Notch up and lobes pointing away from the valley is correct. Number 6 is the frontmost piston. TDC for both at the same time.
Yes I realise no 1 & 6 are at TDC the same time, but all the manuals say to set no 1 at TDC, so I thought this would mean with the distributor at No 1 ignition - this is not how the cams are set - it is with no 6 at TDC and on ignition.
Yes that is confusing. I would just set the timing with 6 at TDC as it is.
Iâve knocked this nail in twice already John, but Iâll hammer it again.Using Jaguars terminology. ie front cylinder number 6 and the cams set for number 6 to fire , logic informs that the firing order is 624153. ALL the books, including Jaguars own ,are incorrect to state 153624.
Hi JohnâŚthis will explain xk camshafts http://www.georgiajag.com/Documents/Camshafts.html Not sure what manual you are useing but my Jaguar S1 manual clearly says that âwhen refitting the head turn No6 (front) to tdc with the distributor rotor arm opposite the No6 segmentââŚcamshafts already in the correct positions by useing timing guage to set themâŚSteve
Iâve never understood why something so basic, so simple, can be so misunderstood.
Ah, the confidence of youth! Surprising to see it in a mature person though.
Did it ever cross your mind, Grasshopper, that if âAll the books, including Jaguars ownâŚâ (and of course the books of many other in-line six manufacturers) all say 153624, thereâs just the teeniest chance that everyone else is right and you might be the party that is off-base? Whilst weâre at it, can you supply any firing order for any other multi-cylinder engine that does NOT begin with cylinder number 1? Thought not.
Don Quixote, eat your heart out!
Whatâs the difference?
If, when starting the engine, number 2 is the first cylinder to fire, has the firing order become
241536? As Kirbert points out, it is all about the starting point, sequence is the same.
I think the later cams I have seen all have a plug at the rear where a tach drive goes. Do those cams have a threaded hole for it or do you have to tap them for a drive?
Well perhaps John Briggs will inform that, if the firing order was stated as 624153 , any confusion twixt cams and static ignition set on 6 , but the firing order stated as 153624, would not have arisen.
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Interesting concept. Every manufacturer should stop writing the firing order starting at #1, in case seventy years later someone on an internet forum who is working on the engine for the first time gets mixed up by not reading the manual.
Iâve heard of âfuture-proofingâ, but there are limitsâŚ
The whole problem could have been avoided if the front cylinder had been #1, as in every other car ever made?
What does it matter, which end is #1?
Itâs just convention. Call the front cyl #1, start the firing order with #1, set the ignition timing and cam timing based on #1, confusion avoided.
Just the confidence of logic Peter, and as to the lack of logic in a mature person, well !!
As we know Jaguar state that all dimensions etc are viewed from the drivers seat, therefor logical that , the rear cylinder being nearest the driver, is number1. Number 6 primed to fire of course cannot, there being no mixture in the cylinder, so, in theory, I repeat theory, the first cylinder to fire is , because itâs on its induction stroke, number 1. HOORAY 
firing order 153624 humble pie, grovel. etc , so perhaps Jaguar state a theoretical firing order. But hang on ! can anyone, including yourself, guarantee that number 1 will fire first? thought not.
Sticking with inline 6s, is the convention in the USA for number 1 at front ? if so firing order 1- - - - 4 , but this brings on a conundrum, we know that number 1 cannot fire first, so is a theoretical order quoted, ie 6- - - - 3, so answering my own question, I think not,
the theoretical Jaguar firing sequence can be dismissed also methinks.
So cam(s) and ign set on number 1front
- to 4 logical.
Set on number 6 , front, 6 to 3 logical
Don Quixote. ? more like Sancho Panza, for if it looks like a donkey it is a donkey, if its logical then >>>
As I already live in interesting times ( Brexit ) I await you Confucian reply.
If indeed this post is worth your reply .
NO: All American sixes that Im aware of are 1-5-3-6-2-4.
Yes mistake on my part ,i will edit.
Get the plug out andtap 3/8 NF
It isnât. Have it your way Peter. I get more traction explaining stuff to my grandchildren.