Monthly Archives: July 2013

eBay 24v e30 longtube header update

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After fitting the longtube headers per this post, I had to fabricate the rest of the header back exhaust. I completely green fielded this exhaust and opted to go completely custom rather than try to adapt an e30 or e36 catback. My plan was to Y the headers together into a single 3″ exhaust pipe and run a rather loud Thrush 17661 Welded Muffler. Due to packaging challenges, I wanted to make the Y section removable so that the headers can be removed or installed with the engine in the car.

Trying to wear out the credit card

Exhaust parts – or trying to wear out the credit card

Close Up

Exhaust parts - Close up

 

So, what all did I order?

  1. 24x 7mm copper exhaust nuts (exact item on amazon)
  2. 2″ Stainless Steel Mandrel Bend 45 Degree Elbow(eBay)
  3. 2x 2″ stainless steel v-bands (eBay)
  4. 3.0″ Stainless Steel V-Band (eBay)
  5. 3.0″ Mild Steel V-Band (eBay)
  6. ER309L Stainless Steel MIG Welding Wire 2-Lb Spool 0.030″ (0.8mm)(.023 pictured, .030 is probably more appropriate)
  7. 3″ Stainless Steel Straight Tubing – 1 Foot (12″)
  8. 3″ Mild Steel, 180 Degree Mandrel Bent Elbow (didn’t use)
  9. 3″ aluminized / mild steel exhaust tubing
  10. Thrush 17661 Welded Muffler
  11. O2 Sensor Ring, Weld-on, Mild Steel, 18mm x 1.50 Pitch

I started by breaking out a spare head and mounting the headers so that I could mock the Y section up off the car.

Mocking up exhaust - Part 1Note that these cheap headers neck down to 1.75″ on side but stay 2″ on the other side… very odd indeed. I tacked on the first 2″ v-band for fitment in this picture. Also notice that the 1.75″ side has a bend that causes it to intersect & interfere with the other side. This is fixed by cutting it at the bend.

header mock-up part 2

 

And another angle

header mock-up part 3

I should also take the time to mention that I have very little experience with welding, so please take it easy on me! The 2″ sleeve clamp pictured came with the headers and I actually decided to use it after seeing how tight the clearance would be with two v-bands – perhaps I’ll update the design to use both v-bands in the future. I continued to work on the Y and used the 2″ stainless tubing with the 45″ mandrel bend to make the Y.

Y mockup

 

This was then dumped into a 3″ stainless steel tube. I clamped one end of the 3″ tubing in a vice until it was flattened to 2″ on one side.

Flattened 3" tubing

 

Then it was all welded up, and a 3″ stainless v-band was welded on.

Y

 

I didn’t want to spend a lot of money at this time, so I continued the rest of the exhaust in aluminized, mild steel. Stainless steel and mild steel expand at different rates and should not be welded together, although ER309L can do it. Because they expand at different rates, any welds between stainless & mild steel tend to crack after they have been heat cycled many times. I addressed this problem by using the v-band as the transition point. I bought identical 3″ stainless & mild-steel v-bands, then used one stainless v-band and one mild steel v-band to join the mild steel exhaust to the stainless exhaust. The mild steel exhaust section is not pictured as it is very simplistic.

Y under the car

Fitment under the car

And showing where the 3″ section begins under the car

Fitment under the car part 2

Finally, here’s the end product

E30 exhaust

Video:

Closing notes – the exhaust is LOUD and raspy. When I say, I actually got pulled over on the way back from the alignment shop, maybe 12 miles after the car was running. The LEO said, and I quote, “Dude, your exhaust is WAY too loud. I heard you a mile away!” I would suggest getting a different muffler or at least adding a resonator. The 3″ tubing is also very large. 2x 2″ exhaust actually flows better, but it doesn’t hang as low under the car. The 3″ hangs low under the rear subframe and looks like it could easily scrape. Other than that, it worked out pretty well!

 

A/C Leak Freeze with Magic Frost Review

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LDSC00069ike many, our home is cooled by an aging heat pump originally built in 1993. It’s been a good unit, but last summer the fan on the heat pump gave up the ghost and had to be replaced. Soon after, we noticed it was not cooling as it should and was blowing nearly 70 degree air inside the house with the thermostat set to 82 degrees fahrenheit. Generally, you want to see a 20 degree “split” – that is, the air exiting the air handler should be 20 degrees cooler than the incoming air. In our case, the incoming air was between 76 and 77 degrees with the basement air in the mix, giving a 7 degree split. Not good. Furthermore, we noticed the interior A-coil, called the evaporator, freezing at the bottom which is an indication the system is low on refrigerant.

The HVAC tech only confirmed what we already knew, that we had a refrigerant leak. He said it was a pretty substantial leak on the order of a pound of R-22 refrigerant a month. Service calls are not cheap and neither is the refrigerant, not to mention that refrigerant leaks are not exactly eco friendly! On old units, like ours, repair is seldom an option. The labor costs involved with finding a leak are substantial and, as explained by the tech, even if the leak is found, it often is not repairable. Our suspicion is that the condenser coil, located on the heat pump itself, started leaking after the fan replacement. The fan replacement process involves partially disassembling the heat pump and leaves the condenser coil unsupported and vulnerable to damage. With repair an expensive prospect, there were two options left – total replacement or a stop leak product. Since this nearly 20 year old heat pump would be headed to the scrap heap anyway, we decided to try “A/C Leak Freeze with Magic Frost.”

According to the manufacturer, A/C Leak Freeze is “not activated by moisture or oxygen” meaning that it shouldn’t “gum up” the controls inside the air conditioning system like many other products. Our HVAC tech assured us the worst that would happen with A/C Leak Freeze is that it wouldn’t work at all. Before giving the OK, I did some homework online and read reviews on HVAC forums; many techs advised against putting stop leak type products into an air conditioning system, but the ones that had used A/C Leak Freeze had not experienced any compressor failures. Furthermore, many noted that A/C Leak Freeze had successfully stopped small refrigerant leaks on systems deemed “over-the-hill!” This was certainly encouraging and we forged on.

Actually using A/C Leak Freeze is simple; the heat pump or air conditioner must be running, then the syringe is connected to the low side service port on the suction line.  At this point, A/C Leak Freeze is slowly injected into the refrigerant. Due to high pressures, pushing the syringe in by hand can be difficult so the manufacturer recommends placing the syringe in a caulking gun. Once A/C Leak Freeze is in the system, the refrigerant should be topped off and then the heat pump or air conditioner should run continuously for at least 30 minutes to circulate the product. That’s it!

So far our system has been kicking out 58 degree air ever since the refrigerant has been topped off and A/C Leak Freeze with Magic Frost added, with no refrigerant loss noted. We’re hoping this is one for the “success” column! Please note, carefully weigh the pros and cons before adding A/C Leak Freeze to your HVAC system. While it seems to have worked successfully in our case, I still feel it could be damaging and it should only be used as a last resort on systems not worth repairing!

*July 30th Update*

The A/C again measured down to 58 degrees a month later. The compressor is still going strong so it seems like A/C Leak Freeze did the trick!

*August 30th Update*

The A/C continues to work. The last measured temperature was 62 degrees, but given the different environmental conditions I’m not sure how much meaning can be derived. Perhaps some ground has been lost or maybe it’s perfectly fine. Either way, the compressor is still running just fine and the A/C is blowing cold. I think it is clear that the A/C Leak Freeze product helped slow or stop the refrigerant leak.

*June 20th 2014 Update*

It’s still going! See the video here.