X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 21 Oct 2013 07:39:46 -0400 Message-ID: X-Original-Return-Path: Received: from nm16-vm6.bullet.mail.ne1.yahoo.com ([98.138.91.109] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6547519 for lml@lancaironline.net; Sat, 19 Oct 2013 19:36:12 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.91.109; envelope-from=n20087@yahoo.com Received: from [98.138.90.57] by nm16.bullet.mail.ne1.yahoo.com with NNFMP; 19 Oct 2013 23:35:38 -0000 Received: from [98.138.84.40] by tm10.bullet.mail.ne1.yahoo.com with NNFMP; 19 Oct 2013 23:35:38 -0000 Received: from [127.0.0.1] by smtp108.mail.ne1.yahoo.com with NNFMP; 19 Oct 2013 23:35:38 -0000 X-Yahoo-Newman-Id: 453778.34858.bm@smtp108.mail.ne1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: WoaKBo8VM1kyquMlnOfcGti42p_2suuHvv2cXIB0rMnpFLm xxAgwbWxr3SrD9OvWvjHqOdKk9WmRYISyrsMp_8pzFvshyMFaqTRqlr89Ci1 qu4HfWuvvSPwCNnDwZ8TdIlgxjedZIoeRVbQ_BgfyltzxUrQKLe9UzgutoGs HndgNOkSXImgWS1_MuJgZ6D3bKKK5lYxjLHvlGDW9piU_AW0yREwvoWce6.j F8LpOC50U7IedPf3jbmfExgCkZ0izSsYpdIsWX0M6mj5DLndt3SlBNfE6UrM ptEyAnFLpDnQkLPBjjv.NVv7LwX2lOYVeo11dfGJ8Hl31lIN03XgJPFaZK2b EZXKzPLxdaRc3NsJ7GQFh8OTsbDXhR9sy4s9Am7rOzTEl7CwZ._go1ftw4jY P7l.Nwivr195m.NA7thU30MfU7hnkQqkH72Vk.nkn12bXLU_MxahdTd.OZ1Z fb9DAxD5M8hrf9Q5A4r3xYDZGFJ8x_d6oOZ3I5ROr9ynYasclHhlU2DFDgJQ LRRE6UDdi0lwH4XLTVqNSPjCOiqI6XEkIxfvwD2kn4h74lnrSJM7w.GY- X-Yahoo-SMTP: NQQt3c2swBAKSrExoA1eZuT7_w-- X-Rocket-Received: from [10.152.230.106] (n20087@198.228.225.239 with ) by smtp108.mail.ne1.yahoo.com with SMTP; 19 Oct 2013 16:35:38 -0700 PDT Subject: Mag timing io360 References: From: Tom Content-Type: multipart/alternative; boundary=Apple-Mail-F3F8C615-58B9-41DD-98A2-EA05F75974FB X-Mailer: iPad Mail (11A465) In-Reply-To: X-Original-Message-Id: <712BED03-4BEC-4018-8F2C-D2C0A9C72142@yahoo.com> X-Original-Date: Sat, 19 Oct 2013 19:35:31 -0400 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-F3F8C615-58B9-41DD-98A2-EA05F75974FB Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable > Folks, I am considering adjusting my mag timing in order to lower my chts. My engi= ne is an io360 exp with a name plate stamped at 25 degrees. My eci flywheel= is only marked at TC and 25 degrees but I figure each tooth is worth 2.5 de= grees. The slick mags are 4373 and 4370 both marked at 25 degrees lag There was a lycoming service instruction back in the mid 70s si1325a that ad= vocated backing timing off to 20 degrees to improve CHTs. =20 I have three questions for the group.=20 1. Anybody running 20 degrees advance after changing from 25 degrees? Worth t= he effort on CHT? 2. Anybody running 20 degrees on this engine type and chts running in the 38= 0 max range? 3. If I move my timing down to 22 or so and leave the magneto lag on the imp= ulse magneto alone would there be any adverse effects other than lower power= and maybe a little more difficulty starting? The si stated that the lag should be adjusted to 15 degrees for better start= s Thanks in advance=20 Tom Lnc2 285 hrs Service Instruction No. 1325A=20 (Supersedes Service Instruction No. 1325)=20 Engineering Aspects are=20 FAA (DEER) Approved=20 DATE: May 14, 1976=20 SUBJECT:=20 MODELS AFFECTED:=20 TIME OF COMPLIANCE:=20 Timing Change for IO-360 Series Engines=20 IO-360-A series (not -A1B6D), -C, -D series, HIO-360-C1A, -C1B, AEIO-=20 360-A1B6 with serial numbers prior to 14435-51; IO-360-C1D6 with=20 serial numbers prior to 14445-51, LIO-360-C1E6 with serial numbers=20 prior to 1063-67 and AIO-360-A1A, -A1B, -B1B with serial numbers prior=20 to 219-63; TIO-360-A1B with serial numbers prior to 145-64. See=20 Service Bulletin No. 380 for IO-360-C1C and -C1F models.