3.9 Deck Clearance Measurements

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308RRC

New Member
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3
Location
Melbourne, Australia
Hello LandyZone, I am a new member from Melbourne, Australia. Have 2 Range Rovers in the shed at the moment, a manual 1988 3.5 and a 1985 with a 5 litre Holden motor and A727 auto. The 1985 also has front and rear ARB air lockers and a winch. They both run on LPG.

I have reposted this in the engine section as it relates to my engine.

I have gone ahead and purchased a 3.9 to replace the 3.5 in the 1988 Range Rover. The 3.5 is very tired and I am pretty sure the camshaft is worn. Over the weekend I dismantled the 3.9 motor. Its a low compression, the crankshaft measured up ok and is useable, as are the pistons. I will replace all bearings, rings, timing chain and gears, camshaft and lifters. One strange thing was the marks in no.1 cylinder wall, never seen them before. I took the motor down to my engine man this morning. We measured the deck height to bring it down to 0.010 to increase compression. All piston to deck measurements were 0.050 to 0.052 thou except for the front of piston no.1, it is 0.030, tried several pistons in the position and still got 0.030. After scratching our heads for a while we determined the liner must be in the block on a slight angle. Not sure how we are going to get around this. The carbon buildup in cylinder no.1 is consistent with the other cylinders, nothing to suggest there has been a problem, except for the marks in the bore.

Any other ideas on what it may be?

I am also going to replace the camshaft, there are many to choose from. Does anyone have suggestions on what lift and duration I should be looking around for or a grind you have successfully used.

(This picture is not the actual block, just a picture to show the measurements)

Block.jpg
 
Checked the conrod is straight & the little end bush is parallel to the crankshaft?
I'd try that rod in another cylinder & see if it's the same.
 
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