Tuesday, February 07, 2023

Nearly finished, and I'm exhausted


We're nearly at the end of the VW engine build, and it's time for some of the larger bits in the box to be fitted - the exhaust system. 

It's interesting that the pipes emerging from the cylinder heads into the silencer, are very thin. Under the rocker covers on later VW engines are a set of heat exchangers. The pipe is finned and an outer jacket contains the air that will be blown into the cabin. Obviously, those fins take ages to warm up, and then warm the air supposedly providing heat. Worse, if the finner pipes develop a leak, you'll be blowing exhaust fumes into the cabin.

It's a clever system when it all works perfectly, but I haven't owned a VW where it was any more than useless. There wasn't much warming air in the cavernous space of my Type 2, and I don't recall the Beetle being much better. Mind you, it helps if everything is buttoned up properly and using original VW heat exchangers, any air gaps let the precious heat escape. The fins on the pattern version tend to be a bit rubbish too, reducing the effectiveness of the whole system. 

The main pipes are two-part items screwed together. I've sprayed it all with primer as that's the colour these things are normally supplied in, even if the paint quickly burns off and is replaced with rust. 

One good thing about building a kit is the speed of assembly. I've replaced several VW exhausts, and without fail, each one takes 6 hours work. Mostly trying to get pattern pipes to line up, a trick that required brute force and bad language!

No comments: