4.6 block build or short motor?

[Seight-V8]

hiya all,

Been sitting on this for a while now and i need to get things moving in building a 4.6 engine.

Anyone know how much to re-con a 4.6 block fully?

As i am wondering wether it would be better to go for a short motor instead?

cheers

scott

[Teesdale_landrover]

if i was investing money into a 4.6
i would buy a brand new one from rpi cosworth casting, it think they are a shade over 2k

but a rebuild and maybe a new liner or two is going to be a thousand (dont recal how much the last one we had done was) and there is no gurantee it wont have block issues again.

just my opinion

[chodjinn]

Well my opinion is that I wouldn't waste money on a 'coscast' block or new short engine because although the casting process might have been improved slightly, it hasn't changed the block or liner issues as that is an inherent problem with the block design.

For the money, it would be cheaper to use a seasoned block (a 4.6 block/engine with a dropped liner can be had for peanuts - I've bought two at no more than £50). Top-hat liners can be fitted for around £800 (I know a local place that will do them for £700 and they have done several before).

I'd then use ARP mains, rod and head bolts (around £300) for a very very strong bottom end and to keep the heads in check. You could also add in a camshaft kit depending on your application (high torque, road/race etc) which can be had for £300-400 depending on spec and parts. Add about £300 to bolt it all together

So, for about £1800 you could have an excellent short motor, far sronger and more powerful than a new short motor.

Personally, I would give V8 Develoments a call and discuss your options, they are very knowledgable and very helpful, plus they are forum sponsors and give a bit of a discount!

[kiwicar]

Can I suggest building a 3.9 bottom end that doesn't have the reputation for dropping liners and could be rebuilt without £700 worth of top hat liners, then spend the money saved on a set of merlin heads. With the right cam you have an engine that would match the power of a 4.6 with ported standard heads, and have an engine you could develope further that isn't limeted by head flow.
Mike

[ChrisJC]

Although the 3.9 doesn't have a reputation quite as bad as the 4.6 for dropping liners, this is probably because it was run with a different fuelling system and developed less power rather than any difference in the construction of the block around the cylinders.

Additionally, the 3.9 only had 2 bolt mains.

Chris.

[Seight-V8]

thanks for all the replies.

Does anyone know how much discount V8D will give.

As i might get my block top hatted which they qoute at £835 + vat

Then build the rest myself.

As short motors are £1895 now.

cheers

scott

[CastleMGBV8]

Scott.

I would think that any 4.6 block which has been top hat linered may have had problems with liner slip and probably cracking of the block itself and therefore there is no guarantee that you would not have future problems.

If you can afford it I would recommend one of the Cosworth blocks from TVR Power which come with a three year guarantee and are high pressure cast to much finer tolerances at £999.00 + VAT.

Link.

http://www.powerstores.co.uk/?t=si&item=286

Kevin

[chodjinn]

I disagree, a seasoned block with top hats is the best option for a Rover block, period, unless you are a millionaire and can afford a Wildcat one. Top hat liners are not going to move, I have not heard of a failure of a tophat block yet. Mind you, that doesn't mean it hasn't happened.

With the Coscast blocks, yes the casting process is slightly improved, but the inherent design problems with the large journal blocks have not been addressed at all and they still use the same OEM liners, which are cack.

However, that link you posted is by far the cheapest I've seen. I RPi were doing them for nearly double that . . ?