VSCCA - VIR - 2009VRG - NJMP - 20091500cc SAAB/Ford V4Vapaa Vintage Racing
VSCCA - VIR - 2009

VSCCA - VIR - 2009

George Vapaa, Lotus 7 CC leading

VRG - NJMP - 2009

VRG - NJMP - 2009

Stefan Vapaa, SAAB Sonett

1500cc SAAB/Ford V4

1500cc SAAB/Ford V4

built with a great deal of help From Jack Lawrence

Vapaa Vintage Racing

Vapaa Vintage Racing

Formula S, foreground - Sonett, background


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05-06-2012 SONEAT Updates

Written by Stefan Monday, 07 May 2012 18:24

Finally, I'm putting the Sonett back together after last summer's issues!

  • The gearbox has been rebuilt with a Sonett ring & pinion and a Spec 1 SS&R gearset. It is bolted up to the bellhousing, has drivers installed, and is ready to go into the car.
  • The engine has been rebuilt and is ready to go into the car with new stuff:
    • Bottom ball seat lifters
    • Tubular pushrods
    • Heads clearanced for the longer pushrods
    • Narrower diameter and stiffer valve springs

  • The left front wheel bearing has been replaced (with new).

  • New VDO tachometer is installed.
  • Pertronix rev limiter is hooked up.

The next step is to bolt the Accusump in place in the passenger's compartment, plumb it in, and fabricate a handle that can be operated from the driver's seat.

After that, the engine and trans can go back in.

Once in, I have a final improvement I want to make... I want to add a bit of positive crankcase ventilation to try and stem some of the oil seepage from the engine. It should be a simple enough task, right?


11-06-2011 BBSL+TP (Bottom Ball Seat Lifters and Tubular Pushrods)

Written by Stefan Friday, 11 November 2011 19:01

Here's some parts for the Sonett engine that have very little to do with power and everything to do with reliability and longevity... Bottom Ball Seat Lifters and Tubular Pushrods!

The lifters are wonderfully light! While the pushrods are slightly heavier that stock, the combined weight of the lifter and pushrod is less than my current setup with the stock pushrod and lightened lifters.

The goal here is to reduce the stress on the valve springs, increasing their service life and reducing the likelyhood of floating a valve, smacking a piston, shattering a spring retainer and cracking a valve guide.  All of which I accomplished last season.

These come from Jack and Pat Lawrence of MSS (Motor Sport Service) in Jamestown, NY, USA. Jack fabricates the pushrods from individual pieces.

lifters and pushrods

lifters and pushrods

lifters and pushrods

lifters and pushrods


04-16-2011 SAAB SS&R Special 1 Gearset

Written by Stefan Sunday, 17 April 2011 12:08

This may be the single most exciting race part we've ever bought. So much of what I struggle with on track, in competition with other cars and drivers, is the standard gearset and its street ratios with the "highway" top gear. It means I am handicapped by a massive gap between 3rd and 4th gears and a top speed that is theoretical only.

This SAAB Sport & Rally (SS&R) gearset is the "Special 1" set. Its ratios are "closer" than the standard set and provide me with a lower top end. This could make all the difference in the world when I'm competing on track.

For a full explanation of the ratios and speed-in-gear, see this spreadsheet that my Dad and I have put together.


Last Updated ( Monday, 18 April 2011 19:21 )

09-05-2010 Solex Carb Modification

Written by Stefan Monday, 06 September 2010 12:02

Back in July I reported that I was having trouble with SONEAT's engine stumbling in the corners. It was the worst in the right hand turns and was slowing me down. The only fix I was able to find was to not dive so hard into the turn. If I went as fast as I could, the engine would cough, hack, and eventually blubber its way back to life as I feathered the throttle.

My friend Chris, who like me also drives a yellow Sonett better known by its nickname than by any year-make-model-serial combination, reported that I was describing a well known fault of the Solex 40 PII carburetor. When installed on the engine in the north-south orientation and combined with a suitably exuberant driver, the fuel in the float bowl will climb the walls of the float chamber under hard cornering. It may do so enough that it uncovers the fuel pickup ports, as they are located in the extreme easterly (in my case) corner of the bowl (see below).

fuel pickup ports

The fix Chris said, was to install a "windage tray" in the bowl. I think of it as more of a horizontal baffle, but whatever. The point was made. It is intended to do much of the same job as the windage tray commonly seen in engine oil pans (sumps). That is, to keep the oil (in this case fuel) from sloshing away from the pickup point.

