G3l hot rod???

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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Pharisee
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Re: G3l hot rod???

Post by Pharisee »

raffles wrote:SH cams are available from the club sparse
Tony
Any idea what the part number is, please?
I've had a quick search on the AMOC website and I can't find any cams for the heavyweight singles.
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raffles
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Re: G3l hot rod???

Post by raffles »

just phone Gary and ask I know they did have two sets
Tony
Rickdiculous
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Re: G3l hot rod???

Post by Rickdiculous »

yup this is my plan. nothing too crazy, maybe some of these sh cams if i can find a set. also i think i will give special attention to the intake tract, taking off any edges, port matching and such. one thing (aside from cams) that i have been having a hard time finding is a piston and rings. the later model ones are all over but not so much for the 46 and earlier.
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Re: G3l hot rod???

Post by Triumph-Legend »

Rickdiculous wrote:yup this is my plan. nothing too crazy, maybe some of these sh cams if i can find a set. also i think i will give special attention to the intake tract, taking off any edges, port matching and such. one thing (aside from cams) that i have been having a hard time finding is a piston and rings. the later model ones are all over but not so much for the 46 and earlier.
The WD type pistons frequently come up on Ebay, often as new old stock. But why on earth would you want to use one. The last thing that you want in a tuned motor would be a piston with a split skirt and large expansion slots under the crown / ring lands. If the piston lets go, it's bye bye to the entire engine. Better to use a solid skirt piston and relieve the sides below the lower ring groove to reduce friction. If you need to lighten the piston then part of the bottom / sides below the gudgeon pin may be reduced to remove weight. Also the pin itself may be lightened and polished internally. Just a note. Sort out the piston and gudgeon pin bush in the con rod during the rebuilding of the crank big end. A new bush fitted into the small end will need to be line bored and reamed to be parallel to the big end bearing. Some new pistons do have a slightly larger gudgeon pin.

WD piston. http://www.ebay.co.uk/itm/AJS-MATCHLESS ... SwImRYe7f9

Typical solid skirt piston. http://www.ebay.co.uk/itm/BSA-AJS-Match ... Sw-itXug6x

I think that a copy of TUNING FOR SPEED would be a worthwhile investment as much of the information does relate to earlier single cylinder engines.
Rickdiculous
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Re: G3l hot rod???

Post by Rickdiculous »

i really like the idea of using a solid skirt piston but im not sure how to do it. would i have to know all the specs of a stock piston and order a 1 off? or is there a later piston the crosses and would fit. i am going to have the barrel sleeved to get back to stock bore(because of the class i will enter). the compression height is where i get worried as they changed that height for different models.
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Duncan
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Re: G3l hot rod???

Post by Duncan »

If there are plenty of later pistons about one solution is to just fit a later (shorter) connecting rod and use them.
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Re: G3l hot rod???

Post by Triumph-Legend »

Interesting comments regarding cams and valve gear in the general section, oil plunger difference.

Ref ajscomboman: Along with the SH cams another worthwhile mod is to fit a Lightweight inlet rocker arm. Gives a higher lift on the inlet allowing better filling of the combustion chamber and therefore a bigger bang and increase in lowdown power which is sometimes lacking with these cams.

The use of the light weigh valve gear is interesting. I'll try to get hold of the part and do a few measurements to determine the extra valve lift on the inlet.

As an aside comment. A friend with an Ariel Red Hunter tried my bike a while back. His comment was that he wished his bike well as well. My 350 will stomp all over his bike. :rofl:
Rickdiculous
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Re: G3l hot rod???

Post by Rickdiculous »

that is interesting stuff. i'm still unable to find an alernative piston. i have a triumph t100 500cc piston that uses the same bore as a g3 but the shape of the dome looks like i would actually loose compression. i have some a65 pistons but they are not even close. there has to be something out there that will work, all the discussion i've read reguarding piston are to up their cc's. i need to keep the standard bore. are the stock split skirt pistons prone to fail? the link mentioned earlier looked good i think it even had the correct compression height but it was 71mm and thats too big.
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Pharisee
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Re: G3l hot rod???

Post by Pharisee »

My late brother-in-law ran a much modified 350... or what started as a 350, anyway. The bore had been opened up and I believe that he used a Triumph piston of some sort to raise the capacity to 400 or so. I also believe that he'd somehow grafted on a Velocette cylinder head (possibly the cylinder also). I know that the bike went exceptionally well and he used it to tour around eastern Europe, two up... even after he lost a leg following a motorcycle accident.
I'm from the Fens.... Gimme six.
Rickdiculous
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Re: G3l hot rod???

Post by Rickdiculous »

been quiet for a while, i've been working on my frame and it's coming along nicely. i wish i could figure out how to post pictures. i have found one sh cam, it looks to be the intake as it has a keyway cut in it. unfotunately the mate for it was not in the same box. so i'm still on the hunt for a sh exhaust cam and a solid skirt piston.
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