Navigation

You are here: Home / Messages / Heavy Twins / 500SS cylinder head

500SS cylinder head

Up to Heavy Twins

500SS cylinder head

Posted by tony_harris at August 07. 2017

Does anybody know if the 500SS head is the same as the 600SS and 650SS heads. As the 500 is 66 bore is the combustion chamber smaller as the 600 and 650 is 68mm bore.

Re: 500SS cylinder head

Posted by anna jeannette Dixon at August 07. 2017
Previously tony_harris wrote:

Does anybody know if the 500SS head is the same as the 600SS and 650SS heads. As the 500 is 66 bore is the combustion chamber smaller as the 600 and 650 is 68mm bore.

Hello Tony to put your mind at rest   the very first  down draft cylinder head  was fitted as standard to the very first  Norton Manxman 650  in November 7th 1960 frame and engine number 18-93601 shop 7  and every Norton Manxman had the same down draft cylinder heads,  by late march of 1961 the team at Norton decided to give more life into its home models and they used the crank cases from the Manxman 650 and the camshaft and the pushrods and followers but the model 88 and 99 sports models did not have the down draft head from day one they had a twin carb manifold fitted with splayed carbs   it was later in 1962  they then fitted the down draft heads   the model 88-ss  are machined to fit  this model  the model 99 only got the down draft heads at the end of their line in mid 1962,  they were the same as the 650 models had earlier ,   now does this make you more happier    have fun YOURS Anna J 
Attachments

Re: 500SS cylinder head

Posted by howard_robinson at August 07. 2017

Hiyah Tony - The early pre-downdraught big-valve heads fitted to the 88SS and 99SS models are the same.  Similarly the downdraught heads fitted to the 88SS and 650SS prior to engine number 114870 are the same.  (At this point the barrel spigots were removed so the heads did not have a recess for the spigot.)  As far as I remember the 88SS was discontinued before this so all 88s and 99s had the spigot.  Regards, Howard

Re: 500SS cylinder head

Posted by tony_harris at August 08. 2017

Thanks Anna and Howard for the in-depth answers.

Tony

Re: 500SS cylinder head

Posted by anna jeannette Dixon at August 08. 2017
Previously howard_robinson wrote:

Hiyah Tony - The early pre-downdraught big-valve heads fitted to the 88SS and 99SS models are the same.  Similarly the downdraught heads fitted to the 88SS and 650SS prior to engine number 114870 are the same.  (At this point the barrel spigots were removed so the heads did not have a recess for the spigot.)  As far as I remember the 88SS was discontinued before this so all 88s and 99s had the spigot.  Regards, Howard

 Hello  Model 88ss are not the same as the model 99ss  early heads were not down draft  type  until old stock was used up,  by August of 1961  and the first down daft head were from the 650 Manxman and machine to suit  said models 88ss and late 99ss  but the model 88ss right up to 1966 had  three types of cylinder heads  as for big valves they were only the same size as the 650 Manxman and 650 sports special     i have all the facts  and all part numbers   yours anna j  
Powered by Ploneboard
Upcoming Events
2017 International Rally Aug 24, 2017 - Aug 28, 2017 — Open Huis, Ieperstraat 157 - 8840 Staden, Belgium
2017 MGP Reunion Aug 29, 2017 03:00 PM - 06:00 PM — The Shore Hotel, Old Laxey Hill Laxey. Isle of Man IM4 7DA
Tay Valley Branch Camping Weekend - Town Yetholm Sep 08, 2017 - Sep 10, 2017
CRMC Track Parade - Anglesey Coastal Sep 09, 2017 - Sep 10, 2017 — A55, Ty Croes, Gwynedd LL63 5TF
Zoë Cano at Surrey Branch Sep 13, 2017 07:45 PM - 10:45 PM — The Stepping Stones PH Westhumble Street Westhumble, Dorking, Surrey RH5 6BS
Upcoming events…
This is Brio Diazo Plone Theme