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Twin cam head for the L6 from Derek at Datsunworks

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#1061 Derek

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Posted 29 December 2016 - 03:08 PM

Ok time for a small update.

 

The head work is being done at Rebello Racing. I was interested in getting a head in his hands and everything kind of fell into place for that to happen. The only down side was they are always slammed so it's taken a little longer than I would like. They worked the bowls a bit but other than that it's basically the same as it was after the new owner smoothed it out. There was no major shape changes. Dave's opinion is the head as it is now has the capacity to produce in the 420 HP range based on the numbers they got.

 

He is onboard at this point and will be offering and recommending the head to his customers. He deals with Schneider Cams and the cores are there getting the lobe profiles done. 

 

I know it's been slow going for while. It's just amazing how long it takes to get  things like this moving.

 

I'm attaching the flow sheet he sent me. 

Thanks

Derek

 

DSCN07221_zps45gf8ult.jpg


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#1062 rturbo 930

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Posted 29 December 2016 - 06:31 PM

443 @ .5" lift? Isn't that about double what a ported P90 does? Did I get that right? Wow.

 

 

Did you ever get a driving video of the one in your Z? I'm dying to hear this thing at WOT.


Owen | 1976 280Z | 1988 325is | 1986 Jetta | 1953 CJ3B

A car is a hole in the air, suspended there by four rubber doughnuts which you can not eat.
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#1063 Derek

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Posted 29 December 2016 - 06:51 PM

443 @ .5" lift? Isn't that about double what a ported P90 does? Did I get that right? Wow.
 
 
Did you ever get a driving video of the one in your Z? I'm dying to hear this thing at WOT.


Yea I read it wrong at first too. That row is the scale value that the flow bench is using at that lift. Then below that is the factor that you use to derive the actual flow. Dave explained it but I'm probably not describing it properly. The intake flow at .5 is 301 CFM.

No video yet. My video recording with the iPhone isn't sounding at all like what it sounds like in reality. I picked out a lavaliere mike on Amazon and I'm going to give it a try.

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#1064 JoshuA

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Posted 29 December 2016 - 09:22 PM

Been a while since I've had an opportunity to check in on this project. Pretty awesome that you got Rebello involved, those flow numbers look great! 



#1065 JMortensen

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Posted 30 December 2016 - 10:11 AM

420 with what bottom end? I want a straight up comparison to that diesel block 3.35L build. I'm betting yours would be right in the same ballpark. Honda knows a thing or two about valvetrains...


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#1066 Derek

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Posted 30 December 2016 - 12:09 PM

 

 

420 with what bottom end?

 

 

Well the "right" bottom end of course:)

 

Here is how Dave put it to me. You can do it with a 3.0L but you would need to spin it 10,000 RPMs to get there. A 3.4L puts you around 7500 to hit the same mark.  He feels that a 3.2L will give you a decent amount without going to extremes.


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#1067 HuD 91gt

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Posted 30 December 2016 - 01:55 PM

Nice work getting involved with Dave.   Hopefully it sends you plenty of business to pay off all your hard work.  Great stuff!


1971 240z - Balanced .040 over L28 w/ Ported P90 head - Colt c542.s cam, SU w/SM needles, MSII (ignition)- LS2 Coils Wasted Spark, MSA Premium Exhaust - 6-3-2 Header

 


#1068 Derek

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Posted 11 January 2017 - 09:59 AM

Just uploaded a new video.

Trying out some new microphones. The placement on this video is one in the cabin and one next to the exhaust pipe. The exhaust mike is dominant at this point as you can't hear the induction noise which in my opinion is the best part:)  It's a pretty accurate depiction of what's coming out the back end though. I'll shoot one with the mikes in the engine bay next. Shifting at about 6800. On the second run I hit the limiter in first. OOps. The camera mount sucks and I need to work on it. If you look closely through the shaking you can see the front of the car lift when the cam comes on.  I drive it this way a lot. I just love the sound of it!

 

Thanks

Derek

 


EDIS Mounting kits are BACK IN stock!!!
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#1069 rturbo 930

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Posted 11 January 2017 - 10:53 AM

Sounds good! Not like I was expecting, interestingly. Sounds pretty vintage actually, I think.

 

I'd move the mic away from the exhaust. You're getting a lot of distortion there.


Owen | 1976 280Z | 1988 325is | 1986 Jetta | 1953 CJ3B

A car is a hole in the air, suspended there by four rubber doughnuts which you can not eat.
Into this hole, you throw money, which you will never see again.

 


#1070 Flexicoker

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Posted 11 January 2017 - 11:08 AM

That sounds amazing. Great job!!


