Tuesday, November 1, 2016

More Is Better. 5 Is More Than 4.

Dear Reader. Very happy to be back in the blogosphere, and happier still that you're along for the ride.

We've got a lot of catching up to do, and there's a lot of work yet to be done on the car. Funny thing about these old cars - you never really run out of things to do just to keep the thing on the road even when you aren't trying to modify every last thing that makes the thing go and steer and stop. Add to this the not-so-smart notion of getting the thing on the road only to then take apart something that you haven't taken apart yet just because it's next on the list as part of your sensible approach to a rolling restoration kind of long term project. At the rate I'm going, I'll have to replace worn out modified stuff before I finish modifying the rest of the stuff.

Smart way: take it all apart, collect all the bits, assemble, enjoy.
Our way: not the smart way.

Since our last session, a whole bunch has happened with the car. And in keeping with our tradition, it's not all getting into pixels in exactly the order that it's all going down. Alas. We've replaced the rock solid B18 with a slightly modified AQ130-converted-to-B20 with a nicely ported head and Schneider 274 cam (more on this later!), and we ditched the cute single Cibie Tango fog lamp in favor of a pair of Cibie Iode 45 long range driving lights. Thank you, ebay France!

We are not afraid of the dark. There is no dark.
As you know, one of the very best upgrades you can make to an old Volvo is the addition of an overdrive transmission to replace the original 4 speed... actually, though, this car started life with a 3 speed, but that's not the point. Simply put, the result is that you have the same four forward gears that you had before, but you also get a 5th 'gear' (not really a gear, exactly) that drops your highway rpms by 20 or 25 percent (depending on which version of overdrive you end up with). This is a big deal and it's all kinds of awesome. Example: cruising at 3500rpms with a 4.10 rear and a 4 speed in the 444 we're dealing with results in a highway speed of 62. With an overdrive, that same rpm speeds us along at about 78 mph. At 4000, the difference is 71 versus 89 mph.
This won't necessarily increase your (my) top speed by 20%, because torque and horsepower and wind resistance and a bunch of physics related BS conspire against us in our quest for unadulterated velocity. With a relatively standard B18, the top speed would likely be higher in 4th than in overdrive. And much as it pains me to say it: top speed isn't the point here - engine rpms while cruising on the highway is what we're tweaking.

I'm leaving out a bunch of stuff related to changing the rear axle ratio when converting to overdrive so that you can tailor your effective final drive ratio such that your engine will reach redline in overdrive. We're not worried about that just now.

Anyway, let's jump in.

The organ: M41 taken from a 1975 240 series Volvo.

The recipient: our venerable 1957 PV444.
The reason a lot of PVs don't have overdrives is that their transmission tunnels are too small for the thing to fit. 122 and 140 series have big cavernous tunnels. PVs do not. Proof:

Originally, this car had an H6 (3 speed) transmission. The one in the pic is an M40. It barely fits.

4 speed as viewed from above.
To accommodate the larger M41, we collected a transmission tunnel from an 1800 (bottom of the next pic). Then we removed the 4 speed from the car and tossed everything on the floor to get a good look.
The M41 is about twice the size of the M40.
Next, we cut out most of the old tunnel and some of the floor. I was super happy to find that the floors were much thinner than when they were new - all that metal that's rusted away results in a lighter car overall. It also ensures that any welding you might do will either blow holes in the old metal; or the weld slag will plop itself about in messy blobs.

Mind The Gap.

Test fit with 240 shifter.
The initial plan was to use the 240 shifter and its dandy overdrive switch that's built into the shift knob, but the dry fit demonstrated that the tunnel would have to be 3 inches taller than if we stuck with the original shift lever. And the original, nearly a meter long, is cool.

Tunnel dry fit.

Rough fit.
We made another change along the way: the brakeline that feeds the rear wheels used to tuck nicely into the tunnel alongside the transmission. The new tunnel, though, is placed such that there's no room at all to spare under there and we want to be able to remove the transmission without worrying about bonking a brakeline. So the brakeline is now routed inside the cabin, connected to important looking things with knobs and stuff:
Bias valve on the left, line lock on the right.
Two coats of Gloss Smoke Grey Rustoleum, and the new tunnel looks like part of the old car. The next step will be to add a platform atop the existing floor that will bring the driver's feet up about an inch and will also ensure that nobody steps on the brakelines. Because that would suck.

And now we wait. The driveline is away being shortened and balanced, so we can't test the new setup until that comes back. And we don't know anything about this 'new' M41. Condition unknown, other than that it looks ok inside the gearbox, and the solenoid works. Unknown quantities keep us on our toes.

Here's hoping.

'til then -



  1. I always love seeing your posts and I've been burned out on the latest e-mail case or Anthony Wiener's latest fiasco......so, thanks!

  2. nice work. thanks for posting