RE: Stuffing a V8 into a Spider? -- LONG

[White Anthony <anthony.white@domain.elided>]

I'm inclined to think that, while not quite Immoral and Wrong, this isn't very interesting. And in my book, that's a far more damning criticism.  A warmed Maserati Biturbo engine and gearbox would be far more original, innovative, would develop a similar power to weight ratio, and would still go round corners.  

However, as this friend has already bought the Spider, I gather he's pretty serious about this.  

The problems he's going to face are size of engine, weight, and the impact of these on handling.  This is going to be a very serious undertaking anyway, and I presume he wants to be able to go around his first corner, rather than understeering through the Armco and plunging to his fiery death.  

The first thing to do is to find an appropriate engine, and get it as low a profile as possible.  A Windsor small block, with a dry-sump (to decrease the height the sump required) and a specially manufactured low profile fuel injection system, again to keep the engine height as low as possible.  (Remember, there are difficulties slipping an Alfa Twinspark into a spider due to size, and that has the same number of cylinders in the same configuration.)  Rather than a stock cast-iron block, order an SVO aftermarket alloy block, and alloy heads, and save a couple of hundred pounds.    

Next, strip the Spider of just about everything.  Empty the engine bay and the interior.  Empty.  Take a gas axe, cut out the firewall, the inner guards, the transmission tunnel and the front half of the floor.  Dummy together some type of frame to stop the body from collapsing in on itself at this stage.  Hoist the engine into place, again in some kind of dummy-frame, and manipulate it until it is inside the car, and under the hood.  In order to get it under the slope of the hood, it's going have to be sitting way back in the chassis.  This is a good thing, as even an alloy block is going to weigh three times what the original twin-cam did.  The further back it is, the better the weight distribution, and the more likely the car will go around corners.  

Find a gearbox.  Seeing as things are getting so dramatic, I'd be a little original here, and stuff a transaxle under the tail.  Two reasons for this: weight distribution, and the associated all important ability to go 'round corners;  and interior space.  That engine is mounted way back by now, and you're not going to have much room for a gearbox and a pair of seats all taking up the same space.  I've been told that the Alfa transaxle is vastly overengineered, and so should take the punishment.  If so, use one from a 75 turbo or Twinspark: better gear ratios for this type of silliness, and they came with an LSD, which is going to be needed.  If you don't want to use an Alfa box, then the transaxle from a Porsche 944 is a good one.  

Subframes/half-chassis:  There are a number of Rod Shops around the US that will build a good independent rear end that the transaxle can be mounted in.  It's then a matter of cutting a big enough hole under the tail of the Spider to fit it in place.  

A front half chassis will require the help of a good engineer, and someone who can weld chromolly.  The half chassis needs to give a good stiff suspension platform, hold the engine in place, and support the body panels.  The nose panels themselves are not likely to be of any structural use, and will be there just to keep the weather out; refabricate them out of fibreglass or Kevlar to get that front weight down even further.  

Engine in place, driveshaft connecting engine to transaxle, then fabricate a firewall and transmission tunnel.  These need to be well braced to provide strength and torsional rigidity.  With a transaxle, there will be more space around the driveshaft to build in additional strength.  If it's going to be built for driving (rather than for show), then there may be local regulations requiring inner guards -- attempt to fabricate them to fit in any space that is remaining between exhaust headers and tyres.  The firewall needs to be built in such a way that clutch and brake masters can be mounted, though God Himself probably won't be able to find the space.  

That should be most of the engineering.  Brakes, of course, are important.  Big ones.  Reattach all of the interior in any way that it will fit.  This will probably involve significant mods to the dash, and then custom built carpets, steering column, seat mounting points, and everything else.  Door trim should still be usable.   

Now, that's barely comprehensive -- there will be a hell of a lot of detail work to do.  There are probably a few steps he could do differently -- just beat the inner guards into shape, rather than cutting them out; using a Detroit-built (Ford Nine Inch!!) live rear axle and 'normal' gearbox instead of the transaxle and subframe.  He'd have to cut out the firewall and transmission tunnel in any case.  

I hope he's not planning to do this to impress anyone except himself.  As we've seen, very few of the Alfisti will be very impressed, even if he does make the thing handle.  And from my experience with V8-heads, they are seldom impressed by anything that's not big and American (or Australian) from shiny chrome bumper to shiny chrome tailpipe, no matter how well engineered.  

Regards,
Anthony
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