[DeTomaso] Dry Sump

[MikeLDrew at aol.com]

In a message dated 1/18/14 16 07 47, julian_kift at hotmail.com writes:


> Perhaps the analogy to a GT40 is a little mute as they were all wet sump, 
> albeit quite a shallow oil pan. 
> 
>>>The Mk II, and Mk IV both had 427s that were dry sump.   I am fairly 
certain the later Mk 1 (Gulf cars) were dry sump also?

> >In a Pantera it likely depends on what you want to achieve and how much 
> work you want to take on. I don't have a Pantera here to measure, but if I 
> recall the wet sump oil pan is the lowest point, 
> 
>>>True.   On an Aviaid pan (which may be a bit deeper than stock?), it's 
about an inch lower than the bellhousing.   My car is in the air at the 
moment so it was easy to verify just now.

> >therefore replacing it with something shallower (e.g. dry sump) provides 
> some degree of freedom to lower the engine. 
> 
>>>True, but if you look at a comparison of dry vs. wet sump pans, it shows 
what you can gain.

Aviaid doesn't list a 351C dry sump pan (although they will make one if 
asked) so it's interesting to compare their 351W offerings.   The 351W Pantera 
pan is shown as being 7 1/2 inches deep (from pan rail to bottom of pan).   
Their 351W GT40 dry sump pan is 6 1/2 inches, while their generic 351W dry 
sump pan is 5 1/2 inches.   Assuming you went for the gusto, you could 
therefore lower the engine two inches with a dry sump pan.   Doing so would then 
have the bellhousing hanging down at least an inch below the chassis, if you 
could lower it at all, which you can't.

The bellhousing is considerably wider than the chassis rails, and you can 
only lower it about 3/4 of an inch or so before it's resting on the top of 
the chassis rails.   The bellhousing is the limiting factor in how much you 
can lower the engine/gearbox assembly.   Running a dry sump pan, and inverting 
the gearbox and running a smaller flywheel/bellhousing is the only way to 
effectively lower the drivetrain.
> 
> >However IIRC the rear of the ZF is also quite close to the rear cross 
> member so assuming you don't want to start cutting up you Pantera the ZF 
> inversion might help. The inverted bellhousing usually has a cut out exposing 
> the flywheel (as you allude to the SPF owner finding out), which provides a 
> little more clearance, however in the Pantera I have a feeling the 
> constraining factor might very well be the largest diameter of the bellhousing 
> against the chassis frame rails.
> 
>>>Exactly right.   But another critical factor is the chassis crossmember 
under the BACK of the gearbox.   Right now, with the gearbox oriented in 
typical Pantera fashion, the back of the gearbox is relatively high.   If you 
invert it, it will hang a bit lower and start running into things even before 
you tried to lower anything.   If you wanted to lower the drivetrain and 
keep it perfectly level, you would have to start hacking up the chassis to let 
it clear.   The other alternative would be to keep the rear of the 
(inverted) gearbox at essentially the same level, and lower the engine/front of 
gearbox as much as you could.   The result would be a drivetrain combo with a 
pronounced nose-down tilt.

> > Then there's the possibility your headers will interfere, so more $$ 
> and teh dry sump scavenge lines need to route out the side of the pan, so 
> maybe interference there.
> 
> FWIW ERA recommend a 157 tooth flywheel and 10" clutch, but that's 
> probably for a 289/302. I'm not sure what I have without digging out paperwork s 
> it's a 351W based 408 stroker.
> 
>>>They would be the same.

At the end of the day, this is a highly academic conversation, because 
lowering the drivetrain would be an enormously difficult and expensive 
undertaking, with little to no practical benefit.   Fortunately for us, the wet-sump 
Aviad and Armando and Kevko Pantera oil pans do an outstanding job of 
guaranteeing proper oil control under full road racing conditions, rendering a dry 
sump setup nothing more than an exercise in complexity and expense (and 
increased weight!) for its own sake....

Mike
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