Topic: BigMike's Big Summer Project: REVIVED!

[unclejpl4x4]

A new thread will be coming soon. I have decided to put this thread to DEATH.

I've been really sneaky and have a lot of updates to share

[Doof]

hey mike are you still running the water injection?

how does that even work?

[BigMike [OP]]

Negative Ghost Rider. I no longer have an intake air heater so I no longer have a need to cool my intake charge.

Concept:
http://en.wikipedia.org/wiki/Water_injection_(engines)

How to do it yourself:
http://www.mirage-performance.com/sonata/WaterInjection/
http://www.turbomirage.com/water.html
http://www.lovehorsepower.com/MR2_Docs/Description.htm

[79coyotefrg]

im starting to consider a  steam engine  for my truck

[THK Matt]

........ i still dont get how water injection works? wouldnt it BLOW the rings and valves?

help on what it does?

[yotadork83]

water vapor.

[CTENG in KS]

You only put a tiny mist in so it is a few teeny droplets per compression stroke.  The water will do two things.  First, it will kool the intake charge to help prevent compression combustion (pinging).  Second, because the water is incompressible, it effectively reduces the size of the combustion chamber increasing the compression ratio. 

There is still plenty of air in the chamber to provide the compressibility necessary for the pistons to move freely, the amount of water injected is really fairly small.

[BigMike [OP]]

I am pretty sure I have spoken on this topic before here on this forum..

First, it will kool the intake charge to help prevent compression combustion (pinging).

This is the biggest and in my opinion the only real reason to use water/alcohol injection.

This occurs due to the following:
Liquid water enters the intake system and travels to the cylinder. On it's way it's temperature is greatly increased causing the liquid to transform into a saturated vapor (and eventually a super heated vapor). And as we all know, it requires a great deal of heat energy to increase the temperature of water due to its relative high specific heat. This consumption (think of "absorption") of heat energy causes the surrounding area of the water molecule to cool significantly.

In my Supercharged MR2, I did not use an intercooler and instead relied solely on the water evaporation phenomena for cooling (internal cooling). My intake manifold would cool down so much that water would condense on the OUTSIDE of the housing. This is NO joke. I had an intake air temp probe, and I would go from 110-degrees intake air at a red light to 45-degrees by the top of 3rd gear. It was very cold to the touch, felt like the inside wall of my refrigerator.


One key thing to keep in mind is that you must have a very high level of water atomization. In other words, you want to squirt, or inject the smallest and highest concentration of ultra fine water droplets. The smaller the water droplet the more efficient the cooling. This is due to the simple geometric properties of a sphere: As the volume of the sphere decreases, it's surface area-to-volume ratio increases at an exponential rate. And the greater the surface area-to volume of the sphere or droplet of water, more heat energy will be required to increase the temperature of the water droplet.

In other words, the smaller the water droplets, the more heat it will "absorb" in order to transform the water droplet into a vapor (gas). And the more heat this little water droplet guy absorbs, the cooler your intake system becomes. Plus there are a lot more fine droplets (same amount of water just smaller and many many more droplets) so the number of "heat absorbers" are greatly increased as well as greater absorption. This is why the higher-end systems like Aquamist use extremely high pressure pumps with very very small nozzles: to get the smallest and most fine liquid mist possible (high water atomization).

Compare your shower head in your shower room to the spray of a can of spray paint. The contents of the spray paint can are at an extremely high pressure and are forced there a very small nozzle, where as the water in your water pipes leading to your shower head is at a much lower pressure and exits through a much larger nozzle.

Question: Why do we want a cold intake air? The key to this is that colder air is more dense and is able to retain more moisture than heated air. So the colder the air gets, the more fuel (gasoline) it may carry. So we can keep a good 12-12.5:1 air-to-fuel mixture ratio by adding a lotttttt more fuel to the same amount of air. More fuel = increased pressure during combustion = increase in mechanical shaft work = huge smile on your face. Maintaining a proper fuel mixture is critical to the engine's ability to prevent pre- and post-ignition detonation.

Question: If this is so good, why don't all cars use it? Set aside the technicalities of every car on the road using water injection (having to fill up a "water tank", etc), and the #1 problem is lack of heat. A normally aspirated engine (an engine that runs purely on vacuum) is able to draw ambient air temperature into it's cylinders with very little heat gain. I am willing to bet that most so called "cold air intake" systems are able to get air to the cylinder at high RPMs with as little as a 20-degree F difference in temperature difference to the out side air. Think about it, that air is moving extremely fast, very little time for the air to be heated.

