19 replies to this topic

[Sprocket]

You seem so certain - it must be piston slap then! New engine required.
Meantime - just for fun - have the head off the old one - just to satisfy our curiosity.

My thoughts too. If the noise is piston, the engine is screwed.

Just to give you an idea. Normal piston clearance is 1 to 2 thousandths of an inch. I purposely built an engine with 3.5 thousandths clearance. Before the engine was pulled apart again, there was no audiable sign of piston slap and the measured clearance was 6 thousandths of an inch. This was a 150hp engine that regularly seen 7000+ rpm. I had no issue rebuilding this engine with this clearance if it wasn't for that piston over there <<<<<. What you have to consider is the factory upper limit on tollerence is around 2 thousndths, and another 4 thousandths did not produce that audiable noise that could be considerd piston slap. So for it to be piston slap, the wear on a standard engine has to be severe.

Now what do you want to do? rebuild the engine? or replace a head gasket that costs £20 at the most and see if things improve? You have already had some one look at it and told you it was the head gasket, and from the information you have given, others have also said the same.

Piston slap it is then

[jackog_mayfair]

You seem so certain - it must be piston slap then! New engine required.
Meantime - just for fun - have the head off the old one - just to satisfy our curiosity.

not certain just worried!
and i will asap try to change it because its killing me not being able to drive!

[jackog_mayfair]

You seem so certain - it must be piston slap then! New engine required.
Meantime - just for fun - have the head off the old one - just to satisfy our curiosity.

My thoughts too. If the noise is piston, the engine is screwed.

Just to give you an idea. Normal piston clearance is 1 to 2 thousandths of an inch. I purposely built an engine with 3.5 thousandths clearance. Before the engine was pulled apart again, there was no audiable sign of piston slap and the measured clearance was 6 thousandths of an inch. This was a 150hp engine that regularly seen 7000+ rpm. I had no issue rebuilding this engine with this clearance if it wasn't for that piston over there <<<<<. What you have to consider is the factory upper limit on tollerence is around 2 thousndths, and another 4 thousandths did not produce that audiable noise that could be considerd piston slap. So for it to be piston slap, the wear on a standard engine has to be severe.

Now what do you want to do? rebuild the engine? or replace a head gasket that costs £20 at the most and see if things improve? You have already had some one look at it and told you it was the head gasket, and from the information you have given, others have also said the same.

Piston slap it is then

im just worried because that is the worse case scenario and i just dont want it to be that! but reading what you did to your engine has settled my nerves! i dont mean to be a pain i was just wanting to be sure that it wasnt the worse case scenario. so hopefully when my head gasket arrives i will get it fitted and let you guys know of the result!
so thank you for your patience!
jack

[Cooperman]

One might expect an engine with so much wear that thge pistons were slapping to be burning so much oil and smoking that it would smoke like an early Boeing 707 on take-off!
I mean, it would be smoking so badly that following traffic would be lost in the haze.
Was it really badly smoking?

[jackog_mayfair]

One might expect an engine with so much wear that thge pistons were slapping to be burning so much oil and smoking that it would smoke like an early Boeing 707 on take-off!
I mean, it would be smoking so badly that following traffic would be lost in the haze.
Was it really badly smoking?

haha yes one might expect and engine to do that! but mine was only giving out smoke from the piston chamber when we did the pressure test so its not when driving!