3 cyl Pip engine

This topic has 166 replies, 11 voices, and was last updated 29 March 2019 at 20:15 by Roy Garden.

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19 December 2018 at 15:53 #386508
David K
Participant
@davidk77137
finished guides
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19 December 2018 at 16:01 #386509
David K
Participant
@davidk77137
While I was making the guide I made a small collet to slide over my 90 degree

cutter to enable me to keep it square while I cut the seat for the guide.
19 December 2018 at 16:01 #386510
David K
Participant
@davidk77137
cutting the seat
19 December 2018 at 16:05 #386512
David K
Participant
@davidk77137
The guides are screwed in with green permanent Loctite

the holes drilled in the cylinder head actually

came out in the correct place in the combustion chamber. I am happy to say the jig did its job.
21 December 2018 at 16:50 #386886
David K
Participant
@davidk77137
Next job is to drill the inlet / exhaust ports.

These are drilled from the centre at a slight angle to the valve guides.

The cylinders are nearly finished so each operation becomes more nervy ,

I would be gutted to mess up now.
21 December 2018 at 16:51 #386887
David K
Participant
@davidk77137
You can see from this picture were the drill breaks into the valve guide.
21 December 2018 at 16:54 #386888
David K
Participant
@davidk77137
Finishing off the cylinders, I made a jig to cross drill the rocker posts and then

rounded the tops with a file
21 December 2018 at 16:55 #386889
David K
Participant
@davidk77137
The cylinder liners are made from seamless 4130 aircraft grade tubing. The tube will only

need a light hone ready for use.

I made an expandable reamer to hold the tubing while I cut the short lengths so I didn't

crush it. I turned a small chamfer on the inside edge to make it easier to fit the pistons.

These will be a push fit held in with Loctite
21 December 2018 at 16:56 #386891
David K
Participant
@davidk77137
That's it , all cylinders done , crankcase next
21 December 2018 at 16:58 #386893
David K
Participant
@davidk77137
The crankcase has a timing gear fitted inside, this is one of the few items I need

to buy for the engine. It is an internal ring gear , 60 tooth , 48dp which I managed

to buy from HPC gears . The gear will need reducing in width and diameter so I

turned a boss on the end of some alloy bar. The gear was then tapped onto the boss and this was enough to hold it

in the lathe.
21 December 2018 at 16:59 #386894
David K
Participant
@davidk77137
21 December 2018 at 17:00 #386895
David K
Participant
@davidk77137
I then transferred it to the mill and drilled the holes for mounting .
21 December 2018 at 17:01 #386896
David K
Participant
@davidk77137
To start the crankcase I cut a piece of alloy bar and mounted in the lathe.
21 December 2018 at 17:02 #386897
David K
Participant
@davidk77137
After turning the ends square I started to turn the inside to the dimensions shown

in the plans. These consist of shoulders and pockets for the bearings, ring gear and clearances

for the crankshaft.
21 December 2018 at 17:07 #386900
David K
Participant
@davidk77137
Then the outside is turned to shape
21 December 2018 at 17:08 #386901
David K
Participant
@davidk77137
The crankcase is transferred to the mill and a flat is milled at 120 degree intervals

and a .75 inch hole is turned central on each flat for a snug fit of the cylinder liner.
21 December 2018 at 17:09 #386902
David K
Participant
@davidk77137
M2 mounting holes are then drilled and tapped to match the cylinder mounting flange.

You can see the false cylinder I made which I used to check the alignment of the holes

before drilling.
21 December 2018 at 17:10 #386904
David K
Participant
@davidk77137
8 holes for each cylinder so 24 in total, on the 20th hole this happened,
21 December 2018 at 17:11 #386905
David K
Participant
@davidk77137
Luckily I had enough of the tap to grip and remove so after completing this hole I then drilled

the next holes in the wrong place. Time to walk away and have a cup of tea, but not before

filling the wrong holes with chemical metal.
21 December 2018 at 17:12 #386906
David K
Participant
@davidk77137
Once the chemical metal had set I finished the remaining holes then moved on to drilling

the holes for the 6 push rods [ 2 per cylinder ]
21 December 2018 at 17:16 #386907
David K
Participant
@davidk77137
Then drilled the 3 holes for the inlet manifolds which will be in copper tubing .

The engine works a bit like a 2 stroke in that the carb feeds into the crankcase

and then the charge is transferred up to the inlet port.
21 December 2018 at 17:19 #386908
David K
Participant
@davidk77137
A flat is milled and centre drilled ready for the carburettor mount hole. I am not sure on the

carburettor I will be using yet so I will complete this when I buy the carb.
21 December 2018 at 17:20 #386909
David K
Participant
@davidk77137
Centring the rotary table flat on the mill I then centre drilled , drilled and tapped

the M2 holes for securing the end plate.
21 December 2018 at 17:21 #386911
David K
Participant
@davidk77137
The locating holes for the timing gear are drilled and tapped inside the crankcase. For this I

had to buy an extra long centre drill and make an extension for the M2 tap.

You can see the timing gear resting on the mill table
21 December 2018 at 17:22 #386912
David K
Participant
@davidk77137
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