I have a 1971 Series 2, which has the emmissions set up with the
dual Strombergs. The distributor has the vacuum retard. The stock
set up is to set static timing at 5 degrees BTDC. At 1000rpm with
no vacuum retard the timing should be 10 degrees BTDC. At 1200 rpm
advance is 13 to 17, 1600 rpm 22 to 26 , 2900 rpm 29 to 33 and 4400
rpm 37 to 41. The distributor weights are marked 16 degrees hence
I would think full advance would be (16 x2) + 5 degrees static = 37
degrees. This seems to agree with the 37 to 41 but not sure how it
would get to 41.
Anyway, I�m going to have the distributor (Lucas 22D6) overhauled
and am contemplating two approaches. My intent, based on what
numerous listers have had to say, is to not connect the vacuum
retard. This would create a situation with centrifugal advance
only.
Option 1 is to go stock because it would be easy to return to a
stock situation simply by reconnecting the vacuum retard. In this
case, based on the built in max centrifugal advance of (16x2) what
would be the appropriate static? My concern is that there is too
much advance and perhaps this set up is too much of a compromise.
Would be very interested in comments from listers with the vacuum
retard setup who are running with the vac retard disconnected.
Option 2 is to have the max advance and the curve modified to be
the same as was used when the jag was set up for performance and
not emission. I believe it was a max centrifugal advance of (2x13)
or 26 degrees and used with a static advance of 10 degrees giving a
max of 36 degrees. I�m not sure at what RPM the max advance occurs
but I think it is more like 3000 to 3500 rpm. Does anyone know
what is appropriate advance spec if there�s no vac advance?
Given that I have antique plates and do not have to meet emission
tests and am not overly concerned with gas mileage I am leaning in
the direction of doing what will have the car idle and drive the
best.
Dick V. hopefully you found a direct e-mail from me requesting a
shipping address.
Ray Mikula
Libertyville, Illinois, USA
1971 Series 2 FHC
RMikula@sbcglobal.net–
RJJM
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from RJJM sent Thu 19 Jan 2006:
Ray -
FYI - you can buy rebuilt distributors from SNG Barrett for around
$200. I think they would have the original 3.8/4.2 curve and the
vacuum advance. You’d have to check the specs with them to be sure.
Another option is a Mallory Unilite, with or w/o vac.adv. The
mechanical adv. is adjustable. If you like to tinker you can get
max performance by getting the advance in as early as possible.
$400+/-.
I’ll probably do that after I finish with my SU’s.
I’m currently using my stock 69 dist. whose mechanical advance is
the same curve as yours. Mine has no vacuum retard. I would imagine
you could unhook that device w/no ill effect. I run 10-12 deg.
static and with that ‘‘slow’’ advance curve, no pinging.
The coventional wisdom is that the Lucas mechanical advance is
prone to sticking. I took mine all apart last year, cleaned &
lubed. The weights ride metal to metal on the plate, so add a
little dirt…I could see how it might be improved upon.
Dave–
1969 BRG OTS
Skaneateles, NY, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Isn’t Dick Vandermayden rebuilding these things too?
pauls 67ots
In reply to a message from RJJM sent Thu 19 Jan 2006:
Ray -
FYI - you can buy rebuilt distributors from SNG Barrett for around
$200. I think they would have the original 3.8/4.2 curve and the
vacuum advance. You’d have to check the specs with them to be sure.
Another option is a Mallory Unilite, with or w/o vac.adv. The
mechanical adv. is adjustable. If you like to tinker you can get
max performance by getting the advance in as early as possible.
$400+/-.
I’ll probably do that after I finish with my SU’s.
I’m currently using my stock 69 dist. whose mechanical advance is
the same curve as yours. Mine has no vacuum retard. I would imagine
you could unhook that device w/no ill effect. I run 10-12 deg.
static and with that ‘‘slow’’ advance curve, no pinging.
The coventional wisdom is that the Lucas mechanical advance is
prone to sticking. I took mine all apart last year, cleaned &
lubed. The weights ride metal to metal on the plate, so add a
little dirt…I could see how it might be improved upon.
Paul,
I believe he is, but he is out of the country currently.
I think he said he would be out for about 2-3 weeks.
Thanks
Bill
paul spurlock wrote:
Isn’t Dick Vandermayden rebuilding these things too?
pauls 67ots
From: “David Ahlers” david.ahlers@brp.com
Subject: Re: [E-Type] Info and opinions late Series 2 Distributor Refurb
In reply to a message from RJJM sent Thu 19 Jan 2006:
Ray -
FYI - you can buy rebuilt distributors from SNG Barrett for around $200.
I think they would have the original 3.8/4.2 curve and the vacuum
advance. You’d have to check the specs with them to be sure.
Another option is a Mallory Unilite, with or w/o vac.adv. The mechanical
adv. is adjustable. If you like to tinker you can get max performance by
getting the advance in as early as possible. $400+/-.
I’ll probably do that after I finish with my SU’s.
I’m currently using my stock 69 dist. whose mechanical advance is the
same curve as yours. Mine has no vacuum retard. I would imagine you
could unhook that device w/no ill effect. I run 10-12 deg. static and
with that ‘‘slow’’ advance curve, no pinging.