So assume a normally aspirated engine, such as a 22R-E engine has a water-injection system installed. If the outside air temp is 80-degrees, the intake air at the cylinder under full throttle has got to be around 90-degrees F in my opinion. Compared to the 22R-TE Turbo engine, imagine running the 22R-TE Turbo under full boost with OUT the intercooler. I am sure the intake air would be over 200-degrees. To put this into perspective, before I learned about Water Injection, my Supercharger intake air temp would go over 160-degrees WITH my intercooler, measured on the COOL SIDE -- the outlet of the intercooler!!

So let's compare the two.
If the air temp on the outlet of a Turbo is 200-degrees, and the water injection cools this air temp down to 60-degrees, that is a difference of 140-degrees
On the other hand, if the intake air on a regular engine is 90-degrees and we are going to cool it to 60, then that is only a difference of 30-degrees.

I once read that for ever 2-degrees celsius in intake temperature drop (or apprx. 4-degrees F), a well turned engine will gain apprx. 1 horsepower. So in the case of the 22R-E, only about 5-7 horsepower is gained by using water injection, where as on the 22R-TE, 30-40 horsepower is gained!! Not to mention also that without the need of an intercooler, you reduce the amount of boost drop through the intake system. So the Turbo engine may put out 1 or 2 more PSI in addition to the cooler air charge, which just equals more and more power.

Least we forget that the water droplets need a high temperature difference in order to absorb the most amount of heat energy, the hotter boosted engine will achieve a more complete water vaporization whereas the non-boosted engine will not. So it is very likely that on a 22R-E, some of the injected water molecules may reach the cylinder while yet a liquid. In this case, mixing water with gasoline will greatly decrease the ability to ignite the fuel which will result in very bad misfire.

Therefore it is EXTREMELY beneficial to use water injection in a boosted engine, and it is marginally beneficial to use it in a non-boosted engine.

That is why I said...

I no longer have an intake air heater so I no longer have a need to cool my intake charge.

Also remember that many people mix a 50/50 Water/Methanol formula. This is to get all the benefits of converting a liquid into a gas, plus the increased octane rating (if that even applies) of the alcohol adds even more to the detonation buffer. All this means that the computer timing can be more and more aggressive without causing any engine damage.

Second, because the water is incompressible, it effectively reduces the size of the combustion chamber increasing the compression ratio.

I would only agree with this on a non-boosted engine. But if the intake charge is hot enough to vaporize all the water before it reaches the cylinder, then you would have vapor entering the cylinder which is compressible.


I remember that if I injected too much water at a lower RPM, it would misfire or foul out or bog down. So I had to be careful with how much water I injected in relationship to the load which is related to how hot the intake charge would get. Cruising on the freeway there is no need for water injection. But under full load there certainly is

Regards,
BigMike

[CTENG in KS]

Don't forget, as the compression in the chamber increases, so does the boiling temperature of the water.  It is very likely that at the top of the compression stroke there is enough pressure in the chamber to force the vaporized water droplets to condense back to a liquid form.

[THK Matt]

Oh....... 

[BigMike [OP]]

Don't forget, as the compression in the chamber increases, so does the boiling temperature of the water.  It is very likely that at the top of the compression stroke there is enough pressure in the chamber to force the vaporized water droplets to condense back to a liquid form.

Ah, excellent point! Well my denso iridium plugs won't have much trouble revaporizing them water molecules

[Doof]

hey mike i was wondering if you had more pics of how you mounted your rear shocks

i noticed that in post # 232 it is higher up on the housing and then in post # 385 they were different and mounted towards the bottom of the housing... do you have any pics of those off hand?

[THK Matt]

hey mike i was wondering if you had more pics of how you mounted your rear shocks

i noticed that in post # 232 it is higher up on the housing and then in post # 385 they were different and mounted towards the bottom of the housing... do you have any pics of those off hand?

good point, id like to see that as well.

[BigMike [OP]]

hey mike i was wondering if you had more pics of how you mounted your rear shocks

i noticed that in post # 232 it is higher up on the housing and then in post # 385 they were different and mounted towards the bottom of the housing... do you have any pics of those off hand?

Well, again, I've been changing a lot on my rig. I will be creating a new project thread hopefully the first week of June.