=20 At overhaul or at owner's discretion.=20 Certain advantages in engine operation have=20 been found by changing engine timing from 25=C2=B0=20 BTC to 20 BTC and reducing the lag angle to=20 15=C2=B0 on impulse coupling magnetos and 15=20 retard angle on retard breaker magnetos whi-chever=20 is applicable. Significant improve-ments=20 in engine operating characteristics are=20 achieved in above listed aircraft engine=20 installations particularly in the areas of=20 normal operation and cold weather starting.=20 During cruise operation, cooler cylinder head=20 temperatures can be expected resulting in=20 improved service life of intake and exhaust=20 valves. During full throttle operation the=20 new spark setting will reduce possibility of=20 detonation during extreme cold weather opera-tion.=20 Consequently this modification has been=20 incorporated in the production of new engines=20 and may be incorporated in engines in service=20 as follows:=20 1. Remove the left magneto and determine if=20 it has an impulse coupling or if it is a=20 retard breaker magneto; if it is a retard=20 breaker magneto it cannot be converted to=20 the 15 retard angle. However, a Bendix=20 blue magneto which incorporates a 15 re-tard=20 angle is available through Avco Ly-coming=20 distributors. See "Parts Data" be-low.=20 Install the replacement magneto as=20 described in step 3.=20 2. If the left magneto has an impulse=20 coupling, replace the coupling with a new=20 one, LW-391429 on all models except reverse=20 rotation engines; on these use impulse=20 coupling LW-391427.=20 3. Install the magneto on the engine and=20 retime both magnetos using the 20 timing=20 mark on the starter ring gear instead of=20 the 25 mark. See Avco Lycoming Operator's=20 Manual 60297-12 for ignition timing proce-dure.=20 4. Replace the engine nameplate with a new=20 one, Avco Lycoming P/N 61548 which indi-cates=20 new timing angle. Also restamp the=20 magneto nameplate to indicate the magneto=20 is -9, -10 or -55 instead of -3, -6 or -45.=20 PARTS DATA:=20 15 Lag Angle=20 Magneto=20 LW-349365-9=20 LW-349365-10=20 LW-51360-55=20 Replaces=20 Magneto=20 LW-349365-3=20 Magneto=20 Model Engine Application=20 S4LN-1227 IO-360-A1B,-A1B6,-C1C,-C1F,-C1D 6, -C1E6, AIO-360-A1A,=20 -A1B, -B1B, AEIO-360-A1B6=20 LW-349365-6 S4RN-1227 LIO-360-C1E6=20 LW-51360-45 S4LN-21 IO-360-A1D PARTS DATA (CONT.):=20 15=C2=B0 Retard Angle=20 Magneto=20 LW-349285-7=20 LW-349285-8=20 LW-163005-11=20 LW-163005-12=20 Replaces=20 Magneto=20 LW-349285-1=20 LW-163005-2=20 Magneto=20 Model=20 S4LN-1208=20 S4RN-1208=20 S4LN-200=20 S4RN-200=20 Engine Application=20 IO-360-A1C, -C1C, -D1A; HIO-360-C1B; AIO-360-=20 A1A; TIO-360-A1B=20 LHIO-360 C1B=20 IO-360-AlA, -A2A, -C1A; HIO-360-ClA; AEIO-360-=20 A1A=20 LHIO-360-C1A=20 LW-391429=20 LW-391427=20 61548=20 18484, 18485 -=20 Impulse coupling, 15=C2=B0 lag angle (replaces LW-349359)=20 Impulse coupling, 15 lag angle (replaces LW-349358 for magnetos on reverse r= o-tation=20 engines)=20 Engine nameplate (replaces nameplate with 25=C2=B0 BTC timing specified). Se= e Ser-vice=20 Instruction No. 1304 for procurement procedure.=20 These numbers for Avco Lycoming reference only. --Apple-Mail-F3F8C615-58B9-41DD-98A2-EA05F75974FB Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Folks,

