Valve rocker clearances

[ROSS TAYLOR]

Back again With regard to the discussion regarding the oil supply to the rocker gear the comment has been that the excess oil is used to lubricate the camshaft and followers, in all IC engines the camshaft is on the throw side of the crankshaft which guarantees a good supply of oil to the lobes as the oil throws off the crank and the oil mist in the crankcase should supply lubrication also, bearings being lubricated from the oil gallery. The cam followers are also made with holes that allow spill lubrication as they fill up and lubricate the cam lobes and act as an oil resevoir. Just a comment to justify a metering jet to be fitted to the top banjo bolt. Also all the early motorbikes had open valve gear with hairpin springs with no lubrication. JUST STIRRING UP FURTHUR DISCUSSION on a contencious point Ross in Tea Gardens

>On Wed, 29 Jun 2005 15:43 -0400, Peter Roberts wrote: > > > "Fascinating. I have before me two workshop manuals, one from Mercedes, > > and one from Jaguar. Both are explicit that valves are to be adjusted > > on cold engines. To quote Mercedes, " The valve clearance on all > > gasoline engines should be checked and, if necessary, adjusted when the > > engine is cold." > > > > My original TC Owner Manual is not specific on hot or cold engine > > adjustment. My Chilton TC Manual is clear that it should be hot. > > Blower is specific that it should be hot. What does Mercedes know that > > Chilton and Blower don't? > >What Mercedes knows is that valve clearance on all Mercedes gasoline >engines is to be adjusted cold. Same for Jaguar, and any other >manufacturer that specifies cold adjustment. That "all gasoline engines" >in the Mercedes manual doesn't mean every gasoline engine regardless of >manufacturer. It means "all Mercedes gasoline engines", which is all that >manual was written for. > >Some manufacturers specify cold adjustment, some hot. MG specified hot >for the XPAG/XPEG. If you prefer to use a Mercedes manual to maintain >your MG, well, it's your car. > >-- >Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 >Cub Hill, Maryland >fold@bcpl.net > > > >Yahoo! Groups Links > > > > > >

[Paroor]

Hi Ross, All those old motor cycle engines with open valve and hairpin springs rotate very slow. One can count each firing. But the modern engines rotate very fast up to 12000 RPM, it is impossible with out good lubrication. Madhu -----Urspr ngliche Nachricht----- Von: mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com]Im Auftrag von ROSS TAYLOR Gesendet: Donnerstag, 30. Juni 2005 14:03 An: fold@bcpl.net; mg-tabc@yahoogroups.com Betreff: Re: [mg-tabc] Valve rocker clearances Back again With regard to the discussion regarding the oil supply to the rocker gear the comment has been that the excess oil is used to lubricate the camshaft and followers, in all IC engines the camshaft is on the throw side of the crankshaft which guarantees a good supply of oil to the lobes as the oil throws off the crank and the oil mist in the crankcase should supply lubrication also, bearings being lubricated from the oil gallery. The cam followers are also made with holes that allow spill lubrication as they fill up and lubricate the cam lobes and act as an oil resevoir. Just a comment to justify a metering jet to be fitted to the top banjo bolt. Also all the early motorbikes had open valve gear with hairpin springs with no lubrication. JUST STIRRING UP FURTHUR DISCUSSION on a contencious point Ross in Tea Gardens

[Peter Roberts]

Madhu, As always, you are a font of wisdom. The issue of hot or cold adjustment is perfectly framed by your comment: "Those who give more importance for a better cold start set the valve at cold engine. Those who want a better performance set the valve when engine hot." _Peter