I am now on my 3rd version of these lower mounts. They are simple to make. I just build a L bracket with about a 75-degree bend to them, put the shock bolt through them and the shock and then put the nut on and cut the bolt down so it no longer sticks out past the nut. Then I use a small ratchet strap around the entire shock and slowly adjust the length of the ratchet strap and make measurements where I think they should be mounted (all while the shocks are still mounted at the top). Then I put in a couple tacks on the bottom of the L bracket and a couple tacks on the nut-to-the-housing. Then I pull out the bolt, get the shock outta there, and then put the bolt back in to hold the nut in place. Then I just burn everything on, let it cool, throw some paint on it, remount the shock, and wa-la.

Do you guys notice anything else unusual with my diff housing?

[THK Matt]

Well, again, I've been changing a lot on my rig. I will be creating a new project thread hopefully the first week of June.

I am now on my 3rd version of these lower mounts. They are simple to make. I just build a L bracket with about a 75-degree bend to them, put the shock bolt through them and the shock and then put the nut on and cut the bolt down so it no longer sticks out past the nut. Then I use a small ratchet strap around the entire shock and slowly adjust the length of the ratchet strap and make measurements where I think they should be mounted (all while the shocks are still mounted at the top). Then I put in a couple tacks on the bottom of the L bracket and a couple tacks on the nut-to-the-housing. Then I pull out the bolt, get the shock outta there, and then put the bolt back in to hold the nut in place. Then I just burn everything on, let it cool, throw some paint on it, remount the shock, and wa-la.

Do you guys notice anything else unusual with my diff housing?

Hi-Pinion w/ E-Locker? on the front?

[BigMike [OP]]

Hi-Pinion w/ E-Locker? on the front?

Negative, rear diff, what is it? What size wheel spacers am I running in the rear?

It's probably hard to see, but a keen eye should notice it.

[BigMike [OP]]

Here is a one-stop list of the lower mounts I've been using...


First version (circa June 2006):
Modified Steering Stabilizer Bracket
Notice how high up on the housing it is mounted:



Second version (circa Feb. 2007):



It's hard to see here, but I never liked how far back they hanged out:



Third (final) version (circa April 2008):
This time I used less material and kept the shock tucked close to the axle housing. I also rerouted my brake lines and put them up much, much higher and out of harms way

[BigMike [OP]]

Which reminds me, I still need to get my e-brake hooked up

[Doof]

thanks for that tid bit of info.... i never thought about using a ratchet strap to compress the shocks and adjust

[BigMike [OP]]

thanks for that tid bit of info.... i never thought about using a ratchet strap to compress the shocks and adjust

Yeah baby, the Bilsteins start feeling reallllllllllllllly heavy after you've been compressing them by hand for over 2 or 3 minutes

I use a small ratchet strap, maybe 1" wide, and I take the whole strap out and feed it through the small space around each shock eyelet housing. Then when I am finished and all the bolts are installed and its mounted in place, just pull the strap out of the ratchet again and it will simply pull right out of the whole shock.

[THK Matt]

thanks for that tid bit of info.... i never thought about using a ratchet strap to compress the shocks and adjust

thats what i've done... makes it very easy to remove and install.. takes the stress off the bolts. to undo them

[Doof]

tips and tricks are simple and you can show off to your friends if they dont know about it.... 

[THK Matt]

tips and tricks are simple and you can show off to your friends if they dont know about it.... 

i know right?
and im not catching what your trying to point out on the rear diff housing Mike

[BigMike [OP]]

and im not catching what your trying to point out on the rear diff housing Mike

Cool, that is what I wanted to hear Carry on

[rockhound]

I'll take a shot at it.
No wheelspacers and the diff housing is not in view, but the axle housing looks like the center section has been clocked. That is to say the axle tubes are in the stock location and the center section of the axle housing has been cut, turned and re-welded. 

Props on the explanation of the water injection. You sound like somebody else I know! 

[Cheesemaker]

LC axle? 

[THK Matt]

I'll take a shot at it.
No wheelspacers and the diff housing is not in view, but the axle housing looks like the center section has been clocked. That is to say the axle tubes are in the stock location and the center section of the axle housing has been cut, turned and re-welded. 

I'll take a bet that you are right!

[rockhound]

I'll take a bet that you are right!

That's all I could come up with.
But why would you go thru all the trouble, when clocking the conventional way, cutting and re-welding the perches, is so easy?

Well, it's not really easy, but conventional.

[79coyotefrg]

Mike what length shock do you have 14 inch stroke ??

mounted in the stock location at the top??

[Doof]

glen... check out post 232 or around there... it will answer your question