[Vwdiesel] Re: going price of 1.6L turbo diesel engine

[Roger Brown]

Libbybapa at wmconnect.com wrote:
> In a message dated 6/7/05 9:01:23 PM US Mountain Standard Time, 
> stephensrw at stn.net writes:
> 
> 
> 
>>The turbo head has hydraulic lifters.  I do not know if this makes the
>>casting, or machining to the casting from the factory any different than the
>>NA 1.6 head with solid lifters.  Others here may know.
>>
>>
> 
> 
> Not quite.  Pre-'86 were all solid lifter heads.  There were solid lifter TD 
> heads and solid lifter n/a heads.  Post '86 were all hyd lifters.  There were 
> hyd lifter TD heads and hyd lifter n/a heads.  Bentley states that the TD 
> heads were made of a special "sodium injected aluminum alloy" to better resist the 
> higher temps of the TD.  VW may just be blowing smoke as far as that is 
> concerned.  I think the alloy is called "expensivium" or possibly "suckerium" and 
> behaves exactly as the aluminum of the n/a heads.  I have also heard that the 
> alloy is in fact the same.  I am not a metalurgist (not even sure if I spelled 
> it right), so I do not know for certain.  Valves may be different.  AFAIK the 
> casting number can be the same for n/a and TD heads of a similar year.
> Andrew

Quoting from the VW TD SAE paper:
	http://www.4crawler.com/Diesel/SAE/vwtdsae.shtml

"Additional modifications are briefly described here: The chemical and material properties of the cylinder head aluminum alloy 
have been optimized. The swirl chamber insert material also had to be adapted to the higher thermal load. For similar reasons 
the crankcase deck thickness has been increased and the region of the cylinder head-bolts was strengthened.

A number of changes were made to the crankshaft. The front end of the crankshaft was reinforced. The highly loaded crank-pin, at 
cylinder 4, has its radius induction hardened and the oil hole ground while radii at the other pins are roll-hardened. A 
torsional vibration damper is used.

Oil cooled pistons with a diameter of 76.5mm and with a ringcarrier are being used. Near bottom dead center, oil injection tubes 
enter into the piston. This requires a notch in the piston skirt. Because of the higher stress in the piston pin region relief 
pockets have been cut out."

and

"Intake and exhaust valves were modified for the higher loads. While the naturally aspirated Diesel engine uses CrSi 9 valve 
steel, a material with higher thermal stress was selected for the turbocharged Diesel. Valve seat wear has been reduced to 
acceptable values by proper selection of the valve seat material.

Because of the valve temperatures being approximately 100 to 150 C higher a better valve head material is also used for the 
exhaust valve. In order to prevent hot-corrosion a chromium-nickel-aluminum-plating is applied by the plasma technique.

Valve seat rings for both intake and exhaust are made of a high alloy casting material."

-- 
    Roger