Upgrades and improvements for longevity

[Steve Bryant]

The idea behind this thread is to share ways we've come up with to improve on shortcomings of this wonderful little car to enhance our enjoyment of its virtues.

As I slowly restore my Seven I am constantly looking to see if there are ways to improve how things work or in many cases last.

Some activities or maintenance activities will eventually cause things like old tired threads to fail etc. One of the things I don't like about the Seven engine is the way that the sump  is held on with bolts into the cast aluminum crank case. Trying to get a good oil tight seal (if that is possible) with the old technology of paper gasket and oval washers to spread the compression on the sump face when you tighten the bolts up after each oil change and screen cleaning eventually leads to thread failure and stripping. More so if your sump's mating face isn't flat or in good shape with no gaps when the face is resting on a flat surface.

So what did I do to improve matters you ask? 

Well first of all I made sure that both mating surfaces were flat checking with a metal straight edge and adjusting the offending surface with either a file or a hammer and anvil (for the sump). When satisfied with the fit  I made up brass BSW studs that would be put into the crankcase permanently.  To hold the flange of the sump flat I fabricated a 1/8" thick by 1/2" wide retainer insert that sits in the flange of the sump.
   
This ensures that the sump stays flat when tightened to the crankcase. Retaining everything  in place are new  deep long neck nuts that would be easier to grip with the spanner.  The old paper gasket is not used but a new one will be made from a silicone  baking sheet from your local  Safeway or Tescos. 
   
All this ensures that you'll get a good oil tight seal with no leaks (hopefully) without wearing out your crankcase sump threads by having to resort to over tightening things and having a reusable gasket that should last for a long time before you have to make another.
   
Oil changes should now be easier and not something that gives you concern over bolt and thread failure.

The nuts and studs in the last picture are not installed but put in place just for the pic.

Cheers,
Stephen

[jansens]

Hi Steve, be interesting to see how you get on. Your spreader plate is a perfect thing to be water jet cut. Just be careful with the silicone gaskets. They are very soft so when you tighten them up they will squish up a lot (and squish out). I used one on the block to head gasket and that worked fine. There is a lot of area there. But then I tried one on the top water inlet on a ruby head and found that with enough torque on the nuts to make sure the head was down the silicone was so squashed up most of it has squished out of the joint. In the end I went for a paper gasket and Hylomar.

With such a thin area for the gasket I would worry that will happen on the sump too but on the sump it is constrained by the sump and raised lip so maybe that will be fine? What are you torquing the sump nuts up to?

Simon

[Ruairidh Dunford]

I am currently using these successfully...

   

[AustinWood]

Once again this is an application where compression of the gasket causes problems. The gasket will compress around the bolts which reduces the pressure on the space between the bolts. It also causes the sheet steel sump to become distorted and aggravate the problem. Further tightening the bolts then makes it worse not better and leads to stripped studs.
Some crankcases have blind holes for the sump bolts. If these have dirt in them the bolt will bottom in the hole and then snap with very little torque. Make sure the blind holes are clean.

[Oxford Jack]

I am currently using these successfully...

And that is what exactly?

[Ruairidh Dunford]

A silicone sump gasket Jack.

[JonE]

Would there also be a benefit in Steve's additional stiffening plate in place of washers, but keeping bolts? I can see that extra studs might be seen as an extra hassle when it comes to putting crankcases down on disassembly?

Ruairidh - is your sump gasket home made, or from stock now somewhere?

[Ruairidh Dunford]

The semi-deep cast aluminium sumps provide good stiffening properties, I find.

The gasket is from The Seven Workshop.

[Colin Wilks]

Steve,
I'm hoping there will be a "Part 2" to this where you address the sealing of the block to the crankcase. I recall hearing about a modification to this joint involving long studs going all the way through the crankcase from block to sump. Does anyone have any details or experience of this mod?

[Ruairidh Dunford]

Chris Gould’s 10’000 mile engine had the long bolts as you describe Colin, design by Paul Bonewell I think.

I have used HT cap srews for this joint which work well. The new silicone block to crankcase gaskets work extremely well here as well, in my experience.