a video on YouTube running the AM15 in my backyard. See link. Engine runs well. Oil pressure is low in this video. I recalibrated the MGL EFIS to read it correctly. Can't get a hanger at the local airport so testing will begin on my farm.

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Nice job. Any cowl-off pics of your installation? What prop did you choose?

Aeromomentum sells the Luga prop with the firewall forward package.

Thanks. What's the diameter on that?


I see there hasn't been any activity on this cowling thread in a while but I just got done with my cowl so I thought I'd pipe in. I didn't keep track of the hours I spent on modifying my former Jabiru cowl to accommodate the AM-15 but it was at least 60-70 before painting. Now I realize that the decision to attempt to modify my Jubiru cowl to fit the AM-15 is entirely on me but I've been following your posts with the issues you've had with the cowl supplied by Aeromomentum and it looks to me like you must have spent a considerable amount of time too. When I was making my decision on the cowl, the lead time on receiving the Aeromomentum cowl was over a year if I recall correctly. In addition, there was the matter of sticker shock. So I decided I could modify my Jab cowl in a relatively short amount of time. Wrong!

I hope Mark has been following this forum because I think the weak link in this whole engine package by far, is the cowling. When I originally installed the cowling supplied by Jabiru in their FWF package for my Jabiru 2200 engine, I would estimate that it took 10 hours max. That's including making the jig to attach to the prop hub to align the cowl. And then there's the matter of price. Cowlings for other engines are available through Zenith for just a little over half the price of the Aeromomentum cowl. Yeah, yeah I know we're comparing a carbon fiber cowl to a fiberglass cowl but isn't one of the main selling points of the Aeromomentum engine, if not THE selling point, supposed to be an affordable alternative to other engines? In my opinion the standard cowl should be a significantly more affordable fiberglass cowl that fits without any alterations, with the option of upgrading to a CF cowl.

The installation time of the AM-15 engine itself was less than when I originally installed the Jabiru but of course I already had much of the electrical system and instruments wired from the Jab installation.  I would say the time required for the two installations, not including the cowl, was very comparable. I've flown the plane with my new engine for about 4 hours now and I absolutely love it. Had an electrical issue with the AeroGraph readings but Mark worked me through that and it's working great now. I really want Mark and Aeromomentum to succeed and I think that resolving this cowl issue is very important. The home-built aviation community is a very tight-knit group and word gets around quickly regarding issues builders have. Despite the long hours I spent fabricating this cowl it still looks very amateurish. If Aeromomentum had an affordable alternative available that fit well without any alterations I'd buy it in a heartbeat. But at a cost of over $1800 plus shipping for their current offering, and seeing the issues you've had, I'll pass. Just my two cents.

At Sun N Fun 2022 I stopped by their booth and voiced my displeasures on the cowling issues I was having. Mark said "You're getting a new one because of the issues other builders are having. Lilli was supposed to let you know." So, they shipped me a new one from a different vendor. It was in three pieces instead of two like the first one. Not happy about that. I still had to modify the new one so it also would not touch the front valve cover area. Yes, the engine is performing great. Aeromomentum needs to focus more on customer service and feedback. I've flown my plane three times now and having high oil temp issues at high rpm's. Running at 245* with the break-in oil. I changed the oil today using Amsoil 20W50 full synthetic. We'll see if that helps.

Hi John, since this is basically a car engine(I believe the block my also be used in suzuki outboards) I was wondering what do all our modern 4 cylinder cars run for oil temp.  The research I found was that they run between 230 and 260 degrees. It also said that modern oil does not start to break down until after 300 degrees.  I have an AM13 in a Onex that's almost ready for inspection.  I'm just wondering if the oil temp you're seeing is something we have to worry about?   Do you know what your coolant temp is at that oil temp?

My research on oil temps came up with the same info as you got. I asked Mark at Sun N Fun what the high side of oil temp was since it is not mentioned in the manual. He recommended to set it at 245`. My water temps at high rpm's runs 210 to 220.

Hi John,  Have you had a chance to fly with the synthetic oil yet?  If so, did anything change with your oil temps?

Hi Randy; I took her up this morning early to avoid the extreme heat we are having in South Georgia. I flew .86 hours which is the longest flight so far. Oil temp rose to 250 at full power then down to 238 - 242 at cruise attitude. I notice on this flight my rpm on takeoff was only getting to 5240 rpm. Thats too low. When I got down and back to the hanger, I did a static run up at full power and only got 5200. It needs to be at 5800 rpm. My prop is set at 18.5 degrees pitch. That may be too much. I remember watching a video about prop being set to high and it put more of a load on the engine causing the oil temp to rise. I'm going to adjust it down one degree and see what happens.


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