Cams will not turn.

[Billmack]

There are two letters on the caps and head as well (DB).

[Billmack]

Im with you on the "coupla tenths" thing.

[Billmack]

To billwill: SAS head is not a lotus head. In the US we would use the term "facsimile head" like the Chrysler hemi parts used on a fuel dragster. Same architecture but has never been near a chrysler factory...

[rgh0]

There are two letters on the caps and head as well (DB).

You see these at times on a few heads. They appear to have been done to keep sets of cam caps together. Not clear if done by the factory at some stage during manufacture for a period or if done after by a shop doing a head rebuild.

cheers
Rohan

[billwill]

To billwill: SAS head is not a lotus head. In the US we would use the term "facsimile head" like the Chrysler hemi parts used on a fuel dragster. Same architecture but has never been near a chrysler factory...

I am well aware that it is not a 'Lotus' head, it is better than a Lotus head, being made with modern alloys and modern computer controlled techniques. It's what Lotus would probably produce today if they were still making the Twincam engine.


However your first post did not specify Lotus heads, so my comment in the second msg above was accurate.

[Billmack]

To Billwill: Im sure those are fine heads. I am trying to resuscuitate two older pieces. Im sure the cams will turn in your head(s) for many years. Just did not find you helpful...

[2cams70]

There are two letters on the caps and head as well (DB).

The “DB” I suspect stands for David Brown Engineering. They were probably contracted to do all the finicky individual final hand assembly jobs on the Lotus Twin Cam such as selecting all the shims and doing the valve clearances. The short block was most probably put together by Ford as there are no special processes required compared to a regular pushrod engine. Different story for the Lotus head. This definitely would not have been a good fit with Ford’s regular production processes! Heads cast by William Mills and final assembly done by David Brown Engineering. My ‘70 Escort Twin Cam engine’s head has the “DB” stamp too. Lotus were car manufacturers and not engine designers / manufacturers. They get way too much credit when it comes to engines. Whilst they may have commissioned engine projects it was actually others that did the work for them.

[Billmack]

Thank you. That's very interesting. This is the only one of the three heads I have with those partiicular letters. I'm checking with the previous owner to see if any of his other heads have the db thing. I did condider Dave Bean also for that.

[Craven]

All factory cam caps I’ve seen have a prefix of two characters of letter + digit or letter+ letter and position #
Also stamped on head itself in a central position. Pic. Head X4 Cap X4 #8
Combination of A – Z = 1352 + 520 single letter – single digit, so using this system means a number of repeats in production.

[Billmack]

Thanks! Hope the previous owner has another head with db on it. Ive got a trashed head with 9 caps so there is hope of finding something with a better fit to avoid major machine shop surgery. Its not lost on me that this would likely mean theres another head with a cam that does not turn

[promotor]

Thanks! Hope the previous owner has another head with db on it. Ive got a trashed head with 9 caps so there is hope of finding something with a better fit to avoid major machine shop surgery. Its not lost on me that this would likely mean theres another head with a cam that does not turn

Is there a chance you've got caps numbered 6 and 9 mixed up?

[Billmack]

I could only hope. Tried them backwards and forwards in both locations. Weird they are on rhe same cam too. We've got 3 out of 4 where the cams will turn now and the machine shop guys are coming back from vacation monday..I'll be keeping us up to date on what happens. I'm thinking and hoping some of the 9 other caps may be closer to a fit.

[alan.barker]

I imagine you are doing this with all Valves removed. Have you checked Camshafts are not bent.
Alan

[Billmack]

Cam is straight and polished journals. All valves are out. Using same cam on all for checking.