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400hp N/A 3.2L How is this happening?!


josh817

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Look what I found guys, it'll make you cringe:

 

 

117hfg2.jpg

 

So who else has joined this guy in a disastrous crank situation.

 

why audi did wel on a 5 cylinder ;)

 

I have to vouch for the landspeed car that two liter started up and we reved it and teh Tach was STUCK!!! at 11K RPM.. there is a picture of it somewhere .. anyhow it is petty insane!

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I have been running a pulley and no balancer for years now, and bring it up to 8000 on a regular basis. Never any problems. Now the internals are all balanced out very close, or maybe just luck, maybe just a matter of time..

Have you had a chance to remove your pulley? Is there any damage from running no harmonic balancer?

 

 

So who else has joined this guy in a disastrous crank situation.

 

My previous owner decided that he would not run a harmonic balancer when he rebuilt the engine (actually that is a bit tongue in cheek, maybe he didn't know what he was doing when he welded it). My crank is not nearly as disastrous as the broken crank (well at least I hope it isn't, will know when I pull the crank tomorrow), but the welded balancer definitely was moving at a different frequency to the crank.

 

IMG_0752.jpg

Oh yeah the key is actually in the keyway in the following picture.

IMG_0765.jpg

 

This was in a turbo motor not revving much above 6000rpm, I guess not balanced as well as any of these high revving motors in this thread.

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That broken crank was exactly the same as mine that broke. same place, same look. This was a stock motor factory balanced. Like I said I could feel the buzz over 7000. My new balanced set-up no longer has the buzz, and has not yet broke :)

Mind if I ask how much the balancing act costs?

 

Also didn't we discuss this sort of breakage somewhere else. I keep remembering people saying they mill off some material on the flywheel end of the crank to prevent I guess the harmonic nodes occurring there.

t6f9cm.jpg

 

Thats from the BHJ Drnamics PDF file if anyone is curious.

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I dont remember exactly what it cost, but I have a crank,rods and pistons getting done now. I will find out. When its done he first matches the rods, big ends then small ends. Next pistons. The crank is then done and zeroed out. He then puts on the flywheel and checks it, then the pulley. I think its all pretty standard stuff. any good machine shop can do this.

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Did Nissan not monitor their cranks as well as their rods? I've read that their rods are pretty close from the factory but I did my thing on mine anyway... When I look at this stuff, I start to not like my setup because I was doing it under a tiny budget over my summer break so I was rushing it. I have polished and lightened rods but the rod bolts are stock, my port job sucks compared to what I've seen, I balanced my rods but I never checked the pistons, etc. I think maybe if I get another block and work on it slowly, over the next 4 years while I'm in school, I can do things the way I like and take my time.

 

Ironically, guess what all is breaking on my car? The stuff I rushed! :] I'm learning for sure. For instance I'm buying another Megajolt board because I burned/messed this one up I think because I was trying to finish it in 1 hour. DUMB! Its $80 so thats ok I guess...

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And you bring this up just as I started shaving my rods Josh, haha. I'm following what you did with yours, but yet to finish the rough grind on each rod. Only actually started a couple days ago.

I'm lightening the rods in my L20A, and I have some concern about this, since I was hoping to have a faster & higher revving motor than my L28. So if I'm going to achieve this and avoid snapping the crank, how exactly should I lighten/balance the bottom end?

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And you bring this up just as I started shaving my rods Josh, haha. I'm following what you did with yours, but yet to finish the rough grind on each rod. Only actually started a couple days ago.

I'm lightening the rods in my L20A, and I have some concern about this, since I was hoping to have a faster & higher revving motor than my L28. So if I'm going to achieve this and avoid snapping the crank, how exactly should I lighten/balance the bottom end?

No, I love my rods.... :rolleyesg Its the rod bolts which aren't up to par. Stock bolts are a no go, especially when ARP makes some for $70 or something. Like I said though, at the time I was poor, worse than poor actually, I was in debt to my mom and I was running out of summer break. I cut a few corners and so slowly it starts to show. Nothing on the motor has broken thank god, just little persnickety things like a leak from the fitting that goes into the back of the head. Had to drain the water, take it out, do it again.

 

The donor I'm looking at now should have a V07 crank in it so that will give me two, and since I'm thriving in left over christmas/insurance money, I will go ahead and buy some Corillo rods. I can then adjust the pin height of the pistons for the compression I would like to see. I think Ross pistons has a "custom" set of 6 for $613. I've never dealt with forged pistons so I will have to do my research.

 

Anyway that's what my outlook is coming to be... I don't want some spectacular motor like the ones I posted, just want something better knowing the things I do now. I kind of jumped right in, you can tell by my first post (which is in the shed) that was "whats the difference between an L28 and an L28et?" :mrgreen:

 

Trust me, I'd mount my rods in my room if I didn't have to use them. They're purdy. :]

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So if I'm going to achieve this and avoid snapping the crank, how exactly should I lighten/balance the bottom end?

