457 replies to this topic

[JonnyAlpha]

Good effort so far Bill.

Phil.

Thanks Phil
Just wish I had a Milling machine, a better lathe, a bigger garage, oh and more money and time

Hopefully have all the head grinding done by the end of this week, then need to get the valve guides pressed in and valve seats cut. May have to send it away as no one around here could do it and those that could I don’t rate them.
Couple of craks rocker post threads on this head, which need Wurth inserts as well.

Edited by JonnyAlpha, 22 February 2022 - 01:32 PM.

[Tones61]

Pete Willis engineering at Tavistock,
Top notch

[JonnyAlpha]

Pete Willis engineering at Tavistock,
Top notch

 

Tones, 

 

As in  pressing in valve guides, valve seats and head machining?

Got any contact details?

[Tones61]

Pete Willis engineering at Tavistock,
Top notch

 
Tones, 
 
As in  pressing in valve guides, valve seats and head machining?
Got any contact details?

Yes he's been in business many years, he does all my machining and also JMRs too,
Look up PWE engineering in Tavistock

[Tones61]

Bill -pm'd

[JonnyAlpha]

So had a little bit more time this weekend, the next job lined up was to remove the remaining remnants of the guide bosses with a carbide burr.

 

 

Then clean up the areas using Aluminium Oxide and Carborundum Mount Point Stones.

 

 

Once the guide boss area was blended in I started on the area between the valve throat and the port, on the dual ports this is referred to as the siamese section. I also did the short side radius, which is the area on the underside opposite the valve throat roof.

 

 

Next job was to start on the inlet and exhaust ports.

Before starting I marked the push rod holes, I did this by holding a pencil in the pushrod hole and then marking the position using a set square. This was to ensure I did not get carried away and grind into the push rod holes.

 

I start removing material with a carbide burr, to remove the locating rings and blending this into the port.

 

 

Checking my research notes, the inlet ports need to be 26.5mm across and 30.5mm top to bottom. The idea with the inlet port is to enlarge the smallest area to square it off slightly.  I used a telescopic gauge to check the distances. 

 

 

The exhaust ports need to be 29mm high and 26mm wide, again I used a telescopic gauge to check.

 

 

 

 

That was it for last weekend.

[JonnyAlpha]

Here's the update from this weekend (well Saturday anyway).

 

After grinding out the ports I needed to 'polish' them. This is not polishing in the sense of shining, it's merely blending in the grinding marks, in fact polishing the ports is potentially bad as it causes the fuel and air mixture to separate!!

 

For polishing you need various types of emery tape, from 50 - 120 grit. You also need a way of holding the tape. Now I do have some ATA bands and holders, these are loops of tape that fit over a rubber drum, the drum is then tightened using a screw which causes the rubber to expand and secure the tape.

 

 

The ATA bands are ok for chambers but no good for the ports.

 

Looking on the Cylinder Head Modding videos by Stuart Gurr of Vmaxcart, he uses a neat little DIY tool, shown below. I could not figure out how to make these though.

 

 

What I did do however, is follow some advice from Keith Calver. He suggested taking a used mount point stone and cutting off the head, cutting a slot along its end to hold the tape. The tape is then inserted and wrapped around. Once wrapped around the rod, the thickness should be the radius of the port corners.

 

 

 

 

 

So using this DIY tool and changing the tape a couple of times, I was able to clean up the ports very nicely.

 

 

 

 

 

 

Next I started to work on the guide boss area and valve throats.

 

 

That was as much as I could do in the time I had.

 

Still a little bit of cleaning in a couple of awkward to get to areas and then I need to finish the chambers.

[D 'n A]

Great job so far!

[ac427]

I was hoping to pick the block up yesterday as it's been a couple of weeks since I dropped it off, however although the face has been skimmed he was having trouble identifying the thread size for the Threaded Oil Gallery Plugs that I purchased from AvonBar Racing.

 

I had asked AvonBar what the thread was but they were away and never got back to me, anyway I managed to get hold of them and they said they were 1/4 NPT slightly tapered. Passed that onto my machinist who is now trying to sort it out. Should be ready for next Monday.

 

I wonder why Avonbar would stock NPT rather than BSP. It seems strange to have American threaded rather than English.

 

Great thread, i'm up to page 14 so far, i really must do some work

 

Please keep the updates coming.

