Author Topic: Bruce Macbeth Engine, European Version  (Read 76285 times)

Offline Admiral_dk

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Re: Bruce Macbeth Engine, European Version
« Reply #585 on: October 19, 2021, 07:05:25 PM »
Achim - every time I look at the pictures of the 'Port end' of your cylinder heads - I can't help wonder what keeps them in perfect alignment with the Exhaust / Cooling Manifold ....  :thinking:
It's not like a cylinder head for multiple cylinders were all the mating surfaces are done in a single pass ....

So I would think that it either had some flexible gaskets or a special sequence of spanning that ensures perfect alignment ....

No matter what - I look forward to see a runner, that you are happy with  :cheers:

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #586 on: October 20, 2021, 12:08:06 PM »
Hi Per, my assembly order should support the alignment as much as possible.


First the Cylinder heads on the cylinders only stuck over the studs.
Next the intake manifold bolted  against all the cylinder heads.
This should give my basic alignment of all 4 heads against the flat surface of the intake manifold.
This is followed by the fixation of the cylinder heads by most of their nuts and one screw with the torque of 1 Nm.
Now we have a given surface over all 4 heads at the exhaust side.
I have made a check with a straight edge, the result was not so bad.


The main problem seems to be more in the weak long M2 studs and the small M2 Nuts, because now change for a big torque there.


But nevertheless, the exhaust manifold was assembled with a reasonable torque by the sensible fasteners with the silicon gasket.
Pressure test was fine no leakage anymore.
Also the usage of some leak detection spray at all surfaces around the interface heads to manifold was inconspicuous that day.
All these operations were done end of May already, before my summer break.
If it will be the same under running conditions, no idea.
It it will last for longer and the silicon will keep the elasticize, no idea.
May be in the next days I will repeat the leakage test, the pressure loss measuring device is under the bench still, very close to the engine.
   
Yesterday the cotton covers has been lifted again
Next challange, assembly of the camshaft with its brackets to the cylinder heads.
I know, that also in the height of each cylinder is a minor difference, so the shaft will have a good reasons for some clamping.
To adjust this aliment, my idea was the usage of some paper shims.
I have drawn the shape in Fusion, outer shape 0,2 mm smaller than the contour of the camshaft brackets, the holes 0,2 mm bigger than necessary.
Currently we do have some shims with 0,1 / 0,2 / 0,3 mm width, four of each, cut with my plotter last week already.
The brackets will be assembled with 2 still remaining studs/nuts to the head/cylinder, with the torque of 1 Nm also.
So no excuses anymore, I have to enter this minefield now too.
Kind Regards
Achim

Offline Craig DeShong

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Re: Bruce Macbeth Engine, European Version
« Reply #587 on: October 20, 2021, 09:48:36 PM »
a one time opened tube will not last very long, due to its property of curing with air contact.

Double bagging in zip-lock sandwich bags will greatly prolong the life of a tube, and I really mean double bagging.
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #588 on: November 03, 2021, 06:41:02 AM »
a one time opened tube will not last very long, due to its property of curing with air contact.

Double bagging in zip-lock sandwich bags will greatly prolong the life of a tube, and I really mean double bagging.


Hi Craig, good idea, thanks.
Kind Regards
Achim

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #589 on: November 03, 2021, 07:20:18 AM »
Some further progress is done.
The camshaft is first time assembled with full torque at all cylinder head nuts with the camshaft brackets in final position.
And the for me very good news, free turning is still possible.
A disassembly of all rockers and rocker shafts was necessary to get clearance for the socket and torque wrench.
I could archive this free turning by an alignment of the camshaft bores with my already prepared paper shims under two brackets.
The thick ones with 0,3 mm has not been needed, only the 0,1 and 0,2 mm.
If the engine will keep this alignment, also if heated in running conditions ? No idea.
But if necessary it can be readjusted, some more shims are available.
The metric Mädler crown wheel has created a minor collision, as already expected here.
A couple of 0,1 mm material has to be removed and the problem was solved. A black Edding will repair the optical appearance nearly complete, anyway it is in a hidden corner.
Next  to do, to shorten the camshaft left hand side to its final length.
Final adjustment off the bevel gear set, the spots for the grub screws are already at the relevant places at both shafts now.
Before I start a hopefully final reassembly with the lobes and spacers, I have to take of the exhaust manifold again.
That should be necessary to get clearance for the timing adjustment of each cam and to tighten the grub screws at the pinion gear.
As I mentioned earlier, that was the reason for me to prefer a cut seal and not to use any sealing compound, if not really necessary.
Hopefully it will be sealed again after the reassembling of the exhaust manifold.
[youtube1]https://youtu.be/oaeIwpwTgIQ[/youtube1]
Kind Regards
Achim

