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Hey dudes,

Well with the RB25 going into the car i thought i would pull apart the RB20 to see what was wrong with it.

I have stripped it back to basically the head sitting on the block....looks like it was leaking oil thru the gasket @ the back (5 & 6) between the head & block.

Anyways I have hit a dilehma. I will try an explain as best as possible.

In between where the cams run in the 'valley', where the spark plugs live, is 3 bolts tourqued up to the BS, holding the head to the block. There are more 'allen key' bolts sitting on the outside under where the cams run, which are fine, just having a issue with the middle 3.

They have a 'allen key' head to them, removing any chance of using socket set. I have figured out that the outer bolts require a 10mm allen socket thing to undo, no probs there. The middle 3 are NOT a 10mm size. It seems they are too big for a 10mm, but too small for a 11mm piece. I have already snapped a fitting used on a breaker bar trying to undo these torqued up MOFOS!!! Also started to 'round' them using the 10mm.

Questions is -

1. Is there a specific tool i require to undo these?

2. If not, is the allen key part required a Imperial or metric sized piece?

Cheers, in advance dudes!!

Ando

There are 14(?) bolts with allen key heads - 10mm, available from any auto parts retailer. The bolts are accessible without removing the camshafts.

The 3 down the middle have nothing to do with holding the head onto the block.

There are also 3 small 10mm head bolts, 2 at the rear, one at the front (driver's side).

Undo from the middle outwards, alternating front and rear.

ie: 7/8, 5/6, 9/10 ...

blind elk - Thanks buddy, well i was halfway there.... now i feel like a numnuts breaking sockets trying to undo those middle 3 bolts.... ahahaha

Such things happen when you pull engines apart for the first time with no manual!

So what are the middle 3 bolts for??? anything?

Cheers dudes!

Thinking about it, undo from the ends and work towards the middle - what I initially posted is the tightening sequence.

The middle three are probably to access the water or oil galleries through the head during manufacturing.

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