Prevention Is Better Than The Cure.
The cure of course, is stripping and rebuilding the twin cam cylinder head with new cam shafts, valves, etc.
The long bolt mod has been proven to eliminate the threat of camshaft breakage.
If you have read the article on our lotus elan blog page, then you will be well aware of the problem.
But luckily, there is a fix, and you can grab it today – A Project for the keen twink DIY mechanic.
We are currently manufacturing/modifying sets of special HT (High Tensile) long bolts to replace the existing short bolts that secure the cam sprockets. They are available for purchase now, but you need to deep drill and tap the cam shafts, (Cams out of the engine) then replace the assembly back into your engine, and continue to blatt around in your hot elan with the knowledge that you have done everything possible to prevent a cam shaft breakage.
We supply two bolts per kit, because it makes sense to modify both inlet and exhaust camshaft.
There are discussions on the lotuselan.net forums about the incidence of broken cam shafts, although, it only seems to be more of a problem with modified engines fitted with high lift cam shafts, extra strong valve springs, and use of a higher than normal rev limit.
But, in one particular case, a head bolt snapped off, and lodged between cam lobe and solid object, the result was a broken cam shaft – Ouch!
Power costs money, and so it seems that engine modifications can also lead to more rebuild costs… if certain precautions are not taken.
If you possess a lathe, and you know what you are doing, you can carry out this mod your self, but if you are in a hurry for the long bolts, why not get them shipped to you straight away.
(The photo above – Head is mounted on the special twin cam cylinder stand for rebuild work)
After machining and drilling, the bolts are installed and tested on a standard lotus cam shaft, with sprocket, special washer, and spring washer, before we ship… just to make sure all components are correct.
The bolts are ready to fit… But you will need to carry out the extra drilling and threading operations (Or have intentions to complete) on your existing cam shafts. If you have machining facilities, well and good, otherwise, take the cams to a machine shop… with instructions.
Installation instructions are provided with each long cam bolt kit. Since these photos were taken, we now machine some metal off each bolt head, to allow more clearance near the “D” plugs.
Beef Up Your Cam Shafts For Protection – Purchase Your Modified Long Bolt Kit (x 2 Bolts) Here Today.
Only $56.95US Per Pair – Price Includes World Wide Shipping.
The Piece De’Resistance – The ultimate piece of gear for the twin cam engine, adjustable cam sprockets, making life a whole lot easier when checking/adjusting degree timing of camshafts with crankshaft. Much less hassle than the offset dowels.
Oh, this photo is supposed to be about the steel retaining washers on the cam sprockets… well there they are. (Above).