Certified Transmissions

Here is the article as it was published in the Hoverclub of America's bi-monthly newsletter, "The Hovernews"

After reading Harold Carter’s article about Robert Hodson and his incredible machine and mission, I was more than a little intrigued. We wrote back and forth by email for awhile as I kept up with his journey. As he neared Memphis, I was excited that he was going to be near enough for me to see him. It turned out that he started having engine problems and really needed a place to do some maintenance and repairs.

I borrowed a large equipment trailer from a farmer friend and waited for his call. He called me from Helena AR, several miles south of Memphis, with engine problems on both engines. The twin turbo diesel 1.9 liter VW engines red line at 3100 RPM’s and normal cruise is at 2600. He was reduced to around 2000 RPM’s and sometimes was barely able to stay over hump. He made the decision to come on to Memphis and I was waiting for him when he arrived at around 8:00pm on July 15^th. After several days on the river, I think that Robert was happy to be on land for a few days.

The next day we began looking for problems with his engines. He has some nice software that runs on his laptop for diagnosing and troubleshooting the VW engines and we found that the main problem was that his turbos were leaking pressure. Since his engines have turbo intercoolers, that means that the exhaust leaving the engine spins a turbine that compresses the fresh air. The fresh air goes into the intake side of the turbo and is pressurized up through a pipe to the top of the craft where it goes through a large radiator and the air is cooled for more efficient combustion. From there, it is piped back down to the intake manifold of the engine. The code told us that there was a negative pressure fluctuation --something was leaking pressure.

A thorough look at the pipes revealed that both engines had a rubber hose at the bottom of the intake and they both had a good sized hole melted into them. A day or two before he arrived, he said that his engines got so hot that his fire detection equipment sounded off a loud warning buzzer and he thought that the whole engine compartment was engulfed in flames. He had been running with his engine covers closed and it got really hot inside. Hot enough to melt the hoses and some other things. I don’t think they have heat like this in England.

It took several days to get the hoses from VW and once they were installed, we retested and found that the code still remained. More testing revealed that there were more leaks in the system. We did further testing and the pipes leading to the intercoolers were leaking. We fixed those leaks and thought that we were done, only to find that the codes would not go away. As a last ditch effort, I grabbed the bottle of soap suds and had Robert start and rev up the engine. I crawled all over the pipes and the intercooler, spraying soap and looking for bubbles. I know, I know, that this is archaic, but, hey- it worked. We found that the port intercooler on top of the craft was bubbling at the seams. After checking the starboard side intercooler, we found it leaking, also. Evidently, not enough to set a code yet.

When Griffon built the craft, they probably installed both intercoolers and both radiators together with a hoist. We opted to dismantle the intercoolers and leave the radiators intact. It was quite a job getting them off as there was a very tiny opening to get to the underside of the intercoolers .

We dismantled them and then took them to my friend, Jimmy Butler the owner of Jimmy Butler’s Radiator Shop. We could see that the brazing used to attach the core to the end cap was really thin and leaked badly.

He said that it would be better to try and replace the cores. Robert contacted Griffon the next morning to figure out what to do. They decided that it would be a matter of several weeks to get replacement cores sent across the big pond. Robert said that he would try to fix them here and we talked Jimmy into re-brazing the cores. Jimmy was concerned about liability issues since these were different types than what he is accustomed to fixing. Robert prevailed and Jimmy did a marvelous job and we put them back together. My son, Joshua, is 14 and really skinny and we sent him in for the disassembly of the intercoolers. He was not around when we reinstalled them, so I went in. Pictures # 7& 8 show the tight quarters for working on these intercoolers.