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Derek

Twin cam head for the L6 from Derek at Datsunworks

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Hey everyone.

I now have a blog about this head on my site. I'm going to continue to post here but the blog is a condensed version of what you see here. There is a FAQ on the left side bar that has a lot of data. If you are new to this build you may want to come up to speed there and then start following it here as there is a lot of great back and forth that isn't on the blog. I will keep them updated in tandom but only with my progress posts.

 

http://www.datsunworks.com/Blog/

Edited by Derek

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Lobe work

 

Got the 4th axis back up in the mill and decided it was time to do the lobes. My plan is to rough it out on one plane then rotate 90 degrees and rough again. Repeat at 180 and 270 degrees. I’m hoping there is enough material removed at that point to go straight to the grinder.

 
First step key slot.
20170707040152-3e7fc5a8-me.jpg
 
 
 
After this is done I have a fixture that clamps on the front and keeps the cam indexed to the 4th axis.
 
I machined a V block in line with the centerline of the cam and added a clamp. This is way too long to machine without a center support.
20170707040155-d4c7f9bc-me.jpg
 
 
First cut!
 
20170707040159-6eaec2dd-me.jpg
 
This is after the first roughing pass. I’m using  .035 depth of cut which is leaving a bit of a step. I may make it a little less on the next cut. If I decide to do a finish pass that will all go away.
 
20170707040204-13a2f1cd-me.jpg
 
Here I’ve rotated it 90 degrees. I also rotate it in my CAM program so it’s looking at it from the new direction when I calculate the new code.  4th axis work can be tricky if everything isn’t setup properly.
 
20170707040210-f35a6a14-me.jpg
 
That's it till Monday.
Edited by Derek
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My steady rest from the lathe is too tall for my A axis and I wasn't comfortable doing continuous motion roughing with just a V block and friction clamp. I'll do it on the finish pass. If I continue to make cores I'll make a steady for the 4th axis and go to town. 

 

Derek

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Cam cores done!

 

IMG_0573_zpsstlcfgjo.jpg

 

Had a problem with my 3D model for the lobes. I didn't catch it until it messed up 2 lobes. It was right on the edge of not needing a weld but I figured better safe than sorry.

 

They are boxed up and heading to Isky today. 6 days to get there, 6 to 8 weeks to grind, 6 days back. Now I know how my customers feel:)

 

I've got plenty to do. The manifolds are on the way to me so I can get that all squared away. Then the valve cover. 

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As always Excellent work! I am interested to see what you do with the intake runner lengths. 

 

Thanks.

Xnke worked out the header design and came up with the intake length.  10.5" to the base of the valve including throttle body, velocity stack and manifold. Manifold is 2.125" long.

 

20170707041252-fa31e9ed-me.jpg

 

Just *wasted* the better part of the day at work catching up on this entire thread. WOW, really inspiring and cool stuff going on Derek. Very cool, can't wait to see the final outcome.

 

Thanks

Yea it can be a bit of a time vampire!

Edited by Derek

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It's an educational vampire though, I've been trying to get in local applied technology college machining classes and toying with the idea of going back to school for a degree in mechanical engineering. Everytime I read through stuff like this it pushes me a little closer

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Tellin' ya Derek, we gotta post our CV's so budding Engineers have a roadmap to obscure and arcane head construction! LOL

 

I gotta ask about the roughing if the lobes. It wasn't uncommon to give full round Nissan Billets to cam grinders to have cams ground. And the blanks from CWC are full round. Is the effort of roughing the lobes resulting in a radically decreased grinding cost or ???

 

Seems if you got the indexing slot cut...that's all you need for them to go further on with the lobes. I assume your journals and any thrust faces are already finished and will simply undergo micropolishing once returned, or will Ron completely finish that aspect as well?

Edited by Tony D

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Hi Tony

 

 

 

I gotta ask about the roughing if the lobes. It wasn't uncommon to give full round Nissan Billets to cam grinders to have cams ground. And the blanks from CWC are full round. Is the effort of roughing the lobes resulting in a radically decreased grinding cost or ???

 

I tried to get an estimate from Ron for doing the cams. He couldn't give me any kind of figure until he saw how much material he needed to remove during the roughing process. So I would say there is a high cost for roughing.  All of the machine surfaces are oversized. He will rough them after coper plating and then bring them to size after heat treating.

