Howell v-2 four stroke gas engine.

[gus]

Don't forget to keep your rpm much lower than you would with high speed steel. If you provide a flute per tooth, even a straight slot, it may go deeper. It might have been just recutting its own chips because they couldn't get out of the way of the cutting edge. If you have 5-10 degrees relief there. Then I think that's all the tooth you need.

Hi Chris,

Got it. One Counterbore Spark Plug Hole done w/o case hardening but quite a few C/B resharpening with file. Redone relief angle to 15 degrees and c/b cuts beautifully. Mental Block removed. Second O/H will complete counterbore tomorrow 10 am.
Too bad I can't cancel order for CaseHardening Compound which will last me thru next life.

Thanks for the expert advice.

 

[digiex-chris]

you'll find another use for it. Plenty of times that I've wished I'd had some on hand.

 

[gus]

Hi Chris,
Armed with good advice from Mentor and an arsenal of lethal tools which included a DIY 3/4'' CounterBore, job was done within an hour.Gus suffers from OuterHead Phobia. Ruined two O/Hds with inclined spark plug socket holes. With second/last O/H drilled/counterbore/tapped for spark plug, can now proceed to finish O/H. I have given up with Digital Protractors which don't last and gone to Japanese Mechanical Protractor.

 

[gus]

Hi Paul,
I got away compromising with Jerry Howell's drawings. M4 Outerhead fasteners did not clash with spark plug c/bore. Jerry's hole centre distance are quite tight.
Have to take it easy today. I can't take too much ice-cream at night w/o getting sinus problem and a spinning head.

 

[Swifty]

Take it easy on the iceream Gus, you must be allergic to something in it. I think that the smaller plugs will look better in the heads.

Paul.

 

[digiex-chris]

Looks great gus! My appologies, my advice was assuming the O/H was aluminium. I misunderstood. Glad you got it done!

In that second photo, is the block partially supported by the bolt head to the right of it? Looks like an idea I can borrow to keep the long end of something from slipping in the vise from cutting pressure.

 

[gus]

First deep fin appearing and the mini mill is protesting at being stretched to take 2'' O.D.x 1/8' Slitting Saw.
DRO and Power Feed chipped to slowly cut fins. Had to remind myself to lower quill by 0.195'' after every fin cut.
Basis I don't get too smart or foolish or goofed,should complete finning of one O/Head today.

 

[gus]

Finning on oneO/Head nearly complete except two more fins. Need to raise on packers by at least 1/4----3/8 to cut same fins. Secured job holding in the milling vise is not quite possible. May have to go back using the angle plate. No rush. Just enjoy watching the one O/head taking near final shape.
Minor goof today. Got the slitting saw reversed but it still cut but very feeble. Goof happened because of arbour change.

 

[gus]

At last both finned O/Heads done and a discovery made. 50mm O.D. x 3.2 mm Slitting Saw is not best option on a 1/4 hp mini mill. The last two grooves which were beyond reach of saw arbor, were cut using endmill. Shallow depth and fast hand feed had one 12mm deep groove milled in 5 mins. Slitting Saw took 20 mins.
No goofs so far and fins on both O/Hds cut to satisfaction.
Sub-assemblies on O/Hd will begin to grow.

 

[digiex-chris]

Looks super good gus! I love it when they start taking shape!

 

[gus]

Day 20.

Both O/Heads completed and mounted on cylinders. Good lesson and experience gained from using 3mm endmills to mill 1/2'' deep grooves/fins. Run mill at highest rpm,shallow depth and hand crank at medium speed with periodic chip clearance to prevent cutter damage. Confirmed took 5 mins to mill groove.
No fishing today as water went bad with Red Plankton Tidal Current with floating fish farms having 80---90% of fish wiped out.
M4 Socket Head Fasteners for OuterHeads a wee bit tight. CounterBore Holes got away. Socket Heads trimmed to slightly to fit in. Bigger counterbore holes not advisable.
The O/Heads took 8 working days to complete. Time was spent making the 3/4'' counterbore,getting it to work and grooving/finning.Luckily no rejects or reworks.