Unlike women, a racecar is an inanimate object. Therefore it must, eventually, respond to reason.

#1071 WhitleyTune

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Posted 11 January 2017 - 02:58 PM

Nice to hear some music Derek! Awesome. 



#1072 grannyknot

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Posted 11 January 2017 - 03:22 PM

Magnificent sound! Sure put a smile on my face, that's got to feel pretty good after all those years of hard work, very well done. :hail: 



#1073 madkaw

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Posted 11 January 2017 - 06:01 PM

Sounds like an L !!
Steve,
9/71 240z. 2.4 -.40 over, balanced. E-88 Bigger SS valves, stage 2, 6x2 header, true dual exhaust. BW t-5 , STI LSD 3.90- triple Mikunis 40mm

#1074 supernova_6969

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Posted 11 January 2017 - 06:29 PM

so, ok. 

 

your car, at least the exhaust, sounds godly.  just the other day, I was listening to a vid with a vintage 1950s aston martin (http://jalopnik.com/...ound-1790551967) and your vid reminded me of that. 

 

yours is a bit more throaty but god does it sound good. what kinds of revs did you go up to, when you were really punching it?

 

let me hijack your thread for about two posts (mine and yours) and ask you what is your exhaust (I've seen your custom headers, but I forget what you're running for pipe and muffler)..

 

thanks!  and I wish my car sounded as good as yours....

 

seb



#1075 JoshuA

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Posted 11 January 2017 - 09:48 PM

Sounds great man! You mentioned before that this was a pretty conservative build compression and cam wise, correct?



#1076 Derek

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Posted 12 January 2017 - 04:00 AM

Thanks everyone.

 

 

 

 Sounds pretty vintage actually, I think.

That is probably the best description of the sound. at least in my ears.

 

 

 

 


Magnificent sound! Sure put a smile on my face, that's got to feel pretty good after all those years of hard work, very well done.

 

 

Thanks. Yea it is a lot of fun driving. I have right around 3700 miles on it at this point. I've had a few issues but nothing related to my work. Biggest problem was a defective KA24 upper tensioner.

 

 

 

Sounds like an L !!

 

 

Thats a good thing! right:)

 

 

 

ask you what is your exhaust

 

Magnaflow round muffler as a resonator and a Magnaflow oval as the muffler. When Xnke designed the header this is the sound I was looking for. Hopefully he will chime in but it had to do with the length of the collectors.  I'm kind of pulling that out of my butt though. Not my department:)

The rev limiter is set at 7000 RPMs. The EDIS gives up at 7100 or so and that is not an elegant way to control your revs. Like really harsh when it kicks back on.  I don't know the specs of the bottom end as I bought it used from a Hybrid member who has gone dark. The crank as absolutely been balanced but beyond that I don't know. At 7000 it is still pulling like a mofo so it's not running out of cam or head.  

 

 

 

Sounds great man! You mentioned before that this was a pretty conservative build compression and cam wise, correct?

 

After I milled the head the second time I was able to get the CR to around 9:1.  Everything I have been told is the design of the combustion chamber will easily work up to 11.5:1 on pump gas. The cam is very mild and really should be considered a test item. 

 

I should be getting the head back from Rebello in a couple of weeks so development can start moving forward again. 

 

Derek


EDIS Mounting kits are BACK IN stock!!!
http://datsunworks.com/page3/page4/


#1077 madkaw

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Posted 12 January 2017 - 04:46 AM

Get someone to video you doing a drive by.
The exhaust mic is really dominant like you said . I just set my camera on a box or something in the hatch - it does a pretty good job picking up the total sound.
It almost sounds like an open header with yours. My car has the same magnafow exhaust as yours- just twice as many:)
Steve,
9/71 240z. 2.4 -.40 over, balanced. E-88 Bigger SS valves, stage 2, 6x2 header, true dual exhaust. BW t-5 , STI LSD 3.90- triple Mikunis 40mm

#1078 JoshuA

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Posted 12 January 2017 - 06:40 PM

Boy that will make for one helluva combination with a Rebello bottom end. I haven't seen much from them lately, did they move forward with the stroker crank they were working on? Supposed to make for a 3.34 liter build if I remember right.



#1079 Metro

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Posted 16 January 2017 - 03:44 PM

It really does sound vintage. Modern I6s, even with ITBs, simply lack that sound.


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#1080 winstonusmc

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Posted 16 January 2017 - 06:43 PM

Yeah, my RB25 with ITBs sounds nothing like that. I don't have the duration of cams this engine has though.

'72 240z w/ RB25DE ITB MS3/MS3X

http://forums.hybrid...40z-rb25de-itb/





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