----- Original Message ----- From: "Paroor" Paroor@t-online.de> To: "Peter Roberts" mgtc@comcast.net>; "'ian thomson'" i.thomson@talk21.com>; mg-tabc@yahoogroups.com>; "fnitz" fnitz@pacbell.net> Sent: Thursday, June 30, 2005 2:42 AM Subject: AW: [mg-tabc] Valve rocker clearances > Hi Peter, > The old VW Golf petrol engine they recommend to set the valves at > 35 C or above. That means the cylinder head had to be hand warm. Inlet > valves 0,15 mm and outlet valves 0,25 mm. It is also written that after > repair the valve clearance on the cold motor to set values inlet 0,10 mm > and > out let 0,20 mm and after 1000 kM to check the valve clearance of the warm > motor. > > In a French Citron 1100 cc engine it also recommended to set the valve at > 35 C or hand warm, inlet valve 0,20 mm and out let valve 0,40 mm. It is > also > recommended to use other values if the clearances are set on hot engine. > The > valve clearances will become less after running, because the vales are > constantly hitting the valve seats. In this case there will be less noise > or > no noise. > > Here we say that the valve making noise is healthy. In Diesel engine it is > important that the valve clearance is set on the cold engine. Because the > cold start in old diesel is more important. With modern engines we can > save > the time to set the valve. > > May be total sum of engines made by VW and Mercedes are more than the > total > sum of engines made by MG or Jaguar. Hence they may have more experience. > The BMW uses Aluminium blocks. So the things may be different. May be I > am > wrong. > > Those who give more importance for a better cold start set the valve at > cold engine. Those who want a better performance set the valve when engine > hot. > > > Madhu > TC 0448 > > > -----Urspr ngliche Nachricht----- > Von: mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com]Im Auftrag > von Peter Roberts > Gesendet: Mittwoch, 29. Juni 2005 21:44 > An: 'ian thomson'; mg-tabc@yahoogroups.com; fnitz > Betreff: Re: [mg-tabc] Valve rocker clearances > > > Fred, > > Let me share a message I sent Gene Roth yesterday: > > "Fascinating. I have before me two workshop manuals, one from Mercedes, > and > one from Jaguar. Both are explicit that valves are to be adjusted on cold > engines. To quote Mercedes, " The valve clearance on all gasoline engines > should be checked and, if necessary, adjusted when the engine is cold." > > My original TC Owner Manual is not specific on hot or cold engine > adjustment. My Chilton TC Manual is clear that it should be hot. Blower > is > specific that it should be hot. What does Mercedes know that Chilton and > Blower don't? > > _Peter > >

[E.Worpe]

Hi Ross, The cam followers are made with two sets of holes. The upper set allows some of the oil that's leaked from the rocker shaft to fill the hollow cam followers. The lower set of holes bleeds away the oil, thus lubricating the cam follower bores and cam lobes. This form of lubrication may well be secondary to the splash lubrication that you've mentioned, we're starting to go beyond the bounds of home spun theory. My concern is that if the rocker shaft and bushes are healthy, then there should not be any need for a metering pin. Any single restriction could be prone to blockage or misuse by someone trying to limit oil leaks from the rocker cover gasket for example. Never underestimate the ability of bodgers to improvise for short term gains. Regards, Eric. -----Original Message----- Back again With regard to the discussion regarding the oil supply to the rocker gear the comment has been that the excess oil is used to lubricate the camshaft and followers, in all IC engines the camshaft is on the throw side of the crankshaft which guarantees a good supply of oil to the lobes as the oil throws off the crank and the oil mist in the crankcase should supply lubrication also, bearings being lubricated from the oil gallery. The cam followers are also made with holes that allow spill lubrication as they fill up and lubricate the cam lobes and act as an oil resevoir. Just a comment to justify a metering jet to be fitted to the top banjo bolt. Also all the early motorbikes had open valve gear with hairpin springs with no lubrication. JUST STIRRING UP FURTHUR DISCUSSION on a contencious point Ross in Tea Gardens [Non-text portions of this message have been removed]

[Robin Montgomery]

And if the flow (which is to one end of the rocker shaft) is metered, and the rocker shaft / bushings are sufficiently worn, you may not get any flow to the furthest rocker. Regards, Robin Montgomery RMontgomery@doriandrake.com _________________________________ -----Original Message----- From: E.Worpe [mailto:E.Worpe@surrey.ac.uk] Sent: Thursday, June 30, 2005 9:51 AM To: rossmvt; fold; mg-tabc Subject: RE: [mg-tabc] Valve rocker clearances Hi Ross, The cam followers are made with two sets of holes. The upper set allows some of the oil that's leaked from the rocker shaft to fill the hollow cam followers. The lower set of holes bleeds away the oil, thus lubricating the cam follower bores and cam lobes. This form of lubrication may well be secondary to the splash lubrication that you've mentioned, we're starting to go beyond the bounds of home spun theory. My concern is that if the rocker shaft and bushes are healthy, then there should not be any need for a metering pin. Any single restriction could be prone to blockage or misuse by someone trying to limit oil leaks from the rocker cover gasket for example. Never underestimate the ability of bodgers to improvise for short term gains. Regards, Eric. -----Original Message----- Back again With regard to the discussion regarding the oil supply to the rocker gear the comment has been that the excess oil is used to lubricate the camshaft and followers, in all IC engines the camshaft is on the throw side of the crankshaft which guarantees a good supply of oil to the lobes as the oil throws off the crank and the oil mist in the crankcase should supply lubrication also, bearings being lubricated from the oil gallery. The cam followers are also made with holes that allow spill lubrication as they fill up and lubricate the cam lobes and act as an oil resevoir. Just a comment to justify a metering jet to be fitted to the top banjo bolt. Also all the early motorbikes had open valve gear with hairpin springs with no lubrication. JUST STIRRING UP FURTHUR DISCUSSION on a contencious point Ross in Tea Gardens [Non-text portions of this message have been removed] Yahoo! Groups Links

