Bore and stroke on early 2000,s V10 engines

[saviour stivala]

Block material:- In the mid 90’s FERRARI investigated a die-cast stainless steel crankcase and even made a fabricated titanium block. Issues of differential expansion between titanium and aluminium were apparently the downfall of the lightweight block, together with issues of thermal conductivity and cast-ability. The potential gains were not worth the risks associated with such a radical departure from long-established practice. When FERRARI went from V12 to V10 it did so using a conventional aluminium structure. Along with others, it later exploited a new ability of the aerospace industry to produce thin-wall titanium castings for the gearbox case. Both material selection and casting process are significant factors in terms of producing the most efficient aluminium engine structure. For example, Cosworth made significant gains in terms of the compactness and weight of its formula 1 engine structure when in the 80’s it introduced the Cosworth Casting Process (CCP). The CCP uses zircon sand molds and pumps the molten metal to fill them up through their base, using an electromagnetic inductive pump. With careful metal preparation this avoids the oxide impurities normally present. It causes only ‘micro-porosity’ – it is described as “virtually die-casting in a sand mold”. The castings have a good integrity, a high resistance to cracking and a strength superior to many irons. The CCP became divorced from Cosworth racing when the original Cosworth company was split into 2 and sold to separate parties, the foundry going elsewhere. But CCP was considered significant enough for Cosworth Racing to buy a license for it and to develop an alternative facility in conjunction with another foundry.

[Tommy Cookers]

Block material:- In the mid 90’s FERRARI investigated a die-cast stainless steel crankcase ..... titanium block ...
.... Issues of ...... cast-ability.

sorry ..... but ....

your potentially interesting source doesn't seem to understand (or correctly translate into English) basic engineering processes
there is no such thing as die-cast stainless steel (because the melting point of stainless steel is far too high)
stainless steels or other steels will be investment cast
(there is such a thing as casting dies made of stainless steel - for die casting lower melting point materials eg aluminium alloys)

anyway why would anyone want to make a terrestrial engine from stainless steel ?
yes I had design experience of forgings made from very high strength (maraging) steels - strength coming after machining
forgings often are made in forging dies

[saviour stivala]

Cylinder head:- The V10 engine structure had each head detachable and incorporating the tappet block (whereas, the Cosworth DFV had a separate tappet block). The head is closed by a separate cam cover, which typically forms the upper portion of each camshaft journal’s bearing surface. The head was traditionally made from the same metal as the block, which might be A357 aluminium alloy. However, as engine speed had risen through the V10 era the thermal loading has increased and it has been found necessary to resort to alloy of more exotic specification for the heads. One that maintains its properties to a higher temperature threshold. The Cosworth EC V8 introduced ceramic inserts into the head casting, between the hot exhaust valves where the bridge was prone to cracking. These inserts were apparently carried forward to subsequent Cosworth V10 engines. At the start of the V10 era ports were typically hand finished after final machining, however, the subsequent development of CNC porting made for more consistent finishing and more accurately followed the design specification. In that era, head attachment bolts could be steel, multiphase steel or titanium, the head was sometimes attached to the block by bolts that were not vertical with respect to the cylinder axis but were instead angled inwards. This approach means that each pair of bolts, in effect squeezes the block around the top of the bore, increasing strength where gas pressure is highest, an additional benefit was the bolt exis is no longer aligned with the camshaft above, simplifying assemble. It was in the 50’s that Vanwall introduced a metal head/block sealing ring for each individual cylinder. Vanwall’s ‘cooper ring joint’ was a stainless steel ring with internal corrugations. Its disadvantage was that it trapped air, which acted as an insulator where there needed to be an unimpeded outflow of heat from the combustion chamber. In view of this many subsequent engines such as the Cosworth DFV used instead a simple bronze sealing ring. As engine speed kept increasing through the V10 era a popular sealing solution became the 'Garlock Helicoflex sealing ring' this is an inert gas filled ring made from high nickel alloy (often Inconel), it fits into grooves machined into the mating faces and under the influence of heat the gas within (typically nitrogen) expands to maintain a good seal. at the same time O-rings seals the water and oil passages, so there is no need for a conventional head gasket.

[saviour stivala]

“Block material:- Quoting:- “In the mid 90’s FERRARI ‘INVESTIGATED’ a die-cast stainless steel ‘CRANKCASE’, and even made ‘FABRICATED’ titanium ‘BLOCK’”. I have re-checked and verified the following. In the mid 90’s FERRARI did ‘investigated’ the possibility of a die-cast stainless steel ‘CRANKCASE’. BUT, my source seems to have confused the making of a ‘FABRICATED’ titanium ‘BLOCK’ with them (FERRARI) making a ‘FABRICATED’ titanium gearbox case, which in fact they did, (and moderator permitting deviating from “bore and stroke” subject). Here is some interesting technical information from the past. First in 1994, when FERRARI was determined to move from magnesium as the material of chose for gear cases, because of its hot stiffness and precise casting limitations. A transverse gearbox for the 412T1, they produced a gear case of which was made-up as a fabricated steel box, with the sides machined out of 25mm plate, CNC-milled down to 1.2mm wall thickness and ribs. The gear case weighted only a little less than the magnesium one it replaced. Which was a disappointment, and so in mid-season the switch was made to titanium instead of steel, yielding an immediate 40% weight reduction. For 1995 the ‘FABRICATED’ titanium gear case was bolted to a CFRP bell-housing/oil-tank, onto which the suspension units were mounted and into which the majority of the suspension loads were fed. The 94 and 95 gearboxes were a 3-bearing arrangement, but in 1996 a 2-bearing design was used. A CFRP rear crash structure was also fitted in 1996, one year ahead of the FIA requirement. The same basic arrangement – CFRP bell housing/titanium ‘FABRICATED’ gear case and rear case/CFRP impact structure – has been in use at FERRARI ever since, but in longitudinal layout since 1968.

[ACRO]

... but I am always keen if at all possible to make the power at lower rpm, that is more beneficial, it is more efficient”.

an "eyeopener" statement from mario illien regarding our bore/stroke discussion !

like discussed i bet he "fooled" other teams espacially in 1998 - 1999 with a basicly to low b/s ratio to achieve comperative top end rpm,s and max power output for that time .

with the bigger stroke he achieved better midrange BMEP and so better midrange torque than e.g ferrari . using be-al liners and pistons he was nevertheless able to go the same max rpm,s like ferrari and so he had both : superior midrange torque and very good top end power !

i bet ferrari wondered in 1998 that he obviously goes a higher stroke but is simultany able to rev as high as they do - how the hack does he do it ?

i assume after some time ferrari started to smell the berrylium pistons as the anwer how he is able to manage the by terms of classic materials destructive piston acclerations with his higher stroke and used their influence to make fia ban this material.

if be-al would stay allowed ferrari was at risk to bet on a dead horse with their very high b/s ratio for top end power and trading a bit of midrange torque .

with the ban of be-al and a still lower b/s ratio ilmor in 2001 had an engine with still superior midrange bmep but he had now to pay the full price of lower max rpm,s and lower top end power.

thats why the 2001 engine has probably no more horses than the 1998 one i guess.

very interesting story i think !