a little more power from 4y-e

[-mick-]

Hi guys,

I have an old 4 runner with the 4y-e 2.2l MPI pushrod petrol super hampster motovation unit It was rebuilt by the previous owner so its really tight and has about 10k on it now. Its got really good compression etc but it still needs that bit more power to tackle soft sand and long highway trips. What can I do

I don't want to turbo or s/c because my insurance is nice and easy/ cheap at the moment Will I get any real benefit from a head shave and port, cam, exhaust etc..... and will it shag my ecu???

The vehicle is on dual fuel so I don't mind having to buy PULP, I rarely use petrol anyway and can usually get it on trips away. The lpg side of things would probably really enjoy the extra compression Anyone suggest the best way/ combination of ways to get that extra 10-20% out of the engine???

Can anyone recommend good shops around Brissie (north is better) for this kond of work.... and suggest what costs I'm looking at?????

[myne]

If you want to tune for LPG and dont mind having to ditch petrol alltogether, you'll REALLY benefit from more compression.
If the combustion chamber has an overall good design, and isnt prone to detonation, you could probably go as high as 13:1 and still be able to run 98 octane if your engine has a knock sensor.
You're probably best achieving this with new pistons, because shaving the head might require a lot of shaving which could affect valve-piston clearances.

Porting probably wont help that much, because your primary goal appears to be more torque down low where you can use it. Typically porting reduces overall air speed which is bad for low rpm cylinder filling.
A regrind of the cams to provide some extra lift should allow a little more air in at low revs, and it may be possible to get a better grind to suit LPG. A pro would know.
Extractors cant hurt, just make sure you dont go too big. Some decent 4-2-1 extractors should help the low end a little.

For the tasks you do, seeking more power at the tp end doesnt sound advisable.
You may find that sacrificing some of the top end will result in a much more usable engine.

Ideally you'd supercharge it or run a very small turbo, as it is and run about 10psi. That'd get you a significant increase in low end torque and it may not affect your insurance much since it'd hopefully not be regarded as a performance vehicle.

Problem with forced induction is that the ecu would have to be replaced.

[Cruiser97_80]

A good exhaust sytem and snorkel would be the cheapest and easiest places to start

[-mick-]

A good exhaust sytem and snorkel would be the cheapest and easiest places to start

got the snorkel already

Good tech keep it coming guys.

[o_man_ra23]

does your snorkel have a forward facing opening?? When you have that forward facing opening, the larger it is, the more air you will force into the motor at highway speeds, providing better fuel economy and overtaking ability. As for the low end stuff... higher comp and a pure LPG tune would be a great start, plus free up extra room under where the fuel tank is (move the LPG there, or get a toolbox for under etc). An LPG grind short duration cam with high lift will be a huge bonus for the low down, and as stated mild extractors will do you wonders in a torquey motor. Opening the exhaust a little cant hurt too much either. Another thing you could do is take out the 4Y and get a 22RE... they have shitloads of torque.

Cheers, Owen

[-mick-]

An LPG grind short duration cam with high lift will be a huge bonus for the low down, and as stated mild extractors will do you wonders in a torquey motor. Opening the exhaust a little cant hurt too much either.
Cheers, Owen

This is probably a good place to start hey without opening up the motor. See how much difference that makes and go from there....thanks mate

will the lpg cam affect petrol performance at all.... for better or worse??? I don't want to ditch petrol just yet cause you never know when I'll be somewhere I can't buy lpg

[o_man_ra23]

itll run like a dog on petrol if you set it up for LPG properly, unless you run 98 ron or better, with octane booster. LPG has an equivalent to about 104 or so octane.

Cheers, Owen

[EldarO]

If you want to tune for LPG and dont mind having to ditch petrol alltogether, you'll REALLY benefit from more compression.
If the combustion chamber has an overall good design, and isnt prone to detonation, you could probably go as high as 13:1 and still be able to run 98 octane if your engine has a knock sensor.
You're probably best achieving this with new pistons, because shaving the head might require a lot of shaving which could affect valve-piston clearances.

Porting probably wont help that much, because your primary goal appears to be more torque down low where you can use it. Typically porting reduces overall air speed which is bad for low rpm cylinder filling.
A regrind of the cams to provide some extra lift should allow a little more air in at low revs, and it may be possible to get a better grind to suit LPG. A pro would know.
Extractors cant hurt, just make sure you dont go too big. Some decent 4-2-1 extractors should help the low end a little.

For the tasks you do, seeking more power at the tp end doesnt sound advisable.
You may find that sacrificing some of the top end will result in a much more usable engine.

Ideally you'd supercharge it or run a very small turbo, as it is and run about 10psi. That'd get you a significant increase in low end torque and it may not affect your insurance much since it'd hopefully not be regarded as a performance vehicle.

Problem with forced induction is that the ecu would have to be replaced.

This is excellent advice,

The basic thing with N/A motors, to get power, is to free the engine up, so it isnt choking on anything, making it breathe in, and out, better, which means, exhaust and intake work, but the main benefit would have to be from Cams, while sacrifising low RPM drivability.

for whatever work your planning to do, your ECU should handle it, even if you decide to run a small turbo, as even 5-6 PSI will show a massive gain in your case.

Eldar.O.

[-mick-]

for whatever work your planning to do, your ECU should handle it, even if you decide to run a small turbo, as even 5-6 PSI will show a massive gain in your case.

