Newbie with more questions

[Steve P.]

Hi Guys,
I'm the guy that started the thread about the XJS. Now that I have one LeMons
race under my belt I have a better idea of what this is all about, but still realize
I've got a lot to learn.

In the previous thread a couple of guys suggested building a Spridget. OK, I'm
on board with that idea as I'm very familiar with them (have 3 now), know parts
are available for a realistic price and have lots of parts here. Starting the search for
a suitable candidate now.

The one area where the Spridget is lacking IMO is the engine. Yes, you can do
a lot to a 1275 'A' block but it can get very expensive (blower..) and reliability
will suffer. So I'm thinking of an engine swap. The two best candiates I can come up
with are an RX-7 Wankel or a Miata 4 banger. Both have a good record for
reliability, are relatively light, parts are available and they can be crammed into
a Spridget without a ton of modifications. Anyone here have any experience
doing something like this

Would the stock rear end in a Spridget handle the power? I think not. Plus
disc brakes in the rear would be darn nice to have. So how about a rear end
swap (RX-7 or Miata)? And yes, I realize this will require a significant
amount of work and engineering to pull off. I'm OK with that.

Last question; which vintage Spridget to look for. I would think the later
ones with rubber baby bumpers (which would go away). More of them out
there, the ride height will be lowered anyway, and wouldn't feel as
bad about ruining one of these. Disc brakes up front are a big plus too.
What do you guys think?

Right now I'm a blank slate and in the process of deciding which car
would be more practical and still have the potential for being a serious
contender long term.
Steve

 

[Billm]

A late model Midget with a Datsun 210 (or B210) engine and 4 speed trans would work very well- it has proven to be a really good combination and is easy (and fairly cheap) to get parts.
A stronger rear axle is a good idea no matter what you do.
For example: https://losangeles.craigslist.org/ant/cto/4804471170.html

BillM

 

[Elva164]

An A-series? And not restricted to vintage regulations?

....I'll just leave this here...
https://www.twinkam.co.uk/shop/page...zIjqbwXtp2SCYY4qCuSQhDtimpsa96jXw&shop_param=

 

[dougie]

Hello Steve -

I have to refer to my original response on this topic. Decide which club or group you want to race with first. Most vintage organizations or SCCA vintage grids will frown on the kind of engine swap you're describing. For the record, I've had some of my most challenging and competitive races agains Sprigets with my big Healey. Its not the top speed that gets your blood pumping at this level, its entering a corner side-by-side or inches away from the car you're trying run down that is really is the thrill.

Former SCCA and IMSA champion Parker Johnstone (https://en.wikipedia.org/wiki/Parker_Johnstone) racers a Sprite with our vintage club and has a
blast in it.

 

[aeronca65t]

............. The two best candiates I can come up
with are an RX-7 Wankel or a Miata 4 banger. Both have a good record for
reliability, are relatively light, parts are available and they can be crammed into
a Spridget without a ton of modifications. Anyone here have any experience
doing something like this.......
Steve

Neither of those engines have small enough gearboxes to allow the normal trans tunnel to stay in place unmodified. Since the trans tunnel is a critical area of a Spridget unibody, this is a big undertaking.

Is it impossible? No. I've seen several rotary powered Spridgets. They have all appeared to be pretty complex projects to my eye.

A standard Spridget rear can barely contain a healthy, racing 1275 motor. So with a bigger engine, a change of rear axle would be mandatory.

I'm guessing you want this for Lemons. Since this type of car could not be used in any vintage groups and would be hugely uncompetitive in any of the SCCA or NASA classes it might be allowed to run in.

As you may know, Lemons racing can be pretty rough (at least that was my observation here on the east coast). It seems a pity to invest so much time for a car that could easily get trashed in just one event.
If it were me, I'd just run any ordinary fwd econobox in Lemons.

But it's your car and your time....G'luck whatever you choose to do.

 

[Steve P.]

Dougie,
Of course you are right about deciding what I will be buidling a car (any car) for.
Frankly my interest leans more toward vintage car racing. TheLeMons thing is new
to me and very exciting. The advantage of LeMons is I am now part of a well seasoned
and competetive team, so I have drivers and support if I go that route. Plus, Sears
Point is very close to home and there are several LeMons races there each year
but only one vintage race. Need to do a lot more research about all of this.

Another important point mentioned is it'd be a shame to beat up a Spridget in
LeMons. Strongly agree with that. What I do may very well depend on the Spridget
I end up with. There are some real beaters out there and for $500 or less that
most likely will be what I get. However if I'm lucky enough to find a nice example,
that would push me more toward vintage racing with a 1275.
Steve

 

[Elva164]

Aww, I'd love to see one with the twin cam head.

 

[Guest]

Get a Tiburon or Elantra with the 2.0 on craigslist and go kill 'em.

 

[Michael Oritt]

Steve--

When folks suggested that you consider a Spridget I believe they did so with vintage/production racing as a goal. If you are considering an engine swap, whether for Lemons or god-know's-what, then by definition it will not be eligible with any organization where the word "originality" is even mentioned.

On a different note, I must take issue with the comments that a sprite rear would not stand up to a serious power increase. My Courier uses a Morris rear axle which is the same as that on a spridget except for being a few inches wider. The power plant is a 1600 MGA which puts out perhaps 110 HP at the rear wheels and though I have had issues with the rear axle they were mainly related to keeping the oil in it. Since I have gotten a decent set of double-bearing hubs (NOT, btw, from Winner's Circle) I have pretty much been trouble-free in back, and so long as there has been oil in the diff--and not on the ground--the R&P always took the power. The MK IV sports racer also uses a series A (sprite) ring and pinion and though it is in a custom carrier and IRS rear axle the third member components handle the power of the 1460 cc Coventry Climax engine.