Seeking advice from Spitfire peeps

clshore said:

In reply to nderwater :

Take away the motor&trans, and everything else is common Spitfire bolt-in stuff that's been done for years

Relocating the front cross member takes a sawzall, a disk grinder, and an arc welder, could be done in one day by one guy.

Compared to that, fabbing up a tubular frame & fiberglass body is like building a starship.

The Spitfire is a body on chassis car, the whole front end is easy to remove, heck, the whole BODY is easy to remove!

You will not find an easier car to swap into, once you've figured out the Tetris challenge of how to make things fit.

But if you are looking for a simpler upgrade, convert your car into a Spit-6, transplant the Spitfire tub onto a GT6 chassis.

The Spitfire & GT6 chassis are virtually identical, there are about 14 bolts securing the body to the chassis, all at the same locations.

You'll get the 2 L motor, closer ratio gearbox (and maybe an O/D), better rear ratio (Spit 4.11 vs 3.27 or 3.89 with O/D), bigger brakes,

and 4 link rear suspension if it's a GT6+.

Still a hoot to drive, the extra torque and better gearing let you squirt into traffic holes, but not as light and nimble as a Spitfire.

You make a clear and good argument  in favor of a GT6 but it lacks the open air motoring pleasure of a drop top.  
Remember when the top goes down the fun goes up ( and price) 

There are convertible people and hard top people. Part of the fun of convertibles is that exposure to the elements dropping the top gives. Oh, sure stiffer etc. blah blah.  But rolling through those back country roads with the top down is the slightly better aerodynamics worth it?  

In reply to wspohn :

Ecotec is big, requires a lot of surgery, kind of heavy. But use the Solstice/Skye RWD version as the easy button.

Miata motor/trans is a better swap candidate, has been done successfully many times, a sure thing if you follow the formula.

As for swing axles, they work well on a Spitfire if you fit a camber compensator, have worked well for me over 50+ years.

Spridget guys snap axles on their live axles too, and over rough pavement the swing axles lower unsprung weight will 'Triumph'

I believe I read in R&T that a 100hp Spitfire was one of the most fun cars they had ever driven.   One problem with Spitfires is you improve the engine and the transmission becomes the problem.  Then the rear diff becomes the problem. Then brakes are marginal.  I love my Spitfires, but it would be hard to make one faster than a good Miata without $$$$.  

It's not too hard to turn a GT6 into a Spitfire. TR6 engine fits as well as the 2 liter. TR6 tranny can be made to fit, though I don't know the specifics. I enjoyed the '70 GT6+ I had in the '80s, though not very much tire would fit under those early rear fenders. I also enjoyed the '65 Spitfire I had in the '70s. Certainly it sorta felt fast, but I recognized that it really wasn't.

I have a rebuilt 1500 waiting to go into my Spit. It has some moderate performance upgrades and should roughly have about 90 hp. Give or take. 

Suspension will be basically original with adjustable perch front shocks.  The rear is generally best left alone for later cars where the camber compensation device isn't required.

Brakes will be GT6 parts. Slightly bigger, which will be nice. But honestly, mainly so I only have to stock one set of brake parts since I have a GT6 as well.

A R160 swap is planned and I'm debating on swapping out the O/D transmission for a T-9. Maybe. The R160 swap requires a conversion to a GT6 type rear suspension, so it'll be a while before I start that project.

When all is done, I'll probably have 2x into the car than I paid for it, but it's fun. 

Can't recall - does the taller block on a TR6 engine require a hood bulge in a Spitfire? Although that may not matter to the person converting the car.

I saw one rather Impressive Spitfire conversion with a Mazda Rotary - could hear it coming for miles.

Yes TR6 motor does require the GT6 hood bulge and a different thermostat cover.  Actually the intake manifold will probbably need to be changed also IIRC.  Barry Rosenberg had a GT6 Weber set up and the manifolds were slightly dipped down the further forward they went.

In reply to wspohn :

The 2.5L is the same height as the 2.0 in the GT6, but it does require a tweaked oil pan to clear the front cross member and steering rack.

In reply to Ian F (Forum Supporter) :

You can use an R160 with swing axles, but you have to use the right one, the ones that have axles retained by a bolt thru the center of the stub axle.

