by Kai » Sat Feb 11, 2023 2:44 am
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.
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Last edited by
Kai on Sun Feb 12, 2023 10:37 am, edited 1 time in total.
Sonex A #0525- SG, DS.
EdgePerfomance EP915ECI, 123HP