My Salt Dream : VW Karmann Ghia

[WOODY@DDLLC]

Failure at the finish line - perfect timing!   

[wickedwagens]

Yes, failure at the finish line.  Just good enough to still pump the engine down and certify the record!

While the heads were off Juan touched up the valve job and we were looking for titanium retainers.  I also had some stuff to check in the transaxle, so we were on a time crunch.  With not being able to source a quality titanium retainer that had the dimensions we needed, we decided to go with chromoly.  These had worked fine on other engines for us in the past....
I get the heads back and get the transaxle back together and in the car and get the engine in and running.  The goal for World of Speed was hit that 175 in the 2 1/4, and of course get the Fuel record back in our name.

We get through tech and we are second in line to run on the first day.  I leave the boost controller set where it was from Speedweek as we ran 170.726 and the fuel record we are going for is 168.xxx.  We get the go ahead and take off from the line.  Everything is going good until right about the 2 mile mark.  I hear a pop and thought it sounded like a silicon coupling split or blew off. 
Everything still looked good on the gauges, except boost pressure dropped down. 

We took it back to the pits and started checking things out.  We found that 2 of the pushrods were now not happy and jumped out of the pushrod cups on the rocker arms to go for a ride.  Maybe these chromoly retainer added just enough weight to where we can now not keep control of the valve train.  I heard of someone running back to Salt lake City for some parts and asked them to pick me up some new cut to length pushrods and luckily they were able to source them.

I cut 2 new pushrods to length and massaged the pushrod tube back into a somewhat round shape.  I noticed that the rocker shaft had a slight bend to it.  No one had one of those for sure, I thought, hopefully it can last 2 more runs.  With everything running again we got back in line.  I adjusted the boost up just a little.

On this next run it was going really good. The GPS was showing 174 and right as the engine hit 7,000 rpm power fell off and I knew it did it again.  Something was not happy in this setup.  I shut it right down and we towed pack to the pits and popped a valve cover off.  This one we were not fixing and it was time to pack up and head on home.  I guess you can't always win!

We will keep finding the weak links and improving!

[manta22]

I think you're right, the added mass of the steel valve keepers created a strong resonance in the valve train at 7k rpm and with everything bouncing around, something was bound to fail. Titanium is your solution, and maybe a bit higher rate valve springs.

[noboD]

As a Beetle guy that's had my share all I can say is I am impressed. I find it hard to believe a Ghia can run 170's without going on the roof. You are doing something right!!

[wickedwagens]

I think you're right, the added mass of the steel valve keepers created a strong resonance in the valve train at 7k rpm and with everything bouncing around, something was bound to fail. Titanium is your solution, and maybe a bit higher rate valve springs.

I think that if we go with titanium valves and retainers, we can probably keep the current spring.  Others with larger titanium valves have been able to use these springs up into the mid 8k rpm range.  I think we will start with that.  I also talked to Pauter and they said that they had changed the rocker design in 2012 because of broken shafts.  I will probably buy the new style shaft and try to come up with a support on the end to tie it into the head.  Only 11 months to go!

[Mr. Schimstock]

Any idea what material and heat treatment is used to make the shaft?

[Tom Simon]

That Ghia is one record breaking machine, looks as good as it is fast! Good to see you and Kerriann last month. Sorry you broke this time out.

I ran the same set up as yours in a 200hp drag engine for 6 yrs of hard bracket and index racing, probably 50 races, broke 1 shaft (at the stud hole, same as yours), and broke 1 rocker arm, and bent some pushrods in the process. The keeper grooves would bur, the underside of the retainers would fret. On the advice of a long-time cylinder head porter, I started measuring and replacing my valve springs more often, after measuring a loss of seat pressure >10%, and my problem went completely away. In my case, it became evident we were floating the valves on tired springs, as both breakages happened well into the life of the engine build or last freshen up. In your case, it could be you aren't running enough spring pressure.

In any case, the new style Pauter rockers arms have no needle bearings, the aluminum rides directly on the shaft. Upgraded to more wear resistant 7075-T6 aluminum if I recall, since there are no needles. I think Mario told me the redesigned rockers themselves have a smaller bore, and the shafts larger in diameter, strengthening both parts.

[wickedwagens]

That Ghia is one record breaking machine, looks as good as it is fast! Good to see you and Kerriann last month. Sorry you broke this time out.

