3 into 1- RV8 rebuild questions

Quagmire · Post by **Quagmire** » Wed Jul 30, 2008 12:19 pm

After lurking around these boards for some time and reading much of the excellent info on here i have decided to join and ask a couple of questions of my own....

I am planning on fitting a 3.5 v8 into my 1984 LR90, which currently has the rover 2.25 fitted. With a view to doing this i bought a couple of engines that were cheap and now have built up the following collection. I want to build a reliable (but not earth shatteringly powerful) engine to make my 70 mile a day motorway commute more bearable.

I am on a pretty tight budget and so would like to minimise or cut out all together any machining work that you might otherwise pay for on a true stump puller of an engine.

Oh and i run on LPG 95% of the time...

Collection as follows

One 10.5:1 P6 engine, complete but with fairly bad scoring in pots 1 and 3, knackered cam and followers, heads with short reach plugs, and topped of with SU's. Full of black gunge. Full ancillaries and exhaust.

One 9.35:1 SD1 engine, again with scoring- but not anywhere near so bad- Cam and followers showing a fair amount of wear. No ancillaries. Much better colour inside, more brown/gold than black.

One 8:13:1 Early Rangie engine. This is complete with Strombergs and again with full ancillaries. This has not been stripped down yet and so condition is unknown....

So- given the parts available what would you suggest putting together? I realise that the higher compression is going to be much better for my LPG running, but i cant really afford to get the P6 block reworked, and i would be looking at oversize pistons anyway. Assuming the pistons are in good nick, could i put them in one of the other blocks with some honing and new rings? Likewise with the 9.35:1's, would they fit the 8.13:1 block? I have a sneaking suspicion that this has a different size bore to the higher ratio engines but can't remember...

I am planning on changing cam and followers, and the timing gear and chain as a matter of course. Can i fit new cam bearings myself if needed, or is this strictly a machine shop job?

Thanks in advance, and apologies for the essay.

sidecar · Post by **sidecar** » Wed Jul 30, 2008 12:31 pm

If the block that you've not stripped is knackered you can have for FREE an SD1 block, crank and pistons. The bores are not scratched, I was told that the crank has been nitrified (or whatever is called). The cam bearings are in good nick too. The pistons are 9.75:1 I believe but I guess that you will be sticking in the 10.5 jobbies.

The block is clean and not full of crap, I was using it until I built a 4.6 lump.

I live in Bagshot.

Pete

ChrisJC · Post by **ChrisJC** » Wed Jul 30, 2008 1:58 pm

OK.
- All your blocks have the 3.5" bore, so you can fit the P6 pistons to the best block. Or the 9.35:1 pistons to the 8.13:1 block. I would agree a new set of rings & a hone is a must.
-There's probably no need to change cam bearings. It is a DIY proposition, but you need to have made up a set of 5 drifts to put them in by a friendly mate with a lathe.
- Definitely renew all timing equipment, chain, pulleys, cam, followers, pushrods, rockers & rocker shafts.
- Use the later heads with the long reach plugs.
- If you can, get the valve guides changed for the later neoprene-seal type. Whilst you're at it, get about 0.7mm removed from each head, then you can use composite head gaskets with the original type head bolts (ignore the fancy new one use only stretch ones). Don't fit the outermost four bolts.

Chris.

P.S. I run a 3.5EFi on LPG with P6 pistons and composite gaskets. It seems a good combination.

kiwicar · Post by **kiwicar** » Wed Jul 30, 2008 3:48 pm

personally I would consider the SD1 block offer very seriously but swap in the 10.5:1 pistons, skim all you can off the heads and fit the comp head gasket (can you run it on gas only?) refresh the heads and fit a new low overlap cam, I can let you have a chevy inlet or exhaust valve co make a valve pocket cutting tool if you need one

.
Mike

sidecar · Post by **sidecar** » Wed Jul 30, 2008 5:12 pm

Quagmire you have a PM!

Quagmire · Post by **Quagmire** » Fri Aug 01, 2008 6:20 am

Well picked up the block and other bits from Pete last night and had a nice long chat, can't wait to get started on the rebuild now as i have a good solid base to go from.

Thanks Pete!

...and thanks to everyone else for such a great response to my first post

sidecar · Post by **sidecar** » Fri Aug 01, 2008 7:35 pm

Quagmire wrote:Well picked up the block and other bits from Pete last night and had a nice long chat, can't wait to get started on the rebuild now as i have a good solid base to go from.

Thanks Pete!

...and thanks to everyone else for such a great response to my first post

No Problem at all Jamie, I'm glad that the stuff has gone to a good home!

Please let "Pocket Rocket" know if you do not need the pistons, he expressed an interest in them.

Speak to you soon,

Pete