Which motors used for large Nuke models? - Which motors perform well?

[mermaid]

I may have asked the wrong question in my last posting. From the responses so far, it appears that estimating the propulsive power requirement for a large nuke model is much more difficult than I had thought.
It's easier just to ask those of you who have built a large scale nuke model to share your experiences. Which motor worked well in your model? Did the model perform as well as you had hoped? Pros, cons and pitfalls?

[PaulC]

What scale? My 1/96 runs

What scale? My 1/96 runs well on the stock Speed 400 in my D&E WTC-3.

[mermaid]

I'm thinking more along the

I'm thinking more along the lines of a 1/48 scale or larger SSN. I'm trying to get some idea of what motor might work well for a 1/41 scale long hull Permit. It would be about 87' x 9.3" . The prop would be about 4.3" diameter. Anybody out there who has built a 1/48 688?