it's better to rebuild the engine or replace it

[MarcoP]

Hi everybody,
I need to make a business plan before start to restore my wedge. So I have a big doubt: if it's better to rebuild the engine or replace it. Now is a 3.9 with only 5k miles, but after 20 years of neglect, it is only a pile of rust and oxide. I have not yet verified if it's locked, but I presume strongly that it is. In addition all ancillaries are in the same condition of the engine. I think is more easy to replace all with a second hand complete engine. Maybe with a cylinder capacity exceeding , but not less than 3.9. I haven't an idea of how much does it cost a decent engine. I don't want less 240 bhp.
Any suggest is welcome.

[dbv8]

Maybe you could pick up a very fair priced 4.6 donated by a dead rangerover.

[pwd95]

Here you go, problem solved.

http://www.pistonheads.com/sales/2755228.htm

[MarcoP]

In fact it was just what I thought, but I've Not idea for a right price. A Range rover 4.6 has 220 bhp so I believe it need only a remapping for have 240 bhp or more. But now I've another doubt: it's a easy work the engine substitution, or the 4.6 required some adjustment for have a good work?
Nice link pwd95, maybe it's too much for me, but very interesting. Do you think it's a correct priced?http://www.pistonheads.com/gassing/imgs/10.gif

[TVRleigh_BBWR]

pwd95 said:

Here you go, problem solved.

http://www.pistonheads.com/sales/2755228.htm

at that price its a bargain esp with that spec. and Box

Would cost more as parts let alone time and money spent to rebuild.

[Wedg1e]

I would take out the spark plugs and try to turn the crankshaft over with a socket on the front end. Don't try to get it all the way round, just see if it will move. If it does, take off the cylinder heads and see if the cylinders have rusted. Depending on which valves have been open, there may be minimal corrosion. If there is it can be polished off with fine abrasive paper before you try the crank again to see if it will turn fully.
It is perhaps an afternoon's work and for the price of a pair of head gaskets, well worth trying.

Once the crank is turning, everything else is easy

[MarcoP]

I've tryed to take out the spark plugs: seven have gone well while the eighth it was broken during the operations. Besides I've got fear that the restoration and the mounting of all ancillaries needs too much work and money. New (or refurbished) alternator, new steering pump, new air con pump, ecc. ecc. one by one aren't a great expense, but the total amount (work and money) is imprevedible. On the other hand I can spend lot of money in a flash but only in a weekend I have solved all principal problems. http://www.pistonheads.com/xforums/smilies.htm#
Engine block and transmission's attack are the same for all engines (3.9, 4.6, 4.5, 4.2, 4.3, 4.0?

[CHJ]

pwd95 said:

Here you go, problem solved.

http://www.pistonheads.com/sales/2755228.htm

Looks a good price. How many hours labour do you estimate a good mechanic would take to properly fit that in a 350i, and what other new parts are probably likely to be required?

Thanks,

Chris

Edited by CHJ on Wednesday 27th April 16:45