BMW Advert 1986 - 635CSi, M6, E9 3.0 CSL, M1 - 'The latest in a short line of supercars...'

Another great advert from BMW, this time from 1986, promoting the benefits of their tuned straight-six power plants and their innovative (for the time!) use of four valves per cylinder. 24-valves were first seen in the E9 3.0 CSL 'Batmobile' in 1974, again in the M1 supercar in 1977 and finally making its way to the general consumer in the 1986 635CSi model E24 6er. 

As BMW discovered years ago, when you need extra power from an engine - on the race track for instance - just double the valves per cylinder.

The extra valves mean the the cylinders can take in more air and fuel on each stroke, burn it more efficiently and expel it quicker. So much so that 6 cylinders with 4 valves can produce more power than 12 cylinder with 2.

Take the three cars above, developed by BMW Motorsport.

The 3.5 litre CSL, affectionately known as the Batmobile, won the first of many races at the Saltzburgring in 1974, beating a 7 litre Camaro in the process.

A 192 mph version of the M1 won its class at Le Mans for the last 3 years. (At the Nurburgring in 1981 it won the race outright.)

The M635CSi, however, is merely a luxury road going coupe. Although it's capable of 158mph, it hasn't won a thing.

Except praise.

BMW M40 Engine - how to check timing, where the marks are located

This must be one of the hardest bits of info to find in the whole world of BMW, but there is a great post on BMW Werks on how to do it [https://www.bimmerwerkz.com/threads/m40-motor-timing-info.59059/].

QUICK TIMING CHECK GUIDE:

** Only if crank pulley has NOT been separated from crankshaft! **

1. Remove the distributor / timing cover at the front of the engine.

2. Check the timing mark on the crank pulley. This is an arrow cast into the block which should line up with the sprocket tooth to the right of the gap in the teeth, as in pic below.

3. Check the timing mark on the camshaft pulley. This is a notch/line mark in the pulley and should line up with the right-angle notch in the cylinder head, as in pic below. If this looks good, your timing is fine.

Thanks again to xdrian on BMW Works for making these pics and sharing this secret!

E46 Clubsport: New split-rims!

Oh yes... it's time the 330CS had some money lavished on it and what better way to start than new wheels. They are the same set of Italian-made Cromodora 18x8 and 18x8.5 2-piece split-rims that come with the car. He still has the old ones, but after 2 failed attempts to refurbish them he's been keeping an eye out for a replacement set, which aren't common. Finally some have shown up and been quickly snaffled for £ delivered. They've been sandblasted back to bare metal, then lacquered and the colour / finish is very nice indeed. Awesome.

Also, a rubber rocker-cover gasket to signify the start of the engine tweaks. Lots more to come...

E60: Engine Autopsy Verdict.

Well, contrary to my earlier verdict of no damage to the head, a bit of informed explanation reveals the corroded surfaces in cyl. 6 are in fact battered metal from the where bits of my swirl flap were bouncing around inside it. Not good!

After having my photos pored over by the engine diagnosis experts on BMW Land, the best version of events of that fateful Tuesday are below:

1. Swirl flap no. 4 breaks up and bits enter cyl. 4.

2. Inlet valves jamming open on cyl. 4 cause a backfire and blasts the loose remains of the swirl flap into the intake plenum.

3. The turbo forces the swirl flap remains along the plenum, with bits ending up in cyl. 5 and the majority entering cyl. 6.

4. Cylinders 4 and 5 continue to fire with slight lack of compression.

5. Trapped debris in cyl. 6 begins to ricochet around, causing damage to the alloy piston-crown and the top of the combustion-chamber in the head until the inlet valves cannot close fully and compression is lost entirely.

Worst bits:

• Cylinder-head is finished. Valve-ports on cyl. 4, 5 and 6 need regrinding and fitting with some new valves. The top of the combustion chamber in cyl. 6 needs completely regrinding into shape.

Best bit:

• The engine still turns freely, cyl. 4 and 5 are virtually damage free and do not need replacing.
• Piston 6 compresses in the block still, so no damage to piston-rings.
• There is no damage or scoring to the cylinder walls.

THE REPAIR [in theory...]

• Repairing the head will cost ~£350, the cheapest Birkenhead-Engines can do and may still need further work, so a replacement is needed. Birkenhead-Engines say they have one such in stock, removed from another E60 530d, though what year they are unsure. It is not re-con and they say I can take my chances for a mere £200, but at least they know the valves etc. all work so it looks like this is the way to go.
• As long as I remove any tiny debris from cyls. 4 and 5, I am happy that they are working 99% as well as they should and do not need any repair.
• Cyl. 6 is battered and, although it is compressing in the block, the jagged metal crown will mess up proper combustion even if it fires ok. Worse, bits of the jagged alloy will probably break off during combustion and ping around the cylinder some more, potentially messing up the valves again so really the piston needs replacing.
• Not only is finding a single replacement piston very difficult, the job to replace it requires removal of the sump and big-end shell. This, with all the under-trays and cross-members is a colossal task in itself and, with the car parked on loose gravel, it's looking like a no-go.
• The short-cut solution to piston-6 looks like it's going to be a jenky regrind with the piston still in the engine. I will turn the crank by hand so that piston-6 is in its topmost position and get in there with a die-grinder, removing all the proud bits of metal and re-shaping the 'swirl-pot' and piston-crown as well can be. This ultimate bodge could be the end of a relatively unscathed engine. It could also be the only way to get the E60 back on the road quickly and with a minimum of fuss... Fingers crossed.

COST:

• Replacement cylinder-head: £225. [Birkenhead Engines]
• New head-gasket: £85.55. [Euro Car Parts]
• New head-bolts: £37.48. [eBay: dusty789blue]
• Swirl-Flap Blanking Plates: £20.99. [eBay: myldanautodesignltd]
• New thermostat: £33.99. [I broke the housing - Ebay: carpartssaver]
• Oil: £85.98. [Halfords, own-brand BMW Fully Syn. 5w30]
• Coolant: £22.99. [Halfords, Comma G48]

TOTAL: £511.98.