Hey all

I am building a p-51 and trying to decide between a DLE 55 and 61. Both will fit (55 a little better) but the 55 does come with rear exhaust pitts muffler where as with 61, I would have to buy a wrap around. My question is for a non 3d plane (just speed) am I going to see a -significant- difference in top speed between the two?

Thx
Z

I own two of the side exhaust 55s and the 61 so I can't do a direct comparison. About the only thing I know about the rear exhaust version is that it has a different power curve than the side exhaust. Some say the rear exhaust version is more powerful but I can't comment on that without real world experience. I would rate the side exhaust 55 as one of the best engines I've ever owned and that includes quite a few engines over the years.

The 61 is a very good engine but overall I prefer the side exhaust 55 and that would be my choice for the P-51. The rear exhaust 55 would be easier to mount and the muffler location is convenient but I believe the side exhaust engine is a bit easier to cool.

I like the two side exhaust 55's I have too. it's to bad that it's not being made anymore.What is different in the 61,If you don't mind saying.

A good portion of your speed is going to depend on propeller selection. You can have the largest engine stuffed in a P-51, but if its not propped right, it going nowhere.

The 55 side exhaust and 111 are still made. The USA importer just chooses not to bring those engines into the country. Keep watching some of the popular dealers as the demand is there for these two engines and they might reappear again.