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Derek

Twin cam head for the L6 from Derek at Datsunworks

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Don't know the clearance. They are the same diameter as the stock cams I have. Keep in mind my hand is 56 years a tradesman so my grip on it isn't that great anymore. A couple of the cam towers have a tiny bit of galling up in the caps so I'll polish them out and see if it helps.

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Yeah they should turn fairly easily by hand. First thing to do is to get the cams in some V-blocks and check for straightness as well as base-circle run out on the cam lobes. If the cams are good and the journal bearing clearances are correct then the next thing to look at is the alignment of the cam towers. Sounds like they could be nipping up on a cap or two. You could try blue them to see the culprit? 

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Plastigauge caps, the nice thing about the Honda towers is they're split so bearing oiling clearance can be checked against spec pretty simply using the correct instruments or some plastigauge.

 

They should spin with light oil on the journals with one finger against a small Allen key in the center hole pushed against an alignment peg, same as the L-Series Cam with no spring or rockers on it.

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Plastigauge caps, the nice thing about the Honda towers is they're split so bearing oiling clearance can be checked against spec pretty simply using the correct instruments or some plastigauge.

 

They should spin with light oil on the journals with one finger against a small Allen key in the center hole pushed against an alignment peg, same as the L-Series Cam with no spring or rockers on it.

 

They do now.

As I said earlier they were a tiny bit tight. I worked them in a bit and I can spin both by hand. I think it was one of the caps had enough galling that it was causing the problem. All is well....carry on..

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They do now.

As I said earlier they were a tiny bit tight. I worked them in a bit and I can spin both by hand. I think it was one of the caps had enough galling that it was causing the problem. All is well....carry on..

Nope - the whole thing is ruined.  Send it to me for disposal immediately.

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Isn't this done yet?? I mean I know I wouldn't be able to sleep until I had the cams and sprockets finished up.  :D ETA on the manifold? 

 

On a serious note, do you plan on doing any engine dyno time or are you just going to throw it in your car? 

 

Just got the word from Xnke. The headers are boxed and shipping tomorrow.

I started on the cam adapters today. I don't know how long it will take to get them finished. They may have to go in and out of the lathe a few times to get the chains tracking properly. I've never setup a DOHC head before so there is going to be a learning curve.  

 

If everything stays on track I should be ready to start the install next week.

 

I have no plans to engine dyno. I may put it on a chassis dyno if I feel that it's putting out decent power. Don't forget it's only 8.5:1 compression ratio so it's not going to be a power house. This is more about longevity and proving the systems work.

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Made some progress on the cam gear adapters.

Each one is a 2 piece affair. The inner hub is keyed to the cam and the outer hub holds the gear. The back side of the inner hub holds a thrust bearing. This way I can shim the bearing if I want to decrease the clearance. There will be 5) 5mm bolts in the outer flange to lock the 2 hubs together. 

 

20170707041024-93bdbe9e-me.jpg
 

Assembled hub.

 

20170707041026-7c82be94-me.jpg

 

With gear. I had to turn the gear around to get it to line up with the idler gear.

 

20170707041031-4684008d-me.jpg

 

And the best part is it fits!

 

20170707041021-4c713721-me.jpg

 

 

Tomorrow I'll do the slots and the bolt holes. I'm going to see if I can get the cams close degree wise before I key the hubs. This way I'll be able to utilize the full travel of the slots.

 

I'm already working on simpler solutions for the next ones.

Edited by Derek
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The problem is the cams on the K20 are too close together to run a 3/8 pitch or 06B chain in a 2:1 configuration. That's why the KA24 works well. To do a single chain you would need to drop down to 1/4" pitch and probably run duplex. Now we are talking custom gears and custom chain guides as the lead from the cams down to the crank will need to be wrestled into alignment to still use the stock lower timing cover.

 

As always. Is it worth it?

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The Z20E timing gear is the same size and diameter as the KA parts...Only difference is that I'm remembering wrong and it's not the Z20E timing gear parts you need, Sorry. I'm dumb....will have to get my book out and find the part I'm thinking of.

Edited by Xnke

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Derek. Long time lurker. You've dragged me into this mate. Just wow.

 

Organising "losing" a kidney and whatever else I can spare!

 

Very keen on results once running and on mods to V2.

 

P.S I learnt an incredible amount from everyone contributing in this thread. Kudos to you all.

 

 

My calendar says its definately February ;)

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A couple of beauty shots:

 

20170707035611-21a89fb9-me.jpg

 

 

20170707035614-5edcd739-me.jpg

 

And it's in:)

 

 

20170707041048-1a95608b-me.jpg

 

Hood clears no problem. The gyrations I have to go through to get the valve cover on qualify as performance art. It just clears the hood latch bracket. I think most of the problem is with the oil supply plate that I added. It won't be on the production heads so I hope it won't be an issue going forward.   Yes I know the wiring is a mess. It's on the list:)

Edited by Derek

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Hey Derek, once you have it in the car, are you going to show it at any of the Orlando events like Festival of the Masters, or maybe the Old Town show? I'd love to see it in person some time.

Probably will do a few events. I'll post here. There is a strong group in Tampa.

 

Derek. Long time lurker. You've dragged me into this mate. Just wow.

 

Organising "losing" a kidney and whatever else I can spare!

 

Very keen on results once running and on mods to V2.

 

P.S I learnt an incredible amount from everyone contributing in this thread. Kudos to you all.

 

 

My calendar says its definately February ;)

 

Thanks

And yes it is February. But I didn't say what year:)

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