Rover 3.9 blocks - really that bad?

AndyC · Post by **AndyC** » Wed Nov 07, 2007 11:33 am

Hello all,

I've been happily re-building the 1993 3.9i in my Land Rover 110 for a couple of months. It's the 2nd RV8 I've done, the other being a fairly basic 3.5 carb in my old Lightweight.

I just got a copy of Des Hammill's book on tuning the V8 and have given myself indigestion reading the chapter on the block and all the horrors of cracked blocks and fretting mains caps. Looking at my block I'm not sure if it's cracked - I'll need to investigate more closely - compression on cylinder 6 is down, but the piston doesn't look particularly 'steam cleaned'. I'll take a closer look at the liner to see if it's moved tonight. What I can see is that the mains caps aren't the 'snap-in' fit he talks about, they just about drop-in with a little push.

What I'm wondering though is does this matter to an engine in general purpose Landy which is unlikely to ever pass 4000rpm rather than tuned motor for 10s quarter miles? I guess if the block is cracked than that will be an issue, but do the main caps really need to be so perfect?

Thanks for any advice!

Cheers,

AndyC.

Post by **katanaman** » Wed Nov 07, 2007 2:17 pm

Replace the mains bolts with ARP and you will get rid of a lot of the problems. What you have to watch though is if the mains have moved then they might not be round anymore. This can cause anything from the clearances being slightly out to the crank wont turn. Obviously this is important on any engine no matter what the use. You also have to remember that although your landy engine might not be a high revving power monster its lugging around a lot of weight which puts a lot of strain on the engine.
Best advice is clamp the mains up and either measure or get measured properly. Only then will you know exactly where you are.

AndyC · Post by **AndyC** » Wed Nov 07, 2007 2:32 pm

Thanks for the reply.

I do have an ARP stud set for the mains, so that should help. I was planning on getting the bores honed at our local engine builders, so I'll maybe see if they can measure up the mains for me as well.

Cheers,

AndyC.

ChrisJC · Post by **ChrisJC** » Wed Nov 07, 2007 4:36 pm

I would get the block pressure tested before doing any work. Preferably tested hot as well. That will immediately eliminate any worries about hidden cracks etc. Your local engine builder should be able to help out with that too.

Chris.

AndyC · Post by **AndyC** » Wed Nov 07, 2007 6:27 pm

Thanks - I'll ask about that as well.

I see your fairly local to me (I'm in Cambridge). Do you have any recommendations for local engine shops? I was going to go to Cambridge Rebores in Burwell, who honed my 3.5 about 10 years ago. I'll definitely be avoiding Ivor Searle in Soham after they ripped me off on a flywheel skim.

Cheers,

AndyC.

ChrisJC · Post by **ChrisJC** » Thu Nov 08, 2007 8:22 am

I started off with Lyndale Engines in Peterborough, but they buggered me around with slipping completion dates that I gave up on them.

More recently I've used Automotive Services in Northampton
Automotive Services Ltd
Mr S Smart
59 Bunting Road Industrial Estate
Northampton
NN2 6EE
Tel: 01604 722064
Fax: 01604 722065

Who aren't the cheapest I'm sure, but they've always done exactly what I asked for, to a high standard.

But they are a bit of a drive for me, so it would be worse for you!

Chris.

AndyC · Post by **AndyC** » Thu Nov 08, 2007 11:35 am

I'd heard of the Peterborough bunch, but sounds like I'll give them a miss. Northampton is a bit far, although I do sometimes find myself up there for the white-water centre, but that's usually in the evening which isn't much use.

I'll see how I get on with Cambridge Rebores and post-back to the forum if it's good.

Cheers,

AC.