Hoglet Build

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I used a 3 fluted chanfer tool just to start the seat that will be mated (hopefully) properly with the valve when they are lapped.

This was done at the same time and setting the hole through the head for the ports and valve guide was made so that (again hopefully) they will be aligned.

Nick

thanks nick.

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Pressing on with the cylinder heads. The jig was placed back into the lathe 4 jaw and dialed in with the heads mounted onto it. This was to enable the cooling fins to be cut with a modified parting tool having ground a rounded tip.

Nick

Bring on the Bling

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I have made the valve guides and pressed them in and have made the 4 valves out of stainless OK (after making a cobblers of 2 'practice' ones)

I have some fine valve grinding paste and I am wondering what is the best technique for lapping in such small valves.?

Cheers, Nick

If its valve grinding paste from the likes of Halfords then even the fine is too rough, you really want a lapping powder and drop of oil.

Have you left the valves on the bar so they are easy to lap like I mentioned above? or have you parted them off

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OOooooops. - Did not see that bit.!

Nick

So you now have the option of using a slitting saw to cut a slot in the head, then you can use a small screwdriver to turn the valve back & forth while you lap it in.

Or use a small drill chuck or length of fuel tube on the stem of the valve to do the same thing.

Just twist, lift, twist, etc

Nick,

Remember the old 'rubber sucker on a stick'

Here; thanks to SMD electronics, is your salvation.

MichaelG.

I still have one in my tool chest for such things.....

Gunson brought one out for use with a power drill that oscillated....

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Cheers for the advice guy's.

Nick

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Bit more progress.

As I said previously I made the valves and guides. Made the 4 valves a bit too long so that the recess made for the live centre could be tuned away.

The supports for the rocker arms have also been made. It's the little bits like this that I find take far more time than you would think.

I also made the valve springs on the lathe out of music wire.

I have to yet still shorten the valves and cut a groove in them that will allow an 'E' clip to be pressed on and hold the valve keeper and it's spring into position.

Starting to 'look' like an IC engine. ............. Although knowing eyes will be aware that the time consuming and tricky bits are yet to be made.

The valves still need to be lapped. Although I have done one of them which took about 2 hours while watching TV

Nick

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I am thinking of using key steel to make the rockers out of. (drawing is American numbers) Is this suitable for the job and what is the stuff like to machine.?

Cheers, Nick

Whats wrong with mild steel?

Drawing only says "steel"

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I will carve up a pair of broken Aldi mole grips then.

Nick

Key steel is good stuff for things like rockers. It has a little more carbon in it than mild steel and machines very nicely.

I wonder if you wouldn't be better off to make an automotive-style valve seat cutter that rotates on a precision spindle that is installed in the valve guide after the guide is installed and reamed to final ID?

Guides rarely go in dead straight so a seat cut to match the hole the guide presses into does not usually line up with the ID of the guide after it is installed.

A one-degree difference in angle between the valve and the seat is common auto practice to get a better seal without lapping at all. Might be worth trying?

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Thanks Hopper.

There are a few areas of the design that seem a bit weak. Having said that there are a large number of them that have been made and running without issues.

Nick

Nick, what are you lapping the valves with? I can usually do one in a couple of mins

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This stuff **LINK** made into a stiff paste with a tad of oil. - It's the 600 grit grade.

Nick