Swifty's build of Howell V4

[Swifty]

Gus, you could handle the heads ok in your mini mill, they are only just over 81mm long. But it's handy having a digital readout and CAD to work out where all the ends of the slots are.

Paul.

 

[gus]

Gus, you could handle the heads ok in your mini mill, they are only just over 81mm long. But it's handy having a digital readout and CAD to work out where all the ends of the slots are.

Paul.

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OK. Will gear up with DRO. Currently I use the Starrett Digital Height Gage to do ''mark outs'' . Pin point centre punching is now up to mark. Mating holes are jig drilled.

Plan to build the V-4 2016 if Gus still alive. Just can't imagine and believe 73 in 2016.
The Rocker Arms are quite tricky to make and to look identical. Calls for careful marking out and scribing. All part of learning curve. Scrapped four R.Arms. Will go on to carbs next week. Very mini and challenging.

Take care.

 

[Swifty]

Here are he Rocker Arm Brackets, a lot of fiddly machining but all good in the end. I still have to remove some machining marks, but that won't take long. I should think about getting a sand blaster, would be great on these small parts. The relief in each end of these brackets will be painted later.



I may look at making something bigger next, just for a change.

Paul.

 

[digiex-chris]

I recently discovered bead blasting. Its like cheating for taking out machining marks without changing things much dimensionally. I shouldn't have resisted for so long.

 

[gus]

Great job on the rocker arm brackets and they look identical whereas my first atempt rocker arms looked
bad.

 

[Swifty]

I recently discovered bead blasting. Its like cheating for taking out machining marks without changing things much dimensionally. I shouldn't have resisted for so long.

I too, have put it off for too long, they aren't too expensive, a local auto shop has small bench top models and they often have 20% off sales. So I better move next time they have a sale.


Gus, working with a stop in the vice made it easier to handle the parts. I just did them in stages. The biggest hassle was the milled relief in the ends, it's only for show, but there were three separate set ups involved due to the tapered sides.



I decided to do a bit of turning for a change, I chose the cover for the air intake. First stage, I machined the outside profile and then the inside, then parted off.



In order to hold the part to machine the parted off side, I used some square poly that I had lying around, mounted it in the 4 jaw chuck and turned it to be a tap fit for the ID of the cover.



A short while later I had the part finished.



Paul.

 

[gus]

Intake Cover looks good. I am getting a fair idea to make same.

Happy Easter.

 

[Swifty]

I've been holding off on further work on the block, as certain sizes have be verified once the gears are cut. The drawings call up for the gears to be 48DP, for some unknown reason the cutters are much more expensive than Module cutters. I have laid out the gear trains in CAD seeing if I could match up everything using Module gears, I can get close but it would mean altering a lot on the engine drawings, it's just too big a risk of something going wrong. I would prefer to buy the cutters, but if all else fails, I will make a hob.

One thing that I have learnt doing this exercise, if I design my own engine, I think that I will start with the gear train first and design the rest around it.

Meanwhile, I have been doing some more parts for the air cleaner.

Paul.

 

[gus]

Hi Paul,
Gus has the same problem. About made up my mind to buy Module 0.5 Gear Cutters. Will have trial and error with metric gears on a dummy gear case to get angles and gear mesh centre distance. In the latest Model Engineer's Workshop No.227 is write-up on Glen Bunts' Depthing Tool to gear gears meshed up and get centre distance. See page 42 --------45. Meshed depth is by eye ball judgement. Am thinking of using hand rolled cigarette paper as shim. The fun will be getting the holes drilled to the precise centre distance.

48 DP Gear cutters is too expensive landed in Singapore.

 

[Swifty]

I did a bit more work on the air inlet / filter / choke assembly.





Here I'm holding the assembly, the choke works by turning the aluminium cover which in turn blocks off the air inlet holes. Just near my thumb in the picture, you can see the choke stop inside the lip. The 2 brass tubes connect to the engine breather.



Paul.

 

[Swifty]

I mentioned earlier that I need to cut the gears to confirm some sizes, these are the centre distances between the gears when they are in mesh. Due to the minor differences that happen with home made gears, it will be necessary to cut the gears then mount one on a dummy plate and have the mating gear in the milling machine spindle. The centre of the first gear is zero on the readout, and when the gears mesh nicely, the readout will confirm the centre distance. Not having these sizes yet, stops me from reaming the camshaft holes in the block and also from finishing the timing gear cover.

However, I decided to push ahead with some of the machining of the timing gear cover. I am using a different method than that specified in the build notes, these notes call up for a dummy base plate to be clamped to a faceplate and the timing cover bolted to this for machining. My first step was to hold the oversize blank in the 4 jaw chuck, turn a boss and machine a bearing location in the centre of the boss, as well as a through hole concentric to the lot.



There is a location spigot required on the other side of this cover, which must run true to the bearing bore. So I turned up a short mandrel that located precisely on the previously bored bearing hole, the cover was then held on by a large washer and screw. This allowed me to finish the thickness of the plate, there was no deviation at all on the thickness, and to turn the spigot. I could only turn the spigot down as far as the washer, but this was fine as it doesn't locate on the whole face.



