Marks Holt 75

[Sloboat]

Mark, your thread and postings, as well as your project are beautiful.... very nice.... I thought I would just post a photo I took this last Fall. Your model makes this old hulk look sooooo pathetic... sitting out for at least 40 years.

 

[dnalot]

I thought I would just post a photo I took this last Fall. Your model makes this old hulk look sooooo pathetic... sitting out for at least 40 years.

Pathetic it may be but I think its beautiful.

 

[awake]

Magnificent! Can't wait to hear it run!

 

[Robert Ritchie]

Wow, nice job, enjoyed reading your descriptions of the tasks you have done on the Holt 75. Can't wait to see her purr, keep up the fantastic work!

 

[peter2uat]

now I know where the Minions come from

 

[dnalot]

now I know where the Minions come from

I had to Google Minions. Now I get it.

 

[kuhncw]

Mark, would you please tell us a little about the portrait cutter you use to cut gaskets.

Thanks.

Chuck

 

[dnalot]

Mark, would you please tell us a little about the portrait cutter you use to cut gaskets.

Here is a link for the cutter on Amazon. https://www.amazon.com/Silhouette-America-Portrait-2/dp/B009GZUPFA/ref=sr_1_1?crid=BFNKV1GT22Y7&dchild=1&keywords=portrait+cutting+machine&qid=1586745838&sprefix=portrait+cu,aps,236&sr=8-1

It does an incredible job cutting gaskets, patterns or decals. Even tiny holes come out perfect.

To avoid using their drafting tool I use my drafting program and draw my gaskets and then draw a box around them. Save the file. I then load the portrait program and import the saved file to the Portrait library, and then load that file. The scale will be wrong. To correct that select everything including the box and then use the tool for scaling. Then adjust the size to match that of the box you originally drew. Its very easy to get the precise size you want.

For paper stock I usually use the "card stock" setting

Mark

 

[cooksservices]

It looks like we are both progressing at a similar rate with our engines but the quality of work you are producing is something I aspire to! Thank you for sharing.
I am very interested in the process you use for making gaskets, I have a silhouette cameo. I think this also can be used to cut card and other craft type materials. What thickness is your gasket material and is it actual gasket making material or something else that you have found suitable?
Thanks, Sam.

 

[dnalot]

I am very interested in the process you use for making gaskets, I have a silhouette cameo. I think this also can be used to cut card and other craft type materials. What thickness is your gasket material and is it actual gasket making material or something else that you have found suitable?

I have used a variety of paper gasket material. Most often I use a paper of .015" thickness but have cut heavier material.

Mark T

 

[kuhncw]

Mark, thanks for the detail on your portrait cutter and materials.

Chuck

 

[Rustkolector]

Mark,
Do you think your gasket cutter would work with .015" Teflon gasket material?
Jeff

 

[dnalot]

Do you think your gasket cutter would work with .015" Teflon gasket material

I don't know if it would stick to the cutting mat. I don't have any Teflon to try. I think the blade would cut the material just fine if it could be made to stick to the mat.

How do they get Teflon to stick to the pan?

Mark T

 

[dnalot]

OK time for rockers, Rock on.

I didn't have any material for making the rockers from one piece, so I fabricated them. The body or web is brass and the cone and hinge point were made from Bronze. These parts were then silver brazed together. To align the parts during the soldering I cut a notch in the cone and turned the hinge with a grove in the center. The end of the rocker that contacts the valve stem was fitted with a bit of drill rod soldered in place with Stay-Brite silver solder (low Temp) and then filed to shape. Once made the rockers were dipped in a solution to give them an aged look. The bit of steel caused some interesting colors to form on the parts. I liked the look so I left them that way.

Mark T

 

[dnalot]

The push-rods and lifters were made from material I thought was tool steel. When tempered they were only marginally hardened. So I case hardened the ends of the rods and the entire lifter. After that a file would only skip across the surface. After that the parts were polished and then I put a Gun-blue finish on the rods. The hardened ends of the rods would not take the blue. Again I liked the look so I left the rods as they were. After assembly I rotated the cam and everything worked and turned smoothly. At this point I have set the rocker's gap at .005”. Does anyone have any recommendations for the proper gap?

Mark T

 

[awake]

Beautiful work!

 

[Robert Ritchie]

I enjoyed your new posts, your work is fantastic, very detailed workmanship. Will be awaiting next post!

 

[johnmcc69]

Natural color/finish of materials is fine, but I really like the treatment you've given these parts. I think it looks fantastic!
Keep up the great work, really looking forward to seeing it run.
-curious how well the finish will hold out...it might get better...

John

 

[CFLBob]

+1 to johnmcc69 - the colors and look of the engine's finish is fantastic. I'm watching every update.

 

[dnalot]

Thanks for the comments and "likes" guys. It motivates me to work harder. And a shout-out to Mr George Britnell for his excellent set of drawings.

Mark T