so that I get more torque in the low revs as well.

My car is equipped with twin webers and a custom exhaust manifold, and I am hoping with the new head it will run faster than now.

btw. the most restrictive part of that engine is the exhaust manifold! The inlet manifold is one of the best designed I have ever seen, and the carb is also really good. So as a first step I would change the exhaust manifold, then I would do something on the cylinder head (with a nice cam, this should give you a big gain) and shortly after that you should think about another carb (Su, Weber or bike carbs), because you should be able to fill the chambers with enough fuel ;).
 
Rtl I may take you up on that will need a bit of time though skint
Is it straight fit no messing about with springs and that? What type of gains can I expect?
 
gtsnissanb said:
Rtl I may take you up on that will need a bit of time though skint
Is it straight fit no messing about with springs and that? What type of gains can I expect?
Click to expand...

Theyre a straight fit as I put it in my 1.2 before fitting the race 1litre engine. With it in it reved alot better, instead of the power trailing off at about 5k rpm, i wasnt changing till about 6k rpm. When I get hold of a micrometer ill measure the lift and duration of it.
 
with supporting mods you will. The cam allows more air in over a longer time so for it to work properly you need to get more air in the engine and more exhaust gas out.
 
porkpie700 said:
Exhaust manifold dude, get yourself a nice performance once. You could also get a super turbo inlet manifold (with injector holes) fit injectors and wire it all up to a k11 ecu, and whammo, fuel injected 1.2. Also lighten up the car a wee bit, and loose a few pounds yourself, it all helps. :laugh:

The egg-shape port is made that way for flow/pressure reasons. All in the name of keeping the cylinders at equal pressures.
Click to expand...

Please don't take this the wrong way but the details your post is entirely and completely incorrect.

1: you cannot run a K11 ECU on a MA10 engine, they use totally different CAS signals.
2: the 'egg' shaped port (there is only one) is for the EGR system on some MA series engines, and has nothing to do at all with keeping cyl pressures equal.
 
porkpie700 said:
Both exactly the same, it's the manifolds and all the other #### that bolts onto the engines that makes them EGR or not.
Click to expand...

No its not. 1.2 ECCS and some others had EGR cast into the head. I had lots of import MA series engines that rather than ran EGR externally around the head it passed through the head to the inlet manifold EGR valve on the other side.

Some MA series had both, Othery MA engines it was cast solid and not opened up at all.
 
I'm going to side with ed he knows his micras lol after watch a video the other day on that k11 you built it makes my knowledge look rather pooh but I'm learning only been here a few months
 
Ed whilst your here, does this sound right not missing anything
Turbo manifold with t25/28 flange, t25 and elbow modded to go with my exhaust, r5gtt or mini turbo carb tuned to suit, all associated pipes, s13/14 WMIC because they are cheap and small some boost controller gizmo profec b ect
 
superls said:
if your going turbo, then id personally, put the stock carb in a sealed box, should make for easier tuning too
Click to expand...
Hmm interesting would also be cheaper too but I'm a novice when it comes to carbs so you'll have to explain it better for me as in what I need to buy make and do
 
basicaly unbolt the carb get a good tight sealed box drill holes in it for where the box will be sandwiched between the carb and the inlet manifold then seal the box and wack a boost pipe up to it although you will have to some how seal the throttle cable and pipes ect where they run into the box
 
It sounds alot simpler to use my first idea or run a pipe off the intake to the turbo fit a flange to match the base of the carb and use it as a draw through carb
 
In theory stock carb would work with low boost. Its already internally sealed. though no one has ever tried it. One thing you would have to do is look at the fuel pump. It may not beable to maintain fuel flow working against boost you may have to put a regulator on it, rather than let it return to the tank via a little bleed port. on the top of the pump.
 
So I have my 1 litre carb and my 1.2 carb, if I try turbo the stock carb and it breaks I'll just use the 1 litre one! Worth a go right save a few pennies I'm only running stock t25 boost I think that's about 7-9psi that's if I use t25
So could I not bung a walbro 255lph pump or would that not work? Is there already a return pipe to the tank or would that be something I'd have to do? How would I regulate it?
 
Ed said:
2: the 'egg' shaped port (there is only one) is for the EGR system on some MA series engines, and has nothing to do at all with keeping cyl pressures equal.
Click to expand...
Thanks! That is what I wrote before... I was pretty sure that I am not wrong!

/edit: Oh I realize I did not mention that I ment the egr :D
 
OMG,,Ive heard it all now carb in a box..lol.....If Youve not got alot of money dont even think about a turbo :eek:

1st port of call would be to change inlet manifold and carb...even this setup using a standard exhaust system gave another 15bhp
DSC00213.jpg
 
Ed said:
No its not. 1.2 ECCS and some others had EGR cast into the head. I had lots of import MA series engines that rather than ran EGR externally around the head it passed through the head to the inlet manifold EGR valve on the other side.

Some MA series had both, Othery MA engines it was cast solid and not opened up at all.
Click to expand...

Ok Ed two things here; on the first post only the first line is serious, the rest of it was just kidding around, adding some levity since things can get a tad #####y on here when different oppinions and experiences meet. I know it wouldn't work unless a collection of custom parts were used, which would cost a fair bit more than simple "bolt-on" mods. Sometimes you have to read what i post twice before you get what i mean.

The egg port; well that's on cylinder two there and the egr pipe plumbs into the manifold over number one, so why would number one not be oval and number two round?
And lastly, i live in the uk, i drive uk cars, i work on uk cars so why would i ever take into account import set-ups? I've had the old import arguments come up on posts i've made before and i just wanna say that i'm not interested in imports. I'm not interested in how k10's are set up in other parts of the world, so i only ever give advice, or whatever it may be, with regards to uk spec models. And on uk spec models the egr stuff bolts onto the manifolds externally.

Gts; if you have an import k10 then yeah, by all means ignore what i have said, otherwise it has every right to stay on the table with everyone elses input. Because ultimately everything you do is entirly your own choice, you don't have to take anything as gospal.
 
Ed said:
In theory stock carb would work with low boost. Its already internally sealed. though no one has ever tried it. One thing you would have to do is look at the fuel pump. It may not beable to maintain fuel flow working against boost you may have to put a regulator on it, rather than let it return to the tank via a little bleed port. on the top of the pump.
Click to expand...

ive tried it:p i used a kkk k03 off a diesel the trouble you will have is making something for the carb top there isn't enough lip on it to clamp the boost pipe on. i ripped all mine off as i had an oil leak and a water leak from the pipe that is pressed into the block and couldn't be bothered with the turbo issue it need setting up properly and a bit of cash spending on it. personally i would just drop a cg13 in it and turbo that its a much better applicant (Y)
 
superls said:
ive seen carbs in boxes for turbo applications before, apparently it works, and can work well
Click to expand...

Yep carb pressure boxes are common in the states where carbs are more common on the old v8 yank tanks! I still think the turbo carb from a different car is a better idea simpler even! But the draw through set up seems a better way if I were to keep the oe carb, the draw back being no intercooler but I could fit an mr2 style charge cooler
 

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