What to do with new block?

davemgb · Post by **davemgb** » Tue Jan 15, 2008 8:22 pm

Folks,

I've acquired a new block but I'm now debating what to do with it...

Its an early 80's style cross bolt unit without liners.
Casting number is ERC6619 and it has the thick cross webs but not the external rib just above the crossbolts.

I had planned to build a 3.5 in it - the liner bores are curently 93.09mm, is that the factory original size for 3.5 liners? EDIT - this should say the bores for the liners are 93.09 cause there are no liners fitted yet !

What is the considered wisdom guys?

Dave

RoverP6B · Post by **RoverP6B** » Tue Jan 15, 2008 10:04 pm

You could have flanged liners fitted, that way no liner problems at any point in the future.

At the same time, new camshaft bearings can be fitted too.

You indicate that it is a cross bolted block. It is my understanding that cross bolted blocks of the early 1980s were special units made especially for racing, usually by the Rover works teams of Tom Walkinshaw and TWR!

Ron.

ChrisJC · Post by **ChrisJC** » Wed Jan 16, 2008 8:43 am

Are you sure it's cross-bolt?, not just a stiff-block?

Chris.

davemgb · Post by **davemgb** » Wed Jan 16, 2008 7:16 pm

Chris,

Yes, I'm sure its crossbolted I just didn't post a picture to prove to everyone else.

I've noticed that the crossbolts are not the later pattern intergral washer things found on 3.9's but have very thick seperate washers and that both rear cap bolts are socket head type.

Dave

ChrisJC · Post by **ChrisJC** » Wed Jan 16, 2008 9:28 pm

That should make for a bullet proof engine then I would say.
Keep it at 3.5" for maximum material around the liner. And with the crossbolted bottom end it should be nice and strong.
Might be worth considering enlarging the bearings etc to take a crankshaft with bigger main journals as I believe the smaller journals can snap.....

Chris.

RoverP6B · Post by **RoverP6B** » Thu Jan 17, 2008 1:23 am

Davemgb,

What is the engine number stamped on the block, along with the compression ratio which should appear adjacent to it?

It may well not have the latter, after all CR is piston dependent.

Some of the competition blocks, as yours may well be, in both 2 and 4 bolt format produced by British Leyland Motorsports cannot be used with hydraulic camshafts and lifters because the appropriate oil passages have not been machined into them!

Ron.