Timing chain [Florida, USA]

Here's the story. I'm changing the water pump on my 75 MGB. Then I decided to change the seal and timing chain gasket while I had it apart. Now I'm thinking of changing the timing chain while I'm at it. Question, do I change to the double chain & sprockets or stay with the single. Do I replace the tensioner also? Any thing I should be aware of before I attempt this. Do I need any special tools? Or should I just leave it be. If it ain't broke, don't fix it approach.

Thanks
Lawrence

I would go with the double set and replace the tensioner.

If you have a manual I think it explains how everything fits back together and how you release tension on the tensioner with an allen wrench.

Lawrence,

Couple of facts for you. There's about a four degree of difference in cam timing between the single and double row timing chains. The late single row chain is advanced about four degrees compared with the duplex (double row) setup. So the single chain setup moves the torque curve downward a bit in the rpm range, while the duplex chain setup retards the cam timing, moving the power band upward a bit. So if you want your engine to spool up a little higher, you could switch to the duplex setup for that reason. Otherwise the chains don't really wear much, and wear is taken up nicely by the tensioner. You can check the rubber foot on the tensioner and, if the foot is not badly worn, it's probably fine to just re-use the entire setup and save yourself some shekels...

Dick

Thanks for the feedback, I think I'll look it over and change the foot or only what's necessary. I'm going to stay with the single type sprocket. No point in looking for trouble.
Lawrence

Lawrence,

If the foot is worn suggest you just get a new tensioner assembly...

Dick

Dick
I have the damper off and the cover, I'm looking at the chain and tensioner assembly. Both look pretty good, no visable signs of wear. However, there is about 1/2" slap in the chain on the opposite side of the tensioner. Is that the norm? If it is ok, I'll just put it all back.
Thanks again
Lawrence

Lawrence,

As soon as the engine turns in its normal direction of rotation (clockwise when viewed from the front of the car), the crank sprocket will take up the slack on the "off side," and the tensioner will then take up virtually all of the slack in the chain...

Dick

That did it, Thanks again.
Lawrence

Happy to help, Lawrence. Three friendly suggestions for you. You might find more/better response if you post technical questions in the MGB & GT category rather than here in Trader, which is mostly buy and sell. And don't forget to reinstall the oil slinger disc before you reinstall the timing cover. The slinger goes in with the concave side and the letter "F" toward the Front of the car (darn clever, those British... ;)). Finally, if you leave the timing cover bolts loose until you reinstall the balancer, the balancer will "self-center" on the seal and the cover, allowing the cover to move ever so slightly within the free play allowed by the bolt holes. This will help give you the best sealing possible.


Cheers,

Dick

I will do that, I'm new at this site. First time I used it. Great Idea about leaving the timeing cover bolts loose.
Would have never thought of that. Putting it together tomorrow.
Lawrence