BDR belt tracking-more

PostPost by: lotuselan2 » Thu Jun 22, 2006 10:30 pm

Roger

I just reread your note about head or block being planned. None since my
ownership but who knows. I did not think about a misalignment in that
direction (horizontal); I figured off like a compass needle.



Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of Roger Sieling
Sent: Thursday, June 22, 2006 7:50 AM
To: ***@***.***; ***@***.***
Subject: RE: [LotusElan.net] Re: valve job recommendation needed



Uh, Ken, wait a minute here? I thought I just heard within the last week
how the BDR was full of reliable HP and would solve all the problems of
our ancient Twinks!

You've obviously got a mis-aligned shaft somewhere. The first thing i'd
check are the idlers, both the fixed one and the adjustable one, cause
if it's one of the other shaftsthen it's probably big money to fix. If a
cam is not parallel to the crank, it means the head to block face or the
camcarrier to head interface is not parallel to the crank. Have either
the head or carrier been milled to clean up a warped condition or blown
head gasket?

Roger


Bill

Do you know a GOOD shop to work on BD motors? I need some advice
and/or
work. My belt keeps tracking forward and eating itself. Please send
contact info if you know someone good.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
[mailto:***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com] On
Behalf
Of Tebbutt, Bill
Sent: Wednesday, June 21, 2006 8:50 AM
To: '***@***.*** <mailto:%27lotuselan%40yahoogroups.com> ups.com'
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Well, my advice is to go to a shop where they do VOLUME twincam work,
not
just twinks on occaisions. Fail to heed my advice, friends, and risk
the
consequences of your shop of choice actually farming out the work
themselves
to someone you have not even met.

I had this extremely unpleasant experience several years ago with a
BDA.
Sent it to one of the "really big" formula ford builders (with whom I
had a
good relationship, as I had purchased 2 national FF engines from the
firm
recently and they were excellent). The finished BDA was a piece of
crap. <
4 hours of running time later, the flywheel shears off the crank,
causing
considerable damage to the crank and destroying the flywheel. About
$5,000
later, all was well. The FF builder, I suspect, had farmed out the
BDA,
because the FF builder (based on my experience with him) would NEVER
have
used only 6 bolts to hold a flywheel on to a 12 bolt crank. Moreover,
the 6
bolts weren't the high strength ARP reduced head bolts made for this
engine
- rather, they were garden variety allen bolts (full threads,
compounding
the problem), and were placed in alternate holes alongside 6 more
shorter
allen bolts turned down on a lathe to act as dowels in every other
hole!

No comp from the builder either.

Cheers,
Bill

**************************************************
AVIS DE NON-RESPONSABILITE: Ce document transmis par courrier
electronique
est destine uniquement a la personne ou a l'entite a qui il est adresse
et
peut contenir des renseignements confidentiels et assujettis au secret
professionnel. La confidentialite et le secret professionnel demeurent
malgre l'envoi de ce document a la mauvaise adresse electronique. Si
vous
n'etes pas le destinataire vise ou la personne chargee de remettre ce
document a son destinataire, veuillez nous en informer sans delai et
detruire ce document ainsi que toute copie qui en aurait ete faite.
Toute
distribution, reproduction ou autre utilisation de ce document est
strictement interdite. De plus, le Groupe Financiere Banque Nationale
et ses
filiales ne peuvent pas etre tenus responsables des dommages pouvant
etre
causes par des virus ou des erreurs de transmission.

DISCLAIMER: This documentation transmitted by electronic mail is
intended
for the use of the individual to whom or the entity to which it is
addressed
and may contain information which is confidential and privileged.
Confidentiality and privilege are not lost by this documentation having
been
sent to the wrong electronic mail address. If you are not the intended
recipient or the person responsible for delivering it to the intended
recipient please notify the sender immediately and destroy this
document as
well as any copies of it. Any distribution, reproduction or other use
of
this document is strictly prohibited. National Bank Financial Group and
its
affiliates cannot be held liable for any damage that may be caused by
viruses or transmission errors.
**************************************************




http://www.LotusEla <> n.net
'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
Fourth Gear
Fourth Gear
 
Posts: 556
Joined: 19 Oct 2005

PostPost by: lotuselan2 » Thu Jun 22, 2006 10:36 pm

Roger

Okay, one little problem..



I have gone through the two idler pulleys. Originally I had the fixed one
with the tapered hex bolt. I replaced that with a stud and the straight
bushing like most of the race engines use. It causes a little problem with
the alternator belt but I have that pretty well worked out. It appeared to
be tracking perfect but after a few hundred miles it started creeping
forward. Whatever is wrong, it is not far off. None of the timing cams
wobbles or other obvious problem. The water pump could be an issue?



