Rotec Water Cooling

[Nick]

Hello everyone I'm new to the Forum. I found this Jabiru section so I thought I might ask a question. I am building a Waiex about 90% built. I bought a 3300A that sat around about 10+ years. The inside was very well preserved. The Cylinders not so much. Anyway I have done a top end by the book. I decided after reading so much about the issues with the Gen 1 and 2, that I was going to go with Rotec water cooling along with all other upgrades. I guess my question is there anyone here that has been running the Rotec water cooling, and any issues? Looking forward to any Info. Thanks Nick

[daleandee]

Hi Nick,

If you haven't found them already there are some great guys over here and some of them do use the water cooled heads. (You'll have to join to ask questions but that is painless):

https://jabcamit.groups.io/g/main/messages


Edit: Here is one thread that might interest you: https://jabcamit.groups.io/g/main/searc ... ter+cooled

Dale
3.0 Corvair/Tailwheel

[rbarber]

I used them for about a year, then sold them for about 1/2 of what I paid for them. What I found was the following:

1) Poor quality control in manufacturing:
a. Blasting grit medai remaining in the interior of the water jacket
b. One of the holes that is tapped for securing the water out port penetrated the water jacket
c. Waterpump leaked right out of the box.
2) They have the same design issue of GEN 1 Jabiru heads; Valve seats are too close together.
3) The water temperature and CH temps were "as promissed", but there is no way to be sure about the material between the valve seats.
4) You have to source your own radiator, and other accessories, lines, reserviour too.

In short, I never felt I could trust the system. You may get better. You never know...

'Best,

R.
N157SX (Sexy Hexy), Gen 4
~1200 hrs

[Kai]

I had them on my 4-banger for some 7 years, after which I dumped the Jab and went EP915ECI (a 120HP R912 development).

Never an issue with the heads- I found their quality to be about the same as the engine. The kit came from Rotec with everything needed for hoses and connections. But after I decided to switch from flange to cone (the heads can take both) on the exhaust ports, I discovered that the Rotec machinist had been a little too enthousiastic on one of them. It was not a big issue, solved after a few hours in a competition engine machine shop.

Sourcing the radiator was simple; the immense manufacturing facilities of the PRC provided me with a beautifully polished and very modestly priced unit originally intended for a R912. E-bay also had several used original R912 coolers on offer. But since my aversion for composite work knows no limits, a split radiator setup was developed, using the cooling air inlets of the original cowling: worked like a charm. The almost indestructible electrical circulation pump is a Bosch unit- it has a calculated working life of some 6K hrs. The drive between the brushless motor and the pump section is magnetic, and is sealed off by a watertight bulkhead. How it could possibly develop a leak beats me.

After the decision was made to go EP915, the 22A´s main issue (not enough power!) was sought rectified by going EFI and hanging an Aerocharger under the engine. Manifold pressure was limited to a modest 42in (!). Of course, without the LCH´s, this would not have been possible; and still not a single issue with the heads- no cracks, no leaks, no nothing. I ran this setup for years.

However, the gen 2 Jab cylinders and pistons did not take too kindly to this treatment, and started protesting after a while. When sourcing new parts from Jab became difficuilt, the swap to Edge Performance was made.

It would have been much wiser workwise to replace the 22A with its bigger brother- IMHO a setup with LCH´s on this engine would be almost indestructible: to make the Sonex sit up and talk you need 120HP.

[daleandee]

It would have been much wiser workwise to replace the 22A with its bigger brother- IMHO a setup with LCH´s on this engine would be almost indestructible: to make the Sonex sit up and talk you need 120HP.

Good information! Let me get a bit off topic and focus on your last excellent point. I had a VW nose roller and I loved the way the airplane flew. But the day I got to fly my friends Jabiru 3300 taildragger I knew my life was gonna change. Anyone that has not, and has an opportunity to, should fly a Sonex with 120 HP on it.

You might even go find a second job ... 8~)