Noble M500 Upgrades & Overhaul

[Magic Beans]

Peter, I must log a complaint here.. Everytime someone posts in this thread I get an offensive email!

Image Replaced With URL For Quote [url]http://i1278.photobucket.com/albums/y504/MuleDesigns/Untitled_zpsb1b63718.jpg[/URL]

Possibly a good job Peter dosn't own one of the ten cars here then Phil

http://www.oddee.com/item_93544.aspx

I wonder if they question why the brochures for some of these cars fly off the shelves so quickly in some countries

[ashley]

Peter, I must log a complaint here.. Everytime someone posts in this thread I get an offensive email!

Classic!!

[Peter Gidden]

Well the engine is almost stripped down.

For those that don't know me or the history of the car, i bought this M400 engine 4 years ago with 3K on the clock. Track day write off, 7 months old.

Installed it (bought complete rear clip) and from the very first time i fired it up it had awful piston slap, which i knew wasn't normal. It also passed some oil through the breather, using about 1/2 litre of oil per 1000 miles.

All the M400 engines were built by a well known company with a name very similar to Noble Automotive. Stock ST220 crate engine, stripped, and rebuilt with forged pistons and Arrow forged rods.

So, heads off, and this is what i find:

http://www.sbits.net/pics/piston.mov

It's a 35Mb video, so those with up-north internet connection, be patient.

What i would REALLY like to know, is how a reputable engine builder could possibly have thought that the bore clearance was anything other than pants.

[ashley]

What i would REALLY like to know, is how a reputable engine builder could possibly have thought that the bore clearance was anything other than pants.

[Magic Beans]

That's shocking! That's how all of those engines are built?!

[Gullzter]

Now I don't have a great knowledge of this sort of stuff but that is very loose looking

[CRAIGROBBO]

Peter,

Thats abit slack! must be 2mm of play there.

Whats your options then? Different bottom end or custom pistons?

Craig

[gerbil1028]

Cracking read

[synXero]

Saw an orange M12 today. Made me want one!

[Peter Gidden]

So, almost ready to start engine build.

Heads and block deep cleaned. New stem seals fitted, valves relapped, and Beehive (USA) valve springs and titanium retainers fitted.



Block bores checked for size and ovality. No issues. Rehoned ready for my new Cosworth pistons.

Block and head surfaces refaced.

[ashley]

Nice- you can get building now

What rings are you using?

[Peter Gidden]

What rings are you using?

Rings supplied by Cosworth.

[Magic Beans]

That's some handsome metalwork

[craig]

Looking good Pete.

[Peter Gidden]

So, onto the build.

I only use the best assembly lubes and sealants. Not cheap, but they're just as important as the component parts. Dirko-S is not only used by manufacturers and top race teams because it does it's job properly and reliably, but also has a much shorter curing time than most sealants.



The block is two halves, upper and lower. So first job was to dry-install the crank to check bearing clearances with Plastigage. So new bearings fitted, block halves torqued together, and clearances checked. All spot on.

Then take apart, clean off all traces of wax, and refit crank and bearings with new bolts.







Crankshaft fitted. Now onto pistons and rods. Noble used Arrow Precision rods in all their 3 litre engines, so they were remove from old pistons, cleaned and put to one side for refitting.

One of a handful of sets of pistons custom made by Cosworth. Compression reduced to 7.9:1. A cool £1700.



First job was to spend a couple of hours gapping all the top and 2nd rings. Done.

Next job was to fit rods to pistons, then rings to pistons. Done.

First piston was slipped into bore, big end cap nipped up, and cranshaft rotated to check for binding.

DISASTER - crank won't fully rotate.

[pistol pete]

was all good till disaster.. any ideas of cause?

[ashley]

F**k me- your camera actually works




More to come this evening I suspect

Looking great btw

[craig]

F**k me- your camera actually works

Of course his camera works, where do you think all my build pics came from?

What happened Pete?

[Gullzter]

That is NOT good! It doesnt help that your trying to have it ready for the Le Mans trip either, do you know where the problem lies?

[Peter Gidden]

On closer inspection, reason crankshaft wouldn't rotate was due to crankshaft balance weight hitting underside of piston.

But how could that be?

Standard Noble/Ford crankshaft. Standard Noble/Arrow Precision rods. And at least 2 others already have their Cosworth pistons installed without problems.

Coffee time, and answer to follow...