So here is what I came up with.

will be held in place by spring pressure

I cut it out of brass shim stock and designed it to fit very snugly in the float bowl. It needs to be very snug, as I am not planning to keep it in place through any method other than snugness.

Here it is installed. I tapped it into place with a custom non-marring positioning tool (a hammer with a pencil and its rubber eraser).

designed to keep the fuel from rushing up the sides of the bowl

The brass baffle is placed so that it is just below the lowest possible resting point of the float.

sits below the float's lowest possible point

I screwed it all back together but made one more small modification.

After the Mt. Equinox hillclimb I noticed that I had loose screws all over the place. It would be bad, I think, to have the carburetor top come loose. With all its sloshing (though less so now) fuel and the extreme heat of competition, any combination of those two things that doesn't occur inside the combustion chamber is best avoided.

So I drilled all the carb top bolts for safety wire and safety wired them for safety.

safety wired to keep the screws from loosening

I want to drill the bolts that hold the air cleaner on too, but they seem to be very hard and are resisting the efforts of my tiny drill bit. I may just buy some pre-drilled or I may employ some thread locker. It depends on my mood.


09-03-2010 Valve Spring Replacement

Written by Stefan Friday, 03 September 2010 17:26

As I was revving the living snot out of the Sonett's engine and struggling to reach 3rd gear going up the Mt. Equinox hillclimb on my last run, it started to occur to me that it had been a while since the last time I checked the valve spring rates. Really, it did.

So upon arriving home and unloading the car I immediately opened the hood.  I did a quick compression check to be certain that all the valves were still sealing.

#1: 215 psi #2: 190 psi #3: 190 psi #4: 185 psi #1 again: 175 psi

I think that's normal.

Then I pulled out the rocker assemblies and valve springs.

I carefully packed each spring assembly (spring seat spacer, spring, damper, inner spring, retainer and keepers) in their own marked Ziploc baggie and shipped them off to Jack Lawrence of Motor Sport Service (MSS) in Jamestown NY. He'd measure them and send me new ones if necessary.

Fast forward to yesterday evening...

I received a package from Pat, Jacks wife, with all my springs in it and a complete set of new ones!  I gather from this that mine were completely pummeled and worthless then.  I called Jack to confirm.  His first comment was "If you've gotten away with it I think you are quite lucky."

Jack has written some numbers on my Ziploc baggies that represented the measurements of the old and new springs. Here's how they break down:

Spring Old New Diff Diff%
#1 in 54 80 26 32.5%
#1 ex 52 75 23 30.6%
#2 in 54 80 26 32.5%
#2 ex 53 74 21 28.3%
#3 in 53 79 26 32.9%
#3 ex 55 75 20 26.6%
#4 in 54 79 25 31.6%
#4 ex 53 74 21 28.3%

That's fairly spectacular, don't you think?

Jack asked if I was still running the oil splash guards. You know, those bent pieces of sheet metal that are bolted under the rocker shaft and tilt up behind the valve springs?  Yes, I am still running them.  "Don't" he says.

His expectation is that those shields are contributing to the spring fatigue rate by protecting them from oil splash. He explained that they are cooled by oil and if they get hot, well, that's not good.  He says "I didn't run them and I think that was why."

In order to install the springs, I needed a tool. So I made it.

  1. Take one old spark plug you don't intend to use for anything.
  2. Cut the ground off.
  3. Grab a punch and a hammer.
  4. Start banging away on the ceramic bits until they are all gone.
  5. File smooth the area where the ground prong was.
  6. Wire brush clean the metal bits on the old plug body.
  7. Grab an air tool fitting (male)
  8. Screw the fitting into the plug body (it is a perfect fit)
  9. Braze them together.
  10. Cool and clean.

Now you can screw this tool into the spark plug holes and connect your compressed air line to it and it will keep the valves tight against the seats for you. They won't disappear into the cylinder or anything.

↑ Mega-Vise caught some of the ceramic bits from the demo'd spark plug.

↓ The new special tool.

I used one of the fittings from a Sears Craftsman spring compressor combined with a rocker-shaft bolt, some big nuts, a washer, and various bits from around the shop to compress the springs. Finally, it was all back together. The springs have an installation height of 1.59". That's what Jack said they should be, and they certainly appear close with the best measurements I can make.  If anything, mine are a little bit more compressed. That's preferable, because if they measured taller (more expanded) it would indicate a recessed valve.

Last Updated ( Monday, 27 September 2010 20:55 )
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