Welcome, Guest
Username: Password: Remember me

TOPIC:

Saving a 1980 750 twin. 27 Jun 2015 21:54 #678564

  • DoctoRot
  • DoctoRot's Avatar Topic Author
  • Offline
  • Sustaining Member
  • Oh, the usual... I bowl, I drive around...
  • Posts: 2544
  • Thank you received: 664
I have been super busy trying to finish up two bikes to sell so that has been occupying my time. I finally finished the seat, but i still need to rivet a few more places to get the edge to be even. Very pleased with how everything turned out considering this is only the second seat i have ever made. The tricky part was getting the seam on the seat to align with the stripes on the tank. The side covers mounts were badly cracked so when i repaired those with fiberglass i extended the edge to fill the gap between the frame. Next up is to finish the swingarm, make spacers for the wheel and arm. and do a little frame bracing.






Please Log in or Create an account to join the conversation.

Last edit: by DoctoRot.

Saving a 1980 750 twin. 28 Jun 2015 01:02 #678575

  • DoctoRot
  • DoctoRot's Avatar Topic Author
  • Offline
  • Sustaining Member
  • Oh, the usual... I bowl, I drive around...
  • Posts: 2544
  • Thank you received: 664
Thinking about how i want to detail the engine. paint n the engine was done very poorly so i'm going to soda blast it off. i might paint the cylinders and head black. with everything else bare or polished. Thinking about doing the polished fin edge if i do them black. but it kinda looks funny with few fins getting the treatment in one spot. Maybe ill do the fin below as well. thoughts?

Attachments:

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 28 Jun 2015 01:30 #678576

  • missionkz
  • missionkz's Avatar
  • Offline
  • Sustaining Member
  • Posts: 1622
  • Thank you received: 184
I prefer all the outside edges of the fins to show semi-polished aluminum if the cylinders and heads are painted satin black.
I don't care for a gloss black engine.... partial black or otherwise.

Either way, when polishing the fin edges, it is had to make them all look consistent though.... some of cooling fins in the head castings are pretty rough.
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 28 Jun 2015 02:54 #678580

  • DoctoRot
  • DoctoRot's Avatar Topic Author
  • Offline
  • Sustaining Member
  • Oh, the usual... I bowl, I drive around...
  • Posts: 2544
  • Thank you received: 664
I dunno, sometimes i see the cylinder done as well and i think its a little over the top. plus getting the cylinder fins to match the head fins would not be easy. I did just a proper job polishing them back and i think it looks a lot better. still up in the air though. kinda reminds me of the new thurxton.
Attachments:

Please Log in or Create an account to join the conversation.

Last edit: by DoctoRot.

Saving a 1980 750 twin. 28 Jun 2015 04:57 #678584

  • 80B4
  • 80B4's Avatar
  • Offline
  • User
  • Posts: 447
  • Thank you received: 105
I have cut the fins on several heads and cylinders on my cnc controlled mill. It gives them a uniform look that you can't get if you do it by hand. BMW and Harley machine cooling fins too.
1980B4 1000
1978 Z1R
1978 B3 750

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 28 Jun 2015 09:36 #678598

  • missionkz
  • missionkz's Avatar
  • Offline
  • Sustaining Member
  • Posts: 1622
  • Thank you received: 184
Yup but I've owned a few and always had a soft spot for Brit bikes....
Bruce
1977 KZ1000A1
2016 Triumph T120 Bonneville
Far North East Metro Denver Colorado

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 28 Jun 2015 22:27 #678670

  • Jbosh
  • Jbosh's Avatar
  • Offline
  • User
  • 1982 Kz440 ltd D4
  • Posts: 142
  • Thank you received: 5
Doc, how you cleaned up the fins here looks really sharp in my eyes! I think you are bang on! Although what's going on with your dohc badging on your case? Nice work so far!
As long as I get to learn something, I'm happy!
The following user(s) said Thank You: DoctoRot

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 03 Jul 2015 16:42 #679307

  • DoctoRot
  • DoctoRot's Avatar Topic Author
  • Offline
  • Sustaining Member
  • Oh, the usual... I bowl, I drive around...
  • Posts: 2544
  • Thank you received: 664

Jbosh wrote: Doc, how you cleaned up the fins here looks really sharp in my eyes! I think you are bang on! Although what's going on with your dohc badging on your case? Nice work so far!


Thank You. Im contemplating casting a new timing cover. I took a mold off the original which i will cast in wax eventually. I don't know what to do on the face of it. Right now options are "DOHC", "KZ750", or "750T" any suggestions are welcome. I also don't know what material to cast it in. I have never cast aluminum before, but have a good deal of experience with bronze. Heres a bronze belt buckle i cast a few years ago.
Attachments:

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 03 Jul 2015 16:52 #679309

  • DoctoRot
  • DoctoRot's Avatar Topic Author
  • Offline
  • Sustaining Member
  • Oh, the usual... I bowl, I drive around...
  • Posts: 2544
  • Thank you received: 664

80B4 wrote: I have cut the fins on several heads and cylinders on my cnc controlled mill. It gives them a uniform look that you can't get if you do it by hand. BMW and Harley machine cooling fins too.


You and your fancy tools... Im quite jealous.
The following user(s) said Thank You: 80B4

Please Log in or Create an account to join the conversation.

Last edit: by DoctoRot.

Saving a 1980 750 twin. 04 Jul 2015 07:49 #679377

  • 80B4
  • 80B4's Avatar
  • Offline
  • User
  • Posts: 447
  • Thank you received: 105
When I carve a new ignition cover for my B3 I'll do one for your bike Vic.
1980B4 1000
1978 Z1R
1978 B3 750
The following user(s) said Thank You: DoctoRot

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 04 Jul 2015 07:59 #679379

  • SWest
  • SWest's Avatar
  • Offline
  • Sustaining Member
  • 10 22 2014
  • Posts: 22432
  • Thank you received: 2621
We did sand casting in metal shop. As I remember aluminum melts at 2500*. You should be able to do it. I'd like to see how it comes out.
Steve

Please Log in or Create an account to join the conversation.

Saving a 1980 750 twin. 04 Jul 2015 09:29 #679388

  • 80B4
  • 80B4's Avatar
  • Offline
  • User
  • Posts: 447
  • Thank you received: 105
The melting temp of Aluminum is between 860° and 1240° f. depending on the alloy. There are lots of utube videos on back yard aluminum casting. I did a lot of foundry projects in grad school, it was fun!
1980B4 1000
1978 Z1R
1978 B3 750
The following user(s) said Thank You: DoctoRot

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum