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Twin cam head for the L6 from Derek at Datsunworks


Derek

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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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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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I'm sure you could find a way to bolt it on.  Heck, anything can be a bolt on.  Whether or not it works or not is the question.  I'm going to bolt on a frozen turkey for the extra torques.

 

As long as you can get over the obvious hurdle of leaving two cylinders at the rear of the engine uncovered, I guess that's true.

The ignorance of the interwebs is never to be underestimated.

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Finally got my intake castings in. They came out pretty good. I may need to tweak my pattern a bit.

 

20170707040233-4e408bd3-me.jpg

 

 

A good part of the flanges will be machined away. I purposely made the a lot larger than I needed. I like options.

 

I left the intake to head port as an oval. I will machine in the injector port area after I have drilled the injector bung.

 

20170707040235-592b650c-me.jpg

 

 

While I was waiting for the castings I went ahead and made my injector caps for the hard lines.

 

20170707040217-0bbc9a2b-me.jpg

 

Not perfect but nothing I make is:)

 

20170707040230-b92ea15f-me.jpg

 

 

Here is a shot of the first two ops

 

20170707040215-4cac0070-me.jpg

 

 

Next week I'll have time to get on the manifolds. I can then start to do the linkage and fuel delivery.

 

Fun stuff!

Edited by Derek
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Did you happen to get a drawing of a 55 DCOE mating flange when you set up those carb-end manifolds? I think you researched and found  the Honda guys were using up to 54mm ITB's.

 

The OS Project ongoing found the N/A size required to run was 52mm at the intake flange (310CFM) and then it was losing flow from the intake and the ITB Throttle  Shaft. The ITB used was a 55mm opening, and tapered to a 52mm Butterfly.

 

Feedback given was 'they run along at 1,500 in fifth gear in traffic just fine' which seems amazing. There is a video online now running along and matting it with theOS HEad and 55 carbs. Very nice. This one flows around there... and can likely get better. Mowhahahaha!

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My ITBs are DCOE pattern and the cores are 3D printed so I would imagine it would be a case of printing cores with a larger bore. I think there will end up being a few choices for manifolds. That is one of the reasons I did 3 2 barrel manifolds. One pattern to carve.  With the engine leaning towards the right space may get a little tight for some throttle bodies. 

 

Do you have a link to that video?

Edited by Derek
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Jenvey makes throttle bodies that are 20mm wide, since the injectors  are  in the manifold, no need for the standard 109mm length!

 

I think the bolt pattern is different on 50-55-58 from 36-40-45's... The bore can always be ported conventionally. The SK Manifolds were set up the same externally for the 40 or 45.... the dedicated 40 manifold tapered from 40 to 25mm (whatever the stock L20A port size was) and the 45 was tapered to the larger L24 port size, like 30mm.

 

Don't know positively and can't find anything quickly right now on 55DCOEs with dimensions. The EFI Hardware site seems to indicate that 40-50 is the same dimensions given the stuff on their technical data drawing page. https://www.efihardware.com/efi_documents_technical.php

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Jenvey makes throttle bodies that are 20mm wide, since the injectors  are  in the manifold, no need for the standard 109mm length!

 

I think the bolt pattern is different on 50-55-58 from 36-40-45's... The bore can always be ported conventionally. The SK Manifolds were set up the same externally for the 40 or 45.... the dedicated 40 manifold tapered from 40 to 25mm (whatever the stock L20A port size was) and the 45 was tapered to the larger L24 port size, like 30mm.

 

Don't know positively and can't find anything quickly right now on 55DCOEs with dimensions. The EFI Hardware site seems to indicate that 40-50 is the same dimensions given the stuff on their technical data drawing page. https://www.efihardware.com/efi_documents_technical.php

Not super helpful, but I think you are correct. Even borla lists different bore spacing after 50mm throttle size is passed.

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Today....Was a good day...

 

Got started on the first manifold.

 

Probing the ports. This will establish my zero point. The cores were 3D printed and the ports ended up being 90.114mm apart. I can handle .114mm:)

 

20170707040249-0b38d4da-me.jpg

 

 

Action shot of the fly cutter doing the finish pass. on the flange.

 

20170707040251-3ed1d98d-me.jpg

 

 

In order to make the linkage that came with my ITB kit work I needed to shift the ports .025” It is going to be a lot easier to blend the shift than rework the linkage.

 

20170707040304-098f57e0-me.jpg

 

 

I didn’t have a CAD drawing of the ITB so I traced around it, scanned it and then imported it into my CAD program. I’m happy with the fit.

 
 
20170707040307-65db14d9-me.jpg
 
 

 

WFO

 

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Working on the injector bungs. I drilled all the way through with a .4375” bit then opened it up to .655” part way down. I use the method described here:

http://www.sdsefi.com/techinta.htm

 

It leaves an air gap around the injector body and help guard against heat soak. It’s the same method I used on my manifold and it survives August heat in Florida.

 

20170707040313-094bc3ea-me.jpg

 

I pulled one of the injectors out of may car for a test fit.

 

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That’s going to look really good!

 

20170707040322-8279ea3e-me.jpg

 

Now that’s my kind of selfie:)

 

20170707040320-85bcb9f5-me.jpg

Edited by Derek
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