The coventional wisdom is that the Lucas mechanical advance is prone to
sticking. I took mine all apart last year, cleaned & lubed. The weights
ride metal to metal on the plate, so add a little dirt…I could see how
it might be improved upon.
In reply to a message from RJJM sent Thu 19 Jan 2006:
Ray,
The data you quote comes from the information Jaguar
published in their owner’s manuals and is not correct for
your car. Apparently Jaguar was not interested in
documenting the SII cars correctly as they considered them a
stop-gap or something. The numbers you quote appear to be
for a ‘69 N.A. car which had no vacuum unit at all. However
Jagaur did publish technical service bulletins for the SII
and one of them was specifically for the 1970 North American
specification EX/EM cars. It is the only place I have found
that covers the vacuum retard distributor, the B1AR metering
needles, the carbon canister, fuel tank overflow, heated air
crossover, quiet camshafts (.012’’ clearance), etc.
This technical service bulletin calls for the timing to be
set at 10 deg. BTDC static and 0 deg. at idle (750 manual,
650 auto). This means that the vacuum unit provides 10 deg.
retard at idle. When the throttle opens the vacuum drops off
quickly and only the advance springs are in play. The
advance readings from that point should be:
1400 RPM = 6 to 10 deg.
1800 RPM = 14 to 18 deg.
3000 RPM = 18 to 22 deg.
4000 RPM = 23 to 27 deg.
Disconnecting (and plugging!) the vacuum retard won’t make
much difference since it is only intended to cut in at idle.
So you might as well leave it attached (but make sure the
retard unit is working – otherwise you will have a vacuum
leak into your front carb!). Changing the timing without
changing the needles will probably mess up the performance
since the B1AR carb needles are tuned to this distributor
advance curve. Same is true with getting a differnt distributor.
If you change to SU’s somewhere down the line you will want
to change your distributor (or at least the advance weights)
to the S1 or European 4.2 specification.
Richard Liggitt–
The original message included these comments:
I have a 1971 Series 2, which has the emmissions set up with the
dual Strombergs. The distributor has the vacuum retard. The stock
set up is to set static timing at 5 degrees BTDC. At 1000rpm with
no vacuum retard the timing should be 10 degrees BTDC. At 1200 rpm
advance is 13 to 17, 1600 rpm 22 to 26 , 2900 rpm 29 to 33 and 4400
rpm 37 to 41. The distributor weights are marked 16 degrees hence
I would think full advance would be (16 x2) + 5 degrees static = 37
degrees. This seems to agree with the 37 to 41 but not sure how it
would get to 41.
In reply to a message from Richard L. sent Thu 19 Jan 2006:
Richard,
Thank you for the thoughtful and detailed response and thanks to
the other lsiters that have chimed in.
The emission sticker on the car does say 10 degrees BTDC at idle
(750 manual) with vacuum retard disconnected. For some reason I
got it in my head that the static timing was 5 degrees BTDC. I
suppose if one sets up the timing to be 10 degrees BTDC at 750 rpm
with vacuum disconnected the static will be whatever it is going to
be.
Where I’m a bit confused is with the max advance. Since the
weights are stamped 16 I thought I would have (2x16) or 32 degrees
plus the static advance i.e. 42 degrees BTDC at 4000 or so RPM.
Even without the static being added in it would seem like the max
advance would be at least the 32 degrees vs the 23 to 27 at 4000
RPM. I believe but don’t understand.
Ray Mikula
1971 Series 2 FHC
Libertyville, Illinois, USA
RMikula@sbcglobal.net–
The original message included these comments:
This technical service bulletin calls for the timing to be
set at 10 deg. BTDC static and 0 deg. at idle (750 manual,
650 auto). This means that the vacuum unit provides 10 deg.
retard at idle. When the throttle opens the vacuum drops off
quickly and only the advance springs are in play. The
advance readings from that point should be:
1400 RPM = 6 to 10 deg.
1800 RPM = 14 to 18 deg.
3000 RPM = 18 to 22 deg.
4000 RPM = 23 to 27 deg.
Paul,
I believe he is, but he is out of the country currently.
I think he said he would be out for about 2-3 weeks.
Ya know, there should be some sort of effort to document Dick
Vandermeyden’s Brain in a comprehensive and easily
browsable/searchable fashion. ;)–
–chuck goolsbee
65ots, 1E10715
arlington, wa, usa http://chuck.goolsbee.org
In reply to a message from chuck goolsbee sent Fri 20 Jan 2006:
Chuck,
Dick IS amazing. When I decided to buy an XJ engine to hot rod I
asked him for some ID help. I received a long email with detailed
serial numbers, casting numbers, and several ‘‘tricks’’ to help avoid
swapped out parts.
Does he write all this stuff down?
Dave–
1969 BRG OTS
Skaneateles, NY, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
When I decided to buy an XJ engine to hot rod I
asked him for some ID help. I received a long email with detailed
serial numbers, casting numbers, and several ‘‘tricks’’ to help avoid
swapped out parts.
You should see his office.
It is basically a real-space exploded diagram of his brain.
I hope so, but somehow I doubt it… other than his occasional
contributions here (which can only be some microscopic bits on the
tip of the iceberg.)–
–chuck goolsbee
65ots, 1E10715
arlington, wa, usa http://chuck.goolsbee.org
