Jump to content
Forum software update now live Read more... ×
meesonia

TR4A Timing Marks

Recommended Posts

Hi all

 

 

Engine has been stripped down, during the strip I noticed that there were no obvious TDC marks on the pulley (wide belt) but the Timing Chain Cover does have a pointer. So now in the clean up phase and start to put back together, the pulley doesn't have any marks except a small neat hole in the rear flange. So couple of questions, is this TDC? Can't see why it couldn't be, and if so should it be immediately adjacent to the woodruff key slot on the Hub, which means the slot is TDC, or 180 deg to it? Pics below. Thanks as ever.

 

Ian

 

post-12001-0-11744700-1528618531_thumb.jpgpost-12001-0-40060400-1528618557_thumb.jpg

 

 

Share this post


Link to post
Share on other sites

Hi Ian,

the hole does denote TDC (nearly).

 

if you have the original pulley then it can come apart and allow the hole to be anywhere.

 

The Woodruff key slots are at BDC when #1 piston is at TDC.

 

It is always best to accurately position #1 piston at TDC then mark the pulley for an accurate setting.

 

Roger

Share this post


Link to post
Share on other sites

+1 for Roger's remarks, unsurprisingly he beat me to it. S.T had not heard of poka-yoke and since the holes in the hub are equidistant it is possible to have six different orientations for the assembly and for the timing to be up to 180 degrees out. I had this on my car once after the engine had been reassembled in 1982 by Dunham and Haines in Luton, a BL main agent at the time!

 

Tim

Share this post


Link to post
Share on other sites

Hi Ian

 

my car came with the drill set 120 deg. wrong, because it is not 100% correct, so one of the former owners made his own mark.

 

I set it back (drill to arrow on TDC) and added further marks up to 25 deg. before TDC. That makes the work with a stoboscope / timing lamp much easier.

 

If wanted I look for photos on my computer.

 

Ciao Marco

Edited by Z320

Share this post


Link to post
Share on other sites

Thank you all, good information as ever.

 

Ian

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×