Timing Lights & ignition timing

[Peter Pleitner]

Hi Skip, I agree, that's what I've been doing. However, one caveat should be in the back of everyone's mind. This technique assumes the distributor (dizzy) works like new. A while back Chip Old supplied to us advance curves. A timing light with dial-in advance is handy to check this. However I used a distributor machine, and "fettled" my distributor on the bench. Problem I encountered is replacement advance springs are wrong. Any good source for these? The two springs are not supposed to be the same. But that was how they were supplied by either Moss or Abingdon 15 years ago. So some dizzys out there may not perform to specification. For these reasons, and my experience with Italian engines, has re-booted my thinking on static timing. Ignition timing is most important at high rpm where the engine is working hardest and consuming the most fuel. If the distributor's advance behavior is not known exactly, I now believe the best course of action (not necessarily safest) is to set the advance on XPAG engines for 30 degrees BTDC at 4500 to 5000 rpm, then see if behavior at idle and on acceleration is acceptable. If the distributor is a 40367 from a late TD MK 2 or a TF, 24 degrees BTDC is correct. This procedure is dangerous, so make certain your working condition is safe and exposure to injury (like flying fan blade) is minimized. Thoughts and comments welcome. Cheers, Peter -----Original Message----- From: Skip Kelsey [mailto:kelsey@shadetreemotors.com] Sent: Thursday, January 03, 2002 7:44 PM To: Tombutlercpa@cs.com; anngene@bellsouth.net; mg-tabc@yahoogroups.com Subject: Re: [mg-tabc] Timing Lights At 06:40 PM 1/3/02 -0500, Tombutlercpa@cs.com wrote:

>I believe the correct dynamic timing setting is 5 degrees advanced at 1000 >rpm. There is a chart available which shows the timing curve for the TC.

Tom: Set your timing at approx. 5 degrees advanced statically. Dont rely on a timing light. You will be very retarded at 1000 RPM/5 degrees. Use a statice light or buzzer to set this. Trust me on this one. Skip Kelsey............................................... Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

[Skip Kelsey]

At 10:06 AM 1/4/02 -0500, Peter Pleitner wrote:

>advance on XPAG >engines for 30 degrees BTDC at 4500 to 5000 rpm, then see if behavior at

Peter: Depending on the general state of tune, I use 27 degrees on highly tuned,stage 3-4 engines. To this I add about 5 degrees statically. I set for full advance at approx 3000 RPM. On stock engines, I use about 32-34 degrees, again at about 3000RPM. I also add approx 5 degrees statically. I have been using this for over 40 years with good success. I currently am running an old Long neck Mallory dual point distributor, and my engine runs at approx. 9.5 compression ratio. I had the dist. re profiled by Mallory several years ago, to the present specs. The engine puts out very good power, but my 1 1/5 in. SUs require EL needles to get the most out of the tune. I once tried the stock TF needles (GJ), but started burning valves. I talked to "Gerry Brown" in England, and he said to use the EL needles. Part of the problem is that I also use a Derrington extractor manifold , which is very efficient , and that coupled with the fact that the head is completly ported and polished, requires more fuel to perform. Skip...................................................... Skip........................................................

[Davidtasa@aol.com]

Hi Skip, I agree, that's what I've been doing. However, one caveat should be in the back of everyone's mind. This technique assumes the distributor (dizzy) works like new. A while back Chip Old supplied to us advance curves. A timing light with dial-in advance is handy to check this. However I used a distributor machine, and "fettled" my distributor on the bench. Problem I encountered is replacement advance springs are wrong. Any good source for these? The two springs are not supposed to be the same. But that was how they were supplied by either Moss or Abingdon 15 years ago. So some dizzys out there may not perform to specification. For these reasons, and my experience with Italian engines, has re-booted my thinking on static timing. Ignition timing is most important at high rpm where the engine is working hardest and consuming the most fuel. If the distributor's advance behavior is not known exactly, I now believe the best course of action (not necessarily safest) is to set the advance on XPAG engines for 30 degrees BTDC at 4500 to 5000 rpm, then see if behavior at idle and on acceleration is acceptable. If the distributor is a 40367 from a late TD MK 2 or a TF, 24 degrees BTDC is correct. This procedure is dangerous, so make certain your working condition is safe and exposure to injury (like flying fan blade) is minimized. Thoughts and comments welcome. Cheers, Peter

[Robert Grunau]

