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NA 3.1L=>head & camshaft questions. No shortcuts, max


zredbaron

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Updates are slow this year...

  • JE pistons received. Pics below. Mock assembly went well.
  • Rocker arms received.
  • DP oil pan received. Pics below. (Wow!)
  • Coated: head (CC and exhaust port), piston skirts and domes, valve faces, crank bearings
  • Valve spring retainers from Kameari won't work. Joe ordered custom dimensions from Isky, I don't have the numbers at this time. (I think the Kameari dimensions didn't work because I'm using outer springs only.)
  • Outer valve springs received
  • 3x45mm DCOEs with Cannon Intake received

 

Waiting for confirmation:

  • Crank repair and rebalance
  • Block bore/hone to match coated pistons ("new" block)
  • Intake manifold port match (45mm)

 

It's been a long year. Targeted engine dyno date is June 10.

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Edited by zredbaron
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I highly recommend tossing the Cannon manifold in favor for almost anything else, especially if it has that giant balance tube running through it. A couple of easier to obtain "good" DCOE manifolds are the TWM and Harada, although there are many more available if you look around.

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Steve --

Engine build details start at post #277 of this thread.

 

Leon --

Huge balance tube between the runners, I'm not particularly a fan of it either. I'll probably purchase a different manifold down the road, but keep this one for now. Incremental changes. My primary reason is the 40mm/45mm dyno comparison is arguably moot if the manifolds aren't apples to apples aside from the port sizes. Plus the Cannon more or less came bundled with a new set of 45 DCOEs. I've more than busted my budget this year, too. Am I to understand you prefer shorter runners? Better peak hp at the cost of driveability, is that about right? Or are you primarily looking at the balance tubes?

 

Jon --

Yep, the Cannon only comes crudely matched for 40mm DCOEs, 45mm cuts out quite a bit of material indeed...

Edited by zredbaron
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Steve --

Engine build details start at post #277 of this thread.

 

Leon --

Huge balance tube between the runners, I'm not a fan of it either. I'll probably purchase a different manifold down the road, but keep this one for now. Incremental changes. My primary reason is the 40mm/45mm dyno comparison is arguably moot if the manifolds aren't apples to apples aside from the port sizes. Plus the Cannon more or less came bundled with a new set of 45 DCOEs. I've more than busted my budget this year, too. Am I to understand you prefer shorter runners? Better peak hp at the cost of driveability, is that about right? Or are you primarily looking at the balance tubes?

 

Jon --

Yep, the Cannon only comes crudely matched for 40mm DCOEs, 45mm cuts out quite a bit of material indeed...

 

It's nothing to do with runner length, my dislike of the Cannon comes from poor design/craftsmanship. I can appreciate doing an apples-to-apples comparison though.

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So... the fat lady coughed up a hairball: my LD28 crank is cracked.

 

Obviously, several humans had several opportunities to catch this before now, but luckily, it was caught before it was put in my engine. The short version is that the crank was magnafluxed late-stage (should have been performed prior to any welding and balancing, no doubt) after it was found to *still* be out of round... and a crack was discovered.

 

So... my June 10 target just got a little tighter.

 

Let the scramble for an LD28 begin... Anyone have one or know of one? Thoughts and recommendations welcome. I'm starting to get that while-I'm-at-it nervous tick....

Edited by zredbaron
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madkaw - was planning on calling Dave today... I'm ill-prepared for a discussion about the possibility of a non-LD28 crankshaft. From what I understand, Dave doesn't like the harmonics of the Nissan Competition 3.1L (stroke and rod length combination) and recommends either the 3.0 or 3.2. As far as my "painful and expensive journey" with my 3.1L is concerned.... I'm not sold on the 3.0 or 3.2 at this time. For me, I'm very attached to "my" unique 3.1L build... I've never heard another L6 sound quite like it, and I'm more interested in my intoxication by the engine than having a competitive FP car (3.0L limitation). I truly have come to enjoy the incremental improvements and noting the dyno graphs' evolution -- changing the bottom end was never a part of my experimentation at this stage... I always put that part off for "one day" when performance has plateaued both as a car and a driver. Still going to call Dave!

 

LanceVance -- PM sent!

Edited by zredbaron
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Interesting timing. Just got off the phone with Dave... evidently he is expecting a billet LD28 crank to arrive in a couple of days. It's a new part for him, so he hasn't seen the quality and doesn't have the price yet either. He suggested I inquire again later this week.

 

As for the 3.0/3.2 liter setups... Dave doesn't use the L24 rods in those kits, so his pistons have a different compression height. (It wasn't "harmonics" as I stated earlier.) My new pistons certainly have me "locked in" to my current configuration.