I have been thinking of getting a stud made with about a 1 degree angle to
it with a mark on the "high side". This way I might actually be able to
adjust it to get it true.



Any idea I might check adjust the water pump pulley? It is the Ford type
pump with a Gilmer pulley.



I think that you may very well be right about the cams being slightly off
relative to the crank, and I mean slightly. The head bolts are not an exact
snug fit on the holes through the head like on any motor, so there is some
chance of being off slightly there. Then the same can be said for the cam
carrier onto the head, which would be a lot less work to try to see if there
is any movement possible on those bolts. Since it is a gasket-less fit I do
not even have to lift it off the head. Now if I can only think through the
logic of which way I need to move it! (I'll work it out.)



You have given me a bit of hope to a new remedy; I was about to order two
spare belts and make a small tool kit to carry in the car.



Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of Roger Sieling
Sent: Thursday, June 22, 2006 7:50 AM
To: ***@***.***; ***@***.***
Subject: RE: [LotusElan.net] Re: valve job recommendation needed



Uh, Ken, wait a minute here? I thought I just heard within the last week
how the BDR was full of reliable HP and would solve all the problems of
our ancient Twinks!

You've obviously got a mis-aligned shaft somewhere. The first thing i'd
check are the idlers, both the fixed one and the adjustable one, cause
if it's one of the other shaftsthen it's probably big money to fix. If a
cam is not parallel to the crank, it means the head to block face or the
camcarrier to head interface is not parallel to the crank. Have either
the head or carrier been milled to clean up a warped condition or blown
head gasket?

Roger


Bill

Do you know a GOOD shop to work on BD motors? I need some advice
and/or
work. My belt keeps tracking forward and eating itself. Please send
contact info if you know someone good.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
[mailto:***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com] On
Behalf
Of Tebbutt, Bill
Sent: Wednesday, June 21, 2006 8:50 AM
To: '***@***.*** <mailto:%27lotuselan%40yahoogroups.com> ups.com'
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Well, my advice is to go to a shop where they do VOLUME twincam work,
not
just twinks on occaisions. Fail to heed my advice, friends, and risk
the
consequences of your shop of choice actually farming out the work
themselves
to someone you have not even met.

I had this extremely unpleasant experience several years ago with a
BDA.
Sent it to one of the "really big" formula ford builders (with whom I
had a
good relationship, as I had purchased 2 national FF engines from the
firm
recently and they were excellent). The finished BDA was a piece of
crap. <
4 hours of running time later, the flywheel shears off the crank,
causing
considerable damage to the crank and destroying the flywheel. About
$5,000
later, all was well. The FF builder, I suspect, had farmed out the
BDA,
because the FF builder (based on my experience with him) would NEVER
have
used only 6 bolts to hold a flywheel on to a 12 bolt crank. Moreover,
the 6
bolts weren't the high strength ARP reduced head bolts made for this
engine
- rather, they were garden variety allen bolts (full threads,
compounding
the problem), and were placed in alternate holes alongside 6 more
shorter
allen bolts turned down on a lathe to act as dowels in every other
hole!

No comp from the builder either.

Cheers,
Bill

**************************************************
AVIS DE NON-RESPONSABILITE: Ce document transmis par courrier
electronique
est destine uniquement a la personne ou a l'entite a qui il est adresse
et
peut contenir des renseignements confidentiels et assujettis au secret
professionnel. La confidentialite et le secret professionnel demeurent
malgre l'envoi de ce document a la mauvaise adresse electronique. Si
vous
n'etes pas le destinataire vise ou la personne chargee de remettre ce
document a son destinataire, veuillez nous en informer sans delai et
detruire ce document ainsi que toute copie qui en aurait ete faite.
Toute
distribution, reproduction ou autre utilisation de ce document est
strictement interdite. De plus, le Groupe Financiere Banque Nationale
et ses
filiales ne peuvent pas etre tenus responsables des dommages pouvant
etre
causes par des virus ou des erreurs de transmission.

