Breezy Bonnet Syndrome

[jbcollier]

After a couple of short trips, and fettling the few final issues after a major refresh, I went for a proper 700 km round trip.  Overall it went very well.  Economy is not as good as my Europa but reasonable none the less.  Suspension is as good as can be expected with the rear being quite firm on the big bumps.  I did some experimenting and buffeting can be reduced to reasonable levels by either shrinking an inch or so, or by adding a small clip-on extension to the door frame.

 

All well and good.

 

However, I was alarmed to find that three of my bonnet latches “weren’t” upon arrival.  They all stayed latched on the return journey but I’m afraid my confidence has been shaken.  It’s a somewhat original 69 Seven S3 and I’m trying not to stray too far from stock.

 

Any suggestions on how to keep the bonnet firmly in place while I further push back the Seven’s horizons?  

[MV8]

Might could use a new gasket on the bonnet side to tighten things up. With no modification, you could add L-tabs on the latch side (attached by the same points as the latch, then fit a hair pin that must be pulled for the lever to move away from the the latched position. The hair pin can be retained with a couple inches (after twisting) of safety wire to keep from losing it. There are a number of locking over-center latches available that are also adjustable for tension but I don't know of any direct fits.

[JohnCh]

It might be worthwhile to post a picture of a latch so other S3 owners could chime in regarding originality.  I'd also start with MV8's suggestion about tightening things up with a new or thicker gasket.  Maybe try some foam rubber shims under each latch point to see what works best?

 

In terms of other options, Caterham uses terry springs on the front and conventional over center latches in the rear.  For my Westfield, I went with overcenter catches with a locking pin from https://protex.com/.  With those pins in place, there is no possibility for the latch to open.

[jbcollier]

Yes, definitely original latches.  Good suggestions, thanks.  I'll start with replacing/adding foam gasketing to give the latches more tension.  I also thought adding a small “super-magnet” might also help.

[IamScotticus]

@JohnCh which Protex latches did you use?

[JohnCh]

9 minutes ago, IamScotticus said:

@JohnCh which Protex latches did you use?

 

27-1570SS with the 613/7SS retaining pin.  The latch has a safety catch, so with the pin, it's a belt and suspenders approach.