Question on Lag...Slick Magneto??

I took the magnetos off my Lycoming, to do the carbon brush/cam SB. My right mag was a Slick 4370, the left (impulse) mag a Slick 4281R. I decided then for purposes of keeping track of parts etc in the future that I wanted both mags to be the same model so I ordered a new left 4370 impulse mag from ACS.

On the data plate of the new 4370 mag, Lag is listed as 20, on the old 4281R mag, Lag is listed as 5.

What is Lag? and is there a problem that the old one was 5 and the new one is 20?

Thanks....

This might help...

Bushcaddy said:

I took the magnetos off my Lycoming, to do the carbon brush/cam SB. My right mag was a Slick 4370, the left (impulse) mag a Slick 4281R. I decided then for purposes of keeping track of parts etc in the future that I wanted both mags to be the same model so I ordered a new left 4370 impulse mag from ACS.

On the data plate of the new 4370 mag, Lag is listed as 20, on the old 4281R mag, Lag is listed as 5.

What is Lag? and is there a problem that the old one was 5 and the new one is 20?

Thanks....

Click to expand...

Lycoming has a SI that details the magnetos approved for each engine model number -

http://www.lycoming.com/support/publications/service-instructions/pdfs/SI1443F.pdf

They also have one giving replacement model numbers - SI 1374, but that one is not on line.

The applicable page is here -



I presume you are playing around with an O-235...

Engine is an O-235

Hi Gil and Seth,

The engine is an O-235 L2C. Seth I did get a model number 4371 mag, which is a left impulse. According to Gil's chart, it looks like I should have gotten a 4381. I bought the mag through ACS and they didn't offer other types other than 4370 or 4371, so I assume I have to return this mag and find a 4381 elsewhere??

Thanks....

Per the Lycoming SI 1443...

Bushcaddy said:

Hi Gil and Seth,

The engine is an O-235 L2C. Seth I did get a model number 4371 mag, which is a left impulse. According to Gil's chart, it looks like I should have gotten a 4381. I bought the mag through ACS and they didn't offer other types other than 4370 or 4371, so I assume I have to return this mag and find a 4381 elsewhere??

Thanks....

Click to expand...

...the Left mag. should be a 4372 or a 4381 for a O-235-L2C

AERO has them in stock...

http://www.aeroinstock.com/products/Magneto/5880/8271/product_detail/index.html

Newbie engine frustration - HELP!

I don't what it is with these engine sellers websites, but I swear it's as if they don't want to make sales, at least to anyone who doesn't have a PhD in aircraft engines or has already built two or three aircraft.

My starting point is I want a zero time, 180hp, fuel injected, horizontal induction, and CSU ready (which as far as I can make out is a XIO-360-M1B). I'd like electronic ignition too... but that's where the trouble starts.

I have no idea if electronic ignition is standard on the XIO's that Van's offers or if it is optional, or if it is only available on certain engines or who sells it, or what different electronic ignition systems exist and what the benefits are of each...

I also see that there are a bunch of other things not included with the engines bought from Vans "alternators, exhaust systems, vacuum pumps, governor, etc" as they vary with engine types - but if Vans can't provide pricing and options on these things, how am I meant to figure it out with some degree of confidence that I am not going to make some appalling and expensive mistake? I would assume that an alternator is required - so again, why isn't it listed as an option? I understand that exhausts should be fabricated to the aircraft and engine, so understood. But are there pre-made stainless exhausts available? Vacuum pumps? And so the questions go on....

I'm paying for the engine with the NZ peso (and shipping and local taxes add another 25%) so I want to keep the cost down as much as possible. I understand Van's pricing is very good, but even $26,500 for a basic, not everything included M1B is pushing my budget pretty hard with the QB and CSU. With Sun n Fun coming up, is there a different approach that might arrive at a more complete solution for similar $$$? Or is this as complete and as cheap as it gets?

Can anyone offer a very frustrated novice some basic advice? (even if it is to take a breath, go into low gear, and do the research, one step at a time...)

My O-235L2C has two 4381s. From what I understand (correct me if I'm wrong) the 5 degree lag mags are more appropriate for engines with fast turning starters

Identifying how old your mag is.

On a Slick mag. S/N the first 4 digits will tell you the MFG. date.
Example: Slick 4370 S/N 06040298
Spec:
Slick 4370
S/N 06040298
Manufacture Date: 04/2006
Lag: 0 Degrees
Left Rotation
Rev. C

Here's a good link from Aircraft Spruce on application. Section (4) http://www.aircraftspruce.com/catalog/pdf/L-1318G_Text.pdf

Thomas S.

chinch said:

Can anyone offer a very frustrated novice some basic advice? (even if it is to take a breath, go into low gear, and do the research, one step at a time...)

Click to expand...

Chris,
Your plan is to have fuel injection, horizontal induction, electronic ignition and a constant speed prop. This will add cost above the stock engine price with a fixed pitch prop. New engines include an alternator, a starter, and magnetos. Exhaust systems and baffling are always extra.

Van's sells engines assembled by Lycoming. They are certified or not certified and may or may not meet your needs. Certified engines can not be modified, they are what they are by certification spec. Vans non certified engines are what they are also because Vans is always trying to keep prices as low as possible.

Go to the Lycoming web site and investigate their experimental engine offerings to see if they provide what you want. The engine will not be available through Vans but it is available directly from Lycoming - or any of the other engine shops such as Barrett Precision Engines where my engine came from. Barrett and other such shops will build the engine exactly as you specify.

This process can be confusing but once you have decided what you MUST have, it will be less confusing and then you can focus on what it will cost and perhaps follow the KISS (keep it simple, stupid) rule to save money.

There is a fundamental premise in this business, if you want to save money keep the project simple. There are lots of guys flying RV's with a stock engine and a fixed pitch prop. Anyway you do it, flying an RV is the best thing you can do for your life as a pilot. Perhaps that enjoyment can be augmented with the extra goodies you think you need and want, but the difference between flying and not flying from one to the other is miniscule.

Any RV that flies is a delight. Don't get too consumed by options, in the end they won't make that much difference once the airplane is flying. You can always if upgrade later if more is essential. You've been thinking about an RV too long, it is time to do it!