Copyright © 2007 - 2024, Coachworks For contact data Click Here.
Copyright © 2007 - 2024
Copyright © 2007 - 2024,
Coachworks For contact data
Click Here.
This year we didn't make it to Bonneville (rain), but we did run at the Mojave Mile.
If you haven't already, we recommend you read the materials about our first year's efforts, found in the "about our machine" links above. In particular, many have reported enjoying the various sections that describe specific parts of the machine and then going through the (photographically illustrated) "blog" section as the narration there gives the back story and carries you through the process. (One reader opined, "Rivetting!!!!! Like a great novel, I couldn't put it down and wish I had been there to help.")
After achieving our goal as first Karmann Ghia to enter The One Club, we are now focused on entering The One Thirty Club!
This year we were effectively rained-out (please see the "blog" section below for details) at Bonneville's World of Speed.
Then, in October, we ran the Mojave Mile. On our first run, we over-ran fourth gear at about 119 mph (GPS), and bent a valve. It was mostly driver-error, but we never anticipated this much power out of the engine that we'd reach red-line while pulling in gear!
From last season (2011), our fourth gear was too tall. In fact, we realized that our problem since '09 was that we didn't have enough power to pull forth gear to where we felt we should be.
Our choices were to either rebuild the transaxle with alternative gearing or add power, and we chose latter because re-gearing would require we have custom gears made, and we'd rather know we had done all we were planning to do with the engine first.
"There is no replacement for displacement," so, we decided to take that to the limit. We adapted pistons and cylinders intended for different purposes to our cause, and the pistons and cylinders came from completely different types of engines from what we're doing and from each other! (That is, the pistons did not come with the cylinders.) Increasing the displacement can be done by either increasing stroke or increasing bore, or both. We chose to push the bore out as far as it would go.
Recall that the rules say we aren't allowed to relocate the head studs, so that limits things very directly. We bored the case spigots open as far as we dared - remember, we have high-compression, too, and we can't afford a pulled head-stud either! And we then fitted the cylinders to the case:
This work required that the stud-holes through the cylinders be re-drilled - a particularly challenging task. Of course, it also required that the cylinder skirts be cut down to match.
After fitting to the case, we then fitted the pistons - a fairly easy task. Do note in the image below that the piston pretty much fills all the space in the crankcase spigot - there's not much room for a cylinder in there! We don't think anyone will ever get any more bore in one of these under the 36hp Challenge rules.
We actually hired out the boring of the cylinders themselves because a friend of ours has a special tool for that job. However, through a mis-communication, we thought he was going to complete the cylinders for us - we noted the long skirt, but he said he matched our previous cylinders in that regard. So, we installed the cylinders.
We didn't get very far when we accidentally broke a skirt! Note the broken skirt (left) and the cylinder skirt shape we were looking for (right):
Luckily, the break actually happened at precisely the right spot, and we were able to complete the notching of all the cylinders pretty easily - it was just time consuming at a moment we really didn't want to be working on cylinder skirts. (See the "blog" section below.)
At that point, we could finally reassemble the crankcase - here's the bottom end with the new pistons and cylinders installed:
We think it looks pretty good!
While snapping pics, we caught the one below and like it because it shows clearly the inclined angle of the Denzel valves - they are not horizontal as VW and Porsche valves are!
We sent updates on our efforts to the Karmann Ghia Club of North America's email list - that's as close to actual blogging as we got. Still, it may be of interest as it tells our story pretty well.
Um... I need to update this! What happened was, in short, rain was forecast,
and significant rain was encountered in route through the Reno area, and we
decided to turn around - racing in salt-water isn't our idea of fun!
So... There's a write up I sent to the email list but I really should put it
up here! I'll get to it someday!
There's a nice long story here, too, that I sent to the email list but haven't yet taken the time to post here. I'll get to it! The short of it is that on our first run we reached top speed not far past the half-mile mark and inadvertently red-lined the engine somewhere before the 3/4 mark. The GPS was reading 119, and we know it lags.
Unfortunately, the damage could not be repared on-site.
This error was:
...I carry _all_ of this one! Oops! Just never thought the engine would pull it that fast!...
Comments? Errors? Additions? Please email us!