Subject: Building a Spit 6
Joe Augenbraun asks about building a Spit 6. I suppose it happens
every spring. Tired old Spitfires are rolled out of the barns and the
owners are looking to give them a second wind. Since the '76 Spitfire
I just bought came with a broken block and pieces of main bearing in
the oil pan sitting in the trunk, I'm also in the market for a new
powerplant. After looking at two poor Spits and an average GT-6
($750) last night, I was looking some of the old Spit-6 messages this
morning to get some idea what that conversion would entail. So to
save those folks from reposting, I've appended the Spit-6 messages
that I found below.
Lawrence "still looking for another 3.5L aluminum V8" Buja
ccm0b@vm.cc.purdue.edu
> -----------------------------------------------------------------------
> Date: Tue, 27 Jun 89 20:36:53 GMT
> From: mjb%hoosier@cs (Mark Bradakis)
> Subject: Some Spit 6 thoughts
>
>
> Since I have a 74 Spitfire which I plan to use along with a 71 GT6 for
> my own Spit 6 I thought I would discuss a few things quickly. The GT6
> motor is one of the nicest pushrod engines I have ever driven. Smooth
> and reasonably torquey for a car as small as the GT. The motor is the
> same as the TR6, for the most part, with the TR6 getting a longer stroke
> to displace 2.5 liters.
>
> The easiest way to do the conversion, alas, is also the wrong way in my
> opinion. One could drop a GT6 motor into a Spit frame, cover it up with
> the GT bonnet and zoom away. It would not stop very well or corner that
> well either. The GT motor is a LOT heavier than a Spit 4 banger. I wish I
> had some actual weights handy, but I don't.
>
> The BEST way to do it would be to pop a Spit tub onto a GT frame. This would
> give you the beefier front suspension and bigger front brakes as well as a
> GT trans and diff. The GT parts were made (well sort of) for the 6 cylinder,
> the Spit parts were not. The resulting car should have good acceleration
> and the center of gravity moved about 2 inches forward. Certainly more
> understeer than the Spit, but that motor singing through the breeze in your
> hair...
>
> mjb.
> ps: I've also got this nice GT body that someone put on an early Spit frame,
> that is, the leftover halfs of someone else's Spit 6. I'll have the motor
> back together soon, and then it goes on the market. I'll drive it anyway
> for way cheap!
>
>
> -----------------------------------------------------------------------
> Date: Tue, 27 Jun 89 17:30:41 pdt
> From: linus!harvard!cse.ogc.edu!sequent!george@ursa-major.SPDCC.COM (George Em
> Subject: Re: Some Spit 6 thoughts
>
> Yes, Mark, I agree that the second method is the only "real" way to
> make a SpitSix. I've given careful thought to making this conversion
> and detailed the steps necessary -- even to the extent of checking 90%
> of the schematics to see what wires need to be swapped. Remember, there's
> also a "2.0 Liter" decal from the TR-7 which can be applied once the
> conversion is complete!
>
> Time estimate for doing the conversion (assuming all the cars are ready
> to go and there aren't rusty nuts and bolts, etc.) is one weekend for
> two people. Most of the work can be carried out by one person, but when
> it comes to lifting bodies on and off frames, you're going to need two
> people.
>
> The biggest problem, assuming you started with a Rotoflex GT-6, is that
> new brackets for the leading arms on the rear suspension have to be
> welded in the Spitfire body. You'll note the holes are already there,
> but the bracket is in the normal Spitfire location.
>
> Other little items to do: swap out the brake master cylinder, the speedometer,
> and the tachometer. The Mk III GT-6 uses a cable for the throttle and the
> earlier cars use a rod throttle linkage. Spitfire bodies will probably
> need some extra floor cut out on the passenger side in order to clear the
> transmission. And save the GT-6 heat shield (at the foot of the passenger
> well).
>
> George Emery ...!tektronix!sequent!crg3!george
> (503) 257-9731 (voice, home)
>
> -----------------------------------------------------------------------
> Date: Wed, 28 Jun 89 22:46:30 GMT
> From: mjb%hoosier@cs (Mark Bradakis)
> Subject: Further note on Spit 6
>
>
> As for putting the 2.5 liter TR6 motor in a Spit 6, it should be no problem.
> Well, it won't be much different than putting in a GT motor. The size of the
> block is the same, except the TR6 may have a wider bottom for extra rod
> clearance. The TR6 head may be a little taller (around 0.120" or so) but
> the main problems will be the cooling and the intake manifold. The themostat
> housing on the GT6 is different, as it it made for the lower clearance of
> the GT bonnet. Also the intake manifold on the GT is stepped down for the
> same reason. This puts the carbs lower on the GT than they would be on
> the TR6. And of course, the TR6 uses 175 Strombergs, the GT uses 150. You
> can get some adapter plates to mount HS6 SU carbs on the GT manifold, that
> may work with the larger Strombergs as well. I have been thinking of getting
> some just to see how they work, as soon as I get a running GT6. But the swap
> to the bigger engine should be pretty easy, I have often thought of doing it
> for my Spit 6. Of course, so far ALL I have done on the Spit 6 is think
> about it.
>
> Oh, one more thing, the Spit body tub is setup for the starter on the left
> side, the GT has it on the right side. It will no doubt require some fiddling
> in that area. Well maybe this fall I will actually try to slap a Spit 6
> together, but don't bet on it just yet.
>
> mjb.
>
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