Aluminium half moon seals for V12

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #44

Are they rubber? If so, how are they any better than the V12 half moons?

(ronbros) #45

NO made of aluminum , wonder where Jag figured that out?

seen the pic somewhere on net!

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #46

I found it! You didn’t lie!

I should sue them for a percentage, doncha think?

(John) #47

Just from looking at the picture it looks like they are smaller in size… I presume V6 has smaller diameter valve cam bearings then V12 but that is just a guess… If someone could tel me the cam bearing size of V6 I could confirm or deny if it fits :slight_smile:

(L.Lynn '68 OTS, '73 2+2) #48

Just want to thank Jonas for the Al 1/2 moon seals he made, they look to be a much finer finish than the ones in the link and fit perfectly. If you order from him though, expect shipping to take awhile at least to the US.
Thanks again Jonas.

(John) #49

Thanks For a good word! Glad that you like them. :wink:

(Ole Würtz) #50

I’m very pleased with mine as well. And the SS oil feed banjo bolts. Not sure when they will be used, but good to have them.

(Arron ) #51

I am interested in the half moon seals and the chain tensioner plug please.
Also Ole mentioned SS oil feed banjo bolts… do you make these as well?

Parts look great
Can you contact me at

Thanks very much

(John) #52

Yes I do make half moon seals, chain tensioner plug, SS oil feed banjo bolts and radiator bleed pipe banjo bolts.
I have just sold the last set of half moon seals yesterday… I will be making another lot next week and let you know when they are ready

(John) #53

Just out of curiosity I have ordered one half moon for V6 and I can confirm that they will not fit. Diameter is a bit bigger and the height is a bit lower so it is actually a bit less then half-moon :wink: Also it is way too wide. Few pictures of V6 half moon seal next to the one I have made:

(chris gruchawka 1988 XJ-SC) #54

I am interested in your half moon seals, chain tensioner. Would you contact me at

(John) #55

Better later then never :slight_smile:
Another batch of half-moons is ready!

[v12-engine] Light engine rebuild
(JimD in Alabama) #56

Those look good John. :+1:

(Paul Wigton) #57

Gosh, I wish my Rover had any place for some!

(ronbros) #58

pic of my fix for the chain tension hole, works for me ,$3. dollars pumbing store.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #59

As discussed before, I did the same thing on my '83. After it was in place for a few years, it proved really difficult to get out! The rubber swelled around the inside edge of the hole.

IMHO, a far better idea is to use the OEM part – but start with a brand new one, and cut off the tangs that hold it in the hole as soon as you take it out of the box. Then fab a small tab that sits under the head of that nearby bolt on the water pump that presses lightly down on the center of the plug to hold it securely in place.

You can go fancier and machine an aluminum part with an O-ring, but I still recommend the little tab to hold it in place. Much simpler and more reliable than most of the retention schemes that have been dreamt up.

(Ward Macfarlan) #60

Hi John. If the half moon seals are still available, please contact me so we can arrange you sending out a pair to me. Thanks!

(Ward Macfarlan) #61

I’m happy to report that I received the seals, and they look fantastic! It might be of interest to anyone ordering these from Canada that they took a couple of days short of a month to get here.

(Jurgen ) #62

Hi John. I am interested in a set of the half moon seals. Please could you mail me,
Thank you.

(Paul Stoneman) #63

Hi John, the next time you are making a batch of half moon seals and a chain tensioner plug I would be very interested! Could you contact me?