MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - camshaft bearings.

Engine stripped down with camshaft out- slid out easily. What is the easiest way to check whether my camshaft bearings need changing knowing this is not easily achieved even by specialists and therefore expensive.
JK Mazgaj

JK the camshaft bearings (almost) never wear out.
The front bearing / bushing can be installed easily when using a front camshaft journal placed inside the cam bearing, backed up with a large washer & gently taping into the block. They do not need line boring.
Before you do anything, why are you taking the block apart?
Len Fanelli
Len Fanelli

JKM
To answer your question-
IF camshaft bearings wear it's usually at the bottom caused by the load on them from valve springs etc. The heavier the springs the faster they wear-
To measure any wear you need to clean it all up spotlessly and refit the camshaft into it's running position 'dry' into dry bearings, set your dial indicator up on the top of the end of the cam and manually lift the cam up and down to measure the movement 'clearance'
The clearance specs.--
Front bearing--.0016"-.004"
Rear and centre bearings---.0018"-.0037"

So basically speaking , if it's got more than 4 thou. up and down movement on either end they need replacing

willy
William Revit

Thank you William for that comprehensive reply. Will do as suggested. Regarding Lens' query "Why"? Well this car had reportedly not been run since 1956. So although since run with no horrible noises as the rest of the car needed obvious work and the car being stripped to bare chassis and a new tub purchased etc. the decision to competely strip the engine was easily taken. It's also having a steering conversion and 5 speed box. Hopefully all will then be ready for extensive touring.
JK Mazgaj

Let’s hope the world is too. We are lagging here in my area in the States with vaccine deployment..I already buried one brother in law in October and had a second just dodge the grim reaper in Dec/Jan/early Feb.
Because I operated a flight into London within 10 days of my next trip, a Frankfurt, they pulled my Frankfurt trip. This virus is a lethal bugger.
Regards, Tom
tm peterson

JK, can you give a little bit more info on "having a steering conversion?"

My steering ('53 TD) feels a bit heavy but that may just be compared to the MGA.

Thanks.

Jud
J K Chapin

Jud,

make sure you have gear oil in the rack and not grease.

Jim
James Neel

Also 26/28 PSI in the tyres if on radials
Ray TF2884
Ray Lee

Thanks. I run 32 psi in radials but I need to check to oil in the rack.

Jud
J K Chapin

Tom
Sorry to hear of your Brother-inlaws
My thoughts are with you and your family
And yes-- This virus is a lethal bugger.
Stay safe
willy
William Revit

At 32 mine feels like I am on roller skate and it tends to oversteer because of the lightness.
Ray
Ray Lee

Jud,

At 32 lbs cold, you would be at 38 when the tires are hot and that's pretty high for such a light car. 26-28 would be a more reasonable range I believe.

Jim
James Neel

We've got a 100+ mile mountain drive coming up on Sunday. I'll lower the pressure (cold) to 28 and see how it drives. The tires are Vredestein classics.

Jud

ps: The second picture has nothing to do with tires, camshafts or anything in this thread - It's just one of my favorite pictures.




J K Chapin

I always replace cam bearings if the engine is apart. Too many times have I found Babbitt fatigue and or delamination. These issues can be difficult to see in situ so it is cheap insurance to replace them. Cam bearings are often not replaced on the generalization that they "don't wear out" but in fact they do wear and have other significant failure modes as well.
I have changed cam bearings (searching for a low oil pressure issue) that were in the engine for 50 years (they are dated on the back) that were mostly gone, with only the steel outer shell remaining. Cam bearings can and should be measured with a dial bore gage, like most other engine clearances.
J Stone

Appreciate your comments J.S. Having never attempted cam bearing change before and not having the necessary tooling I have approached a number of local shops all of whom seem to be reluctant to take on the work. Will have to keep trying.
JK Mazgaj

Interesting reading B.Stones ccomment regarding his experience with a siezed cam bearings
JK Mazgaj

This thread was discussed between 17/02/2021 and 07/03/2021

MG TD TF 1500 index

This thread is from the archives. Join the live MG TD TF 1500 BBS now