 

I'm hoping that they aren't too pricy or if they are he can give me some dimensions that are closer so he doesn't have to do so much grinding on the next ones. 

 

They don't do K20 grinds and grinders that do don't want to talk to me. So they have to come up with a profile as well. They are going to give me a price when they get the cores hopefully it will be workable. If they are going to charge me to develop a K20 profile on top of the grinding then that may bust the bank.

 

I'll be really happy when this cam shaft drama is behind me. It's kind of sucking the fun out it.

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Couldn't you provide a sample profile in the form of a k20 cam set from a junk head to simplify that part of the senario and then maybe some cam card specs of the performance grind you are thinking would work best?

Edited by 1969honda

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I gave them stock A2 cams to work with but they still have to measure everything and then tweak that data to suite my build. 

 

I may be worried about nothing but I've never ordered custom cams before so I have no idea what to expect.

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You might want to give Guy Henson at Damn Good Motors in Minneapolis a call.  He is a real personable buy and does some of the best custom cam work I have ever witnessed. He even designs his own camshafts, down to the profiles and ramps for existing engines and has worked on some rather odd stuff.  He is VERY good at one offs and customization.  

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You might want to give Guy Henson at Damn Good Motors in Minneapolis a call.  He is a real personable buy and does some of the best custom cam work I have ever witnessed. He even designs his own camshafts, down to the profiles and ramps for existing engines and has worked on some rather odd stuff.  He is VERY good at one offs and customization.  

 

Thanks for the tip.

No website though. Call me new fashioned but if a place can't be bothered to put up even a rudimentary site I tend to not be drawn to them. I work at a pretty high level of technology and it just becomes frustrating dealing with luddites. I'm already pulling my hair out as Ron at Isky doesn't seem to read his email or at least respond that he read it when you specifically ask that he respond. That means I need to get him on the phone every time. I then read him the email I had already sent twice. Drives me bananas. 

 

I threw my fax machine out 6 years ago and never looked back:)

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Well that's the paradox of experience, the more experience someone has, the less they care about enabling technology? :)

 

Believe it or not, I prefer calling people and having a real talk, then using email as the reminder for that...

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Yes I had a nice conversation with Ron months ago. And ultimately that's the last time I would have liked to talk to him. If I'm listing things to him over the phone and he's not taking notes then what good is that. If he was answering my emails there would be a nice chain to reference. I'm all about personal relationships in business but unless you are brainstorming real time I feel email outweighs phone conversations hands down.

 

Rant over:)

 

Edit: I apologize to everyone hoping to see something new on the head and it's just me being cranky about email etiquette:)

Edited by Derek

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Ron is busy like you wouldn't believe. There's a reason they say to call him after 14:00 PST. From then on....he's on the phone. EVERY day. It's unreal. The only time I've NOT seen him on the phone is when you set up a personal appointment which invariably come after 14:00 as well. He's running the business from arriving to 14:00, and on the phone doing technical and engineering from 14:00 onwards. It's about an hour's drive from the house.

 

Web-Cam, on the other hand, is about 10 minutes from my house in Riverside, and when I was commuting to the office I literally passed within 100 yards  of their place coming and going. 

 

I might suggest looking for racers or Honda guys selling old used cams, and just stick them in the profilers. I saw the results from those Racer Brown cams profiled in UK and was really impressed with that profiler technology. Ultimately buying a used one and profiling it would give one of two things: A good starting point, or a check against what Ron Engineers with his slide rule and drafting board.

 

If nothing else, once you have the rough dimensions, giving those dimensions to Web-Cam for an acceptability check may give future purchasers two places to choose from to get their profiles done. If Web Cam needs something finer, check to see if Ron can work with those numbers  as well. That gives a machining spec...and not to be too turfing about it...but if someone wants to make their own billet cores to send out let them have at it! Like a Megasquirt, "the head is the hard part, you make the rest"---you then have two sources for grinding. Maybe more.

 

And that can't be a bad thing.

 

Now there is a marketing slogan if I ever heard  it: "Datsunworks DOHC L-Head: the head is the hard part, you provide the rest!"

Edited by Tony D

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