something question regarding to my m20b20

[yim1986]

hi everyone, i'm new here, and is still fresh with the e30...there are some questions that i really need everyone to help me solve it or give me an advice...is quite long and plenty, hope that you guys willing to finish reading and help this little fellow...because i just got another 7 months in malaysia... not much time to be with my e30 and try to understand him more...here is my questions:1. normally what is m20b20 f/c? i found that my car is a bit higher on this, it costs me about rm6 from ampang tasik area using kesas highway to usj1, is this ok?2. my m20b20 is overhauled and everything seems to be fine, but when i open the engine oil cap while idling, the idling will become rough or maybe drop until stall.... is it the clogged PCV or other causes?3. the m20b20 is known as a mysterious engine because of it's valves noises to me... i have checked and adjusted following a manual specification but it still having the same problem... some said changing the rocker arms will do but my friend did it and failed... anyone solved it before?4. is it any interchangeable injector with the m20b20 one? because i was trying to find a nice spraying pattern so that it can lower my f/c...5. is it any connecting rod which is interchangeable with the m20b20's rod? because i'm trying to find a longer or a shorter spec, hope that you guys can be more specified on this and give me what is the length differences because i hope to rebuild the engine myself this time...6. about the differential and manual gearbox, anyone knows which model has the lowest gear ratio(more on high end and low torque) compare to m20b20?7. how much will a tachometer cost me?8. following the questions above, hopefully you guys can tell me the exact price and place to get....so far i just remember this few questions...hope you guys can lend me a hand... thanks

 

[yim1986]

anyone? if you know just only one you too can give me your advice...thank you...

 

[miepower]

I'll attempt to answer your questions as I'm also a nube.

hi everyone, i'm new here, and is still fresh with the e30...
there are some questions that i really need everyone to help me solve it or give me an advice...
is quite long and plenty, hope that you guys willing to finish reading and help this little fellow...
because i just got another 7 months in malaysia... not much time to be with my e30 and try to understand him more...
here is my questions:

1. normally what is m20b20 f/c? i found that my car is a bit higher on this, it costs me about rm6 from ampang tasik area using kesas highway to usj1, is this ok? Hard to answer as it depends on your speed, temp, jam, and others. Suggest taking km reading rather rm6 as an indication.

2. my m20b20 is overhauled and everything seems to be fine, but when i open the engine oil cap while idling, the idling will become rough or maybe drop until stall.... is it the clogged PCV or other causes? Other m20's will behave similarly

3. the m20b20 is known as a mysterious engine because of it's valves noises to me... i have checked and adjusted following a manual specification but it still having the same problem... some said changing the rocker arms will do but my friend did it and failed... anyone solved it before? try to observe other m20's if you can, and did you notice anything different from yours. I believe its common for older engines to produce noises.

4. is it any interchangeable injector with the m20b20 one? because i was trying to find a nice spraying pattern so that it can lower my f/c...

yes, there are few interchangeable injectors that you can use. However, there's pros and cons of any swap. Commonly used m50 but please ask around on the caused and effects.​

5. is it any connecting rod which is interchangeable with the m20b20's rod? because i'm trying to find a longer or a shorter spec, hope that you guys can be more specified on this and give me what is the length differences because i hope to rebuild the engine myself this time...
Mind me asking, what actually you plan to achieve with your ride? It seems that you are thinking either to lower or higher the compression. Both are achievable however it’s contradicting from your fc question.
6. about the differential and manual gearbox, anyone knows which model has the lowest gear ratio(more on high end and low torque) compare to m20b20? Do more research, you don’t have to go for other model as e30 alone has abundant of diff ratios from 2.79 up to 4.45. Again, what do you plan to achieve?

7. how much will a tachometer cost me? Ori or aftermarket

8. following the questions above, hopefully you guys can tell me the exact price and place to get.... Give me a call and I'll drain your pockets heheh

so far i just remember this few questions...
hope you guys can lend me a hand... thanks

 

[yim1986]

I'll attempt to answer your questions as I'm also a nube.

thanks for your reply and i found that most of the answer are useful...
and i feel like wanna buy an extra cylinder head to do some experiment...
maybe i will use shorter con rod and bolt on 2 TD025 at about 0.5 bar with a bigger injector to spray more fuel so that my engine won't kaboom, and shorter con rod is better than using metall gasket because the gasket wont be harder than cylinder wall,i'm rather make the BDC lower to use the whole stroke but it can't be too low if not i will be taking the risk that i scratch my one cylinder wall, and shorter con rod makes the pistol easier to cool down since that they are nearer to the oil sump,so the oil that spread on it will be more... and i wanna find that differential is because i wanna find out what is the m20b20 potential,maybe i will be getting one at about 3.0,because too low my car will be suffering at the low rpm, and this project is to build a midnight wangan car, sound stupid right? but i willbe learning a lot on i...hehe... i think it might cost me about 3k to do this experiment so that i hope that i can find cheap parts too...then i can diy since that i'm a mechanic....clear?

 

[McFir7]

4. is it any interchangeable injector with the m20b20 one? because i was trying to find a nice spraying pattern so that it can lower my f/c...

yes, there are few interchangeable injectors that you can use. However, there's pros and cons of any swap. Commonly used m50 but please ask around on the caused and effects.>>

bro what do u mean by the pros n cons of m50 injector?cause i was thinkin to swap in to my m42.so pls let me know..
​

 

[mizhan]

i'm using m50 injectors on my m20.. you can feel the power increase, but consumption also increased by 40%!

 

[McFir7]

i'm using m50 injectors on my m20.. you can feel the power increase, but consumption also increased by 40%!

is that true guys?i heard some other also change to m50 injectors..but i didnt hear the say the consumption will be like that.i was thinking to chnage my m42 injectors to m50b25 injector..or should i change to m50b20 injectors to maintain the same consumption

 

[teejay]

if you only have 7 more months in malaysia, then i suggest just keep the car as it is, wait till you come back for good, then do it up properly.....

if you are serious about tuning engines, the m20b20 is not a good base to start with

again as miepower has stated, what are you really trying to achieve with the car? power? efficiency? economy?

 

[yim1986]

if you only have 7 more months in malaysia, then i suggest just keep the car as it is, wait till you come back for good, then do it up properly.....

if you are serious about tuning engines, the m20b20 is not a good base to start with

again as miepower has stated, what are you really trying to achieve with the car? power? efficiency? economy?

i know that...the m20b20 compression is too high to bolt on twin turbo... but my achievement is different a bit... i just wanna find out how fast does this engine can goes... i dun want to use bigger engine block is because this is malaysia...hehe...(you know what i mean)
and high capacity engine is comfirmed got higher output, then it is no fun at all...