Its housekeeping,clearing up all the swarfs and chips on the lathe and mill. I have another DIY counterbor to make for the crankcase top up hole. CaseHardening Compound arrived just in time.

No serious chip making next week as I have to pack fishing equipment for Burma Bank deep sea fishing March 14-----18th going for Tunas,GTs and large Groupers.

Serious metal bashing to begin March 30th.

 

[Swifty]

Gus, metric cap screws have larger proportion heads than imperial, so no problem turning the heads down a bit to fit.

Paul.

 

[Brian Rupnow]

Nice work Gus!! You're not the first man to turn down the heads of capscrews. It's never a great idea, but then again, like you, I subscribe to the philosophy "Whatever it takes to make it work!!!"---Brian

 

[Charles Lamont]

For making tool like you counterbores why not use silver steel (drill rod)?

 

[gus]

Gus, metric cap screws have larger proportion heads than imperial, so no problem turning the heads down a bit to fit.

Paul.

Hi Maestro Paul.

You are very sharp. Cap O.D. 6.84----6.91mm . Turned it down to 6.60. All 8 socket heads fit in nicely.
Made a counterbore for the Crankcase Oil Plug Hole. CaseHardened but this simple counterbore can only cut shallow depth cut,good enough to take ''O" ring.Did file test to confirm hardness.
Next attempt will do it the '' Taig'' design with flukes to do deeper counterbores using medium carbon steel.
Have not done casehardening since trade school 1961----63. But the instructors did not teach us to reheat to cherry red and quench to get hard surface.

 

[gus]

For making tool like you counterbores why not use silver steel (drill rod)?

Hi Charles,

How sad. I have 3/8'' 1/2'' Silver Steel and no 3/4'' So had to make do with casehardening hi tensile steel. Plan to buy some 3/4 and 1'' Silver Steel. Best to have them tagged Silver Steel.
Making good DIY CounterBores for now to Gus is a black art. However with persistence will turn it around.

 

[gus]

A fishy mate called. Some fishos landed good catches yesterday. So I changed my mind and went fishing. Gus no the champ with only two but his fishy mate landed five. Here is shot of the Ugly Beast(Gus) holding the 2.8kg,6.2 pounder Beauty(Javelin Fish). Metal Bashing tomorrow.

 

[gus]

Day 21
There is a long unending list of small parts to make.
Crankcase Oil Filler Plug
Took entire day to turn,thread-die and mill the hex head. The DIY RT with graduated table came in handy to mill the mini hex head.

Crankcase Oil Filler Hole
Having come so far,I had no desire to ruin same and make new c/case. Had same firmly held in ToolMaker's Vise to drill.tap and counterbore. Made a casehardened 15 mm O.D. Counterbore.This engine requires quite a few DIY tooling,jigs and fixtures.Japanese Spiral Tap and Tapmatic Tapping Fluid with cut very clean and good looking threads.

 

[gus]

Day 22.
Valve Guides
Been working very hard. Turned 4 Brass Valve Guides. To prevent grabbing and messed up Guides,had to regrind drill rake.First piece took two hours but all four took 4 hours.

Tappet Valves
Above were straight forward to turn though first piece took an hour but all in,four pieces took 2 hours to get done.
Come Day 23 .Will be fitting on valves and guides to O/heads. Tappet Valves and guides have to be hand lapped. Valves were not parted off from bar stock and was left with a short butt to provide hand/finger hold for lapping. This idea was invented by Brian Rupnow. Thanks!!! Brian.

 

[Brian Rupnow]

Gus--I have found that with valve guides it is better to not put the valve seat in them until they are pressed/loctited into place in the cylinder head. That is because the guides can deform if the pressing in requires much force, the guides will go out of round. I generally press/loctite the guides into place, then use my Geo Britnell tool to put the valve seat in by hand, then lap the valves into the seats "in place'. I get more consistant results that way.---Brian