1 reply to this topic

[Matpaul]

What is the best way to stop the connecting rods and caps twisting and ending up with a step at the parting line when you are doing up the rod cap bolts on a 998 / 1100 engine? I tried feeler gauges on each side against the crank which I thought I had seen somewhere but it didn't seem to work very well...

[Spider]

Hi Matt,

 

The Caps are stepped with a very small interference fit over the Rod and the correct Bolts will have a small increase in the Shank Size right under the Head of the Bolt. These two will locate the Cap on the Rod, if they don't then it's likely the Rod is scrap.

 

(sorry, the only file photo I have is of a Rod modified from a standard Rod)

 

 

and the parting 'line' and can see is stepped

 

 

The Stock Rod Bolt - you can see the Locator on the Shank of the Bolt here

 

 

Before fitting the Cap, the Rod Bolt should be tested on the holes of the Cap. There should be the very slightest of interference here, but definitely no play what so ever.

 

 

Just a warning / caution on Rod Bolts. These should always be replaced at an engine overhaul, in particular if the engine has come from somewhere unknown and also keep in mid, with an 1100 engine, they work pretty hard due to their very long stroke. If you are replacing these Bolts, then only fit those you 100% know are factory items. The A+ Rod Bolts will fit your Rods and there are some small stocks of these around but you'll have to look. The other reliable source of Rod Bolts are ARPs, though not cheap. The consequences of a Rod Bolt Failure will write off everything under the Cylinder Head including the Gearbox. They really aren't worth taking chances with.