Does a cam tend to move longitudinally in operation?

[promotor]

But is this maybe a fault across this rather closed industry at the time and not peculiar to Lotus?

I have of late taken an interest in the various relationships of the day, particularly Ford with Lotus and Cosworth and find it amazing the speed of many developments, and the number of players tumbling in. Was there any time for such niceties as keeping detailed blueprints or carrying out quality control?!

Re my head - do not get me wrong, it, to me, looks superb. It is an SAS head that I bought from John Wilcox as 'his' head. But if you look at Tony Ingram's 'own' head, it is identical in spec? ported and polished 45 with 38 throttles etc. The cams are Kent D144 purchased new from Kent direct.

I think you've hit the nail on the head - Colin wanted to get things done quickly to sell some cars so he could fund going F1 racing. I'm sure some things were good enough, and still are today, but with some areas that need a bit closer attention. like cam lobes etc!

Not sure on the head specs, but it's not inconceivable that as engine tuners they have a certain spec supplied by SAS and they then fine tune the ports and combustion chambers if / where needed on their own heads, or just use them as supplied.

How close are the lobe positions on the D144's to each other? The lobes may be equally spaced but may end up in slightly different positions relative to the follower bores due to the placement of the thrust ring and also where it's recess was cut in the head. And that has a knock on effect on where the sprocket runs and whether that's in line with everything else in the chain line! Some engines will just naturally end up with the chain more in line, and some a little bit more out of line, but they'll still work nicely.

I wouldn't mind having an SAS head to build up - I bet the casting is much better due to modern casting processes, and the engine builders opinions of the SAS head would suggest that it's the best available. I'm sure it'll make a very nice engine added to the right bottom end!

[HCA]

The sixties, to those of us who will remember, were not that long ago. Did things move at a quicker pace then? Certainly, and this is what I like reading about, there were no clear definitions or silos. Racing drivers became engineers and vice versa. Everyone had an idea to explore. Chapman was maybe the greatest of these, but so many followed, Brabham, Hart etc all went on to be greats. I am completely fascinated by what went on then. I cannot get to grips with modern day players!

Re the head - I am very far form being qualified to discuss the merits or not of SAS. I can though say that the lobes are such that each is placed so that the 'front' side of the lobe is directly over the 'front' of each valve stem. It is almost uncanny to see the accuracy of this now that I know what I am looking at/for.

Rohan has seen this actual head and maybe as you and he speak the same lingo, have a conversation with him. He did make a lot of observations that went over my head on various aspects of the design. He did, as you, comment on the quality of material making it much more acceptable than yesterday's offerings.

[promotor]

It looks very nice indeed, and the material looks to be very uniform cast. Looking forward to updates on the engine once it's built.

[HCA]

You asked what the bottom end is. I forgot to elaborate.

It will be a 1700cc based on a 711M block, nitrided crossflow crankshaft, BDA rods pushing CP pistons. All this fed by an Emerald EFI.

I have come from a rather more agricultural genre - BMC A and B series engines (having said this, the Lotus 18 was briefly powered by a Downton A series I believe)! On my bucket list is a desire to build a complete Twin Cam using all new parts...

Rohan is giving me more help than I desreve, so there may not be many updates, but I will try to remember to take photos of the build.

[promotor]

You asked what the bottom end is. I forgot to elaborate.

It will be a 1700cc based on a 711M block, nitrided crossflow crankshaft, BDA rods pushing CP pistons. All this fed by an Emerald EFI.

I have come from a rather more agricultural genre - BMC A and B series engines (having said this, the Lotus 18 was briefly powered by a Downton A series I believe)! On my bucket list is a desire to build a complete Twin Cam using all new parts...

Rohan is giving me more help than I desreve, so there may not be many updates, but I will try to remember to take photos of the build.

Very nice indeed!