A disk at the end (AKA 'the button') transfers thrust loads from the axle to the spider gear, to the thrust washer, to the diff carrier, and finally through

the carrier bearings into the diff case. That arrangement has proven to be quite robust over the past 30 or so years.

Need an older R160 from before Subaru converted to the slide in CV axles with snap rings on the stub to retain them.

The R160 used on Datsun 510 had flanged stub axles like Spitfire uses, with 4 bolt UJ flanges:

https://datsunrestomods.com/products/datsun-510-r160-axles-stubs-for-subaru-suretrac-or-viscous-differential

https://www.bing.com/images/search?q=datsun+510+r160+stub+axles&qpvt=datsun+510+R160+stub+axles&FORM=IGRE

But these are getting very thin on the ground nowdays.

In reply to frenchyd :

Perhaps my post was not written clearly.

I've owned perhaps 15-20 Spitfires, only 1 GT6. If you saw my first SCCA competition licence photo, you'd understand I'm an open air guy.

Wet hair from the shower, no comb, hop in the Spitfire and drive till it's dry, an unruly bundle of curly snakes.

My proposed L15 swap was Spitfire oriented, but the L15 swap will work equally well in a GT6, and with 350 HP on tap, the extra weight of

the tintop would be moot, since the L15 is maybe 200 lb lighter than the GT6 lump. Viking Aviation lists the L15B7 at 270 lb:

https://www.vikingaircraftengines.com/engine-options

My car is pretty much the best you can do without cutting the car up to death. Miata engine and transmission fit without having to cut out the firewall or battery tray. Subaru diff and GT6 rotoflex suspension handle the rear and it still looks and drives like a Spitfire. Many  have tried the Miata rear suspension/subframe without success, there is just no room back there unless you are willing to cut it all out and start over. At that point, you don't have a Spitfire. I wanted it to handle and feel like a Spitfire, but have a ton more power. I get it back from the tuners in the next week and I'll let you know how it drives in the real world. The picture below shows how you can package everything into the Spitfire chassis and still get it to fit the body. No you don't have to mount the body shell upside down 

In reply to clshore :

Hmm...   I have two sets of GT6 CV axles and $320 for those stubs is probably cheaper than custom CV axles...  

dherr (Forum Supporter) said:

My car is pretty much the best you can do without cutting the car up to death...

That is excellent, excellent info, thanks.  Please follow-up with driving impressions (and video!!)

In reply to nderwater :

If you are in love with the appearance of the spitfire, there really are no cheap, low effort ways to reach your goals. 

Most of what I've read here  is for serious gear heads only. 
      
I strongly suggest you try a Miata  as your base. The potential is there to beat the much modified spitfire simply by getting it running properly.  
 
If you just like the the 60's era car try working with a MG Midget or B or Sprite.    They are affordable and can tolerate power updates better. 

clshore said:

In reply to wspohn :

Ecotec is big, requires a lot of surgery, kind of heavy. But use the Solstice/Skye RWD version as the easy button.

Miata motor/trans is a better swap candidate, has been done successfully many times, a sure thing if you follow the formula.

As for swing axles, they work well on a Spitfire if you fit a camber compensator, have worked well for me over 50+ years.

Spridget guys snap axles on their live axles too, and over rough pavement the swing axles lower unsprung weight will 'Triumph'

i stuffed a 2.2 ecotec with a w/c t5 tranny into my alfa spider.. was not mush taller than the oem alfa romeo 2 liter engine, and it is not very heavy.. better built than a maita engine.. 4 bolts per main.. about a 3 inthch thick bedplate supporting the mian bearings..i have taken aprt quite a few 2.2 ecotec engines.. with 150,000 to over 200,000 miles,, and the main and rod bearing look all must new

dherr (Forum Supporter) said:

My car is pretty much the best you can do without cutting the car up to death. Miata engine and transmission fit without having to cut out the firewall or battery tray. Subaru diff and GT6 rotoflex suspension handle the rear and it still looks and drives like a Spitfire. Many  have tried the Miata rear suspension/subframe without success, there is just no room back there unless you are willing to cut it all out and start over. At that point, you don't have a Spitfire. I wanted it to handle and feel like a Spitfire, but have a ton more power. I get it back from the tuners in the next week and I'll let you know how it drives in the real world. The picture below shows how you can package everything into the Spitfire chassis and still get it to fit the body. No you don't have to mount the body shell upside down 

So, How did it turn out?