cowl contact

210TC · Post by **210TC** » Thu Mar 20, 2008 7:24 am

Anyone,
Have you ever compared massive 4 tips to the standard 2 tip plug?
Many years ago I used the 4 tip plugs in a high compression engine. They worked great.
I have not used fine wire and may go that route. This is for the the TO360.
If I understand fowling correctly, the lead deposites form in the cold area of the plug (under the WIDE tip). The fine wire reduces this cool area substantially thus reducing fowling.
If this is correct a 4 tip would fowl more??
I have not read any tech stuff on plugs in many years.
If you have please add to this.
BTW: I have new untested 4 tips in the TO360.
Hijacked

a64pilot · Post by **a64pilot** » Thu Mar 20, 2008 8:23 am

All I can tell you is that so far in a high compression IO-540, the fine wires really make a difference. I really, honestly had to turn the idle down some. I am usually the guy that runs up the BS flag and call things snake oil. Now maybe my big single drive mag is weak and the fine wires work so well because I have a weak ignition to begin with, I don't know. It was overhauled by a Mag shop and has a new harness.
So far there is no electrode wear on the fine wires. I really think they will make it to TBO of the engine. Every 100 hours, I rotate them top to bottom, but I have not had to clean or re-gap them. I was warned against bead blasting them. Unfortunately with the single drive mag, you cannot apparently rotate your plugs from neg firing to pos firing so wear is more of an issue. Lean occurs about a 1/2 gallon less on the fuel flow meter now, so I burn less fuel. I have GAMI's and an engine analizer w fuel flow. The fine wires made more difference than the GAMI's, or maybe the GAMI's needed fine wires to make a difference, I don't know. Or maybe like I said maybe the fine wires are just covering up a weak ignition system, but for me I like em. It even runs smoother especially at idle, and so far I have not had a single rough mag check.

Kirk · Post by **Kirk** » Thu Mar 20, 2008 8:37 am

I'm glad to hear your results on the fine wire. My plugs are getting pretty worn down and will need replacing sometime soon, I asked a mechanic at an engine shop I was parked at what he thought of fine wires and he kind of blew them off. Saying the difference really doesn't show up except in high altitude flying aircraft.

Based on your experience, I might have to consider anything above 500 AGL to be high altitude. 1/2 gallon per hour would save me 50 gallons per year. So maybe fine wires don't really cost that much...

Kirk

a64pilot · Post by **a64pilot** » Thu Mar 20, 2008 9:10 am

If you want to go that route, try www.plugguy.com They found me mine at a very good savings. 10 were "used", but I looked real hard and could not see any wear. Or at Sun-N-Fun either Champion or Autolite were there and had a real good deal.
I would contact the people at plug guy. I got the feeling they could be trusted and would tell you if fine wires were justified in your engine or not.

UP-M5 · Post by **UP-M5** » Fri Mar 21, 2008 9:05 am

testimonial: we run fine wires in all of our beavers, and they go 200 hours between cleanings. i have never had an issue with a fouled plug in the 985's with fine wires.

enough said!

i put autolite fine wires in my 540 and haven't had a fouled plug since. the massives used to foul a bottom plug every 20 hours or so. i like 'em.

benflyn · Post by **benflyn** » Tue Apr 01, 2008 7:28 am

I see that autolite plugs are about half the price of champions??

Is there that big of difference in quality?

Performance wise are they the same?

Thanks

a64pilot · Post by **a64pilot** » Tue Apr 01, 2008 8:15 am

I've run Autolite and Champion massives and can tell no difference between them. I'm not sure about the Autolite fine wires, but I suspect there is no difference there either. I only went with the Champion fine wires because the Plug Guy got them for me cheaper than I could get a set of Autolites.
On edit: the Champion massives are painted and therefore rust. The Autolites are nickel plated and don't. The Champion fine wires are painted gold, so I assume they will rust too.

Mr. Ed · Post by **Mr. Ed** » Tue Apr 01, 2008 10:22 am

Back to the cowl contact problem. The contact has been occuring since before I owned the airplane. I noticed paint missing on the front of the starter and a smooth spot on the cowl when I inspected the plane prior to purchase. I knew it was something I would have to play with at some point. I checked the lord mounts and engine mount and I don't seem to have a problem there.

I currently have the lower cowl in my shop. Repaired the starter contact point as well as several other prior booboos. I just finnished putting the last coat of paint on the repairs and am waiting for it to dry before buffing it out. I'll reinstall after putting on some teflon tape per Wayne's suggestion.

Dang, missing a nice day to fly with the plane in the shop.

Thanks for the suggestions/tips folks.

maules.com · Post by **maules.com** » Tue Apr 01, 2008 10:47 pm

Problem is the initial mounting of the cowl at the factory.
The lower cowl was mounted too far back because that was easiest for the fellow who used to do it. Then the top cowl had to go too far back and was trimmed too low along the sides, at front.
Best to leave the starter hole open to stop a repeat, or to change to a lightweight and faster starter. The cowl is ridgid to the airframe, while the engine rotates on its mounts and raises up slightly.
Cut the air ingress aluminium box back a half inch or so, thus the cowl does not contact it or you will have a chain of breakages that starts with the airbox, the oilcooler flange, and the Y bracket if it is an O540. IO540 does not have this contact.
The teflon idea works for a short while but you will still have ridgid/moving contact.

a64pilot · Post by **a64pilot** » Wed Apr 02, 2008 5:27 am

Or, remove a little of thine offending part with a grinder

I can't afford a lightweight starter, would be nice though.

cowl contact

fine wire plugs

cowl

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