I ran the same set up as yours in a 200hp drag engine for 6 yrs of hard bracket and index racing, probably 50 races, broke 1 shaft (at the stud hole, same as yours), and broke 1 rocker arm, and bent some pushrods in the process. The keeper grooves would bur, the underside of the retainers would fret. On the advice of a long-time cylinder head porter, I started measuring and replacing my valve springs more often, after measuring a loss of seat pressure >10%, and my problem went completely away. In my case, it became evident we were floating the valves on tired springs, as both breakages happened well into the life of the engine build or last freshen up. In your case, it could be you aren't running enough spring pressure.

In any case, the new style Pauter rockers arms have no needle bearings, the aluminum rides directly on the shaft. Upgraded to more wear resistant 7075-T6 aluminum if I recall, since there are no needles. I think Mario told me the redesigned rockers themselves have a smaller bore, and the shafts larger in diameter, strengthening both parts.

Thanks for the advice Tom.  I think that is the direction we will go.  Ti valves, Ti retainers, The new style Pauter roller rockers, and then keep a close eye on valve spring pressure.

Mark

[wickedwagens]

Well we are ready to go after the G/CBFALT record of 168.417 mph. We upgraded to titanium valves and retainers, went to tapered pushrods, and to upgraded rocker arms.  It got towed to Wendover and back, but never made it off the trailer. We shall see if there are any more events this year.

[Stan Back]

You were lucky!

(You didn't take it off the trailer.)

[slowalex]

Here is the start to the 2018 season.  A destroked crank for my H engine.  66mm stroke x 85.5mm bore for 1516cc or 92.5 cu in.

Thanks for this thread, I've learnt quite a lot about the classic classes for small capacity cars. Although I might never own or race a VW or any air cooled car, I've owned another small car designed by a former VW/Porsche engineer, so some of the technical info looks familiar to me.

The Classic class was changed a few years ago to allow foreign makes and the allowable engines were expanded all the way down to H specifically to give air cooled VW's a place to run.

Exactly, I can?t compete with modern inline 4 cylinder engines. I appreciate the change to allow foreign cars in classic. I wouldn?t have built this car and run out there without this change.

I noticed in the Lake Gairdner speed week events in Australia, they didn't appear to run the H/CPRO or H/CGALT class, or any of the other smaller classic classes, so cars that would have been in those classes were running in H/PRO, or equivalent modern classes instead. From my understanding DLRA rules are based on SCTA rules and the classes appear to included in the rulebook.

I noticed in the ECTA rules for the classic category: Foreign Coupes and sedans are limited to ʻFʼ (123.00 to 183.99 cid, 2.016 to 3.014 L) engines sizes.

Is it just SCTA events that run the smaller classes for classic cars?

[wickedwagens]

I'm not sure on that.  You would have to contact the organizers for the other events to see what they allow or not.

[wickedwagens]

With our land speed races cancelled for this year, I'm starting to plan for next year.  I keep running into fulcrum and axle wear with my swing axle style transaxle. I just don't think they were designed to run 170+ MPH. So I am thinking I.R.S be better up to the task.  It should have a better bearing setup, two CV joints which keeps the wheels flatter to the ground and I have to switch to 5 lug wheels anyways, so I might as well tear things apart.  This would also help with gearing changes too as I could build and borrow other transaxles from VW friends and change them out easier.   

[slowalex]

Thanks for replying. In hindsight I might have mostly answered my own question, and in any case, I know that in my own country there are no "classic" classes recognised for land speed racing.

What sort of drive shafts and suspension were you planning to use for your full I.R.S. setup for the Ghia?

If you were looking to use something from the VW/Audi parts bin, then I'm pretty sure all the early Audi 80/90/100/200 and quattro models used a longitudinal mounted engine with equal length drive shafts. Same with the VW Passat. The Audi 200 drive shafts should certainly be able to handle the power/torque if that was a major concern.

[wickedwagens]

Thanks for replying. In hindsight I might have mostly answered my own question, and in any case, I know that in my own country there are no "classic" classes recognised for land speed racing.

What sort of drive shafts and suspension were you planning to use for your full I.R.S. setup for the Ghia?

If you were looking to use something from the VW/Audi parts bin, then I'm pretty sure all the early Audi 80/90/100/200 and quattro models used a longitudinal mounted engine with equal length drive shafts. Same with the VW Passat. The Audi 200 drive shafts should certainly be able to handle the power/torque if that was a major concern.

VW switched to an IRS set up in 1969.  I can steal all of the parts from a donor car and I just have to weld in some brackets to attach the swing arms to.