Where to apply paint; gold head?

[64etype]

I was looking at photos in the "FACTORY FIT - Series 1 3.8" sticky for guidance as to where to apply gold paint to the cylinder head and noted that the first series of photos (a late 3.8 red OTS) show the gold color in the "valley" ending at the cam cover flange. The second car in the string is a '63 white OTS, and it shows the gold paint ending at the horizontal plane of the head bolts. (In other words, the paint does not cover the elevated, near vertical areas between the head bolt surface and the cam covers). I much prefer the look of the later, but wonder if it's "factory fit"? Thanks.

[jag68]

It's a question that has come up without any satisfactory answer as far as I'm aware. I've always painted the complete head on the engines that I've done on the basis that I can't see Jaguar actually bothering to mask, in some way, the flat vertical machined area above the seats for the nuts - and for no purpose to boot. On some of the older heads I've seen that surface has occasionally had bits of paint on it - but that's not entirely reliable as to the practice as over the past 50 years somebody could and probably did repaint it.

[abowie]

Don't know if it's right but this is what we do.



No paint on the manifold faces either.

[SEJohnson95]

This is how Richard painted his 3.8 head:









Once again no paint on the manifold faces. I kind of like that sacrificial set of old plugs in gold!

[Simon P]

Once again no paint on the manifold faces.

Psssttt..... Top left in the first photo

[SEJohnson95]

Once again no paint on the manifold faces.

Psssttt..... Top left in the first photo

Yeah alright thanks Simon. I'm not very well ATM so probably not thinking straight! ;)

[Simon P]

Nothing a bit of wire wool won't fix (the paint that is, not your cold... )

[64etype]

Thanks for the replies, but I'm still curious as to what is "factory fit" for those vertical strips between the plane of the head bolts and the cam cover flanges. One of the cars I identified in my original post (both listed as definitive, unrestored and original in the "FACTORY FIT - Series 1 3.8" sticky) is apparently "incorrect". If the head on the white car is "factory fit" and unmolested, then every other car in that string of examples is suspect. (I realize this is an obscure detail).

[jag68]

This is also obscure - but you should not paint the surface under the nuts that secure the head. This distorts the torque setting, and can lead to loosening of the nut as the paint moves away from the pressure. I've seen this failure in aircraft engines painted under the nuts that secure the jug to the block with very bad results.

[SEJohnson95]

This is also obscure - but you should not paint the surface under the nuts that secure the head. This distorts the torque setting, and can lead to loosening of the nut as the paint moves away from the pressure. I've seen this failure in aircraft engines painted under the nuts that secure the jug to the block with very bad results.

The paint was removed from the threads afterwards, I saw it. Incidentally Richard has built and flown his own aircraft for five years (RV7) and held a license for a long time so I think he's got it covered. Thanks for the heads up though :)

[64etype]

This is also obscure - but you should not paint the surface under the nuts that secure the head. This distorts the torque setting, and can lead to loosening of the nut as the paint moves away from the pressure. I've seen this failure in aircraft engines painted under the nuts that secure the jug to the block with very bad results.

The paint was removed from the threads afterwards, I saw it. Incidentally Richard has built and flown his own aircraft for five years (RV7) and held a license for a long time so I think he's got it covered. Thanks for the heads up though :)

I believe he's talking about the paint where the nut/washer seat against the head surface as opposed to threads.

[SEJohnson95]

Yep, I suppose he is :) I'm just going to stop digging the hole now, somebody take the shovel off me? ;)

[Heuer]

Thanks for the replies, but I'm still curious as to what is "factory fit" for those vertical strips between the plane of the head bolts and the cam cover flanges. One of the cars I identified in my original post (both listed as definitive, unrestored and original in the "FACTORY FIT - Series 1 3.8" sticky) is apparently "incorrect". If the head on the white car is "factory fit" and unmolested, then every other car in that string of examples is suspect. (I realize this is an obscure detail).

I suggest you rely on the red OTS and blue FHC as I know their provenance.

[64etype]

Probably right, although the red car has some odd little inconsistencies as well...particularly on the right side in the vicinity of the fuel filter. As Angus noted there are screws attaching the data plate, and I noted red paint on the data plate...also red paint on the bolts that attach the front frame to the firewall on that side...plain black oxide (slightly corroded) hardware everywhere else on the frame, which I believe is correct.

[Heuer]

The car belongs to a friend of Bob Stevenson and Bob reckons it is untouched. The US importer was fond of touching up the paintwork after the cars landed because rust formed quickly in the salty air of the ship.