 

1) Make Box.

2) Ship Box to Velasco's Crankshafts, ask for 'the works'.

3) Enclose money and return address.

 

But seriously, if you have a decent electronic drug dealer's scale you can match the weights on all your components within 0.1 gm, which in and of itself will be very helpful. But until you get the entire weight to a known quantity and have access to the big lathes to cut down counterweights and do the balancing really all you can do at home is match component weights, polish the rods, and if you get really spunky polish the counterweights on the crankshaft to remove stress risers and promote oil shedding. For the final balance, you're going to have to find a balance shop and have them do their thing. It's the last step, and what ties it all together.

 

FWIW, the buzzy little engine in my you tube video which Frank 280ZX comments upon in this thread doesn't have anything like that done to it, just a damn good electronic balance on the crank, after the weightmatching of the rods and pistons were done in the shed with the drug dealer's scales.

 

(Hey, it's what everybody in L.A. calls them, including the scale company where we bought them from!)

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Haha! I use one too, now! I did use a triple beam but ever since the existence of my 5 year old step brother, the little pieces just.... disappear.

 

Weird.

 

 

If its under $500 to balance crank, pulley, flywheel/clutch, along with pistons and rods I do myself, I'd pay for it!

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http://www.kameariengineworks.co.jp/

 

It is all about the head, the reason that you cannot buy it now is because they hand make every one. They are a work of art, milled, combustion chamber argon welded and then reground. You will never get a big motor builder in Japan to give you all their tricks but bring $$$$$$$$.

Of course a 5K billet crank helps too!

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From the pictures I have it appears you can still open up the valves a little bit more on the P90... I'm seeing a lot of 45 intake and 36.5 exhaust. Kameari has 46 intake and 38 exhaust. Either way, its worth a shot to just ask my machine shop how far they could take it before they hit each other or water or something. I'm curious if it would be advantageous to increase only the intake and leave the exhaust alone. This way you get more of an increase (maybe 1.5mm rather than 1).

 

I need to do more research but I think you can take an E88 and do the big valves however I don't know the big valve size... Just saying since I have a spare E88 on tap...

 

This was my P90A chamber, doesn't look like much room to go anywhere. I WOULD say go ahead and cut into the head surface a little bit and then I would run a 91mm head gasket so I can unshroud the valves too but I think the main problem is the valve seats will start to run into each other in the chamber... That would be a question better suited for my machinist! A 1mm increase on the intake, since it is a circle, will mean a .5mm increase on each side. 2mm is 1mm on each side. I can see a 1mm gap between the exhaust and the intake, however Kameari takes the exhaust up from 36 to 38 too meaning the exhaust is 1mm larger all around too. Unless my millimeters are off, I don't think that will fit! Never know though, I'd love to find out! I'll work on it, men.

11l34ex.jpg

 

It is all about the head, the reason that you cannot buy it now is because they hand make every one.

Most porting is hand done unless you have a CNC which brings me to my second thought. Nothing is stopping you from eating the $5000 and having someone scan the head so if ♥♥♥♥ hits the fan, you can take another head and have them CNC port it to the same specs as far as ports go. The chambers my not be the same, but if you can spare the springs, retainers, cam, valves, etc. and put them into a CNC ported head, that would be nice to keep as a backup. I wouldn't try to sell for a profit though... Thats stooping into no mans land. I'm sure if Braap (or is it John, I'm confused :bonk:) wouldn't like it if their work was duplicated and sold under someone elses name.

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imagine the shrouding of an L20A bore of an E88 raceworked head for an L28 GT3 engine... then imagine the harrowing work of 'notching' the block to accept said valves on the L20A block. Look at the specifics, and draw the picture in your mind's eye....

 

Did you know an L20A with triple 44 mikuinis 'starts to pull nice and gets quiet at 140KPH---it seems that's just where it likes to run, honey' according to my wife.

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Hey Guys, here is some nice big pics of my Rebello head.

 

Listen to the specs, maybe interesting

 

Valve seats are Oversized Kamearie for the 46 and 38mm valves, You can see them overlapping in the picture. I also have the Kamearie shortened special material valve guides.

 

So I talk to Dave a bunch about this, and here is what he did. We ran the oversized valve seats and matched/ blended the port bowls into them. However, We stayed with the stock size intake on the oversized seat. Dave said going bigger on the intake shouds the valve too much and felt the smaller valve with the big seat would flow better. Did the same thing on the exhaust, but went 1mm oversized there.

 

This head is also set-up with their 10 bizzillion RPM springs and titanium retainers.

 

Any thoughts on the oversized seats?

 

Jeff

 

Picture_01011.jpg

 

Picture_01111.jpg

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