Jump to content
Sign in to follow this  
triumphlux

Austin Mini A-series engine noise

Recommended Posts

Hi,

I restored my Mini for the 3rd time in 20 years. Its my classic to use during the winter and I did a few upgrades this time to try to keep up with the moderns.

The engine is a 1293 ccm which had been done 15 years ago (45.000 km) so we pulled it apart and fitted new shells, oil pump, timing chain etc.

It also got a flowed cylinderhead , high lift rockers, an LSD and adjustable suspension :banana:

From the first time I started the car it has a loud 'tapped' noise coming from the rear of the engine.

All the parts are sourced from a friend who builds A-series engines for 30 years and together we were unable to find the fault .....

We changed the rockers back to the original setup, no difference.

I checked without the rocker cover, no difference.

I took the valves springs from th last 4 valves off the check, everything is fine :craig:

I fitted new pushrods and screws, no difference.

The car goes really well and rews up to 5.500 without a problem.

So if you have any ideas what it could be, please let me know.

JC

20180113 (2).MOV

Share this post


Link to post
Share on other sites

I can download (how slow is your connection Alan?) but not play it - some codec issue?

If suspecting it is valve train noise (hanging tappet?) you could try temporarily reducing the valve clearances to zero and seeing if it shuts up.

Nick

Share this post


Link to post
Share on other sites

30Mb Symmetric, but I suspect I was trying to play streamed and it was encountering trouble decoding hence the time estimate.

Well actually I had gone off on a tangent after trying to track down a sharp tapping noise at the end of last season which turned out to be hole in collector in manifold, so was wondering as everything was running all right if it could be something stupid like blowing plug or manifold, hence half rpm or full rpm timing.

Alan 

Share this post


Link to post
Share on other sites

Well, after much searching we didn't find out what was wrong ….. so we decided to drive the car and see what happens :rolleyes:

After less then 1.000 km it finally broke down late one evening with a load BANG …. 

The engine stopped itself and the gearlever linkage was stuck. So engine/gearbox out and dismantling to check what went wrong.

IMG_9524.thumb.JPG.e68cf4eb64420546629fec977002fe8d.JPG

Share this post


Link to post
Share on other sites

A socket bouncing between gearbox and engine would probably not last as long :smile:

Nick is correct, the lower part of one cam follower broke into 3 pieces which got eventually smashed by the camshaft and fell into the gearbox housing …

broken_follower.png.6281352582f0ec3de1121152eff44297.png

cam_follower_block.png.19b0b44c0fac7503f8003daaefec9961.png

The damage is quite bad BUT not terminal. One piece got between the diff gear to gearbox gear so that needed to be changed and the gearbox housing has got a hole so that needed changing too :unsure:

The cam is toast as well as the timing gear!

timing_gear.png.d9a94ba3f4a924719f0a0953c0054072.png

You can also see that the follower got crashed by the cam to he engine block and that needed careful filing so that the upper part from the follower left would come out. But I managed to save the block and the new follower moves freely :biggrin:

Share this post


Link to post
Share on other sites

The gearbox has already been rebuild in to one of the freshly sodablasted housings. Looks way too good to put in the Mini that I use during the winter!

gearbox_new.thumb.png.5971446b5866ab33aab208da897f0ed6.png

The engine will get fixed next week.

JC

Edited by triumphlux

Share this post


Link to post
Share on other sites

We didn't change camshaft or followers as everything was (or seemed to be) in perfect condition. Less then 50.000 km in ten years on this engine.

We changed the bearing shells and oil pump as well as a new modified head.

Why it happened now I don't know.

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
Sign in to follow this  

×
×
  • Create New...