RUMCars Forum

General Category => Unusual Microcar Discussion => Topic started by: Bob Purton on October 30, 2010, 09:19:56 PM

Title: pistons and crankshafts
Post by: Bob Purton on October 30, 2010, 09:19:56 PM

1. What formular are you guys using for piston ring gapping?
  

2. Can anyone recommend a company for crank shaft rebuilding [ in the south east] , I have a conrod kit and need somebody to pop it and fit the new one.

Title: Re: pistons and crankshafts
Post by: Chris Thomas on October 30, 2010, 10:07:51 PM

Dear Bob

What gap  are you wanting the Axial clearance, or the end gap, or both?

Which of the rings are you considering and on what engine?

Potentially the answer to your question will depend surely upon these differing parameters.

From the pedantic Chris Thomas

Title: Re: pistons and crankshafts
Post by: Chris Thomas on October 30, 2010, 10:20:52 PM

Dear Bob

I do not have any experience with popping cranks!!!!!!

But one of these guys should be able to help you 

http://www.fer.co.uk/fer/portal/main/SearchList.asp?Postcode=southeng&Section=Find%20a%20Member&SubSect=21+Southern+England

Chris Thomas

Title: Re: pistons and crankshafts
Post by: Bob Purton on October 31, 2010, 09:03:14 AM

Hi Chris. I'm referring to end gap. Of course it depends on the engine which is why I ask for the formula. I have been using the formula .003 per inch of diameter, this has long been a general guide but just wondered if there was anyone out there with specialist knowledge. At least this formula was around at the same time as our old engines with cast iron rings so maybe its still the way to go. There will be manufacturers figures for each engine but my engines are all funny old obscure foreign ones for which I have no detailed spec. Thanks for the list or crank shaft companies.