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You could try the pistons from the D17A7 natural gas engine, with wiesco rods.

The compression is 12.5:1. part number

or possibly get them machined to 11.1:1.

........

of course with any High compression setup you'll need the supporting mods and I can't tell you if this will last long term.

 
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If D17 successfully achieved all the power gains to a D17 he has contemplated about wtihin the last year he'd be able to get groceries slightly faster.

 
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lol =D

 
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Swimmers shave their legs to go faster. Ah, wait, no convertible civics.

 
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D16 pistons need to be modified to accept the D17 rod...i think the D17 piston rod end is wider.
or you can possibly use the d16 piston and rod combo but then the rod ends will need to be modified...i do believe the d16 crank rod end is thicker than the d17...

or just slap a turbo on it!

 
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UPDATE: It's pretty much fixed now. I put on a larger K20 throttle body, and now the fuel trim is consistently within +/- 5 percent. Thanks for the help!

 
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I know that this question depends on many factors. But generally, presuming that there isn't any rust or collision damage, does the car's chassis itself "wear out"? Basically, I am asking if the chassis becomes weaker or less rigid over time. Thanks!

 
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According to this the answer is yes: https://www.reddit.com/r/askscience/...ker_over_time/


Here's more reads if interested: https://www.google.com/search?num=50....0.1fnvcWm_FLY


To easliy sum up the answer in two words it is at the time mark 0:37 seconds in the video below:


It's Science!

 
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Thanks. So basically the steel develops microscopic cracks?

 
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Sounds reasonable. I don't feel like researching through metallurgy info to find an answer. Not really something I ponder..I'm more of maintenance per service manual and fix something when it breaks type of person. Honestly, being in my 50's and the past few years (several repairs) the less work I have to do on my car the more content I am. However, I'm glad and appreciative of this site, it's members and others like it as a resource if repairs need to be done.

 
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Thanks.

 
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well known stress failures and fatigue.

did you not even try googling it? It's an easy thing to do when someone have internet. Isn't that how you found the site?

here in one, from my control arm.

 
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Yesterday, I evacuated the R134A and filled my system with Enviro-Safe Industrial R134A replacement. Here's what I noticed:
1. The AC gets cold much quicker after it is first turned on.
2. The AC blows colder at idle. 5 degrees colder to be exact.
3. The compressor doesn't cause as much drag on the engine as it is running, and it runs for less time before cycling off.
4. The compressor's discharge temp is way lower. With R134A., the refrigerant line coming out of the condenser was hot enough that it would be uncomfortable to hold on to, but with Enviro-safe refrigerant, it's warm, but not burning hot. This will help the compressor live longer, as well as the rest of the system.

However, be aware that this is a flammable refrigerant, so I can't recommend that anyone tries this unless they are okay with their AC system being full of flammable gas.

 
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Hmmm..let's weigh this out: 5 degrees cooler versus possible harm or death?


Hell, I'll take swamp nuts over death any day...lol

 
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Lets see.

First we will start with your new refrigerant is NOT approved for use on highways in the US.

Second lets hope you don't get into any wrecks that cause leakage because YOU will liable to damages caused to people by your own negligence. This might involve occupants of your car or other cars. It might involve first responders including paramedics, police, or firefighters.

The system was designed to work a certain way with a certain chemical. In the past you have shown a complete willingness to assume you know better than engineering teams when in fact you don't. Was your system working at peak design efficiency? I bet it wasn't.

Presumptions and assumptions. You compare before and after cooling times. Did you measure starting temp in the interior? Did you record the starting vent temp? Solar load? Heat load in the ducting? Did you record the ambient humidity? Did you check operating pressure before and after? These all affect cool times.

The compressor causes less drag on the engine? Explain how. The compressor runs less time before cycling. How much refrigerant did you recover? Was it properly full of proper R134a or was it already low or filled with an unknown blend of mystery gases. Counterfeit/bad R134a is a serious problem in this country. It doesn't perform as it should and is cheaply available in bulk.

Did the system just have a small leak and needed the system brought back to a full charge? If so you have made it infinitely worse because now you have a small leak with different operating pressure characteristics and flammability to boot.

Here is another goodie to think about. Any shop that is smart will have a refrigerant identifier to help protect their expensive AC equipment. As soon as they test your car they will let you know that they are not going to work on your AC system. They don't want that crap inside their machine, hoses, or tank. You have successfully rendered your car a DIY car forever. On the bright and sunny side of things you likely still get the AC service by shops of less repute that don't invest in proper equipment.