Offline Admiral_dk

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Re: Bruce Macbeth Engine, European Version
« Reply #590 on: November 03, 2021, 11:33:56 AM »
I think that you are right about most people will never notice the 'Ajustments / Tweaks' made for the revised layout. It can't be long before first pop  :cheers:

Per

Offline Roger B

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Re: Bruce Macbeth Engine, European Version
« Reply #591 on: November 05, 2021, 07:53:20 PM »
Looking good  :praise2:  :praise2: As Per says not long now  :)  :wine1:
Best regards

Roger

Offline Don1966

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Re: Bruce Macbeth Engine, European Version
« Reply #592 on: November 05, 2021, 11:00:10 PM »
Awesome achim ……. :Love:


Don

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #593 on: December 04, 2021, 01:20:16 PM »

Per, Roger, Don, thanks for watching.


Here another progress report.
Timing the next adventure, first time that I  have to adjust 8 single lobes at a camshaft.
First job here, a big timing disc made from white acrylic glass.
That was the basic, for this engine a special drawing/paper disc was made and glued at the basic disc with some double-faced adhesive tape.
Hopefully a good idea to avoid mistakes.
At the very first, a fine adjustment of the valve clearance, all between 0,15 and 0,2 mm.
Next pictures my high sophisticated set up for the measurement of the valve lifting.
Here a short video of the movement.
[youtube1]https://youtu.be/9tfaH-TcC68[/youtube1]
I am coming close to it now.
Kind Regards
Achim

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #594 on: December 05, 2021, 06:31:05 AM »
Some more necessary helpers were made.
A spark plug adapter for the 10-40 UNS Rimfire plug. A set of 4 pieces.
These should help to check and to see the spark, if it really is available at each cylinder.
It is a long way after it is generated in the ignition system down in the base, going up to the distributor, leaded there to the relevant cylinder and followed its way to the plugs.
Also a starter dog for this crankshaft was missing so far.
I took the drive pin, as used for the Snow Engine earlier and made something suitable for this crankshaft.
My crankshaft has got a M5 thread in each end, so an easy connection by a bolt is the plan.
Kind Regards
Achim

Offline Roger B

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Re: Bruce Macbeth Engine, European Version
« Reply #595 on: December 05, 2021, 07:54:55 AM »
I like the idea of your spark plug adaptors so you can see what is going on  :ThumbsUp:  :ThumbsUp:  :wine1:

How did you cut the ramps on the starter dog? I have tried various milling set ups but now just use files.
Best regards

Roger

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #596 on: December 05, 2021, 09:30:24 AM »
I like the idea of your spark plug adaptors so you can see what is going on  :ThumbsUp: :ThumbsUp: :wine1:

How did you cut the ramps on the starter dog? I have tried various milling set ups but now just use files.


Hi Roger,
we had a long discussion at the Fusion Forum some month ago there.
To do it really proper in design and cam operation is a real pain in a......
Also with Fusion.
So I have done it in two set ups only at the conventional mill.
As shown in the first picture,  the vice to the table with nearly 144° to Y.
Than a straight milling in Y the slot is done 0,5 mm wider than the pin.
Pins are 3 mm the slot is 3,52 mm.
Flipping the dog in the vice by 180° and doing it again.
That`s all, no filing was necessary.
The material chosen is CK45, so a heating to cheery red and some cold water should have given the necessary hardness, hopefully.
« Last Edit: December 05, 2021, 11:36:36 AM by fumopuc »
Kind Regards
Achim

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #597 on: December 06, 2021, 02:57:02 PM »
Hi everybody,
the blue box under the bench has got some attention now.
So powder coating again.
The long water pipe was nearly to big for my toaster oven.
But with 2 pieces of wood and some wire the problem was solved.
Kind Regards
Achim

Offline fumopuc

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Re: Bruce Macbeth Engine, European Version
« Reply #598 on: December 07, 2021, 08:48:45 AM »
Attack to the last remaining things.
The high voltage wiring has to be made.
I am not sure if it will work like this, so plan B is to make some small caps from POM to cover the nut and cable socket for better isolation.
First the epoxy glue has to cure for one night.
Kind Regards
Achim

Offline Roger B

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Re: Bruce Macbeth Engine, European Version
« Reply #599 on: December 07, 2021, 08:40:04 PM »
Those spacings look rather small to me for ignition voltages  ::)
Best regards

Roger

 

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