Hi everyone, I made a disturbing discovery - the carb and manifold that came with my 1963 Constellation are for a 500 twin. (376/92 with 1 1/16" bore, while the heads have inlets 1 3/16" bore.) Does anyone have the spec's for a single carb on a 1963 model? This could be a tough one as only 106 Connies left the factory that year. Interceptors were in production so the model was changed greatly, downrated from 51 hp to 40 hp. Bacon says most were sidecar spec and solo version available on request. Mine came to me with a sidestand lug, so maybe solo but who can say.... Anyway, with so many changes the carb must have been changed too. Does anyone have the spec's? Chris Overton
Chris According to Burlens website the carb would be a 376\41 which would be a 1 1\16 carb . However the earlier Connies had a 389\41 which is a 1 3\16 bore . It's entirely possible that someone swapped the heads at some point and thus the reason for the discrepancy . Or possibly the factory just downsized the carb and left the ports alone as they were in a detuning stage . Someone who actually knows will probably be along to set the record straight . George
Hi! The mystery continues! Since I deal with bitsa bikes, I never have a clue what was standard...especially on a "real" English model. I have a variety of single manifolds varying from small to huge and generally figured the smaller ones were for the older models. Sorry I cannot add any info to the fray! I would lean towards thinking it suffered from modifications by a previous owner, or even the selling dealer! 62/63 was a puzzlement year on both sides of the pond! I recently saw/inspected a 700 VAX Interceptor in Fla...supposedly a 62! I expected it to basically be a dual carb Connie configured for the US. Man, was it unusual! Single carb/K2-f competition magneto/ No sign of ever having a tool box or battery/Cast iron steering crowns with a single speedometer/center stand only/aluminum fenders/ and many other odd bits. The show card on the bike claimed it to be standard!!! Go figure! By the way Chris: Do you mean an actual cast frame lug for a side stand? I have not seen one of those yet... Guess I have lead a sheltered life!
George, The Burlen site is a good find - thanks for the lead. The only difference between the 376/41 specified and the 376/92 in my hand is the main jet. The /41 has a 240 and the /92 has a 250 according to my source lifted from the triumph-twins list. Maybe I do have the original carb after all. If I was scraping around for parts to build the last 100 Connies, had no /41's, but had /92's on the shelf....
And I was once concerned about the poor fit of the manifold gasket. Comparing areas of the bores, the 376 carbs have 90% of the capacity of the 389 carbs with 1 3/16" bores. It would be like having a throttle limit, with perhaps better idling characteristics. Chris
I think 1962 was the last year for the Super Meteor so in 63 the Constellation sort of took its place. The 63 home market version for the UK had a 1 1/16 AMAL 376 carb and I'm certain that even though they still listed the US export version to have the 1 3/16 389, that they probably did away with that spec even for much of the US market. I know that they weren't big sellers here anyway and few were likely imported here at that time, what with the 736cc Interceptors available.
The detuned 692cc engine is a pleasure to ride and maintain. The 1 1/16 376 or 1 1/8 389 monoblocks were completely adequate for these engines.
Bigtwin I was looking in the "By Miles the Best" book by Gordon May and it listed an Interceptor Scrambles model that had no battery/tool box and no headlight. It looked like it had no speedo or tach but they may have been dealer optional. The bike looks like a dirt bike except it had straight through open header pipes mounted low. The bikes made for US import all had VA or VAX numbers in 60 through 61/62 if they were a 692cc Interceptor. Some RE enthusiasts refered to these as Coopers Connies/Interceptors but I don't think he is the only one that ordered them here in the US I just don't know for sure.
And another thing.... I was looking at an early 500 twin manifold and saw the flange bolts to the heads are closer together at the top of the manifold than at the bottom. Were the Meteor Minor manifolds the same? The 1 1/16" bore manifold I have has the flange bolts vertical to fit the 692cc heads. Another indication I have the correct parts after all. I learn something new every day. Chris O.
The heads were the same after mid 57 but before that they were a lot different. I'll have to go look at my junk pile to see if the pre 57 heads are as you describe. I think the 57 & later meteor Minor or Tomahawk manifold is the same as a Super Meteor with the AMAL 376 Monoblock carb.