DISCLAIMER: This documentation transmitted by electronic mail is
intended
for the use of the individual to whom or the entity to which it is
addressed
and may contain information which is confidential and privileged.
Confidentiality and privilege are not lost by this documentation having
been
sent to the wrong electronic mail address. If you are not the intended
recipient or the person responsible for delivering it to the intended
recipient please notify the sender immediately and destroy this
document as
well as any copies of it. Any distribution, reproduction or other use
of
this document is strictly prohibited. National Bank Financial Group and
its
affiliates cannot be held liable for any damage that may be caused by
viruses or transmission errors.
**************************************************




http://www.LotusEla <> n.net
'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
Fourth Gear
Fourth Gear
 
Posts: 556
Joined: 19 Oct 2005

PostPost by: jbrady2804 » Thu Jun 22, 2006 10:52 pm

timing belts can creep axially along the center line of a pulley if the axis
of one of the pulley shafts is out of parallel alignment. first guess is that
the idler shaft center line is not parallel with the cams and crank. i hope
that the head gasket surface is parallel to the cam centerlines
jack brady
jbrady2804
First Gear
First Gear
 
Posts: 19
Joined: 22 Jul 2004

PostPost by: lotuselan2 » Fri Jun 23, 2006 12:35 am

Jack

I have replaced the stud for both idler pulleys. The non-adjustable one is
now more rigid than the original and less play between stud and bushing (it
is not a very tight fit with parts from Cosworth). This improved tracking a
lot but it still creeps forward. At one time I measured the deflection in
the top of the bolt in the idler pulley and it actually deflected a few mils
before reaching correct belt tension. The new stud only deflects if you
over tighten the belt. This leads me to believe that this idler may be the
route cause of the creep. As I mentioned in earlier reply there could be a
small amount gained by slackening he bolts in the cam carrier and seeing if
I can shift it very slightly on the bolt holes. It amazes me that the
tracking could be dependent on such slight changes.



Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of ***@***.***
Sent: Thursday, June 22, 2006 6:52 PM
To: ***@***.***
Subject: Re: [LotusElan.net] BDR belt tracking



timing belts can creep axially along the center line of a pulley if the axis

of one of the pulley shafts is out of parallel alignment. first guess is
that
the idler shaft center line is not parallel with the cams and crank. i hope
that the head gasket surface is parallel to the cam centerlines
jack brady
'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
Fourth Gear
Fourth Gear
 
Posts: 556
Joined: 19 Oct 2005

PostPost by: holywood3645 » Fri Jun 23, 2006 3:29 am

John McCoy in Seattle or Steve Jennings in Orange Count California
are the only 'experts' that I would use. Also maybe Ingram in Santa
Barbra... be carefull of self proclaimed experts, they can cost you
a lot of money.
Good luck
James

--- In ***@***.***, "Lotus" <lotuselan2@...> wrote:














User avatar
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PostPost by: saarhus » Fri Jun 23, 2006 3:39 am

Some speculation, for what it's worth.

Perhaps the belt became slightly distorted while running on the mis-aligned idler pulleys. If the idler(s) were replaced but not the belt, this possible distortion of the belt may be enough to cause it too to not track correctly with the new idlers. So, my suggestion is to change the belt and see what happens.

Stan


Jack

I have replaced the stud for both idler pulleys. The non-adjustable one is
now more rigid than the original and less play between stud and bushing (it
is not a very tight fit with parts from Cosworth). This improved tracking a
lot but it still creeps forward. At one time I measured the deflection in
the top of the bolt in the idler pulley and it actually deflected a few mils
before reaching correct belt tension. The new stud only deflects if you
over tighten the belt. This leads me to believe that this idler may be the
route cause of the creep. As I mentioned in earlier reply there could be a
small amount gained by slackening he bolts in the cam carrier and seeing if
I can shift it very slightly on the bolt holes. It amazes me that the
tracking could be dependent on such slight changes.

Ken

'69 Lotus Elan +2 with BDR
saarhus
Third Gear
Third Gear
 
Posts: 468
Joined: 12 Oct 2003

PostPost by: elansprint71 » Fri Jun 23, 2006 5:52 am

Not an uncommon problem in industry- I suspect the belt is at fault too.
To eliminate this just turn it around, i.e. take it off and put it back
on the other way around. If it is the belt, it will "creep" the other way.

Cheers,
Pete.



Stan Aarhus wrote:

User avatar
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PostPost by: Dave-M » Fri Jun 23, 2006 8:37 am

Ken, One bit of info that I am sure you are aware of, but if not it may help.
The belts always track to the high side of the pulley. Maybe this will let you
choose where to check
Regards
Dave
----- Original Message -----
From: Lotus
To: ***@***.***
Sent: Thursday, June 22, 2006 10:58 PM
Subject: [LotusElan.net] BDR belt tracking


Roger

Okay, one little problem..

I have gone through the two idler pulleys. Originally I had the fixed one
with the tapered hex bolt. I replaced that with a stud and the straight
bushing like most of the race engines use. It causes a little problem with
the alternator belt but I have that pretty well worked out. It appeared to
be tracking perfect but after a few hundred miles it started creeping
forward. Whatever is wrong, it is not far off. None of the timing cams
wobbles or other obvious problem. The water pump could be an issue?

I have been thinking of getting a stud made with about a 1 degree angle to
it with a mark on the "high side". This way I might actually be able to
adjust it to get it true.