I am considering adjus= ting my mag timing in order to lower my chts.  My engine is an io360 ex= p with a name plate stamped at 25 degrees.  My eci flywheel is only mar= ked at TC and 25 degrees but I figure each tooth is worth 2.5 degrees.  = ;The slick mags are 4373 and 4370 both marked at 25 degrees lag

There was a lycoming service instruction back in the mi= d 70s si1325a that advocated backing timing off to 20 degrees to improve CHT= s.  

I have three questions for the gr= oup. 

1. Anybody running 20 degrees ad= vance after changing from 25 degrees? Worth the effort on CHT?
2. Anybody running 20 degrees on this= engine type and chts running in the 380 max range?
3. If I move my timing down to 22 or so and leav= e the magneto lag on the impulse magneto alone would there be any adverse ef= fects other than lower power and maybe a little more difficulty starting?

The si stated that the lag should be adjusted= to 15 degrees for better starts

Thanks in a= dvance 

<= div style=3D"-webkit-text-size-adjust: auto;">Tom

Lnc2 285 hrs

<= /div>

Service Inst= ruction No. 1325A 
(Supersedes Service Instruction No. 1325) Engineering Aspects are 
FAA (DEER) Approved 
DATE: May 14= , 1976 
SUBJECT: 
MODELS AFFECTED: 
TIME OF COMPLIAN= CE: 
Timing Change for IO-360 Series Engines 
IO-360-A serie= s (not -A1B6D), -C, -D series, HIO-360-C1A, -C1B, AEIO- 
360-A1B6 wi= th serial numbers prior to 14435-51; IO-360-C1D6 with 
serial number= s prior to 14445-51, LIO-360-C1E6 with serial numbers 
prior to 1063= -67 and AIO-360-A1A, -A1B, -B1B with serial numbers prior 
to 219-63= ; TIO-360-A1B with serial numbers prior to 145-64. See 
Service Bull= etin No. 380 for IO-360-C1C and -C1F models. 
At overhaul or at owne= r's discretion. 
Certain advantages in engine operation have been found by changing engine timing from 25=C2=B0 
BTC to 20 BTC a= nd reducing the lag angle to 
15=C2=B0 on impulse coupling magnetos a= nd 15 
retard angle on retard breaker magnetos whi-chever 
i= s applicable. Significant improve-ments 
in engine operating charact= eristics are 
achieved in above listed aircraft engine 
inst= allations particularly in the areas of 
normal operation and cold we= ather starting. 
During cruise operation, cooler cylinder head =
temperatures can be expected resulting in 
improved service life= of intake and exhaust 
valves. During full throttle operation the&n= bsp;
new spark setting will reduce possibility of 
detonation dur= ing extreme cold weather opera-tion. 
Consequently this modification= has been 
incorporated in the production of new engines 
an= d may be incorporated in engines in service 
as follows: 
1.= Remove the left magneto and determine if 
it has an impulse couplin= g or if it is a 
retard breaker magneto; if it is a retard 
= breaker magneto it cannot be converted to 
the 15 retard angle. Howe= ver, a Bendix 
blue magneto which incorporates a 15 re-tard angle is available through Avco Ly-coming 
distributors. See "Parts= Data" be-low. 
Install the replacement magneto as 
describe= d in step 3. 
2. If the left magneto has an impulse 
couplin= g, replace the coupling with a new 
one, LW-391429 on all models exc= ept reverse 
rotation engines; on these use impulse 
couplin= g LW-391427. 
3. Install the magneto on the engine and 
reti= me both magnetos using the 20 timing 
mark on the starter ring gear i= nstead of 
the 25 mark. See Avco Lycoming Operator's 
Manual= 60297-12 for ignition timing proce-dure. 
4. Replace the engine nam= eplate with a new 
one, Avco Lycoming P/N 61548 which indi-cates&nbs= p;
new timing angle. Also restamp the 
magneto nameplate to indic= ate the magneto 
is -9, -10 or -55 instead of -3, -6 or -45. PARTS DATA: 
15 Lag Angle 
Magneto 
LW-349365-9&nb= sp;
LW-349365-10 
LW-51360-55 
Replaces 
Magneto&= nbsp;
LW-349365-3 
Magneto 
Model Engine Application = ;
S4LN-1227 IO-360-A1B,-A1B6,-C1C,-C1F,-C1D 6, -C1E6, AIO-360-A1A, <= br>-A1B, -B1B, AEIO-360-A1B6 
LW-349365-6 S4RN-1227 LIO-360-C1E6&nbs= p;
LW-51360-45 S4LN-21 IO-360-A1D


PARTS DATA (CONT.): <= br>15=C2=B0 Retard Angle 
Magneto 
LW-349285-7 
LW-3= 49285-8 
LW-163005-11 
LW-163005-12 
Replaces <= br>Magneto 
LW-349285-1 
LW-163005-2 
Magneto <= br>Model 
S4LN-1208 
S4RN-1208 
S4LN-200 
S4= RN-200 
Engine Application 
IO-360-A1C, -C1C, -D1A; HIO-360-= C1B; AIO-360- 
A1A; TIO-360-A1B 
LHIO-360 C1B 
IO-36= 0-AlA, -A2A, -C1A; HIO-360-ClA; AEIO-360- 
A1A 
LHIO-360-C1A=  
LW-391429 
LW-391427 
61548 
18484, 18485 -=  
Impulse coupling, 15=C2=B0 lag angle (replaces LW-349359) Impulse coupling, 15 lag angle (replaces LW-349358 for magnetos on reverse r= o-tation 
engines) 
Engine nameplate (replaces nameplate wit= h 25=C2=B0 BTC timing specified). See Ser-vice 
Instruction No. 1304= for procurement procedure. 
These numbers for Avco Lycoming referen= ce only.


=


= --Apple-Mail-F3F8C615-58B9-41DD-98A2-EA05F75974FB--