[Dave A]

Hello all! I don,t know about Mercedes, but on a Jag you have to PULL THE CAMS to change the shims under the lifters which makes the adjustment to the valves. A long sentence, and alot of work! It can only be done cold...... Cheers, Dave 48' TC -----Original Message----- From: mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com]On Behalf Of Chip Old Sent: Wednesday, June 29, 2005 11:36 PM To: MG-TABC Subject: Re: [mg-tabc] Valve rocker clearances

On Wed, 29 Jun 2005 15:43 -0400, Peter Roberts wrote: > "Fascinating. I have before me two workshop manuals, one from Mercedes, > and one from Jaguar. Both are explicit that valves are to be adjusted > on cold engines. To quote Mercedes, " The valve clearance on all > gasoline engines should be checked and, if necessary, adjusted when the > engine is cold." > > My original TC Owner Manual is not specific on hot or cold engine > adjustment. My Chilton TC Manual is clear that it should be hot. > Blower is specific that it should be hot. What does Mercedes know that > Chilton and Blower don't? What Mercedes knows is that valve clearance on all Mercedes gasoline engines is to be adjusted cold. Same for Jaguar, and any other manufacturer that specifies cold adjustment. That "all gasoline engines" in the Mercedes manual doesn't mean every gasoline engine regardless of manufacturer. It means "all Mercedes gasoline engines", which is all that manual was written for. Some manufacturers specify cold adjustment, some hot. MG specified hot for the XPAG/XPEG. If you prefer to use a Mercedes manual to maintain your MG, well, it's your car. -- Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 Cub Hill, Maryland fold@bcpl.net Yahoo! Groups Links

[LKe1021587@aol.com]

While everyone is adjusting their valves, you may want to take a minute to check your oil plugs in the ends of the rocker arm shafts. I recently found one had worked it's way loose and was rolling around amongst the oil and rockers. Upon checking the other end, I found it was missing! No idea where it went or if a PO had neglected to install it. I replaced both with loctite and gained 5 more psi of oil pressure at idle and the engine was a bit quieter. Mike K. TC 1307 [Non-text portions of this message have been removed]

[David Lodge]

Hello Rick, I have always understood that loose pushrod ends could be soldered in place. Regards, David Lodge Hello ----- ORIGINAL MESSAGE ----- From: "Rick Waters" rwmgtc@yahoo.ca> To: "Rothgene Roth" rothgene@msn.com>,"Peter Roberts" mgtc@comcast.net>,"Maurice Paton" maurice.paton@wam.co.nz>,mg-tabc@yahoogroups.com,"Liz Harris" lizandtweed@yahoo.co.uk> Subject: Re: [mg-tabc] Valve rocker clearances Date: 29.6.2005 - 1:52:21

