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PostPosted: Sat Nov 15, 2008 9:31 am
by Shannon
Hi Pete,

Welcome. Yes, personally I like wheelpants also. Don't see any way to get around cutting the fabric to install (factory method) the compression tube motor mounts. As for the P-tips I've heard of no failures with small cranks and a number of guys are currently using them. The wood P-tips weigh several ounces less than the stacked Bi-props and turn an approx 800+/- rpm slower. Personally I'd be looking to add the J-struts. Very little weight gain for a huge increase in strength. The doubled outer wing attach fittings definitely give piece of mind. Could you get along without J-struts...absolutely !
http://www.lazair.com/files/Lazair%20Jury%...izer%20kit1.pdf
http://lazair.com/forum/index.php?showt ... ury+struts
The CDI is definitely something to look at. I plan to try them out myself. From the reliability standpoint they make perfect sense as the point ignition can be really problematic. I've yet to be convinced however that there is any real performance increase with the CDI. A few reports from people on their CDI conversion contained mention of "carb adjustments" that were not in line with the normal long-established tuning process.

Pic: Same engine being tested with a Carbon P-tip. RPMs 5140

PostPosted: Sat Nov 15, 2008 1:48 pm
by JPXman
Hi Peter

Cutting into the tedlar to do the long bolt modification is a no brainer. As long as you have some tedlar tape to "sew" it back up again. If you don't have any on hand let me know, i can spare a few feet to allow you to do this great modification.

If you're going to be letting it sit for the winter and give it a "rejouvenation" then I would definitely consider the long bolt mod as one of the things to do. Jury struts are good as well if you plan on leaving your bird outside at all or flying in rough conditions, as most negative loads come from snow on the wings on a lazair - not too many lazair heads pushing -2 or -3G that i know of - and turbulence causes negative loads.

doubled outer strut attach fitting - YES

P-tips and cranks - no idea, however as Shannon says it does slow the engine down which means the prop is torquing the engine harder, but the slower the 185 turns the less HP it develops and so the less torque it delivers and on and on....

where is your lazair going to be based?

Tyler
Edmonton

PostPosted: Sun Nov 16, 2008 10:01 am
by peter
Hi Tyler....I appreciate your help....this plane has fabric, stits I think, and I'm unsure as how to go about opening it up...I wonder about a V on either side of the rib top and bottom or an L type incision....and then how do I repair the fabric? I've had no experience with fabric repair.....I read just recently about someone doing the long bolt mod, but I haven't been able to locate it again to study it further but I'll keep looking......The doubler and J strut mods make good sense but my priorities are make sure the engines are reliable.....rebuild the carbs,new plugs, maybe new points and condensers.....I'm going to have to replace the rubber mounts also ...a couple of the top ones are showing some cracks.....does Shorty still have some on hand?.....I know the guys with P tip props swear by them, and I know last summer at the Big Bay lazair get together Dale George had to throttle back so Lyn and I could keep up.....anyways, gotta quit talkin and just do it....
My farm is in south western Ont. on the western edge of Harriston, about 50 road miles south of Owen Sound........I have a 1200 foot nw by se strip in a hay field but no hanger yet...I put a platform on an old boat trailer and am able to pull the plane to the barn to store it when the weather turns bad .....works not too bad.
We got about 5in of wet snow last nite. so I've got a bit of time to get my act together.
I ramble on Thanks Pete

PostPosted: Sun Nov 16, 2008 9:29 pm
by peter
Hi Tyler.....I found your decription of how you did your long bolt mod in rebuilding tips from back in '06 I think ....explaines things pretty well....thanks guy......
Pete

PostPosted: Sun Nov 16, 2008 9:55 pm
by Shannon
Long Bolt Mod 1

PostPosted: Sun Nov 16, 2008 9:56 pm
by Shannon
Mod 2

PostPosted: Sun Nov 16, 2008 9:57 pm
by Shannon
Mod 3

PostPosted: Sun Nov 16, 2008 9:58 pm
by Shannon
Mod 4

PostPosted: Sun Nov 16, 2008 9:59 pm
by Shannon
Mod 5

PostPosted: Sun Nov 16, 2008 10:09 pm
by Shannon
Mod 6