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About pkz

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    East Bay Area

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  1. A little while back I wrote code for calculating stress and retention force for press fits. If you know the nominal outer diameter of the valve seat I could do a quick calculation to find a suitable range of interference fits, then use that to determine hole/seat sizes. Also, a quick calculation indicates that about .00065" interference is lost when the head expands. I assumed a valve seat outer diameter of 1". CTE Chromoly (4130) 7.6*10^-6 in/in degree F CTE Aluminum (6061) 13*10^-6 in/in degree F T1 (room temperature) = 69 degrees F T2 (High Safe Operating Temperature) = 190 degrees F ValveSeatDiameter=1" Change in interference=(CTE Aluminum - CTE Chromoly)*(T2-T1)*ValveSeatDiameter What hole diameter tolerance are they hitting when they post machine the heads? What about on the valve seats themselves? EDIT: Also, you mentioned that any time you press something in you are shaving metal. My understanding is that unless the yield strength of one of the materials is exceeded, the press fit does not remove material or permanently deform either the seat or the head (at least not a significant amount). I would argue that using a press fit probably isn't bad practice unless there were other errors in the process as well.
  2. What material are your valve seats made of? And what interference did you spec?
  3. pkz

    WTB 240z Tail Lights

    NW240z I'm interested! I just need the driver's side (no pigtails) after taking a closer look. My passenger side one is in better shape than I thought. Pictures would be great.
  4. pkz

    WTB 240z Tail Lights

    gogriz, my Z is a 73.
  5. http://i45.photobucket.com/albums/f59/trygon21/IMG_3882.jpg http://i45.photobucket.com/albums/f59/trygon21/IMG_3885.jpg http://i45.photobucket.com/albums/f59/trygon21/IMG_3887.jpg http://i45.photobucket.com/albums/f59/trygon21/IMG_3886.jpg Willing to trade for that driver's side tail light if you've got one that's uncracked
  6. I've got one from a 73. Has all heater control switches too if you're interested. Missing the knob for the fan. PM me with an offer?
  7. Looking for a set of 240z tail lights. Would also be interested in purchasing just the driver's side tail light if you only have the one. Located in San Luis Obispo California.
  8. I accidentally started a welding fire in my garage in January when welding on a bracket which was going to hold the existing Z throttle shaft in place. I learned the hard way just how important it is to have your fire extinguishers checked- mine didn't work and left me scrambling. I put the fire out with a hose in my backyard, but not before it roasted my fender and alot of my engine wiring. The old flattop carbs went back on the car for a while in an effort to get the car back on the road as soon as I could. Since I had the six carbs off the car I decided to spend some time to clean up the setup. I bought a spectre throttle cable which I'll run directly to the throttle arm. I also made the slide throttle positions relative to one another- Originally I had the single throttle shaft tapped and screwed in the individual slide mechanisms, so the mechanism wasn't adjustable (couldn't think of a surefire way to make it adjustable at the time). Now I've used set screws to hold the slide mechanism to the throttle shaft. In order to adjust them, I have to loosen the set screw, then retighten when they're set correctly. Not quite as easy as with triple webers or stock carbs, but overall not too difficult. I decided to repaint the intake as well. After using a grinder wheel to clean up some of the rough edges from before, I taped off the area where the carburetors mount to the upper plate, then used a few passes with vht paint from oreilly. I'm really happy with the results.
  9. I would be willing if the opportunity arose- however, most members here advised me to go with a male mold so I don't know whether I'd have alot of interest in the female one I printed many months ago. Progress has resumed however- just more sanding.
  10. Looking for replacement fenders, headlight buckets, and hood for my 240z. I'm located in the San Luis Obispo area (93410).
  11. The mold's been sitting in my room for the past few months- I spend an hour or two sanding on it when I can, but haven't made alot of progress (mold prep takes ages on something like this). It doesn't help that I've got a couple other projects going on as well- tail lights on my 240z just went out, been working on some custom engine stuff as well. All that and school has really put this on the backburner. I'll keep updating this once I make a little more progress. Hard to prioritize it over school and the mystery of my taillights though.
  12. I have a broken clock I'd be willing to part with. I've also got fuel and oil/temperature gauges I'd be willing to part with (considering replacing all of them with aftermarket). Send me a PM
  13. I'm looking to buy 2 used four point racing harnesses. I don't need them to be FIA certified, and they can be past their expiration year for track racing. I like takatas, racecraft, and schroth in particular, but I'm working on a tight budget so anything will work. Also, I would strongly prefer centerlocking harnesses. Let me know what you've got. Thanks for your time Z community EDIT: I previously stated that I would consider 6 point harnesses or unmatching sets but I decided I'd like to run a matching set of four point harnesses. Email at mv.pkragen@gmail.com or respond here. Located in San Luis Obispo Area (93410), central California. Could also accept shipments to 94507 (East San Francisco bay area).
  14. Email sent- Info would still be appreciated as I'm working on a tight timeline and limited budget.
  15. Hey everyone, I've got a favor to ask. I have a 1973 240z and I'm looking to remove the brake fluid switch. My existing one was damaged in a fire which destroyed the internal components of the switch, allowing the two brake circuits to mix- so in the case of a leak in just one of the brake circuits, my entire brake system will fail. After some searching I have found that brake switches are very difficult to source and also very expensive when they do come around. I'll be searching parts cars for one in the long term, but I'd like to get my car back on the road in the meantime. Here's a link to the part I'm talking about in case there is any confusion. http://www.zcarsource.com/brake-fluid-switch-240z-260z-280z-70-75-used_8_77812_65000.html Since I'm having such a hard time finding one of these, my plan is to remove the switch entirely and replace it with a brake tee for the front brake system and then run the brake line for the front brakes to the tee, then run the rear brake line directly to the brake proportioning valve. What I need then is to find the length of rear brake line I need to run straight from the mc to the proportioning valve (the red line in the drawing below). Unfortunately, I'm currently a student in San Luis Obispo and my car is up in the bay area, so I can't measure out the length of brake line I need. My plan is to do the repair next weekend, but I need to pick up the brake lines before I head up to the bay on Friday. So, the favor I'm asking you- Z community, is for someone with a 240z to measure the length of line required to run from the front of the mc to the brake proportioning valve (again, it's the red line in the picture)- you could mock it up using a coat hangar or whatever method you think works best. If you could also measure the length of the stock line running from MC to the brake fluid switch (green) that would be very helpful, as mine has a hole in it, but if not I may be able to find that by searching around. The length doesn't need to be exact as I'll be purchasing pre-flared lines from O'reilly- I just don't want to buy a 3 foot length if i only need 2, etc. (Rear brake line- Red, Front Brake line- Green, Brake Tee Fitting- yellow) Thanks for your help everyone! PKZ
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