Prevention is better than cure
After our amazing road trip to the Highlands and Islands of Scotland, it felt right to give the camper a bit of love and some mechanical TLC. It had been really reliable for the 1,800-mile road trip, and I wanted it to remain that way for the next one. So I booked some time in with the guys at Resto Classics.
When they had fitted the replacement original VW heat exchangers before the Scotland road trip, they noticed a small oil leak from one of the engines push rod tubes. Nothing major, but something I wanted to get resolved.
You can struggle and change the pushrod O ring seals with the engine in place, but to do it properly (and to make your life a bit easier) the engines better off out.
Using the opportunity of the engine being out
So whilst the engine was out, it made sense to change the gearbox seal. The engine case had been painted red at some point. The paint was flaking and missing in places and was pretty grubby with dirt and oil accumulated over the years.
Time to give it a good clean up so you can see what you’re dealing with…
Scrubs up pretty well for its age
The cleaned-up engine is transformed with the old paint, dirt and oil cleaned off it. Nice to see a fresh-looking engine case again.
The trouble when you clean one thing, it just highlights the dirt on other areas. So whilst the high-pressure hose was out, the tinware also got cleaned up too!
Spotting problems early on
There was an aftermarket pulley fitted on the engine. At some point, it too had been painted. Areas of the paint had flaked off in the wash. On closer attention, turns out the pulley was also a bit worn. Made sense to swap it out whilst the engine was being looked at.
Fortunately, Resto Classics had a used original stock steel pulley in their stores. With a bit of clean up and some black paint, it was soon transformed (along with the tinware) to get put back on the engine once the work was complete.
More than just a cleaning session
The main reason the engine was out, was to fix a leaky pushrod tube seal. Unfortunately, as the guys taking things apart, other issues came to light.
One of the valve springs seemed to be very weak. On closer inspection, it was easy to see why. This would need to be replaced.
Then they found that the engine block had been fitted with a ‘Helicoil’ insert in the past. Unfortunately, this one had started to pull loose of the engine block, so that the heads were a little loose.
Every day is a school day with vintage VW’s for me. I had no idea what a threaded insert was. Turns out its a helical insert made of coiled wire. The helically formed coils of diamond-shaped stainless steel or phosphor bronze wire screw into a threaded hole to form a mating internal thread for a screw or stud.
These inserts provide a convenient means of repairing stripped-out threads and are also used to provide stronger threads in soft materials such as aluminium, zinc die castings, wood, magnesium etc. They sometimes get used if an engine cylinder head repair gets unintentional over-torqued or cross-threaded and strips the thread of the socket. I guess stuff must have happened at some point in the engine’s history?
Better to find out now
Best this sort of stuff gets found out now and is resolved. The barrels and pistons have to come off to try and effect a repair. Once they were off it was clear to see that a few other Helicoils had been used in different locations on the engine case too.
To provide a better long term solution, the old holes needed to get carefully re-drilled and ‘Time-sert’ solid bushing inserts fitted. Apparently these are a much better long term solution. They allow for full load use of a tapped hole, ensuring protection against any stress and vibration shaking the fixing loose.
Small engine performance gains?
As the heads were off, another opportunity presented itself. OK, it’s never going to be a race performance engine, but the heads could be cleaned up and mildly ported to help improve the speed and quantity of the airflow to optimize the engines power output and delivery. It’s all about marginal gains.
The heads all cleaned up with some mild Cylinder head porting carried out. Proof of the pudding will be when its back on the road and driving again to see if I notice any real-world differences or not I guess?
Back together again
So the three defective Helicoil inserts were removed, and the old holes carefully re-drilled and fitted with ‘Time-sert’ solid bushing inserts. There were some other Helicoil inserts fitted, but they all appeared to be in good condition. To be sure, the guys refitted the heads and correctly torqued them up to make sure everything still held OK.
What’s that sound?!
Nervous moments, but yep, everything held good and torqued up nicely. Happy days! Time to get the engine reassembled and refitted back in the bus. All back in nicely and looking good once again. Quickfire up of the engine to test everything and all seemed to be running nicely until the guys heard a small pop sound from the engine… oh oh!