Of course what do I know I am just a forum poster. Time to sign off and polish my Honda master tech wall plaque.

 
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I think that the risk is extremely small, especially when you consider that there is about 14 gallons of gasoline behind me. R1234YF is also quite flammable, but it makes DuPont and Honeywell money, so it's okay.

 
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The system was full of 19 ounces of Dupont R134A before I converted, and the system is leak free. The reason this refrigerant causes less drag on the engine is because it runs at a much lower head pressure. With R134A, the low side was around 45 and the high side was around 190, but with Enviro-Safe, the low side is still around 45, but the high side is down to around 150. Lower head pressure means less resistance, as well as less stress on the system. I did measure ambient temp also. It was 88 degrees during both tests.

 
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You have a point. Is it made for use in automobile HVAC?
Is it illegal in any state?

 
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Yes it is, Which is why german automakers are NOT using it. But the condition required to burn it are fairly difficult to achieve. The worst part about burning 1234yf isn't the fact that it burns. The problem is the fact that the gases released as it burns are very nasty. Memory tells me that it releases a hydrofluoric acid within its smoke which is some of the nastiest stuff around.

The reason Germany doesn't approve 1234yf is the same as some of the reasons I listed for why you shouldn't have propane/butane/hydrocarbon in your system. They don't want first responders dying inside their nations tunnels while dealing with traffic accidents.


And yes Honeywell/dupont are wagging the dog on this one. It was expected more than 15 years ago that as soon as the patent on R134a ran out that the EPA would require changing to something else that was new and patented by 1 or 2 companies to keep their monopoly going. I believe that author Michael Crichton wrote about this back in the 90s. He was the author of Jurassic park, ER, congo, and many other films/franchises over the course of 30+ years.

 
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It is made for automotive HVAC, it's not illegal where I live, and its auto ignition temperature is 1595 degrees F.

 
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I agree about the fumes from burning R1234YF is much more dangerous than the actual fire itself. For that reason, a hydrocarbon refrigerant could be considered safer in that way. A leak is also less likely since the pressure in the high side of the system is much lower than R134A, and I presume R1234YF also. Great points though!

 
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huh, so everybody here have been sniffing the fumes of the coolant chemical?

Well, the way EPA is now...

 
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Here's a related read that ask some the similar questions here: http://hvac-talk.com/vbb/showthread.php?1584811-Enviro-Safe


See reply #18 in that thread.

 
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My keyless entry remote is broken, and the refrigerant has a strong pine scent, so I would definitely smell it if it leaked. Also, the odds of all of the refrigerant suddenly leaking inside the car is almost zero. The evaporator is not very likely to leak since it isn't subjected to any debris, like rocks flying at it or damage from an accident, and it's on the low pressure side of the system. I've never seen or heard of an evaporator suddenly blowing up in a parked car.

 
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I'd like to get my a/c system cooler. Works fine on overcast days, at night or if I keep my car parked in the shade but on hot, humid Florida days it struggles.

 
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I presume the condenser is clean, the system is correctly charged and you already tinted the windows? If you can make the AC a lot colder by spraying the condenser with water, maybe do number 4. Look into number 2 regardless though, it always helps.

 
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Sytem chareged correctly
Factory tinted windows. Not interested in darker tint.
I clean the condensor with a hose and HVAC foam every six months.
Engine is B20 and the prior owner's friend (10 year a/c tech) installed a complete, new HVAC system minus the evaporator three years ago.
I've owned two 6th gens and this current 5th gen and their a/c systems have all been weak and cools the same way: struggles on hot days. Seems to be a common issue: https://www.google.com/search?ei=Umk....0.LyKhEb9D1jE

My mom has a 7th gen and the a/c works great during the Florida summers and all other seasons.

 
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I'd suggest insulating the low pressure AC line from the evaporator to the compressor. Doing so will always help the system's performance, even if only a little. The cold refrigerant can pick up a lot of heat from the engine compartment on it's way back to the compressor, which isn't a good thing.

 
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I have a Mishimoto racing radiator, so I don't have a transmission oil cooler in the radiator. However, the car has a Hayden 679 cooler that is mounted behind the bottom grille for maximum airflow. The cooler so well that the oil cooling pipes on the transmission barely get hot. Is that bad? I don't think that anything is going to get too cold during the summer here in Memphis, but I wanted to check. Thanks!