I already have an Irvine 39H (new) for my Rap 30 (under construction). The guy in the Model shop swears by his.

However, I have always used OS and know them well.

I thought I'd get the Irvine 39 as opposed to the O.S. 32 for that extra little bit of power when I want it, but I'm hoping the engine will run well and be reliable.

Have I made the right decision? Any comments on Irvine engines? Should I take it back and exchange for the O.S. before I run it?

By the way, when he showed me both engines in the shop, I noticed that neither of them were ringed - does this matter in a Heli? You may have got the feeling by now that I have returned here after a long break from the hobby, and there's a few things I've forgotten

Luke

Irvine 39 is an awesome engine, but a little finicky to tune until you are used to the needles...

Once set you will be rewarded with TT39 performance and OS32 reliability....

I would buy another Irvine 36/39 in a jiffy, already owned 3, and set one up for a friend at weekend... was a missile

OS32 is a plain piston, Irvine is ABC (ally piston Brass chromed liner) neither needs a ring, but ABC's are trickier to tune sometimes... more powerful tho...

Galifrey

I have a problem with my Irvine 39 ABC and suspect that I have over heated the engine

The engine runs really hot and seems only to perform well when relatively lean. If I richen it out there is a marked reduction in power and the engine is clearly "four-stroking"

Today the solder on the manifold melted.

What do you think?

I've had no problems with my Irvine 39 (rappy 30 v2 and zimmerman muffler) running normally it doesn't load up unless it really pushed hard, and has more than enough power for general flying.

Budgy545, what fuel are you running, sounds maybe like you don't have enough nitro/oil. There is a fine line between being too lean or too rich. It definitley overheated if the exhaust solder has melted.

I think ABC engines tend to be a little less forgiving.

Sometimes worries me as each model shop I go to swears by the make of engine he sells!!!

I would stick with the ringed engines. I have heard too often that a single overheated run on an ABC can ruin the engine...
If you need more power, how about an OS50 or something in 46 class?

OS 37, probably has more power and is less finicky than the Irvine.

IMHO

I agree with barracudahockey about the OS37, at least with respect to having more power than the OS32. I do not know the Irvine but you should research and consider the OS37 before making a decision.

I run the os .32 and it is fine except for now I am doing some mild 3D and the power does drop off. I have run 12 gallons in it now and it runs perfect normally. So if you plan to get into heavier flying you will need more power. I am going into a .50 class heli. next. Alan