Any idea I might check adjust the water pump pulley? It is the Ford type
pump with a Gilmer pulley.

I think that you may very well be right about the cams being slightly off
relative to the crank, and I mean slightly. The head bolts are not an exact
snug fit on the holes through the head like on any motor, so there is some
chance of being off slightly there. Then the same can be said for the cam
carrier onto the head, which would be a lot less work to try to see if there
is any movement possible on those bolts. Since it is a gasket-less fit I do
not even have to lift it off the head. Now if I can only think through the
logic of which way I need to move it! (I'll work it out.)

You have given me a bit of hope to a new remedy; I was about to order two
spare belts and make a small tool kit to carry in the car.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of Roger Sieling
Sent: Thursday, June 22, 2006 7:50 AM
To: ***@***.***; ***@***.***
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Uh, Ken, wait a minute here? I thought I just heard within the last week
how the BDR was full of reliable HP and would solve all the problems of
our ancient Twinks!

You've obviously got a mis-aligned shaft somewhere. The first thing i'd
check are the idlers, both the fixed one and the adjustable one, cause
if it's one of the other shaftsthen it's probably big money to fix. If a
cam is not parallel to the crank, it means the head to block face or the
camcarrier to head interface is not parallel to the crank. Have either
the head or carrier been milled to clean up a warped condition or blown
head gasket?

Roger

>>> ***@***.***. <mailto:lotuselan2%40comcast.net> net 6/21/2006 5:24
PM >>>
Bill

Do you know a GOOD shop to work on BD motors? I need some advice
and/or
work. My belt keeps tracking forward and eating itself. Please send
contact info if you know someone good.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
[mailto:***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com] On
Behalf
Of Tebbutt, Bill
Sent: Wednesday, June 21, 2006 8:50 AM
To: '***@***.*** <mailto:%27lotuselan%40yahoogroups.com> ups.com'
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Well, my advice is to go to a shop where they do VOLUME twincam work,
not
just twinks on occaisions. Fail to heed my advice, friends, and risk
the
consequences of your shop of choice actually farming out the work
themselves
to someone you have not even met.

I had this extremely unpleasant experience several years ago with a
BDA.
Sent it to one of the "really big" formula ford builders (with whom I
had a
good relationship, as I had purchased 2 national FF engines from the
firm
recently and they were excellent). The finished BDA was a piece of
crap. <
4 hours of running time later, the flywheel shears off the crank,
causing
considerable damage to the crank and destroying the flywheel. About
$5,000
later, all was well. The FF builder, I suspect, had farmed out the
BDA,
because the FF builder (based on my experience with him) would NEVER
have
used only 6 bolts to hold a flywheel on to a 12 bolt crank. Moreover,
the 6
bolts weren't the high strength ARP reduced head bolts made for this
engine
- rather, they were garden variety allen bolts (full threads,
compounding
the problem), and were placed in alternate holes alongside 6 more
shorter
allen bolts turned down on a lathe to act as dowels in every other
hole!

No comp from the builder either.

Cheers,
Bill

**************************************************
AVIS DE NON-RESPONSABILITE: Ce document transmis par courrier
electronique
est destine uniquement a la personne ou a l'entite a qui il est adresse
et
peut contenir des renseignements confidentiels et assujettis au secret
professionnel. La confidentialite et le secret professionnel demeurent
malgre l'envoi de ce document a la mauvaise adresse electronique. Si
vous
n'etes pas le destinataire vise ou la personne chargee de remettre ce
document a son destinataire, veuillez nous en informer sans delai et
detruire ce document ainsi que toute copie qui en aurait ete faite.
Toute
distribution, reproduction ou autre utilisation de ce document est
strictement interdite. De plus, le Groupe Financiere Banque Nationale
et ses
filiales ne peuvent pas etre tenus responsables des dommages pouvant
etre
causes par des virus ou des erreurs de transmission.

DISCLAIMER: This documentation transmitted by electronic mail is
intended
for the use of the individual to whom or the entity to which it is
addressed
and may contain information which is confidential and privileged.
Confidentiality and privilege are not lost by this documentation having
been
sent to the wrong electronic mail address. If you are not the intended
recipient or the person responsible for delivering it to the intended
recipient please notify the sender immediately and destroy this
document as
well as any copies of it. Any distribution, reproduction or other use
of
this document is strictly prohibited. National Bank Financial Group and
its
affiliates cannot be held liable for any damage that may be caused by
viruses or transmission errors.
**************************************************




http://www.LotusEla <> n.net
Dave-M
Second Gear
Second Gear
 
Posts: 193
Joined: 11 Jun 2005

PostPost by: lotuselan2 » Fri Jun 23, 2006 9:39 pm

Belt was just changed and it tracked good for first hundred miles or so and
then started creeping.



Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of Stan Aarhus
Sent: Thursday, June 22, 2006 11:38 PM
To: ***@***.***
Subject: Re: [LotusElan.net] BDR belt tracking



Some speculation, for what it's worth.

Perhaps the belt became slightly distorted while running on the mis-aligned
idler pulleys. If the idler(s) were replaced but not the belt, this possible
distortion of the belt may be enough to cause it too to not track correctly
with the new idlers. So, my suggestion is to change the belt and see what
happens.

Stan

Jack

I have replaced the stud for both idler pulleys. The non-adjustable one is
now more rigid than the original and less play between stud and bushing (it
is not a very tight fit with parts from Cosworth). This improved tracking a
lot but it still creeps forward. At one time I measured the deflection in
the top of the bolt in the idler pulley and it actually deflected a few mils
before reaching correct belt tension. The new stud only deflects if you
over tighten the belt. This leads me to believe that this idler may be the
route cause of the creep. As I mentioned in earlier reply there could be a
small amount gained by slackening he bolts in the cam carrier and seeing if
I can shift it very slightly on the bolt holes. It amazes me that the
tracking could be dependent on such slight changes.

Ken

'69 Lotus Elan +2 with BDR
'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
Fourth Gear
Fourth Gear
 
Posts: 556
Joined: 19 Oct 2005

PostPost by: lotuselan2 » Fri Jun 23, 2006 9:39 pm

Owww. I like this one; easy job. My problem is that it always tracks the
same way and I have gone through about 4 belts.



Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of Pete Taylor
Sent: Friday, June 23, 2006 1:51 AM
To: ***@***.***
Subject: Re: [LotusElan.net] BDR belt tracking



Not an uncommon problem in industry- I suspect the belt is at fault too.
To eliminate this just turn it around, i.e. take it off and put it back
on the other way around. If it is the belt, it will "creep" the other way.

Cheers,
Pete.

Stan Aarhus wrote:

'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
Fourth Gear
Fourth Gear
 
Posts: 556
Joined: 19 Oct 2005

PostPost by: lotuselan2 » Fri Jun 23, 2006 9:43 pm

Dave

I always struggle with this. I guess I need to understand what "high side"
means. I would have thought belt would go to the low or easy side. Maybe
if someone has a reference with a sketch I would get it right the first
time. (Us Chemical engineers think we understand all engineering but this
one has baffled me for years.) At least there are only two choices.



Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of ***@***.***
Sent: Friday, June 23, 2006 4:36 AM
To: ***@***.***
Subject: Re: [LotusElan.net] BDR belt tracking



Ken, One bit of info that I am sure you are aware of, but if not it may
help.
The belts always track to the high side of the pulley. Maybe this will let
you
choose where to check
Regards
Dave
----- Original Message -----
From: Lotus
To: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
Sent: Thursday, June 22, 2006 10:58 PM
Subject: [LotusElan.net] BDR belt tracking

Roger

Okay, one little problem..

I have gone through the two idler pulleys. Originally I had the fixed one
with the tapered hex bolt. I replaced that with a stud and the straight
bushing like most of the race engines use. It causes a little problem with
the alternator belt but I have that pretty well worked out. It appeared to
be tracking perfect but after a few hundred miles it started creeping
forward. Whatever is wrong, it is not far off. None of the timing cams
wobbles or other obvious problem. The water pump could be an issue?

I have been thinking of getting a stud made with about a 1 degree angle to
it with a mark on the "high side". This way I might actually be able to
adjust it to get it true.

Any idea I might check adjust the water pump pulley? It is the Ford type
pump with a Gilmer pulley.

I think that you may very well be right about the cams being slightly off
relative to the crank, and I mean slightly. The head bolts are not an exact
snug fit on the holes through the head like on any motor, so there is some
chance of being off slightly there. Then the same can be said for the cam
carrier onto the head, which would be a lot less work to try to see if there
is any movement possible on those bolts. Since it is a gasket-less fit I do
not even have to lift it off the head. Now if I can only think through the
logic of which way I need to move it! (I'll work it out.)

You have given me a bit of hope to a new remedy; I was about to order two
spare belts and make a small tool kit to carry in the car.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
[mailto:***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com] On
Behalf
Of Roger Sieling
Sent: Thursday, June 22, 2006 7:50 AM
To: ***@***.***. <mailto:lotuselan2%40comcast.net> net;
***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Uh, Ken, wait a minute here? I thought I just heard within the last week
how the BDR was full of reliable HP and would solve all the problems of
our ancient Twinks!

