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Twin cam head for the L6 from Derek at Datsunworks


Derek

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Yea, I dont come here too often, and happen to see this thread.  The KA head was designed to work on a 600 CC per cylinder motor, and thats why it flows so well stock, and works exceptionally well after being modified.  My flow numbers are with STOCK valves.  The valve and spring system also works exceptionally well at high RPM.  I have no experience with the honda side of things, but when it comes to design and machine work, I can assist if needed.

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  • 4 weeks later...

"Free valve"? I just saw that link...AKA. "Desmodromic Valves" ...

 

Remember, these valves aren't "the size valves in an L-Engine"! That's kinda the point.

How big are the valves in the K20? I assumed that they would be no bigger than or maybe even slightly smaller than an N42 since their are twice as many in the K20.

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  • 1 month later...

Update time:)

 

No it's not dead... Fortunately/unfortunately I got super busy with my regular customers. I ended up having to hire someone just to keep up and this really sapped my free time. The good news is I see light at the end of the tunnel. I managed to get my second mill squared away and I'm putting the finishing touches on the 4th axis I need (want) to do the machine work. Hopefully in a couple of weeks things should start moving forward again. I'm going to machine up a plastic mockup to test my valve angle measurements and after that then it's time to start machining the raw casting.

 

And now for the shameless plug. I did find time to finish up some EDIS mounting kits so if anyone is looking PM me. The link to the kit is in my sig.

 

 

Thanks

Derek

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I don't mean to clog up this thread, long day and not enought sleep. Complete thoughts aren't cumulating at full speed, haha. Another question, before it slips my mind, was whether you had decided on your manifold yet? I think the DCOEs get up to 55mm.... I could be wrong. The K20 can get some pretty wicked flow compared to what these old L heads will do worked over. Where do you stand on that side of things thus far?

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On this head the combustion chamber is going to be larger than I would like. I designed it to be "as cast" but the surface finish of the printed sand is a little too rough. Each combustion chamber will need to be machined smooth. That is not such a bad thing as in the future I'll cast the chambers much smaller. This will allow for tailoring of the chambers for each build. I think this one going to end up in the 53cc range. Bolting it to my flat top piston motor isn't going to set the world on fire but when I build my stroker with custom pistons then it will start to come alive. And at the rate I'm going with this project we'll all be driving electrics :)

 

I'll be doing a custom intake that will match the as cast port size and then becomes round. The size of that final round TBD. I tend to try to design manifold ports so that you can machine them to size with a regular 3 axis machine and then do a little hand blending. So if you are running 50MM like me then you would port match the manifold in the CNC mill to 50MM then hand blend the transition to the rest of the port. 

Edited by Derek
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I am glad you are taking your time to ensure you have good quality control on this.  ( I just got my LS2 Datsun back so I am knee deep in that car).  I haven't started saving at a rapid pace for this head yet so I say take your time....lol.  Where in Central FLA are you?  I am in and out of Daytona Beach/ Ormond Beach from time to time with work.  Have a good friend in Sarasota. Keep at it we are all watching and waiting.

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Keep in mind on a 3.0 a 53cc pent roof chamber is only 9.4:1 CR, and likely the optimal in this configuration is 10:1 minimum, allowing for advance in the 17-22 degree range due to superior flame characteristics.

 

I'm thinking even JeffP will be putting a pop some on a 3.0 to being it to 10:1 even for Turbo Use!

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  • 1 month later...

Made a little progress.

 

Finally got my 4th axis completed and the rest of the mods made to my second mill. I decided to machine a plastic mockup so I could practice on it as opposed to my only casting. Normally if this was a production casting I would have budgeted for at least one casting to practice the machining on. If the casting didn't run I was going to use it as my setup but since I have no budget and a good first casting I'm going with a plastic test head.

 

20170707035625-98107d60-me.jpg

 

20170707035631-3637b451-me.jpg

 

 

20170707035628-00a3c7bd-me.jpg

 

 

I'm only doing as many cylinders as necessary to get my valve angles right. Hopefully I'll get things worked out in the first or second try. It's still rough as I ran out of time today. 

 

Hopefully if everything works out I'll be machining on the actual head later this week or the following week.

Edited by Derek
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Well, I got news my tax refund is finally released from the corrupt Malay Customs Service and last I knew it had left Japan on the way through Anchorage on the way to Portland...Departed 01:29AM...so that's making me breathe better knowing I have money again...soon...

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Excellent. I have been hoping to see someone making some progress, I know I'm not here on my cylinder head projects.

 

Will the plastic head have head-bolt holes and exhaust port bolt holes?

 

 

 

Yes I'm going to proof out the head bolts and dowels and the intake and exhaust as well.

 

Derek

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