MG TA Center Cam Bearing Lubrication Source?

[Monoxidemanor@aol.com]

Dear Faithful: Previously we sent out an APB (all points bulletin) on the list for the center cam bearing specifications for our TA engine (MPJG). We received many helpful replies. Thank you all. While we were not able to find any written or documented specifications, including from the recommended sources, we talked to an engine restorer in Michigan, John Twist, courtesy of Ed Curtis on our list. John is working on two MPJG motors as we speak. It appears that the center bearing has .002-.003 inch clearance and is made of bronze. So far so good. Now comes our next question. The end bearings receive lubrication from the main oil galley via holes drilled in the block but there are no such holes for the center cam bearing. Where does it get lubrication? The middle bearing straddles the oil pump drive gear (which also requires lubrication). Do these gears and the center cam bearing get their lubrication directly from an outlet on the oil pump? For those who seek technical support, the list works. Again, thank you. Kindest regards, Alan Campbell '37 MGTA 1282

[Robert Grunau]

Hi Alan, Eureka, you have found the answer ( sort of ) when you said " The middle bearing straddles the oil pump drive gear (which also requires lubrication). Do these gears and the center cam bearing get their lubrication directly from an outlet on the oil pump?" Answer ( I think ) is YES, except its directly off the oil gallery not the pump outlet. I have several TA engines but have not yet had the need to work on one. However, I have looked at the oil pump of a TA and WA engine and know they have a small groove on the inner spigot of the pump which will direct oil from the main oil gallery along the axis of the drive gear shaft and directly onto the oil pump drive gear on the camshaft. Exactly how this lubricates the bearing I don't know, but for sure the gear receives direct pressure lubrication from the oil gallery. Since the gear gets oil directly, possibly the bearing is also lubricated from splash from the gear?? I am using a similar groove in my TC race car engine to lubricate the oil pump drive gears under high speed/high load condition. Some XPAG engines have experienced oil pump drive gear problems under racing conditions. The groove allows direct pressure lubrication of the gears on the TC and assists the splash lubrication from the engine. I had seen the groove on the TA/WA oil pumps but could not understand why the TC did not have the same groove. Now I know the TA required the groove to provide direct feed to the oil pump gears and cam bearing which I assume are shrouded from the engine splash by the bearing. I'm sure somebody will confirm ( or deny ) this assumption. Regards, Bob Grunau Dear Faithful: Previously we sent out an APB (all points bulletin) on the list for the center cam bearing specifications for our TA engine (MPJG). We received many helpful replies. Thank you all. While we were not able to find any written or documented specifications, including from the recommended sources, we talked to an engine restorer in Michigan, John Twist, courtesy of Ed Curtis on our list. John is working on two MPJG motors as we speak. It appears that the center bearing has .002-.003 inch clearance and is made of bronze. So far so good. Now comes our next question. The end bearings receive lubrication from the main oil galley via holes drilled in the block but there are no such holes for the center cam bearing. Where does it get lubrication? The middle bearing straddles the oil pump drive gear (which also requires lubrication). Do these gears and the center cam bearing get their lubrication directly from an outlet on the oil pump? For those who seek technical support, the list works. Again, thank you. Kindest regards, Alan Campbell '37 MGTA 1282 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.351 / Virus Database: 197 - Release Date: 4/19/02

[Jeff & Merryl Redman]

G'day Alan, I have a copy of 'The Light Car' March 10th. 1939. An article called 'Under The Microscope - The T-Type M.G.Midget' explains the lubrication system of the MPJG. "....The centre passage from the (oil) gallery feeds the centre main bearing and also the centre bearing of the camshaft, together with the skew gearing for the oil pump and distibutor drives....." Hope this helps. Regards Jeff TA2828

----- Original Message ----- From: Monoxidemanor@aol.com> To: mg-tabc@yahoogroups.com> Sent: Thursday, May 09, 2002 12:26 PM Subject: [mg-tabc] MG TA Center Cam Bearing Lubrication Source? > Dear Faithful: > > Previously we sent out an APB (all points bulletin) on the list for the > center cam bearing specifications for our TA engine (MPJG). We received many > helpful replies. Thank you all. > > While we were not able to find any written or documented specifications, > including from the recommended sources, we talked to an engine restorer in > Michigan, John Twist, courtesy of Ed Curtis on our list. John is working on > two MPJG motors as we speak. It appears that the center bearing has .002-.003 > inch clearance and is made of bronze. So far so good. Now comes our next > question. > > The end bearings receive lubrication from the main oil galley via holes > drilled in the block but there are no such holes for the center cam bearing. > Where does it get lubrication? > > The middle bearing straddles the oil pump drive gear (which also requires > lubrication). Do these gears and the center cam bearing get their lubrication > directly from an outlet on the oil pump? > > For those who seek technical support, the list works. Again, thank you. > > Kindest regards, > > > Alan Campbell > '37 MGTA 1282 > > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > >