A friend of mine did the following modification:

Converted his Sr16ve motor to a Sr20ve using:

a. Sr16ve Head - Stock - no port or polish etc
b. Sr20ve Bottom Half - stock - no pulling
c. Sr16 ecu - No piggyback

Did 2 runs on the dyno and it was showing a lean mixture - 16:1

On his way home from dyno the motor blew. It's not yet opened so dont know the extent of the damage, but suspects pistons should be fine.

Questions:

1. What could be the possible cause of this?

2. With the set-up mentioned, what compression ratio is it now with sr20 bottom half?

3. Are the Sr16ve and Sr20ve injectors the same? If not what's the difference? I know the SR20ve should be 333cc


I'd like to know so I could advise him and especially since I'm thing of similar mod or stroke to 2.0 which would be basically the same thing

Thanks.

Peace

THe Compression is the same as a stock sr20ve. Unless the head was milled.

This isn't a Honda. The mix and match doesn't do you any good. The head is the same as the 20ve.

THe sr16ve ECU is calibrated for the 1.6 only. The ECU only has so much fuel correction from the MAF signal and at WOT it has even less.

Figure the Stock ECU is tuned for a 1.6 at 13:1 AFR at WOT. THis is a rough estimate.

Then you go and add 25% more displacement. or 25% more air 3.25:1 for the same amount of fuel.


3.25 + 13 = 16.25:1 This is kind of rough and dirty, but you get the idea. I've had similar problems with running rich on an sr16 with the 20ve ECU.

You can either turn up the fuel pressure, or tune the ECU properly. I would recommend the latter.

It was running lean because the ECU is only delivering enough fuel for a 1.6 engine, not a 2 litre...

It was running lean because the ECU is only delivering enough fuel for a 1.6 engine, not a 2 litre...

this would be what i think to be the culprit

THe Compression is the same as a stock sr20ve. Unless the head was milled.

This isn't a Honda. The mix and match doesn't do you any good. The head is the same as the 20ve.

THe sr16ve ECU is calibrated for the 1.6 only. The ECU only has so much fuel correction from the MAF signal and at WOT it has even less.

Figure the Stock ECU is tuned for a 1.6 at 13:1 AFR at WOT. THis is a rough estimate.

Then you go and add 25% more displacement. or 25% more air 3.25:1 for the same amount of fuel.


3.25 + 13 = 16.25:1 This is kind of rough and dirty, but you get the idea. I've had similar problems with running rich on an sr16 with the 20ve ECU.

You can either turn up the fuel pressure, or tune the ECU properly. I would recommend the latter.

Thanks. Most of what u said makes sense.

What is WOT?

Are u also saying that the sr16 and sr20 head are the same? Are u saying cams, valve springs etc are the same? So why would people want to use sr16 cams and some use the sr16 head on the sr20 bottom half?

If the sr16 is made to rev to 8200rpm and the sr20 rev to 7200 or so, wouldnt there be a difference in the head design?

Thanks

wot...Wide open Throttle

the heades r the same design just the cams that is different.....same springs, retainers, ports etc....

Thor is right, the head is the same, ports, valve springs, retainers, ect the cams are the difference, it is the design of the cams and the smaller stroke of the 16ve (motor has to rev to make power, sr20 has larger disp., dosnet need to rev as high) that allow the revs....

you are leaning out cause a 1.6ltr worth of fuel is supplying a 2lt, its just not enough, get a cheap fuel computer or just get a remap

Thor is right, the head is the same, ports, valve springs, retainers, ect the cams are the difference, it is the design of the cams and the smaller stroke of the 16ve (motor has to rev to make power, sr20 has larger disp., dosnet need to rev as high) that allow the revs....


So when the sr16ve/20ve conversion is done, it's just the cams u really want from the head?

Well I dont see y peeps with sr20ve killing themselves a sr16 head? Why not just buy the sr16 or n1 cams and put into the sr20ve motor?

Ah boy...

its a easier job than pulling up the cams i guess

Cam swap is dead easy. Couple of hours start to finish with the most basic of tools...

its a easier job than pulling up the cams i guess


dont think so at all.

trying to get a sr16 motor (which is a scarce commodity) just for the head vs just getting some cams?

Mmmmmmm...

guys, 1.6 and 2.0 springs are not the same!
outer - the same, inner - different, it is exact info.

i`m using this setup and set +10-15% (depends on revs) on my SAFC to help my engine fight the detonation and to run faster(it really helps).
but 3 months before I used it without SAFC and everything was OK. I`m sure, if your O2 sensor and detonation sensor were OK, nothing could happen. Scanner on my car never showed "lean" A\R...

I'm plannng on doing something very similar,

Sr16ve N1 head,
Sr20ve Bottom end,

What i want to know is will i fit a fuel pressure regulator to get the right AF ratio until i get it tuned?
Will i need to turn off the vvl until i get it tuned? As the AF wouldn't be right for high rpm with vvl if i set it for low rpm or is my thinking wrong?

Now that my sr 16 is screwed (hopefully the head is good) - think i damage bearing - it would make sense to just stroke to 2 litre. Now I want to use my sr16 ecu. What do i need to do to ensure that the motor gets enough fuel and timing etc is ok?

The options I heard of are (when using the sr16 ecu):
1. Add daughterboad to sr16 ecu
2. Upgrade from 333 to 370 injectors and add a Fuel pressure regulator
3. Use Piggyback with with AFC or Greddy emanage
4. Was aslo told that some tweaking can be done and the stock sr16 ecu can be used with no probs. Can anyone explain?

Are there any others? Which is best?

Now will a set of 10:1 de pistons work if i cant get 20ve pistons? I think the sr16ve pistons will make the cr too high and I only have 90 octane fuel available.

Thanks