All I had to do after that, was hold the part in the 3 jaw chuck and bore a clearance hole for the crankshaft gear.



A lot more machining on this part yet, but it will have to wait until I have those centre distance sizes.

Paul.

 

[Swifty]

I blocked off some of the interconnecting holes and slots in the block as per the drawing. These holes and slots were for cooling channels, and so, of course they had to be blocked off to allow the proper flow of coolant. I still have to do the cooling return holes yet. I machined up some aluminium plugs with small grooves around them which I filled with some Devcon 2 part aluminium filled epoxy that I had lying around, it worked quite well considering it's use by date was in 2003. The weather was a bit cool, so to aid curing, I placed the block in a plastic container and poured in some boiling water to help warm the block, it worked great and the epoxy went off nice and hard.

In the picture you can see that I have machined the plugs down on one side, just to show a before and after picture.



Paul.

 

[gus]

Hi Paul,
Gus is watching every move you make. This will decide on the final decision to make the V-4.
Looks like the start on Carbs delayed for a day or two as a mate has urgent request to turn out some ivory necklace clip joints. No Problem as it gives me time to mentally plan routing for Carb machining.Plan to start work early as the humidity kills me by 10 am. Down draft from Ceiling Fan not best. Will figure out how to make it po:fan:werful.

 

[Swifty]

Hi Gus, strange how everyone wants you to make things for them, I had a friend come over yesterday who needed some machining done. Not a problem though, but it stops me working on my own things. Friend left very happy a few hours later. I'm not a fan of high humidity either, just saps the energy from me.

Paul.

 

[gus]

Hi Gus, strange how everyone wants you to make things for them, I had a friend come over yesterday who needed some machining done. Not a problem though, but it stops me working on my own things. Friend left very happy a few hours later. I'm not a fan of high humidity either, just saps the energy from me.

Paul.

Hi Paul.

Done two pairs ivory necklace couplings. Humidity sapped my energy and I am now doing some very unproductive stuff like internet surfing. I have another two pairs to make. After a good pee/tea/surf break,will go on to finish up the two couplings. Will only do this for good friends. Its Thursday and weekend fishing round the corner.The fishy mates are eaching and all looking for another productive fishing. Will be Neap Tide and good for fishing outside Straits of Johore.

 

[Swifty]

Turned up 4 valve guides this afternoon, I was feeling quite happy with them until I realised that I need 8 of them. :wall: That meant going out to get some more bronze bar and starting the whole set up again. Still, it all ended well with a set of 8 guides. I haven't machined the actual valve seat yet, I will probably make up a guided reamer for that.



Paul.

 

[Swifty]

I'm working on the rocker arms at the moment, 8 of them plus a couple of spares. I machined a block down to the correct length and width, but about 100mm long. Next step was to hold it upright in my vice and use a 1mm saw to cut to finished thickness's of .212". Worked great, thickness held within .001".


Next step was to have a set up in the vice for drilling and reaming 2 x .125" holes and 1 x .187" hole in each piece. The hole in the middle is offset to one side by .005", so I have been careful to mark one datum end.


When all the pieces were ready, I held a piece of aluminium in the chuck on my rotary table, reamed 2 x .125"holes and tapped M4 to locate and hold the pieces down. The simple fixture allowed me to machine the tapered sides in one set up (its times like these that a CNC mill would be so handy).


Another piece of aluminium was used for a different fixture to mill the rad's on the ends. Certainly a lot quicker and neater than hand filing.


Still a lot of work to go on these parts yet.

Paul.

 

[gus]

Eleven pcs Rocker Arm Blanks to make eight. Good planning and strategy.

Not much work done. Still at the ''Carb'' Department. Can't see why four M2 holes and one spray bar took entire morning.Broke two M2 taps. Both Triang hand taps. Went over to machine tap.
Its weekend fishing again. I have rising tide and ebb tide to try my luck.

 

[Swifty]

Hope you have better luck fishing than with the taps, I went flyfishing with a mate a couple of days ago, 1 small one each, but we always put them back.

Paul.

 

[gus]

Hope you have better luck fishing than with the taps, I went flyfishing with a mate a couple of days ago, 1 small one each, but we always put them back.

Paul.

Most of the fish we hooked up came from fish farms freed by some ''do-gooders'' to score merit. These poor fish are so used to being fed every day at the fish farms and are ever ready to strike at every hooked bait drop. Fish sold in the local market is some times chemical treated(very formalin dip) to slow rotting by some unscrupulous wholesalers.The AVA of Singapore makes very frequent checks and very heavy penalties for offenders.Pesticides on veggies has come down to very low level with surveillance.

Most natural fish are almost gone. We are entirely dependent on escapees and charity release. Ha Ha Ha. Gus surviving on Charity Fish.


Come Monday will work on the Filter Housing. Enjoying making the so many parts. Never ending. Now waiting for a Sensitive Chuck for micro drills to come in before attempting the orifice drilling.Broke two 0.30'' drills.

Take care.