VQ35DE Dekonstrukt

GEE35FX said:
I'm loving this descriptive pictorial. Thanks Tim, this is great.
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la_fx35 said:
Nice. Thanks for sharing Tim.
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Thanks! Its pretty fun so far and definitely a learning experience. I've only ever torn down a 60's Chevy V8, an 80's Suzuki I4 (bike motor), and a 70's air cooled VW flat 4. Technologically speaking, this VQ is on another level entirely. Kind of amazing really from a manufacturing/machining perspective... ;)
 
Pulled all the cams today. They look good and I was able to brush off the surface rust with a light wire brush. :top:
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Unfortunately that was the end of the good news. Upon pulling the heads I found this...
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...and this...
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...and this...
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...and this...
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Apparently the pseudomechanic, who will henceforth be known as "my nemesis", has pulled the heads as well. Boo. Aside from the obvious scraping on the piston faces, he/she also installed the head studs with about 3ft/lbs because I was able to remove them by hand. I should also mention that I have never been able to rotate the crankshaft 360 degrees. I never tried all that hard because it was obviously binding on something. Now that the heads were removed it still would only turn about 330 degrees until binding, so I removed the lower half of the block to investigate...
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I rotated the crankshaft again with the motor inverted, listening for something to fall out but found nothing. All pistons and rods are intact with no visible signs of water damage.
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Then I found it. This scrape is on the crankshaft lobe adjacent to cylinder #1 where it fully impacts the bottom of piston #1.
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I can't tell without pulling the piston and rod what exactly is the issue. I know it's probably not the case but it appears that the rod is too short because it's pulling the piston skirt about 3/8" out of the cylinder just before it hits the crank. This is a pretty weak picture but you can sort of see the marks on the bottom of the piston and also how far it is pulled out of the cylinder barrel.
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Not sure what I'm going to do about this. I think I might call a pro because it may not even be worth proceeding with this bottom end. It looks like the motor was turned over, HARD, after the "reduced rod length" issue arose, and I'm not sure how much damage that kind of thing can do to the bearings and/or crankshaft. Ugh. I may just rip it apart for kicks and scrap it.
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On a lighter note, I'm pretty sure the heads and cams are in rebuild-worthy shape and also that they will swap onto the FX....
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Very nice thread so far! When you get to it, do you ever plan on porting out the upper and lower intake manifolds too? It's your chance to be a pioneer here for the VQ, a la Lance for the VK. Right now, I have just the upper manifold and I'm getting that worked on, but now I'm thinking of getting the lower one from Jeff since the opportunity exists and I may be able to get somewhere with this.
 
Def a fun thread to follow + pictures are the best. Would love to pull apart an engine for fun :smile (2):. Wonder why Nemesis didnt scrap all the parts and call it a day
 
only thing that's going to cause the problem your talking about is a bent rod. rotating interference clearances are pretty tight and a rod that's a bit out of shape can cause an interference problem like this. from what I'm seeing I wouldn't condemn that block just yet, same for the crank too for the most part, both are probably still good but would need to be torn down to really see the extent of damage from it being forced to rotate past the interference. as long as there's no further gouging or damage to the cylinder the block is probably fine as a core, you'd want to hot tank and machine it anyway if it's going to be built. what did you have in mind, more of a mostly factory refresh or was you leaning more towards a performance build? I would have assumed a performance built but when you talk of wanting to reuse the stock cams and stuff has me question that.

I'm surprised the guy put it all back together after discovering this, especially everything re assembled so completely, when I first saw the pictures I thought you scraped everything to clean it up, must have been a real surprise to get in there and see someone was already there...
 
Dectective Tim. I agree with John once dipped many of those parts will be perfectly useable its just a matter of what your master plan looks like......Aside from that I really enjoy looking at your dirty pictures.
 
The main reasons I'm leaning away from a performance build are 1) the assumption that this 350z (rwd) block won't fit into the FX, and 2) that I figured it would be cheaper to build (have built) and easier to sell a short block rebuilt to OEM specs than a performance unit with parts of my own preference. I also know next to nothing about building VQ's, and really haven't even done much research on the topic yet. I do however have a great shop within a mile of my house whom I intend on contracting to perform all the intricate work involved in the assembly if I do choose to pursue that route.

John, do you know if I can use this block? I seem to remember something about the block and crank being different between the manual and auto trans, not to mention the rwd/awd differences. Am I making that up?

The reason I bought it in the first place was for the heads and throttle body, both of which are definitely getting upgraded.

It is surprising to me that my nemesis tore this thing down so completely before giving up and reassembling. Though I bet someone more familiar and less careful than myself could do what I've done so far in a single day. A quick and dirty assembly would certainly explain the improper torque specs, broken timing cover, and mismatched cam journals...
 
Logan said:
Dectective Tim. I agree with John once dipped many of those parts will be perfectly useable its just a matter of what your master plan looks like......Aside from that I really enjoy looking at your dirty pictures.
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The master plan is infinitely flexible at this point. I like the dirty pics as well. Keeps things interesting.
 
I'm a little more familiar with the HR than the DE but I believe the block itself is the same RWD to AWD. the axle pass through is not through the block itself, it's through the upper oil pan. as an assembly you def can't put a complete RWD engine in an AWD because the lower end below the block is different, you would have to use your own upper pan housing on that block but the block itself should be the same. I'd try to confirm this with an engine builder before investing big $$ though because I can't be 100% sure, I've never actually done it.

stick engine will have a pilot bearing pressed into the rear of the crank, auto is empty and will eventually form a bit of rust. trying to add a pilot bearing to a used auto is a real pain, need to hone the pilot bearing surface clean, but using a stick crank in an auto should be no problem, may need to pull the pilot bearing out if it interferes with converter fit I guess, again, I can't say 100% on this either, best to confirm with a machine shop who builds these things
 
yes 350z blocks will work.

I know because there have been a guy who did a 350z motor into a AWD g35. Also a lot of RWD G35 swaps into AWD g35. The mounting points to the trans is all the same. I see no reason to believe why the FX should be any differnt as they come with RWD and AWD platforms.

bottom end needs some light cleaning and should be good to go. Upgrade the heads and throw a TT kit on this!
 
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