thisoneused

My Feedback: (-1)

I was wondering what rpm's everyone is measuring with digital tachs on the ground with there .46 sized engines?
I am interested in this particular size engine do to its popularity in sport type plane and the prop jet models.
I recently purchased an Irvine MKIII .46 engine and so far am very impressed with its performance!
With a 8.75X9 pylon prop, it is turning 16,400 rpm on the digital tach. I havent ran this engine much yet, so that number will likely rise a bit once its fully broken in. I think thats pretty good for a sport type engine at a low cost to me! What are your readings with other brands...not the advertised! The manufacture likes to exagerate a bit...more like alot!!!!!! Naturaly the Jett manufactured engines come out in front of this figure a bit...not lots but definetly more from my readings on the subject. This is to be expected though....they are out for top performance!!! I just dont like spending the dollar amounts of a single new engine from Jett. Id'e rather buy an engine and another or other items needed for a build....
Anyhow, lets see some real numbers and do are own review!!!!

Thanks,
Jim

daven

My Feedback: (1)

We use the 8.75" x 8.75 quite a bit on the OS .46 FX and get real close to what you are seeing. The newer AX turns up about 500 rpm more.

Sounds like thats a good engine, we've been very happy with the OS for our racing class.

piper_chuck

My Feedback: (12)

You might want to wander over to the Tachometer Readings forum. Lot's of posts for this size engine.

Rudeboy

Well... a Jett Q500 engine (a .40) turns about 19K on zero nitro fuel and an 8.75x9W... what does that say about your Irvine...? Not much: put the same muffler on your Irvine, and you are going to see a lot more rpm's. To be correct, you do not need a Q500 muffler, you need a standard JettStream muffler... that thing will probably get you close to 17,500 on that prop if you are already hitting 16.4K on the stock muffler...

Irvines' are very decent engines... a LOT better than they used to be... so, keep it, no matter what.

I just don't buy 'em because they are so darned expensive

McFlyboy

My MDS was around the 15k mark with a 9x8, 5% nitro. Problem was, with the pipe not being tuned at all(never had time, it died after 20 flights), it wasn't doing anything. Maybe next time i'll play with it.

Rudeboy, you think Irvine's expensive? wow, I thought i liked cheap engines but...

kmtranmd

My Feedback: (71)

I get about 14,100 on my Thunder Tiger Pro 46 swinging APC 10x8 prop. I have not tried 9x8 prop out of concern TT Pro may not be able to handle higher RPM.[:-]