jon_focal_plane

Bob,

Was looking for some recommendations. Just ordered a Magnum and thinking about engine configuration. I'm leaning toward a Jett 65L. The advertisement shows a front intake - side exhaust setup. Is that what most folks are using? How about FIRE side mounted? Does Dubb have a special riser for a tuned pipe for this application? If you go with the muffler, any extensions required? Just general mechanical fitting knowledge will be useful now to help make a decision.

Thanks,

Jonathan

bob27s

My Feedback: (19)

Hi Jon,

The engine of choice here would be the Jett SJ-60LX. This is the high rpm high output version. Same .40 size case - just a bit higher timed, comes with the SS muffler. Killer 18,000 rpm on a 10x6. Unloads a ton in the air. Put a 9x8, 9x9 (or any prop that turns a minimum of 16,500 rpm) on the front with a Magnum, and hang on.

From other Magnum applications, there is no extension required.

As for the FIRE setup, that is possible. However, its not real easy to pull off on the Magnum. Just a lot of work. Quite honestly, the 60LX with the muffler performs almost as well as it will with the pipe.

You can get standard riser header types, as used for the Whiplash and such. I believe its a 1" rise that Dub keeps in stock. I think 1.25" is available too.

Bob

jon_focal_plane

Thanks for the info Bob.

I just ordered a 60LX from Dub. I wanted to include an aluminum spinner before he ships it next week. Any idea what size fits the Magnum?

Jonathan

bob27s

My Feedback: (19)

Jon,

Im not sure on the spinner. Ask around in the ExtSpeed forum. A few folks in there have built them and may have that info handy.

Just for reference, Dub is a week or 3 behind on deliveries. Hurricane and material suppliers have put a kink in the schedule.

Bob

SSAN

Hi Bob,

Are the new engines a .60LX and .90LX size or .61LX and .91LX?
On the post above you mentioned a SJ-60LX, but the picture showed otherwise.

I think those new engines set up would work great for war bird racers in the West coast. I thought about getting one to play around with, but haven't decide yet.

bob27s

My Feedback: (19)

The 60LX is the "40" size engine. Same case size as the 40, 46,50, and standard 60L engine

and the 90LX is the "60" size engine. Same case size as the .76, 1.00, 1.20 and the standard .90L

image on the flyer there is a 90LX.

Ive gotta find some time to fix some of the graphics

(there was a time when we were going to call these .61LX and 91LX just to accentuate the difference from the 'stock' version, but we decided otherwise)

This is a 90LX on the test bench.

Bob

jon_focal_plane

Bob,

I have the 60LX. I assume a break-in with a 9x6 richened up enough to keep it at about 18k is good, yes? Any problem with turning these non-pylon APC's at these RPM's?

Jonathan

bob27s

My Feedback: (19)

You can take the standard APC 9x6 to 18K rpm for break-in. Ive had them has high as 20K (not recommended by any means)

just be careful - stay out of the prop arc (as usual)

If you have an old 10x6, use that - cut it down about 1/2" on each tip - then balance it. Can even be wood, MAS, what ever. Its just something to hang on the front during break-in.

usually I prefer to cut down a bigger prop (as noted in another thread). The hub size and strength is usually better. After a while, one ends up with a handful of props with nicks and chips on the tips..... they are good candidates to become break-in or tach reference props .

My Q-500 break-in prop is an old 8.75x9W cut down to 8" diameter.