 

Proceeding with the LD28 crank, no question. For some reason I thought he was using more than one crank... Must've been something I saw online somewhere?

Edited by zredbaron
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Holy.... What!? A used crankshaft for $2k? (I paid $1,800 for the full 3.1L kit directly from Nissan Competition.) They aren't made of unobtanium just yet! For that price, one might as well go with a new, billet crank, if available. Heck, even a brand-new Kameari crank is "just" an additional $900, but it at least fancies itself an upgrade, not a used mystery source.

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I've sold two of them in the past year for roughly $750 each.   That seems to be the going rate now, but some folks have managed a little more by being willing to sit on them and wait for a desperate buyer.  

If you aren't willing to sit around and wait for an affordable one to pop up, which might take awhile, then you probably wouldn't have any trouble selling your JE pistons at a very modest discount.  Then at least your could move forward with one of Rebello's packages.  

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Dave is adamant about the poor rod / stroke ratio of the L24 rods. He convinced me to have my crank offset ground. My concern was grinding on the journals would limit rebuilds , but not so since he uses a standard Honda bearing size. He has other magic he also performs with the journals. Can't wait to be there.

The sound of your motor was great, but was it about rod/stroke or just a radical cam and open exhaust?

Your videos inspired me to want to have a big bore -big cam motor

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I might have a line on a used LD28 in OR for $900 (vendor is trying to locate it in his inventory). I thought it was high at the time... but didn't yet know that $750 is about the going rate at the moment. He's definitely the patient vendor type, so $900 is in the ballpark it would seem.

 

As for the possibility of tossing my new pistons and going with a full kit from scratch... Ouch! On so many levels. Cost, time, patience, sentimentality (fleeting)... Mostly cost and patience and the enjoyment of custom HybridZs. Kits are less personal, and this car is an expression of me. I'm an only child, never married, no kids. I've had this VIN longer than I've been an adult, and have carried it to the east coast and back. This car is my creation in the world. We all can probably relate to our steed being, well... honorary, inanimate family of sorts. For some reason, the idea of a kit strikes this particular chord. (Which is odd perhaps, because I bought a 3.1L "kit" back in the day... in my mind custom pistons makes it no longer a kit.)

 

Steve, you just might be right about the sound -- I do believe it's *mostly* a result of the head/cam/exhaust, but I'm not sure about rod/stroke. I do suspect that it would change the sound a bit, but in what way and by how much? Maybe I'm being stubborn, possibly a twinge of ego? Maybe it's fear of guessing wrong, spending all this time, emotion and money (3x!), and not achieving or surpassing what I drove "that one time" in Arkansas? Sigh.

 

Now that we're honing in on the detail, part of my engine intoxication is the "raw anger" that is physically felt in my chest in its presence... the aspect of the engine that shakes the camera when it starts up and during throttle blips. Open exhaust to what degree, I wonder? Maybe VP109 fuel is a factor, too (oxygenated). It made a HUGE difference to my ear (and chest) back in 2008, which still used MSA headers, fully muffled with air box and hood, etc. No way to truly know, and only so much can be gained by wondering.

 

As an enthusiast and not an expert, I wonder that maybe the less-than-ideal rod/stroke is why it sounds more rough, and therefore why Rebello engines sounds more smooth. I prefer the rough. This particular steed fills a void in the heart of a Naval Aviator that hung up his flight suit, after all. Details always matter.

 

Thoughts to ponder. (I'm still all ears, of course!)

 

We'll see what Dave R comes back with when he gets a chance to evaluate the potential billet crank. I'll likely inquire about a kit, and fully consider my options. Good feedback, gentlemen! Always appreciated.

 

:violin:

Edited by zredbaron
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I'm running one of Dave's offset ground 85mm LD28 cranks with his Eagle H beam rods and JE pistons. This is a turbo motor mind you but the sound is still fantastic even with the turbo muffling the sound a bit.  More cubic inches is nice but the long stroke/rod ratio improvement in drivability and off boost torque is amazing. On boost is crazy. Worth every penny. 

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We'll see what Dave R comes back with when he gets a chance to evaluate the potential billet crank. I'll likely inquire about a kit, and fully consider my options. Good feedback, gentlemen! Always appreciated.

 

Very interested in hearing more about this.  I have been intrigued about the stroker billet cranks that Crower made for Rebello over a year or maybe even two ago now - per the Youtube video.  These were "greater stroke" than the stock V07 crank, but I haven't heard anything more about them. I plan to get a billet crank for my next engine and consider Dave to be a top 2 source for it.  Wonder what this new one is...

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