Edited by ac427, 11 March 2022 - 03:28 PM.

[JonnyAlpha]

Great job so far!

 

Thanks D 'n A, slow progress but progress none the less

[JonnyAlpha]

 

I was hoping to pick the block up yesterday as it's been a couple of weeks since I dropped it off, however although the face has been skimmed he was having trouble identifying the thread size for the Threaded Oil Gallery Plugs that I purchased from AvonBar Racing.

 

I had asked AvonBar what the thread was but they were away and never got back to me, anyway I managed to get hold of them and they said they were 1/4 NPT slightly tapered. Passed that onto my machinist who is now trying to sort it out. Should be ready for next Monday.

 

I wonder why Avonbar would stock NPT rather than BSP. It seems strange to have American threaded rather than English.

 

Great thread, i'm up to page 14 so far, i really must do some work

 

Please keep the updates coming.

 

 

Not sure where they get / got them from? They're in now and just hope the machinist got the threads correct, I used some Loctite on them as well. 

Edited by JonnyAlpha, 13 March 2022 - 07:18 PM.

[JonnyAlpha]

So a bit more progress yesterday, managed 3 - 4 hours and got cracking on the chambers.

 

First here's the setup, hoover pipe clamped in place to extract metal filings, and head clamped down to prevent movement. The biggest issue is visibility, I had a light mounted overhead but it needs to be lower and more powerful.

 

 

Although I have not widened the valve throats yet, or cut the valve seats yet, to prevent any damage and to help keep the roof height reference, I inserted some cut down valves.

 

 

The chosen mount point for this job was a conical, flat based aluminium oxide.

 

 

With this tool in the chuck, I started on the chamber roof, in the area to the front and back of the valves. valves.

 

 

Next, around the valves and down to the reference mark that I had cut with the milling attachment in the lathe (oh how I wish I had a milling machine).

 

 

At this point I stopped to check the depth of cut with a vernier depth gauge and then marked any high particular spots with a sharpie. 

 

 

 

Then a bit more grinding in the high areas.

 

 

And here's a two of the four chambers after this stage of grinding

 

 

Now it was time to tackle the chamber walls again, before doing this I had to put the used head gasket in place and mark the gasket profile. Next I used the chamber template and marked the chamber profile again and them highlighted the areas of the wall that needed grinding.

 

What is not seen in the pic is that I made a wall profile with a piece of scrap aluminium, this is to get the wall angle to around 7 degrees. 

 

 

Note that the gasket is held in place with 3D printed plugs.

 

 

 

Marking the gasket profile ensures that as long as the chamber profile edge is inside the sharpie and will not compromise the head gasket when fitted (none of this I would have known without advice from the experts out there).

I also used a carbide burr first to remove the largest areas of material.

 

Next up I used an ATA band with some a coarse paper drum (50 or 60 grit I think) and then a slightly finer one and cleaned up the grinding marks.

 

 

These were the results

 

 

 

I think I sorted out the indentations in the chamber above, top left of the exhaust and inlet, but if not I must have missed them and they'll need sorting.

 

 

 

 

And after a little more cleaning up and a spray of WD40.

 

 

 

 

 

Yes there are some imperfections in the ports, but this is a first go (the WD 40 pooling make it look a bit worse). I may do a bit more cleaning up, but I'd be happy to put this in my engine and see how it goes

Edited by JonnyAlpha, 13 March 2022 - 07:17 PM.

[Tones61]

I had asked AvonBar what the thread was but they were away and never got back to me, anyway I managed to get hold of them and they said they were 1/4 NPT slightly tapered. Passed that onto my machinist who is now trying to sort it out. Should be ready for next Monday.
[/quote]

I wonder why Avonbar would stock NPT rather than BSP. It seems strange to have American threaded rather than English.

Great thread, i'm up to page 14 so far, i really must do some work

Please keep the updates coming.
[/quote]

Not sure where they get / got them from? They in now and just hope the machinist got the threads correct, I used some Loctite on them as well.
[/quote]

Standard pipe thread bill,
The porting looks good,
Top build dude

Edited by Tones61, 13 March 2022 - 07:11 PM.

[JonnyAlpha]

Tones61 said:

"Standard pipe thread bill,
The porting looks good,
Top build dude :-)"

 

Thanks Tony, can't wait to get it in and running

 

[alex-95]

Nice work Bill!