RV8 piston slap

[ToneyCaroney]

The head honcho of the service dept at my TVR specialist says piston slap on an RV8 5.0 is not unusual during cold starts..

True?

Cheers, Stu

[rigga]

Yup...
True of many engines, subarus suffer too from my own experience,not really a worry when from a cold start as long as not excessively noisy ....if it does it when it's warm that's another story.

[carsy]

rigga said:

Yup...
True of many engines, subarus suffer too from my own experience,not really a worry when from a cold start as long as not excessively noisy ....if it does it when it's warm that's another story.

Mine has it from cold. Completely gone after a couple of minutes. Shows the engine is nice and loose. Like Rigga says nowt to worry about as long as its not there when hot.

[ToneyCaroney]

Thanks guys. Puts my mind at rest.
It is not too obtrusive but noticeable and gradually diminishes over the first 5-10 minutes of running. Sounds sweet as a peach after that.

My old MX5 used to slap like a bd too!

I'll stop worrying. Cheers!

[vjj]

ToneyCaroney

as the engine warms up the metals therein expand, thus tightening the tolerances between moving parts.

obviously when the engine is cold the gaps between moving parts are bigger.

This is why it is critical to allow the motor to warm up properly as excessive revving during the 'loose' phase can cause all sorts of excessive wear.

[rigga]

vjj said:

ToneyCaroney

as the engine warms up the metals therein expand, thus tightening the tolerances between moving parts.

obviously when the engine is cold the gaps between moving parts are bigger.

This is why it is critical to allow the motor to warm up properly as excessive revving during the 'loose' phase can cause all sorts of excessive wear.

Its more to do with the different materials used in the engine and their expansion rates when heated which won't be the same ....it all needs to be factored in when designing.

[ToneyCaroney]

Thanks for the info chaps. My 4.0 litre didn't do it which is what prompted me to ask the question. I don't mind a bit of slap if it is a normal characteristic of the RV8. The 5.0 is particularly prone, I understand.