SOLD – Norton 500T Spectacles Head, ali barrel 490cc 1948 1949 1950 Suit ES2 M18 upgrade

SOLD – Norton 500T Spectacles Head, ali barrel 490cc 1948 1949 1950 Suit ES2 M18 upgrade


Off to Australia

Norton 500T Spectacles Head, ali barrel 490cc from 1948, 1949 and 1950

This aluminium cylinder head and barrel combination would also suit an ES2 upgrade. The engine cases of the 500T and the ES2 were essentially the same as, in 1948, Norton raided the ES2 parts bin and created the iconic 500T with the addition of an all ali head and barrel.

This cylinder head is commonly known as the “Spectacles head”. If you look at the combustion chamber, only the valve seats and spark plug hole were in cast iron, with the ali part of the head sand cast around the iron.

This was the case from inception in 1949, until they changed the method of construction in 1951. The revised construction process was to die-cast the head. The whole production chamber was in cast iron with the ali construction around it. This was the Wellworthy Alfin process.

This is an early production Spectacles Head for a Norton 500T, with a nice set of ali barrels and a 500t / ES2 rocker box with rockers. 

Head: The exhaust threads and the carb mount threads are fine. It comes with the rocker box studs as you see them. One stud is missing. The threads seem fine but will need a little clean-up. The valve seats look good, but please make your own decision on that. There are two chipped fins on the head. I have shown them in the images. As they are small fins and at the top, they are easily repaired.

Barrels: The barrel bores look good. All fins are good except the obvious top fin repair. It needs tidying up. Have a look at the pictures with the head on the barrel. You hardly notice the repair.

Barrels measure: 81.80mm.

Rocker box: Used but seemingly all there. If you look closely, there are smooth areas on the outside. It suggests that the box has had some repairs in the past. It’s a decent used rocker box.

Other Norton parts: I have some. Please get in touch.




  • International shipping available. Please ask.
  • Combined shipping available if you buy other parts. 
  • I usually ship to most destinations. If you don’t see a price, please ask. Shipping is in addition to the listed price for the item.

Viewing: Please come and check it over before you buy. It is at PE28, near St Ives in Cambridgeshire.

Collection: If you don’t want it shipped, I have plenty of space. If you can’t collect for a while, it’s not a problem. However, I will need to be paid very soon after the sale. Thanks.

Payment: This site has a facility to pay online. Good old fashioned money on collection is preferred. I can accept payment through PayPal or by bank transfer as well.

Import Taxes: Please note that IMPORT DUTIES are not something I can control. If you are buying from outside the UK, there is a chance that you will have to pay import taxes. Import taxes vary from country to country. If there are charges to pay, it is the buyer’s responsibility to research the cost and pay the duties. The price that you see on my advert is for the item and not the item plus whatever taxes might be due.










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