You've obviously got a mis-aligned shaft somewhere. The first thing i'd
check are the idlers, both the fixed one and the adjustable one, cause
if it's one of the other shaftsthen it's probably big money to fix. If a
cam is not parallel to the crank, it means the head to block face or the
camcarrier to head interface is not parallel to the crank. Have either
the head or carrier been milled to clean up a warped condition or blown
head gasket?

Roger


Bill

Do you know a GOOD shop to work on BD motors? I need some advice
and/or
work. My belt keeps tracking forward and eating itself. Please send
contact info if you know someone good.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
[mailto:***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com] On
Behalf
Of Tebbutt, Bill
Sent: Wednesday, June 21, 2006 8:50 AM
To: '***@***.*** <mailto:%27lotuselan%40yahoogroups.com> ups.com'
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Well, my advice is to go to a shop where they do VOLUME twincam work,
not
just twinks on occaisions. Fail to heed my advice, friends, and risk
the
consequences of your shop of choice actually farming out the work
themselves
to someone you have not even met.

I had this extremely unpleasant experience several years ago with a
BDA.
Sent it to one of the "really big" formula ford builders (with whom I
had a
good relationship, as I had purchased 2 national FF engines from the
firm
recently and they were excellent). The finished BDA was a piece of
crap. <
4 hours of running time later, the flywheel shears off the crank,
causing
considerable damage to the crank and destroying the flywheel. About
$5,000
later, all was well. The FF builder, I suspect, had farmed out the
BDA,
because the FF builder (based on my experience with him) would NEVER
have
used only 6 bolts to hold a flywheel on to a 12 bolt crank. Moreover,
the 6
bolts weren't the high strength ARP reduced head bolts made for this
engine
- rather, they were garden variety allen bolts (full threads,
compounding
the problem), and were placed in alternate holes alongside 6 more
shorter
allen bolts turned down on a lathe to act as dowels in every other
hole!

No comp from the builder either.

Cheers,
Bill

**************************************************
AVIS DE NON-RESPONSABILITE: Ce document transmis par courrier
electronique
est destine uniquement a la personne ou a l'entite a qui il est adresse
et
peut contenir des renseignements confidentiels et assujettis au secret
professionnel. La confidentialite et le secret professionnel demeurent
malgre l'envoi de ce document a la mauvaise adresse electronique. Si
vous
n'etes pas le destinataire vise ou la personne chargee de remettre ce
document a son destinataire, veuillez nous en informer sans delai et
detruire ce document ainsi que toute copie qui en aurait ete faite.
Toute
distribution, reproduction ou autre utilisation de ce document est
strictement interdite. De plus, le Groupe Financiere Banque Nationale
et ses
filiales ne peuvent pas etre tenus responsables des dommages pouvant
etre
causes par des virus ou des erreurs de transmission.

DISCLAIMER: This documentation transmitted by electronic mail is
intended
for the use of the individual to whom or the entity to which it is
addressed
and may contain information which is confidential and privileged.
Confidentiality and privilege are not lost by this documentation having
been
sent to the wrong electronic mail address. If you are not the intended
recipient or the person responsible for delivering it to the intended
recipient please notify the sender immediately and destroy this
document as
well as any copies of it. Any distribution, reproduction or other use
of
this document is strictly prohibited. National Bank Financial Group and
its
affiliates cannot be held liable for any damage that may be caused by
viruses or transmission errors.
**************************************************




http://www.LotusEla <http://www.LotusEla <> n.net>
n.net
'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
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PostPost by: richboyd » Sat Jun 24, 2006 12:17 am

Ken,

Let me give the "track to the high side" a whirl. I'll define "high
side" as the larger effective diameter. With constant-diameter
pulleys (none tapered), this is the side with the largest distance
between centers (assuming one "bent" pulley axis). The side where the
belt must travel the furthest.

The "high side" is the point where the belt would be the tightest.
Tight equals more friction. "Low side" would be looser and have less
friction. OK, I know we're talking about toothed belts, but the
"creeping sideways" issue may be differential friction none the less.

Now for the analogy. Imagine a car braking in a straight line - on a
surface with different friction from side-to-side. The car will
"pull" towards the side with more friction. Or imagine a
front-wheel-drive car accelerating on the same surface. It will
"pull" towards the side with more friction. A Gilmer belt will move
sideways towards the side with more friction; the high side.


Rich Boyd

ps. I am less qualified than a chemical engineer to answer this. I am
a genetic engineer. Any mechanical engineer types want to wade in.



