4.6L crank in a 3.5L?

[Sidecarbod]

Originally Posted by TINKA

Sorry to disagree but it is far better in my opinion to get a 3.5 block and bore and reline than to get a 3.9 block. As far as I am aware they are based on the same casting and due to some fuelling issues some 3.9 are prone to having cracks or loose liners due to over heating. I had a 3.5 block relined with 3.9 liners and it ran great.

Hi Martin,

In a book that I read on RV8 lumps it states as Robin mentioned that the 3.9 does indeed have greater wall thickness around the liners on the 3.9 when compared to the 3.5. It also reckons that there have been no problems dropping the 3.9 liners in a bored out 3.5 block as you have done. (However, just because its in a book doesn't mean that any of this is right!).

IMHO 3.9 liners AND a 4.6 crank maybe pushing what the block can cope with!

Regards,

Pete

[Purple AK]

Not Cheap! But it would appear to be the easy option as you only need a +20 rebore and some fettling on the base of 2 bores (according to the blurb) :thumb: http://www.rimmerbros.co.uk/rimmer/rover/v8engine/crank
Realistically by the time you have re-linered the block and machined the crank, This is probably as cheap

[russell_ram]

Or buy a 4.6 short motor new for the price of that kit. As Tony said earlier, enigne numbers aside, you've got to be pretty knowledgable to tell the difference at a glance. Of course, service blocks come with no number stamped from new . . . .

Russ