Stripping Down My Barn Find Triumph T140 Bonneville to Remove Cylinder Head | 02
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- Опубліковано 16 чер 2024
- Stripping Down My Barn Find Triumph T140 Bonneville to Remove Cylinder Head | 02
In this episode I am hoping to remove the cylinder head from my 1975 Triumph Bonneville T140V. I have just bought this as a project bike, and rather than just trying to start the engine I want to assess what condition it is in.
Here are some of the tools I am going to be using for this bike:
Imperial Combination Spanner Set: ebay.us/gYz85M
Imperial 1/2inch Socket set: ebay.us/jylH05
Imperial Allen Hex Bit Sockets: ebay.us/iFV0OQ
This bike is an import from the USA, and has probably not been ridden for over 30 years. Some parts of it seem in really good condition considering the lack of use, such as the outside of the engine and the front forks and wheel. However some parts look quite ropey, and have a lot of rust, the back of the frame and the rear wheel and brakes.
I got the bike registered within 4 weeks. I explained this in an earlier video we have on the channel which you can watch here: • How To Fill In A V55/5...
The engine turns over and the outside of it looks to be quite clean. Looking around it, it appears to have had some work on it, there seems to be a new(ish) base gasket, the case screws have been replaced with Allen headed screws, and the head studs seem to be stainless steel.
The carburettors on these bikes always seem to corrode badly when left, but the carbs on this bike are in quite clean condition. So it looks like some care and attention was put into the bike before it was laid up.
The clocks have been reset and now only read 342 miles. I am hoping that this indicates that the engine was refreshed 342 miles ago. But this is likely to be more than 3 decades ago as well, and time has taken its toll on some parts of the bike.
Unlike the CB750s I have been working on recently the cylinder should be removable without taking the engine out of the frame. It will also make it a bit lighter, so when the engine is going to be removed it should be easier. To remove the cylinder head a lot of other parts need to be removed first.
Obviously the tank needs to come off, which is basically held on by one bolt from the top of the tank. Which is quite easy to do once you have disconnected the fuel pipes. The exhaust and air filters need removing too.
The exhaust came off really easily. It is a push in type and didn't appear to have any sealant holding it in. It is a two into one exhaust and although the chrome has got some pitting, overall it would probably clean up. I am planning to get a new exhaust for this bike, so I might convert the head to have the exhaust stubs fitted that allow the use of the older style of pipes. These are also supposed to be easier to seal
The air filters were quite dirty on both sides. By that I mean where the air comes in and then where the air goes after it is filtered. I don't think the bike has been run like this. I think it more likely that this from the bike having been pressure washed before shipping with the carb side of the airbox not sealed.
Once you have got to this point, with the tank, exhausts and air filter off, the next step is to remove the rocker boxes. There is a head steady between the rockers and the frame that needs removing. It is one of those things that seems really fiddly to remove and then just about falls off. The nuts holding this one had the worst corrosion of anything on the bike, but still came undone ok.
With the rocker covers off, it is very easy to get to the nuts on the head studs. Usually the outer four are bolts that screw into the block, but they have been replaced with stainless studs. There are some allen head nuts for 4 of the head fasteners, but they all came undone quite easily.
It was at this point that I came against my first problem, and it is quite a big one. I was hoping that with a bit of tapping with a hammer and piece of wood that the head would come loose. Unfortunately it is stuck solid.
I used heat tapping with bigger and bigger hammers, and I did try to remove the out studs, using two nuts, but they are not for moving. I kept leaving the job for a couple of days with everything doused in penetrating oil, and coming back and having another go. Although I did find an old T120 for stantion that fitted into the exhaust port, I didn't go mad with it. I just used it to apply some pressure while I tapped other parts of the head.After 3 or 4 different attempts I have come to the conclusion that I may have to try some different methods with the engine removed.
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This is what my mates were riding in the 70,s When I turned up on my CB 750 , Sth Africa .Sometimes I think they're still there tinkering away ,😂
Very likely, once a tinkerer always a tinkerer!
What alot of restorers don't think about with a long standing engine is the piston ring tension and cylinder damage from where the rings were sitting which can't be seen it both pistons were positioned in the lower bore.
I have come across a lot of locked engines in the past, where the pistons are seized in the bore. This is my first one with the head stuck on. Always something new to keep you interested.
you can use the two bolts locked together method to remove the studs witch is some cases will aid you in getting the head off.
I have had a brief go with the two nut method on one of the outer studs, it wasn't for moving. When I get back to looking at this I will have to be a little more assertive with it :)
I was taught yo back off the tappet adjusters begore loosening the rocker box studs to reduce to pressure and help to retain the stud threads.
Thanks for the tip. I realised when I watched the video back that that would be why the manual says to take the tappet covers off. Maybe next time :)
JN is an early Meriden
Co-Op bike, I have JN 62851. A mix of threads and parts as the factory had just begun series production and were starved of cash and parts. John Rosamonds Book, Save the Triumph Bonneville is worth a read.
They were difficult times. There was pretty much only hand to mouth production, they really did well considering. The mix of fasteners and threads can lead to a few head scratching moments. I will try to get that book, I haven't come across it before.
Your care and attention with correct tools is a refreshing change from the usual butchery on you tube. I always apply heat or cold shock to seperate fasteners. A trick for stuck heads is to fill the chambers with oil or melted grease !
A pity but it was going so well, right up to the end
These things are sent to try us! It did seem to be going too well. The last Triumph twin I strpped completely down had seized pistons which had to be taken out with sledge hammers! Hopefully it won't come to that.
Double nut the through bolts and take barrel studs out in situ any you remove will give you some play
It's on the list. But I am concerned that it is the studs that are corroded into the passage ways through the head and will cause damage coming out. I probably don't have a choice though.
@@SPANNERRASH use alot of penetrating oil on the studs you have
I Spanner Rash. I've had similar issues getting cylinder off that are stuck. First I will put some penetrating oil down the studs. The next day, I will try the double mallet method. I don't ever take a swing at cooling fins with a rubber or plastic tipped mallet. I set my big rubber mallet against the fins and use a second mallet to strike the other. I find that this allows you to hit exactly where you want to, while reduce the chances of braking fins. If that fails, I will heat the part that is seized and then go back to the double mallet technique. By this point my language has become quite colourful.
I'm a couple of weeks into that regime! Penetrating oil every couple of days, heating around the studs, big hammer against block of wood to protect head. Lots of colourful language. Still no joy!
750 oif Bonnievilles were known for problems and vibration from the double down tube frame as well as the twin carbs as opposed to a single carb. British motorcycles of the 1970's were known for having mechanical issues. Such a sad end to a once proud industry.😢
It's probably why they are loved so much. Every one has a different character, if you don't mind problem solving. I'm hoping to build this one to be reliable, if it isn't when I've done then it will be down to me. But riding one of these and a Honda back to back you can see why the British industry fell off a cliff.
@@SPANNERRASH there is a difference between unreliability,poor quality and character. I have had my Triumph TR-6 with a hard tail and magneto for 40 years. She is reliable and dependable transportation and has plenty of character. I have had my Sportster for 25 years and has plenty of character while being reliable and dependable transportation as well.
Cracking series - keep it up pls
I'll do my best, but we will intersperse it with our car and other bike videos, why not watch them as well?
Did you forget the stud between the cylinders?
I would love it if there was a missing stud/nut I'd missed. But I think you mean the two in the middle on the 750. Let me know if you mean something else!
Seen this one. Saw a mate turning the air blue trying to get the head off.
Check out the video below..something looks different about the cylinder studs
Not sure what you mean about the studs. The do seem to be stainless, and the outer ones have replaced the usual bolts that are there usually.