Eldar.O.

Interesting you should mention that and Myne did earlier also. If I were to run a small charger of some sort do you think the ecu would handle it ok??? I don't want to change the ECU at all... too much hassle and too many $$$ for an old vehicle.

What would a small turbo all set up cost??? And what would I need???

Or could I supercharge without sacrificing the a/c???

[myne]

If you have a MAP sensed vehicle the ECU WILL NOT! cope
If you have a MAF it might handle it.
If you have an AFM it probably will handle it.

I'd expect an AFM to be the most likely to work since it merely tells the ecu *this much air is going in*

[-mick-]

If you have a MAP sensed vehicle the ECU WILL NOT! cope
If you have a MAF it might handle it.
If you have an AFM it probably will handle it.

I'd expect an AFM to be the most likely to work since it merely tells the ecu *this much air is going in*

yep air flow meter equipped

[EldarO]

5-6 psi is not alot of change, air flow wise, but since your running it into a high-comp engine, you should show a generous gain, nothing mind-blowing, but should meet what your looking for.

although, you look like your lacking torque, youd be better off buying a turbo deisel van.

Just dont do something stupid like add an atmo BOV

Eldar.O.

[-mick-]

sorry to dig guys and big thanks to everyone who helped me make stupid decisions

I'm very keen to add a small supercharger to the engine now because it is by far the most economical, easy to setup and complete solution to my needs. I intend to have the blower push in 5psi because I see this as a safe pressure for near new std n/a internals. Have some q's for the gurus though

* The std comp is 8.8:1. My comp tests well so its actually close to that. If I push 5 psi through it will I still be able to use ULP in an emergency??? Say out bush. Or will I need to keep some octane booster handy for that emergency? The lpg will be fine I imagine and I can use PULP around town.

* Can I retain my a/c? I kinda like that Is it just a space issue there?

* What blower would I use??? Size, vehicle its off etc?

* Pulleys.... Where do I get pulleys from??? I can figure out bracketry and probably belts but need a hand with pulleys.

* Finally is there any real tricks to placing one. Obviously between the snorkle & air box but anything else?

I'm new to all this but I have done a fair bit of research and believe it will be really beneficial. As long as I can come to some arrangement with insurance.. ie not double it or anything... this'll definiently go ahead.

Thanks guys

[EldarO]

sorry to dig guys and big thanks to everyone who helped me make stupid decisions

I'm very keen to add a small supercharger to the engine now because it is by far the most economical, easy to setup and complete solution to my needs. I intend to have the blower push in 5psi because I see this as a safe pressure for near new std n/a internals. Have some q's for the gurus though

* The std comp is 8.8:1. My comp tests well so its actually close to that. If I push 5 psi through it will I still be able to use ULP in an emergency??? Say out bush. Or will I need to keep some octane booster handy for that emergency? The lpg will be fine I imagine and I can use PULP around town.

* Can I retain my a/c? I kinda like that Is it just a space issue there?

* What blower would I use??? Size, vehicle its off etc?

* Pulleys.... Where do I get pulleys from??? I can figure out bracketry and probably belts but need a hand with pulleys.

* Finally is there any real tricks to placing one. Obviously between the snorkle & air box but anything else?

I'm new to all this but I have done a fair bit of research and believe it will be really beneficial. As long as I can come to some arrangement with insurance.. ie not double it or anything... this'll definiently go ahead.

Thanks guys

Custom is a word youll have to become accustomed to, pun intended.

supercharger, id imagine, would be a whole lot of effort, as such, im bailing with the info

Eldar.O.

[myne]

personally I'd go a small turbo, but if you want sc...

I guess the easiest and cheapest path would be rigging something out of an SC14.
The SC14 was on a 2L straight 6 (1ggze) they're fairly cheap, usually between 300-450$, They're not fantasticly efficient blowers as I'm sure oldcorollas will tell anyone that'll listen, but it is cheap, and for low boost should be more than adequate.

If you're competant with a drill, hacksaw and welding bits of metal, I think brackets should be easy enough for you to manage. Whether you can keep your AC or not is up to how good you are with the brackets and how much space there is avaliable.

One thing you will probably have to do is to replace the fuel pressure regulator for one that rises with the inlet pressure. That will negate the relative pressure problem.

Other random things I can think of;
Since your SC will be BEFORE the throttle, you should install a plumb back blowoff valve to prevent the SC from killing itself. It'll also regulate boost.
Since the SC14 comes with an aircon style clutch, you might like to attempt to copy Toyota's system of turning on the SC only when you're under load conditions. If you can find some form of switch that turns on at above a certain pressure/vacume (Stock for the 4AGZE is 8" of vacuum) you'll have a crude version of what toyota use.
Add a small timer, similar to an interior light delay circuit(someone on here will be able to provide a simple 3-5 delay circuit relay) and you will have basically the exact same system toyota use.

Basic concept of the circuit is this :
Pressure switch turns on the timer circuit when the vacuum is below 8". The timer circuit switches the supercharger relay on. When the pressure drops above 8", the timer stays on for an extra 3-5 seconds and then the relay switches off.
Best bit is, you can put a simple switch in the middle of this, and you can turn the SC off permanantly. So you can run any dodgy fuel you like.

I cant really think of anything else that can be sorted out in the planning phase.