23/2006, you wrote:

User avatar
richboyd
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PostPost by: lotuselan2 » Sat Jun 24, 2006 4:07 am

Now add this to the mix: All of the Gilmer pulleys obviously run on the
toothed side of the belt. The two idler pulleys run on the smooth side and
are therefore on the "outside" of the belt loop. Since the idlers are the
most likely suspects for misalignment, how does that change (or not) the
"high side" discussion.



Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of Richard Boyd
Sent: Friday, June 23, 2006 7:19 PM
To: ***@***.***
Subject: RE: [LotusElan.net] BDR belt tracking



Ken,

Let me give the "track to the high side" a whirl. I'll define "high
side" as the larger effective diameter. With constant-diameter
pulleys (none tapered), this is the side with the largest distance
between centers (assuming one "bent" pulley axis). The side where the
belt must travel the furthest.

The "high side" is the point where the belt would be the tightest.
Tight equals more friction. "Low side" would be looser and have less
friction. OK, I know we're talking about toothed belts, but the
"creeping sideways" issue may be differential friction none the less.

Now for the analogy. Imagine a car braking in a straight line - on a
surface with different friction from side-to-side. The car will
"pull" towards the side with more friction. Or imagine a
front-wheel-drive car accelerating on the same surface. It will
"pull" towards the side with more friction. A Gilmer belt will move
sideways towards the side with more friction; the high side.

Rich Boyd

ps. I am less qualified than a chemical engineer to answer this. I am
a genetic engineer. Any mechanical engineer types want to wade in.

23/2006, you wrote:







'69 Lotus Elan +2 with Cosworth BDR
'84 Ferrari 400i
'94 Subaru SVX
'04 Audi allroad
lotuselan2
Fourth Gear
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Posts: 556
Joined: 19 Oct 2005

PostPost by: Dave-M » Sat Jun 24, 2006 8:07 am

The belt goes the way you would think it would not ie. tries
to stretch itself further. On flat belt machine drives the pulley
is usually machined with a convex face so the belt always tries
to find the centre position. Though I don't thing this is the case with toothed belt drives.
I would guess the problem lies with the cylinder head position
relative to the crank c/l. a) Horizontal misalignment of the head or vertical misalignment of
the head, Both relative to the block. Have you had the head skimmed recently? if so the cams
may not be parallel to the head mating face. ie. the head may be tapered front to back
Hope this may be of some help
----- Original Message -----
From: Lotus
To: ***@***.***
Sent: Friday, June 23, 2006 10:17 PM
Subject: RE: [LotusElan.net] BDR belt tracking


Dave

I always struggle with this. I guess I need to understand what "high side"
means. I would have thought belt would go to the low or easy side. Maybe
if someone has a reference with a sketch I would get it right the first
time. (Us Chemical engineers think we understand all engineering but this
one has baffled me for years.) At least there are only two choices.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.***lto:***@***.*** Behalf
Of ***@***.***
Sent: Friday, June 23, 2006 4:36 AM
To: ***@***.***
Subject: Re: [LotusElan.net] BDR belt tracking

Ken, One bit of info that I am sure you are aware of, but if not it may
help.
The belts always track to the high side of the pulley. Maybe this will let
you
choose where to check
Regards
Dave
----- Original Message -----
From: Lotus
To: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
Sent: Thursday, June 22, 2006 10:58 PM
Subject: [LotusElan.net] BDR belt tracking

Roger

Okay, one little problem..

I have gone through the two idler pulleys. Originally I had the fixed one
with the tapered hex bolt. I replaced that with a stud and the straight
bushing like most of the race engines use. It causes a little problem with
the alternator belt but I have that pretty well worked out. It appeared to
be tracking perfect but after a few hundred miles it started creeping
forward. Whatever is wrong, it is not far off. None of the timing cams
wobbles or other obvious problem. The water pump could be an issue?

I have been thinking of getting a stud made with about a 1 degree angle to
it with a mark on the "high side". This way I might actually be able to
adjust it to get it true.

Any idea I might check adjust the water pump pulley? It is the Ford type
pump with a Gilmer pulley.

I think that you may very well be right about the cams being slightly off
relative to the crank, and I mean slightly. The head bolts are not an exact
snug fit on the holes through the head like on any motor, so there is some
chance of being off slightly there. Then the same can be said for the cam
carrier onto the head, which would be a lot less work to try to see if there
is any movement possible on those bolts. Since it is a gasket-less fit I do
not even have to lift it off the head. Now if I can only think through the
logic of which way I need to move it! (I'll work it out.)

You have given me a bit of hope to a new remedy; I was about to order two
spare belts and make a small tool kit to carry in the car.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
[mailto:***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com] On
Behalf
Of Roger Sieling
Sent: Thursday, June 22, 2006 7:50 AM
To: ***@***.***. <mailto:lotuselan2%40comcast.net> net;
***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Uh, Ken, wait a minute here? I thought I just heard within the last week
how the BDR was full of reliable HP and would solve all the problems of
our ancient Twinks!

