RV8 Block Wall Thickness

[russell_ram]

Rover guys,

Remember the thread a couple of weeks ago talking about Rover 4.6/4.0 cylinder block wall thickness due to core shift during the casting process and consequent cracked/porous cylinders? Well, I have finally dug up the relevant info on what to look for if you are considering purchasing a second hand or new X-bolted block.

Firstly block age. Casting age is cast into front face of block, behind camshaft timing wheel. Appears as week number and year ie 15/98. Block part number cast on outside of cylinders 7 and 8.

Blocks with part number HRC2411 - prior to end 96 - no wall thickness measurement applied, wall thickness issue not really a problem on these engines.

Still HRC2411 - post end 96 - thickness measurement introduced following a poor casting batch.

RED thickest - 2.7mm and above.
YELLOW - 2.5 to 2.69mm
BLUE - 2.15 to 2.49mm

Current blocks - part number LFC000250.

RED - 2.7mm and above.
BLUE - 2.5 to 2.69mm.

In both cases all below these thicknesses are scrapped.

Measurement refers to thickness 15mm from cyl face, middle two cyls of each bank - between cylinders ie a measurement of the thickness between 1-3,3-5,5-7 and 2-4,4-6,6-8. Obviously red is the colour to go for, if you have a choice. All factory 4.6 should be built with RED blocks, others used for 4.0 only. Marking should appear on inside of V, usually on cyl 3 wall and also on block rear face above camshaft core plug.

I am also advised that for the aftermarket (read Rimmers, RPI etc) the term 'caveat emptor' should be applied, that is unless you know what you are looking at you could get anything. 'The standards maintained by engine re-manufacturers are not monitored by LR, and consequently the surety of their products is unknown.'

Hope this is some help and may help avoid an expensive mistake (Steve G - no offense Steve).

Russ

[russell_ram]

Of course, in the above post there is obviously no implication that either Rimmers or RPI sell components of sub-standard quality, in fact they are both very reputable companies in the RV8 field. However, their names are only mentioned as an indication of where you might go to buy a new/re-conned RV8 block if you wanted one.

Russ

[PeteV]

Cheers Russell,
Really useful stuff to know !!

Pete.