29 replies to this topic

[merther]

So I’ve been having a ticking or clacking noise from the engine for a while. I’ve changed to new rockers because I thought it was that, it has quietened of down a little bit it, it is still tapping/ ticking. I’ve driven it a good 100miles over the weekend and although the noise is still there it hasn’t got worse or better. The car seems to be lacking a little bit of power and almost sounding flat when it’s foot to the floor in fourth. It also occasionally hesitates for a split second when I put my foot down in third or fourth gears. 
I'm at a loss as what the noise can be my only thought now is a leaking exhaust manifold because I believe this makes the same noise as a loud tappet? I’ve had a look and I can’t see anything obvious but could this be my issue? Is there any way to test if it is or not or simply replace the gasket? I can’t see the centre manifold pipe as it’s hidden by the twin carts inlet manifold so I can’t inspect what it looks like.

[cal844]

Gas leak detector spray

[68+86auto]

is it only when moving or also stationary?

[merther]

is it only when moving or also stationary?

Both

[bpirie1000]

What kind of engine is this for?


If it is a carb, is there suitable oil in the dashpot? Could be carb issues if is bogging down i would suggest mixture has gone off balance.

May I also suggest stethoiscope or the screwdriver head on the cylinder head and listen and see where the noise is loudest. Cylinder head or carb.

You suggest the noise is all top end. Is that correct?

[Steam]

Worth rechecking and resetting the valve clearances as that is most likely the issue.

[merther]

It's a twin carb car. I've replaced the rockers with brand new roller rockers, clearances have been checked three times now. (15 thou) Since I fitted the new rockers the noise has quietened down by half but it's still there. It definitely sounds top end, when I put a screwdriver on the tappets I can hear the noise but I don't why it's there now as I've replaced with brand new.

[Shooter63]

What type of camshaft are you using?

Shooter

[merther]

What type of camshaft are you using?

Shooter

Swiftune sw8

[Shooter63]

What type of camshaft are you using?

Shooter

Swiftune sw8

These short duration fast ramp cams can be a bit noisy,especially if the lifters aren't that special. I put a SW5 in my Mrs car, it's not the quietest cam in the world.

Shooter

[Steam]

Does your specific cam require 15 thou clearance as the standard is 12 thou cold. Though I am not sure that 3 thou would make much difference but it would be worth the while to see.

[merther]

Does your specific cam require 15 thou clearance as the standard is 12 thou cold. Though I am not sure that 3 thou would make much difference but it would be worth the while to see.

Yes been told by swiftune to do 15 thou on both inlet and exhaust

[PeterG]

There seem to be many possible causes for this type of noise. I am currently working thought the same issue, top of the engine disassembled and waiting on parts from MS.  Block is A plus SPi bored to 1380, head is a new MPI unit from MS (many years ago) straight from the Rover production line when mini stopped production. After market 1.3:1 rockers on a thick wall rocker shaft. New Spi camshaft when I rebuilt the engine. Best cam followers I could get from MS. Duplex timing chain.

 

1st issue I found is best described as "push rod slap". The push rod hole in the block is smaller than the hole though the head. I had push rods hitting the wall of the block while clear of the wall of the hole in the head. The 2 outer holes in the block are larger than the others so 1 and 8 were clear. 2 through 7 had witness marks on the pushrods, some of them quite severe.

 

2nd issue, with the head off and the valves removed, there were scoring and scuff marks on some of the valve stems indicating inadequate valve guide reaming on this "factory head".

 

3rd issue was on the inlet valves where the keepers had lifted burrs on the top of the valve stem. I had to file these burrs down to remove the inlet valves from the guides.

 

4th issue was with the dual valve springs that I had fitted. The springs have witness marks all over where the inner and outer springs have been making contact. The opposing winds on the springs should mean that this is not a noise issue, but it was there.

 

5th issue oil leakage due to crappy valve seals. No noise issue with this one.

 

Currently waiting on parts delivery from MS.

 

I have reamed the valve guides. One was nearly OK, 5 needed a mild ream, 2 were in need of serious reaming.

 

When I get the parts, I will be installing new valves and lapping in the the valve seats which are all in good condition. New MPI Viton valve seals, new A Plus single valve springs. For the inlet valves I will be using Metro Turbo valves which are dimensionally the same as the std valves but have hardened tips/collet area. Then an MED 1.5:1 roller rocker assembly, new performance push rods from MS, finishing off with an MPI rocker cover to clear the MED rockers.

 

In a couple of weeks I will find out if all this works.

 

If this info is any use too you, great. Your issue could be totally different. Mini joy!

[merther]

There seem to be many possible causes for this type of noise. I am currently working thought the same issue, top of the engine disassembled and waiting on parts from MS. Block is A plus SPi bored to 1380, head is a new MPI unit from MS (many years ago) straight from the Rover production line when mini stopped production. After market 1.3:1 rockers on a thick wall rocker shaft. New Spi camshaft when I rebuilt the engine. Best cam followers I could get from MS. Duplex timing chain.

1st issue I found is best described as "push rod slap". The push rod hole in the block is smaller than the hole though the head. I had push rods hitting the wall of the block while clear of the wall of the hole in the head. The 2 outer holes in the block are larger than the others so 1 and 8 were clear. 2 through 7 had witness marks on the pushrods, some of them quite severe.

2nd issue, with the head off and the valves removed, there were scoring and scuff marks on some of the valve stems indicating inadequate valve guide reaming on this "factory head".

3rd issue was on the inlet valves where the keepers had lifted burrs on the top of the valve stem. I had to file these burrs down to remove the inlet valves from the guides.

4th issue was with the dual valve springs that I had fitted. The springs have witness marks all over where the inner and outer springs have been making contact. The opposing winds on the springs should mean that this is not a noise issue, but it was there.

5th issue oil leakage due to crappy valve seals. No noise issue with this one.

Currently waiting on parts delivery from MS.

I have reamed the valve guides. One was nearly OK, 5 needed a mild ream, 2 were in need of serious reaming.

When I get the parts, I will be installing new valves and lapping in the the valve seats which are all in good condition. New MPI Viton valve seals, new A Plus single valve springs. For the inlet valves I will be using Metro Turbo valves which are dimensionally the same as the std valves but have hardened tips/collet area. Then an MED 1.5:1 roller rocker assembly, new performance push rods from MS, finishing off with an MPI rocker cover to clear the MED rockers.

In a couple of weeks I will find out if all this works.

If this info is any use too you, great. Your issue could be totally different. Mini joy!

Thanks that's interesting I've also seen marks on some of my pushrods where they have been scoring the hole. I fitted new 1:3 roller rockers along with the 1mm shim to try and move the pushrods more central in the hole. They look better but maybe they are still touching..

[merther]

https://streamable.com/20v4pn

This is the noise I'm getting..

ignore the straight cut drop gears rattling it’s the tick tick noise I’m unsure about.

Edited by merther, 23 July 2024 - 03:09 PM.