You've obviously got a mis-aligned shaft somewhere. The first thing i'd
check are the idlers, both the fixed one and the adjustable one, cause
if it's one of the other shaftsthen it's probably big money to fix. If a
cam is not parallel to the crank, it means the head to block face or the
camcarrier to head interface is not parallel to the crank. Have either
the head or carrier been milled to clean up a warped condition or blown
head gasket?

Roger

>>> ***@***.***. <mailto:lotuselan2%40comcast.net> net 6/21/2006 5:24
PM >>>
Bill

Do you know a GOOD shop to work on BD motors? I need some advice
and/or
work. My belt keeps tracking forward and eating itself. Please send
contact info if you know someone good.

Ken

'69 Lotus Elan +2 with BDR

_____

From: ***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com
[mailto:***@***.*** <mailto:lotuselan%40yahoogroups.com> ps.com] On
Behalf
Of Tebbutt, Bill
Sent: Wednesday, June 21, 2006 8:50 AM
To: '***@***.*** <mailto:%27lotuselan%40yahoogroups.com> ups.com'
Subject: RE: [LotusElan.net] Re: valve job recommendation needed

Well, my advice is to go to a shop where they do VOLUME twincam work,
not
just twinks on occaisions. Fail to heed my advice, friends, and risk
the
consequences of your shop of choice actually farming out the work
themselves
to someone you have not even met.

I had this extremely unpleasant experience several years ago with a
BDA.
Sent it to one of the "really big" formula ford builders (with whom I
had a
good relationship, as I had purchased 2 national FF engines from the
firm
recently and they were excellent). The finished BDA was a piece of
crap. <
4 hours of running time later, the flywheel shears off the crank,
causing
considerable damage to the crank and destroying the flywheel. About
$5,000
later, all was well. The FF builder, I suspect, had farmed out the
BDA,
because the FF builder (based on my experience with him) would NEVER
have
used only 6 bolts to hold a flywheel on to a 12 bolt crank. Moreover,
the 6
bolts weren't the high strength ARP reduced head bolts made for this
engine
- rather, they were garden variety allen bolts (full threads,
compounding
the problem), and were placed in alternate holes alongside 6 more
shorter
allen bolts turned down on a lathe to act as dowels in every other
hole!

No comp from the builder either.

Cheers,
Bill

**************************************************
AVIS DE NON-RESPONSABILITE: Ce document transmis par courrier
electronique
est destine uniquement a la personne ou a l'entite a qui il est adresse
et
peut contenir des renseignements confidentiels et assujettis au secret
professionnel. La confidentialite et le secret professionnel demeurent
malgre l'envoi de ce document a la mauvaise adresse electronique. Si
vous
n'etes pas le destinataire vise ou la personne chargee de remettre ce
document a son destinataire, veuillez nous en informer sans delai et
detruire ce document ainsi que toute copie qui en aurait ete faite.
Toute
distribution, reproduction ou autre utilisation de ce document est
strictement interdite. De plus, le Groupe Financiere Banque Nationale
et ses
filiales ne peuvent pas etre tenus responsables des dommages pouvant
etre
causes par des virus ou des erreurs de transmission.

DISCLAIMER: This documentation transmitted by electronic mail is
intended
for the use of the individual to whom or the entity to which it is
addressed
and may contain information which is confidential and privileged.
Confidentiality and privilege are not lost by this documentation having
been
sent to the wrong electronic mail address. If you are not the intended
recipient or the person responsible for delivering it to the intended
recipient please notify the sender immediately and destroy this
document as
well as any copies of it. Any distribution, reproduction or other use
of
this document is strictly prohibited. National Bank Financial Group and
its
affiliates cannot be held liable for any damage that may be caused by
viruses or transmission errors.
**************************************************




http://www.LotusEla <http://www.LotusEla <> n.net>
n.net
Dave-M
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Posts: 193
Joined: 11 Jun 2005

PostPost by: mikecauser » Sat Jun 24, 2006 2:21 pm

On Fri, 23 Jun 2006 17:17:02 -0400 "Lotus" <***@***.***> wrote:


It's definitely true, here are a couple of references:
http://www.belttechnologies.com/designinfo/crown.html
http://kmoddl.library.cornell.edu/model.php?m=183

As to the theory of why it is so, I /think/ that it may be connected with
the concept of a Great Circle being the shortest distance from place to
place on a sphere, and a crowned pulley is a part of a sphere. The
pulley we are considering here merely being half of a crowned pulley.


Mike
--
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