@@SPANNERRASH looks like your bike has 4 studs with nuts versus the other video has bolts which come out totally..
@@SPANNERRASH check out your video at 31:26 mark. The 4 large head bolts you have are studs with nuts..Lunmad video shows 4 large bolts with head attached..if that makes sense
@@SPANNERRASH look at the video closely..stay cool
Im up against exactly the same problem...its corrosion on those 2 5/16" centre studs ... i managed to remove all the other studs but those 2 centre ones are absolutely solid , not that easy to work on due to the close proximity to the rocker box faces. I have removed the whole assembly completely, no easy task as my engine was seized from standing, next step will be my expert machinist/engineer he will machine out both studs enough to loosen their grip on the narrow bores in which they are seized, a right
Faff but discretion is the better part of valour .
Be interested to see how you proceed 😮
You seem to be doing much better than me.
Have you tried putting the head and barrel in an oven for a while? Heat it to 250c or so for an hour, then let it cool. Maybe cycle it a few times.
This is what I am thinking of trying. I hope it doesn't come to machining the studs out.
Let me know how you go on. Good luck.
Looking like a good motor so far,think you dropped on a good Bonny there..Ian.
Cheers Ian. It will be interesting when I get deeper into it. I have been really surprised at how easy the fasteners have come apart so far. The head being so stuck was a bit of a surprise. I have heard that the composite head gaskets that have been used on these engine can cause this, hopefully it will be solved soon.
@@SPANNERRASH yeah always better using copper ones..
Great video but what happened to the CB750?
Like me it is waiting for the rain to stop, on a day that I am not already committed to something else. I am sure this is the wettest start to a year I can remember. I am sure you will see it soon, I really do want to get it painted.
Will the barrels not lift off without removing the engine?
Probably, but I am going to remove the engine anyway to sort out the frame.
How about hitting the aluminium around the areas where the studs come out with a blow torch - then a squirt of duck oil. Repeat a couple of times then try your long lever again (gently) ?
Labour of love and a money pit right there but TBF as my dad always said "you can't put a price on a hobby" . .. My work colleague bought one new back in '79, great bike but very unreliable..
Good luck
I do love working on old bikes. Some costs you can't avoid, but I don't intend to spend a fortune. I remember these from first time around too, everything seemed less reliable back then :)
@@SPANNERRASH Sadly you won't be given the option of spending or not. Anything mechanical is mad expensive these days. Engine work is eye wateringly crazy dear, as are the numerous silly small items you'll inevitably end up replacing ..
Personally I wouldn't touch anything like this with a barge pole knowing I'd be hemorrhaging money at every turn of the spanner. Once finished it will be endless fettling as it tries to shake itself to bits. :-)
Unless of course was the bike of my dreams or worth it. This isn't neither or either for me personally in any way shape or form. It looks a well beaten dog to me tbf, and I've bought too many of these in the past to revisit those times again.
But if it's yours then more power to you and I'm sure it'll be worth every penny and hour spent on it. :-)
Stop with the mallet..its so easy to break a cooling fin. Im thinking soak the heck out of the studs
Good advice. I am soaking with penetrating oil every couple of days. If I am tapping with a hammer, I am using a block of wood, and I am not being too extreme.
Can you not heat the head. With a cast barrel this would probably work…..
If I don't have any joy this sounds like a good idea. See if I can cook it for a bit to break the seal.
Why have I personally never found anything remotely like this in any barn?
Ha, nobody let's you look in barns these days. Unless it is an estate sale. We all want to keep looking though
Had a Meridian kick start Bonnie for 15 years … absolutely fun lively ride … but bloody hate the crap engineering design.
Yes, it is all a bit rudimentary. Maybe that is what give them a personality and a bit of soul :)
750 Triumph Bonnievilles with the double down tube frame were known for vibration not only because of the twin carbs instead of the single carb versions. 1970's British motorcycles were known for problems left ,right and center. Such a sad ending to a once great industry😢.