Author Topic: Two Cylinder Engine  (Read 9643 times)

Offline AlexS

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Re: Two Cylinder Engine
« Reply #90 on: October 06, 2018, 09:45:35 PM »
Hi Roger. Great progress. What about to fix the wrist pin from below while bore though the pin and so in the piston again? Assemble the whole and then tap the holes (m3?), then use a set of adjusting screws? I did uses this method to fix my cams at the shaft (with some loctite 401 glue). greets

Offline Roger B

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Re: Two Cylinder Engine
« Reply #91 on: October 07, 2018, 05:00:09 PM »
Thank you both  :ThumbsUp:  :ThumbsUp:

This time I decided to try brass plugs. The 18mm long gudgeon pins were made from 5mm silver steel (genuine Stubbs with the stamp on the end  :) ) drilled through 2mm and hardened. The 0.75 mm thick plugs were from 4mm brass rod and were cut just using a blade parting tool then pressed into the ends of the pins. Finally I smoothed of the corners of the plugs with a file in the lathe.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #92 on: October 10, 2018, 07:56:25 PM »
I decided to fix the liners with Loctite 577 thread sealant. The water jacket on the diesel is fixed with 648 but that is fairly permeant. After assembly it all turned smoothly and there is probably enough compression to run without piston rings.


I then skimmed the top of the block and liners with a fly cutter.


Next step is to turn the pistons to the correct length to give 1mm depth.

Best regards

Roger

Online Ye-Ole Steam Dude

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Re: Two Cylinder Engine
« Reply #93 on: October 10, 2018, 09:06:48 PM »
Hello Roger,

Looks great, anxious to see it running.

Have a great day,
Thomas

Offline fumopuc

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Re: Two Cylinder Engine
« Reply #94 on: October 11, 2018, 07:29:12 PM »
Hi Roger, nice progress.
Kind Regards
Achim

Offline Roger B

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Re: Two Cylinder Engine
« Reply #95 on: October 16, 2018, 08:03:18 PM »
Thank you both  :) As I was in milling mode I decided to make the blanks for the cylinder head and rocker support. I have kept the small step at the base of the rocker support from the original design although it is probably not really necessary to keep the alignment.


Lots off holes to drill and slots to cut (hopefully in the right places) ::)
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #96 on: November 03, 2018, 12:13:51 PM »
The rocker support needed a long 3mm hole which I decided to drill in the lathe in hope of keeping it on axis. I started with a 2.5mm stub drill and worked up to one of the 2.5mm long series drills I had bought for crankshaft oilways. I had to ream from both ends due to the length of the reamer and hope that it followed the drilled hole. OK  :) a length of 3mm silver steel would go through.

Next up was drilling the many holes in the cylinder head. The 6mm reamed holes for the valves went ok but I obviously got confused with the head fixings and water ways  :( I could plug and redrill but decided to start again. This time I had to use a vice in vice to hold the stock in the band saw.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #97 on: November 05, 2018, 07:32:52 PM »
The next attempt went rather better  :) In the same way as before I marked everything out first and then used the milling machine scales to confirm. All the holes seemed to coincide with the marks and the six fixing holes lined up  :wine1: I'm not sure what went wrong before  :headscratch: Possibly tired due to a major machine problem at work.
The next step was to drill the water passages which went without problems.
Now I have to work out the best way to machine the angled and siamesed ports. It looks like it is best to use the RT in the mill as I can set each 6mm valve bore over the 6mm mandrel in the RT and then set the angle. The ER11 chuck looks like it will have enough clearance as long as I lock the quill in the extended position. The ideal way would be with a 5mm long series centre cutting end mill, but I don't have one so it will have to be done in stages starting with a 4mm centre cutting end mill, then a 5mm end mill and finally a 5mm drill.
« Last Edit: November 05, 2018, 08:21:28 PM by Roger B »
Best regards

Roger

Offline AlexS

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Re: Two Cylinder Engine
« Reply #98 on: November 08, 2018, 04:44:04 PM »
Great work! Like the cylinder head with port design. May I ask how do you want to connect the different waterways in the cylinder head?

Offline Roger B

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Re: Two Cylinder Engine
« Reply #99 on: November 08, 2018, 05:27:10 PM »
Thank you Alex  :ThumbsUp: There is a horizontal waterway at the sparking plug side of the head and two waterways that pass between the valves. The open ends will be closed with aluminium plugs in the same way as I did on the single cylinder version.

Moment of truth  ::) I aligned the mandrel in the RT on centre and then clamped the cylinder head in place. The x axis was then aligned and I started out as planned with a 4mm centre cutting mill, no problems. I then followed with a 5mm end mill and 5mm drill again no problems  :) The head was reset for the other port and the process was repeated again without problems. Result a correctly aligned inlet port pair. I followed the same procedure for the two exhaust ports remembering to set 25 instead of 27. Sometimes everything works as planned  :wine1:
Best regards

Roger

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Re: Two Cylinder Engine
« Reply #100 on: November 08, 2018, 05:39:16 PM »
Hello Roger,

That is some nice looking work and glad all went well.

Have a great day,
Thomas

Offline Roger B

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Re: Two Cylinder Engine
« Reply #101 on: November 11, 2018, 09:23:07 AM »
Thank you Thomas  :ThumbsUp:

The next steps were to mill out the slots for the rocker arms in the rocker support and bore out the combustion chambers in the head.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #102 on: November 11, 2018, 04:27:07 PM »
Next up was the sparking plug recesses and threads. As these were to be a 45 I decided to use V blocks to support the head. For the first operation it was clamped using a short length of 4mm rod pushed into one of the water ways. First centre and then mill a small flat are to stop the drill being deflected. The 3mm pilot holes came out neatly on the corner (as I hoped  :) ). The head was then turned over as this step required some more significant milling it was clamped with a piece of 8mm rod bearing on three 3mm rods in the head fixing holes. The recesses were cut with a 14mm end mill in 1mm steps and the pilot hole was opened out to 5.5 mm for the 1/4-32 tap.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #103 on: November 11, 2018, 04:31:44 PM »
The holes were then counterbored with a 10mm end mill and threaded. I tool the drive belt off and used the ER chuck tommy bar to rotate whilst keeping the feed neutral with the quill feed lever.

A quick deburr and ultrasonic clean and all looks good  :wine1: Next step some plugs for the waterways.
Best regards

Roger

Offline Kim

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Re: Two Cylinder Engine
« Reply #104 on: November 11, 2018, 06:20:11 PM »
Great work Roger!
Looks kinda like a block of swiss cheese, doesn't it?  :Lol:
Kim