Humber FV1600

[fv1620]

Yes please do. Will look forward to that. Hairstyles are always a give away & of course trousers can tell you a lot too.

[Richard Coutts-Smith]

While at Corowa in March I was stopped in the main stree for an hour talking to an ex Humber owner of many years, and as always, if you listen, you learn.
He saw the badly cracked and repeat welding repairs on the cast iron "Y" exhaust and laughed, saying that this happened on all Humbers as the exhausts were never set up properly. His theory was that one of the 3-1 manifolds needs to "Undertightened" (I think I just invented a new word). The manifold gaskets are a simple aluminium shim that allow the manifold to expand and contract along the head itself, thus saving the "Y" from splitting down the middle. This of course fails immediatly we tighten the manifold up "properly". Much clearer when you have it all explained while looking at it.
However, I have just added to the amount of weld that others before me have laid down, the crack was out to 3 mm when hot, so will try the method outlined above while I save up for a set of headers.
Same Chap also asked if my Humber growled on a cold morning.
Funny he should say that.....I had been trying to tell myself only that morning that the funny deep sounds under the bonnet where nothing to worry about.
Stock phrase for Humbers, "they all do that". It's just the cold dense air coming back from the fan, makes a growling sound that rises and falls with the revs, and fades away once things warm up a little, about 3 or 4 minutes.
Must say it was quite unsettling the first time I heard it.
Shown below is the crack inside the "Y", "Y" in place with the 2x 3-1 manifolds: one of which needs to be just that little bit loose.
Last pic demonstrates the more than noticable engine off-set, just line the tappett cover up with windsreen centre.
Todays photos were brought to you with the courtesy of ARN 105 674.
This was the first ARN assigned to a Humber One Ton (so the lowest number), with the highest being 105 823.
Other trivia for today, ARN's are listed for HUMBER 1 ton CT Cargo, not a Commer as plated, same for the Australian Change in War Materiel (ACWM)
Rich.

[oztankboy]

Hi there Rich!

Well the old "Y" crack happened to mine too! Lucky it happened while i was still posted to a base workshop. I mannaged to get it welded by some one who knew what they were doing then I proceeded to surface grind the face of it so the 2 faces where in the same plane.

When I checked the 2 manifolds I noticed they were not in the same plane but stepped. The proper way to have fixed it would have been to remove them both and got them surfaced ground as a pair however I did not have the time then. What I did do is checked the off set and found that it was about the thickness of the gasket i was useing so ended up useing a double thikness on one side and a single thickness on the other.

Now that was back in 1995 and the old beast has done well and truely over 10,000 klms and still no re-cracking.

Phil...

[Richard Coutts-Smith]

Hi Phil,
Yep, going down that path too, after all the welds the faces are out, although the manifolds look quiter true. Although after seeing the size of the ports in the "Y" and the head manifold I think some fine tuning of the pipework will give a major benefit.
Does yours have a heat shield fitted over the manifold, below the distributor? Noticed today that my spare engine has a casting threaded for the shield, while the original engine has neither the shield or the casting?
Rich.

[fv1620]

That does seem to be a common problem I have seen several over here with that. As you know the Y-piece is different & longer on armoured Humbers & don't think I have ever seen occur on those. Although on the Hornet I did have the front manifold crack.

Ferrets seem to get round the problem by having a gap & once heat expansion takes place a sort of 'seal' is formed.

Rather than shims I use copper covered asbestos gaskets. I found that gaskets for a Vanguard car will do. Although the 4 holes are not quite centred because the holes are larger they fit the studs fine. As the 'square' gaskets are not flat-sided but elliptical I have trim a small section where they are next to each other.

I note there were two types of Y-piece fitted to the GS

FV175019 from chassis 20,000 to 20,681
FV228288 from chassis 20,682 onwards

So I don't whether that was to address the cracking problem or indeed how they differ.

Interesting the official recognition that the 'Commers' are proper Humbers after all

[Richard Coutts-Smith]

Hi There Clive.
Did not know that the Pig had a different "Y", or indeed that there was a choice depending on chassis number. Aust. delivered chassis were in the 11 000 to 14000 range so all had what I assume is the short "Y".
Ferret does seem to have a way better design to allow for the expansion.
We use the Copper/asbestos gaskets on the Champ, thought they were genuine for the B40, either way, they do work well
Any idea as to why I have one engine with a heat shield casting, and one not?
Rich.

[fv1620]

Originally Posted by Richard Coutts-Smith

Any idea as to why I have one engine with a heat shield casting, and one not? Rich.

Rich I think it is because supporting the heat shield from the two manifolds meant there had to be two different components, a forward one & a rear one.

Supporting the heat shield independently meant one manifold could be used in either position. Another factor might have been the difficulty of removing the retaining stud if it had become too encrusted with the effects of heat, rust & time.

[fv1620]

Here is a Pig Y on the left & a GS Y on the right. I have no idea whether it is early or late type.



The parts book for the Hornet gives the same Y piece as for the Pig. But the book is wrong the entire Hornet exhaust system is quite different. The book was based on the prototypes using the Pig system.

But that meant you had a heat source directly under one of the spare missiles in the rear. It also meant loaders were tempted to stand on the end of the tailpipe, although this was later protected by a small armoured cowl.

The production Hornet had quite a different silencer mounted below the radiator accommodated by an enlarged belly plate with the tail pipe exiting in front of the front wheel on the driver's side, sometimes causing hypoxia for the driver.

Hornet Y on the left, Pig Y on the right.



You can see the gaskets I have fashioned from the Standard Vanguard gaskets.