Royal Enfield Bullet tuning 2 - Alloy cylinder barrel stud hole issues delay progress.

In many cases fitting an alloy cylinder barrel presents no problems, but this one presented a problem or two. A follow up video will describe how I dealt with the issue and got the barrel fitted.

[@speedfinder1]

Could I suggest that you might bore the incorrect long stud hole in the cylinder barrel to oversize, but to the correct position with a long shank, end mill in a milling machine. You could then shrink in a long steel sleeve and regain the "Land" between the edge of the cylinder liner to give the head gasket a good face to seal on. Obviously a little refacing in a lathe would be needed. For the other side, Re-drill the other hole oversize but again in the correct position and shrink in a top hat spacer perhaps ? 🤔.

[@simonrdew]

Gentle application of a rat tail file is how I fixed exactly the sam3 problem.

[@shug831]

Not got a 3/8" round bastard file to hand and open that stud hole by hand?

[@Jimdirt7898]

Whoever made the barrel must have cocked up and it should have been rejected but it got sold anyway. If you had a milling machine you could run an endmill down the outer edge of the stud hole to line it up.

[@Kirandarshak-y6b]

Good work Paul. Thanks for sharing the knowledge. I need help with a 1959 Constellation. The motorcycle starts but the clutch is not working. When I put the 1st gear, the motorcycle jumps and turn off. So the clutch is not working. It has a scissor type clutch. Any help would be much appreciated. Thanks for sharing your work Paul.

[@hermangibbs8163]

Thanks Paul.

[@norsehall309]

G'day, Paul mate l have no dought you will do the right thing and it will work, not like some cowboy's out there that just hit with a hammer 🔨⛏️⛏️ and say she'll be right, cheers mate, Neil 🤠.

[@basilwatson1]

Tis what I do to my Enfields .. lap the head and use a thing copper gasket to stop oil

[@adammedyna2365]

Pattern parts at it worst and lots of extra work for a person fitting them.

[@whalesong999]

Old Japanese twins from back in the '60s had necked down studs, a feature which might suffice here.

[@keithchessun5085]

No doubt you already know that there's a difference in the barrels between the early G2s with square oil pump housing and the later oval type. Push rod tubes centres are different. Same stud centres though.

[@paulhenshaw4514]

Thanks and yes, this is an alloy barrel 'made' for the early G2 engines, rather than the 1955 and on types. The sud holes look more like they were cast in, rather than drilled. Quite messy, tbh.

[@anythingoldmechanical]

Loud and clear Paul. You always find a way, being the genius that you are.. But what you need, is a job like a BSA A7! 😅😅😅

[@Kirandarshak-y6b]

Good work Paul. Thanks for sharing the knowledge. I need help with a 1959 Constellation. The motorcycle starts but the clutch is not working. When I put the 1st gear, the motorcycle jumps and turn off. So the clutch is not working. It has a scissor type clutch. Any help would be much appreciated. Thanks for sharing your work Paul.

[@williamnethercott4364]

By the look of the face of that cylinder liner you'll need to do a lot of lapping. That's a very annoying problem to have, you did well to restrain yourself when describing it!

[@daveperry4391]

Go down on stud size a little, and helicoil the tapped hole to suit ? A 1/16 thinner would be fine and you could keep the gasket land ?

[@stevehill4228]

the stud hole above tappet cover is drilled correctly as it is an Indian barrel, also when you fit the head you will see redditch head fins are narrower and will not match the Indian barrel.

[@paulhenshaw4514]

This barrel was supposedly made to fit the earlier, British engines such as seen here. It is the narrow type you mention, and was bought as such. I know the later barrels are different and how they differ from this type.

[@coco-te1op]

Hi Paul how much difference would a 0.5 head gasket make in terms of compression ratio?

[@paulhenshaw4514]

Hi - barely noticeable, to be honest.

[@coco-te1op]

@paulhenshaw4514 thank you Paul.

[@grateberk6435]

Weird. You would think they were all drilled the same at the factory

[@paulhenshaw4514]

I think there may be more than one 'factory' making stuff like this ...

[@neilmcintosh1200]

Top quality authentic pattern part as available in the '60s and '70s. Wow, you really are living the dream....

[@Kevin-cy9cv]

After watching your video on fins, I'm drawn to checking them every time I see a barrel...

[@lozh8002]

How about a reamer

[@ralphjohnson4041]

The bad stud looks wonky though. Is it vertical if screwed in without the barrel?

[@paulhenshaw4514]

Vertical and straight.

[@nobbyclark2764]

Is it possible it's the crankcase studs threads that our out, and not the barrel holes.

[@paulhenshaw4514]

No, the crankcases are fine.

[@davidmarkwort9711]

Can't you turn the shank of the screw down so that the barrel flops down? It might be easier than drilling out the existing hole, from the look of things it is around a quater of the diametre out of line.

[@MONTY-YTNOM]

Thats what id do

[@craigward7102]

Agree, if it doesn’t work you’ve only got to replace the relatively inexpensive stud and go to plan “B”

[@MONTY-YTNOM]

@@craigward7102 He drilled the barrels in the end :)

[@grantbaker3336]

Its important that the studs are all of the same diameter and made of the same material with a suitable rate of expansion this is so that the cylinder head and barrel are pulled down evenly irrespective of engine temperature, to have one stud different would lead to a compression leak and blown gasket.