> I use this Cam, and I just set both to 19 thou hot. > > BTW, I did not need new pushrods, perhaps because my > rockers have been refaced at the valve stem end. I > wonder if using new rockers would necessitate the > shorter pushrods. > > If so, can pushrods be shortened by a competent machine > shop. It seems the ends are just pushed in to the > tubular rods, then the rods are hammered to hold the > ends in place. > > -rick > > Rothgene Roth rothgene@msn.com> wrote: > Hi > ----- Original Message ----- > From: Rothgene Roth > To: Peter Roberts ; Maurice Paton ; > mg-tabc@yahoogroups.com ; Liz Harris > Sent: Tuesday, June 28, 2005 10:23 AM > Subject: Re: [mg-tabc] Valve rocker clearances > > > Group, > The valve setting for the Crane cam shaft part > #340-0002, grind #553-OS is: Intake .018, Exhaust .020 > HOT. This is the cam shaft referred to as the " > standard " grind. They state: " If pushrods are too > long use Crane pushrod part # 905-0003. > I have this set up in my TC. > Crane PH. # 386 258 6174 > Gene Roth > ----- Original Message ----- > From: Liz Harris > To: Peter Roberts ; Maurice Paton ; > mg-tabc@yahoogroups.com > Sent: Monday, June 27, 2005 3:12 PM > Subject: Re: [mg-tabc] Valve rocker clearances > > > ....sorry Peter,a warm engine......as for the 12 thou > on a TD....d`know !!! > > > > Peter Roberts > wrote: > "hot motor"?????? > > _Peter > ----- Original Message ----- > From: "Liz Harris" > > To: "Maurice Paton" ; > Sent: Sunday, June 26, 2005 7:39 PM > Subject: Re: [mg-tabc] Valve rocker clearances > > > > Hi Maurice, when you say `standard`, do you mean > > Crane`s replacement for > > an original profile and lift? in which case should`nt > > they should be set > > at 19 thou....on a hot motor.... > > Tweed > > TC 2259 Cambridge, England. > > > > Maurice Paton wrote: > > I have just completed a total rebuild on my TC engine > > during which the > > camshaft was replace with a standard 'Crane' cam from > > Moss Motors. Does > > anyone have any information regarding recommended > > rocker clearances > > using this cam? Currently they are set at 15 thou. > > > > Maurice TC9357 > > > > > > [Non-text portions of this message have been removed] > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > --------------------------------- > > Yahoo! Messenger NEW - crystal clear PC to PCcalling > > worldwide with > > voicemail > > > > [Non-text portions of this message have been removed] > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > --------------------------------- > Yahoo! Messenger NEW - crystal clear PC to PCcalling > worldwide with voicemail > > [Non-text portions of this message have been removed] > > > > > Yahoo! Groups Links > > > > > > > > > [Non-text portions of this message have been removed] > > > > > Yahoo! Groups Links > > > > > > > > > -Rick Waters > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam > protection around > http://mail.yahoo.com > > [Non-text portions of this message have been removed] > > > > > Yahoo! Groups Links > > > > > > >

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[David Lodge]

Hello Dave, Ditto Alfa Romeo! Regards, Dave L. ----- ORIGINAL MESSAGE ----- From: "Dave A" davea@symbolicdisplays.com> To: mg-tabc@yahoogroups.com Subject: RE: [mg-tabc] Valve rocker clearances Date: 30.6.2005 - 16:44:24

> Hello all! > > I don,t know about Mercedes, but on a Jag you have to > PULL THE CAMS to > change the shims under the lifters which makes the > adjustment to the valves. > A long sentence, and alot of work! It can only be done > cold...... > > Cheers, > > Dave 48' TC > > > > -----Original Message----- > From: mg-tabc@yahoogroups.com > [mailto:mg-tabc@yahoogroups.com]On Behalf > Of Chip Old > Sent: Wednesday, June 29, 2005 11:36 PM > To: MG-TABC > Subject: Re: [mg-tabc] Valve rocker clearances > > > On Wed, 29 Jun 2005 15:43 -0400, Peter Roberts wrote: > > > "Fascinating. I have before me two workshop manuals, > > one from Mercedes, > > and one from Jaguar. Both are explicit that valves > > are to be adjusted > > on cold engines. To quote Mercedes, " The valve > > clearance on all > > gasoline engines should be checked and, if necessary, > > adjusted when the > > engine is cold." > > > > My original TC Owner Manual is not specific on hot or > > cold engine > > adjustment. My Chilton TC Manual is clear that it > > should be hot. > > Blower is specific that it should be hot. What does > > Mercedes know that > > Chilton and Blower don't? > > What Mercedes knows is that valve clearance on all > Mercedes gasoline > engines is to be adjusted cold. Same for Jaguar, and > any other > manufacturer that specifies cold adjustment. That "all > gasoline engines" > in the Mercedes manual doesn't mean every gasoline > engine regardless of > manufacturer. It means "all Mercedes gasoline > engines", which is all that > manual was written for. > > Some manufacturers specify cold adjustment, some hot. > MG specified hot > for the XPAG/XPEG. If you prefer to use a Mercedes > manual to maintain > your MG, well, it's your car. > > -- > Chip Old 1948 M.G. TC TC6710 XPAG7430 > NEMGTR #2271 > Cub Hill, Maryland > fold@bcpl.net > > > > Yahoo! Groups Links > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > >

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[Donald Wilkinson]

David writes: "I have always understood that loose pushrod ends could be soldered in place." digitaldon sez: better to silver braze 'em, as in the famous Brit bicycle frames, (Raleigh, etc). Easily done with oxy-acetylene torch, or possible with even a Bernzomatic torch, especially if using Mapp gas. Don TC 7993