HI Skip, I am a bit confused by your "27 degrees on highly tuned engines , to this I add about 5 degrees statically",. Do you mean 27 degrees TOTAL advance, with 5 degree static setting, ie using an 11 degree advance distribitor plate for highly tuned engines or do you mean 27+5 = 32 degrees total advance? Also on stock engines your "32-34 degrees, I also add about 5 degrees statically" Does this mean TOTAL advance of 32-34 degrees with a 5 degree static setting using a 14 degree distributor plate or do you mean 32-34 degrees + 5 degrees = 37=39 degrees total advance? I use 32 degrees total advance on my race TC and set it with a timing light at 3500/4000 rpm. Therefore the static setting is not a consideration except for starting ). Regards, Bob Grunau Depending on the general state of tune, I use 27 degrees on highly tuned,stage 3-4 engines. To this I add about 5 degrees statically. I set for full advance at approx 3000 RPM. On stock engines, I use about 32-34 degrees, again at about 3000RPM. I also add approx 5 degrees statically. I have been using this for over 40 years with good success. I currently am running an old Long neck Mallory dual point distributor, and my engine runs at approx. 9.5 compression ratio. I had the dist. re profiled by Mallory several years ago, to the present specs. The engine puts out very good power, but my 1 1/5 in. SUs require EL needles to get the most out of the tune. I once tried the stock TF needles (GJ), but started burning valves. I talked to "Gerry Brown" in England, and he said to use the EL needles. Part of the problem is that I also use a Derrington extractor manifold , which is very efficient , and that coupled with the fact that the head is completly ported and polished, requires more fuel to perform. Skip...................................................... --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.313 / Virus Database: 174 - Release Date: 1/2/02

[Skip Kelsey]

At 11:31 AM 1/7/02 -0400, Robert Grunau wrote:

>I am a bit confused by your "27 degrees on highly tuned engines , to this I >add about 5 degrees statically",. Do you mean 27 degrees TOTAL advance, with

Bob: I do mean that on the original 27 degrees or 32 degrees, I add about five degrees statically. This is for starters. Then I use a timing light and check the total advance at the 3000-4000 mark. This can be varied depending on the engine tune otherwise. I also have had very good luck with this approach for the past 42 years. All of the engines that I have approached this way run very well. Skip........................................................................

[Mark McCombs]

----- Original Message ----- From: "Skip Kelsey" kelsey@shadetreemotors.com> > I also have had very good luck with this approach for the past 42 years. All of the > Skip........................................................................ So Skip, you started this MG stuff at age 4, the young man that you are... Regards Mark TC8126

[Skip Kelsey]

At 03:27 PM 1/7/02 -0500, Mark McCombs wrote:

>So Skip, you started this MG stuff at age 4, the young man that you are...

Mark: You are very kind. I was born right at the end of prohibition!!!!!!!! Skip.................................................

[Ray]

Not so! I heard that he was a student pilot with Orville and Wilbur......... Best, Ray -----

> At 03:27 PM 1/7/02 -0500, Mark McCombs wrote: > >So Skip, you started this MG stuff at age 4, the young man that you

are...

> > > Mark: > > You are very kind. I was born right at the end of prohibition!!!!!!!! > > > > Skip................................................. > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > >

[R. Zwart]

END OF WHAT PROHIBITION?????? I was prohibited from slamming the door, drinking out of the faucet, chewing with my mouth open, not wiping my feet, etc, etc, ad infinitum........ AND I STILL AM! Of course then came the wild and woolly 1930's and 40's... I tell you TV and radio have sure lowered our values and our abilities since then BOB. Skip Kelsey wrote:

At 03:27 PM 1/7/02 -0500, Mark McCombs wrote: >So Skip, you started this MG stuff at age 4, the young man that you are...

Mark:

You are very kind. I was born right at the end of prohibition!!!!!!!!

Skip.................................................

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

[Skip Kelsey]

At 05:30 PM 1/7/02 -0600, Ray wrote:

>Not so! I heard that he was a student pilot with Orville and >Wilbur......... >Best, >Ray >Ray:

Thats correct, Soloed off of the Langley!!!! Skip.................

>----- > > > > At 03:27 PM 1/7/02 -0500, Mark McCombs wrote: > > >So Skip, you started this MG stuff at age 4, the young man that you >are... > > > > > > Mark: > > > > You are very kind. I was born right at the end of prohibition!!!!!!!! > > > > > > > > Skip................................................. > > > > > > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > > >