Cuong Nguyen Posted August 18, 2007 Share Posted August 18, 2007 (edited) well I finally got the heads off then engine... now I'm like dumbfounded. I don't know what to do next. Edited August 18, 2007 by Cuong Nguyen Link to comment Share on other sites More sharing options...
zonianbrat Posted August 18, 2007 Share Posted August 18, 2007 I'm no mechanic, but would say you need some new pistons rings and have those cylinders cleaned out or bored out. Then maybe have the heads grinded to make sure they are "true and straight" and to get all that gasket material off. Good luck Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted August 19, 2007 Author Share Posted August 19, 2007 do you think I could hone away the "rust/water" spots in the cylinders? How do you know I would need new piston rings? Link to comment Share on other sites More sharing options...
unccpathfinder Posted August 19, 2007 Share Posted August 19, 2007 that looks pretty rough...I'd say do an entire rebuild...pull the pil pan then the cradle and then pop the connecting rods loose and pull the pistons out then pull the crank out and get it all checked out and machined as required...it looks like that thing had some water in the cylinders for a while... Link to comment Share on other sites More sharing options...
Slick Posted August 19, 2007 Share Posted August 19, 2007 (edited) meh, i managed to go from this (see below) to this (see below).. I bought that motor from N.O.W... it had been sitting a WHILE (to say the least).... just takes time, and a good steady hand so you don't damage the surfaces. *time out, won't DL my pics* ~~> Upload failed. Please ask the administrator to check the settings and permissions Edited August 19, 2007 by Slick Link to comment Share on other sites More sharing options...
zonianbrat Posted August 19, 2007 Share Posted August 19, 2007 I am not saying you necissarily need new rings but by the looks of the cylinder walls, you gotta think what the rings are supposed to do. besides you have the engine torn down this far already. What if you eventually need the engine then put it in only to find out your compression sucks. Just my .02 Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted August 19, 2007 Author Share Posted August 19, 2007 Looks like I'll have to follow in yall's footsteps Slick and unccpathfinder! I'd like to add that I think I'm black. I have the worst luck ever. How do I go about painting the block? I live on the coast and would like to keep it rust free. Link to comment Share on other sites More sharing options...
unccpathfinder Posted August 19, 2007 Share Posted August 19, 2007 (edited) the cylinder walls dont look horrible...but the rust on the top of the pistons where the rings are does and I would suspect where it looks scaly that it put some nice pits in the walls which would eat up the rings and burn oil and then start blowing oil out of the dipstick... I havent done a complete rebuild on a nissan engine b/c I dont have all the right tools to do it completely...I have rebuilt the top end and disassembled everything except for the bottom end on an altima engine (whose cylinders had that rust haze on it from sitting but no rust actually down in the cylinders (now that i think about it i bet thats where they pulled the intake and let the coolant run down in the cylinders)I didnt like the way it looked so I put the heads back on it and everything and did a compression check which came back good...then I got my 95 engine dash and wiring harness and didnt ever run that engine... I have rebuilt a couple of lawn mower engine completely and learned that letting the owner talk me out of taking it to the machine shop to bore out the cylinder was bad...it prob had a good 3000-4000 cutting hrs on it and started drinking oil b/c of the bad rings...so we honed it and I installed the new rings...it cut about 20 mins b4 billowing blue smoke and lost all compression...the cylinder was egg shapped from wear and needed to be bored over with an oversize piston/rings so now it sits and waits for me to come back home and do it again...the right way to remove the rust I coated a rag in motor oil and wiped it all down and it all came out so i wasnt worried about it... Slick has a good paint tutorial...send me a PM with what year pathy/egnine is and i'll possibly be able to give you some insight... Edited August 19, 2007 by unccpathfinder Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted August 19, 2007 Author Share Posted August 19, 2007 (edited) I just shot you a PM. Can I go ahead and pull the pistons out without a ridge reamer? It looks like I'll be replacing the rings anyways. There's pitting in the brown marks and spots in the cylinders. I'm hoping honing will get rid of them, if not then i'd have to overbore and get oversized pistons. Considered the VH45DE pistons as used in the Project Pathfinder of Nissan Sports Mag... Also I will be using the 3.0 crank since I can't find anyone local that can machine down the crank snout which would mean new bearings for the rods and crank. Edited August 19, 2007 by Cuong Nguyen Link to comment Share on other sites More sharing options...
Slick Posted August 19, 2007 Share Posted August 19, 2007 (edited) painting the block.. well... first, you have to clean the sucker with gasoline (please don't smoke during this part...), make sure allt he crud, crap and festering whatever's are ALL GONE (have just the bare block btw).... then, cover the pistons and head surface as much as possible. **the best time to paint the block is AFTER the pistons have been cleaned, and ALL the head gasket crud is off the surface, this way, should you, like i, get any paint of the surfaces, you can easily remove it with acetone** anyhoo, once you have plugged any and all holes, put bolts in other holes, and covered the pistons/head surface, you can wheel yer special puppy outside n get to painting, i put 2 good coats on the purple turd. i used ENGINE PAINT from autozone/kragen's, i think it was $5 a can.. after rbackets n all, i used 2 cans of dodge plumb crazy purple. for the valve covers, i just used wal mart brand black gloss paint, 2 coats. lemme see if it will lemme post up pics today.... *prepares hammer if not* *bangs hammer on puter* apparently not.. check out these pics of before n after .... i took a LOT of time cleaning every bit & piece with gas or carb cleaner (CC works GREAT on the intake inside!), just be careful with it all. I even cleaned the INSIDE of the heads with gas, but i made sure not to get the gas anywhere near the valves as there is rubber in there! a shop towel and a steady hand help. and the final result... (minus a few bits n pieces lol) and YES, they ARE the same engine tyvm.... time, hard work, and a bf who "hones good" made it happen Edited August 19, 2007 by Slick Link to comment Share on other sites More sharing options...
zonianbrat Posted August 19, 2007 Share Posted August 19, 2007 Well if your going to replace the pistons shoot a PM to AK9849cy (hope he doesnt mind me referring him) I know he has rebuilt that engine in his truck and I believe he put in pistons that were non-interference. Anyway I am sure he could give you some tips on what to do the guy has dome some amazing things to his pathfinder. Good luck. P.S. Slick you did an amazing job with that motor looks sweet Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted August 20, 2007 Author Share Posted August 20, 2007 I got the pistons out of the block. I scratched a bearing along with the journal as well.. nothing serious. Number 4 piston's rings are frozen from all the carbon. Doesn't look good. I checked with Courtesty Nissan and they have .025 OS, and .50 OS, along with standard size Rings. Link to comment Share on other sites More sharing options...
unccpathfinder Posted August 20, 2007 Share Posted August 20, 2007 I would ask the opinion of a trusted shop...if they think the walls can be honed and call it good or if they would recommend that it be bored and honed...I am not familiar with the thickness issues with nissan blocks but i know the older 350s had casting problems and it was always a good idea to get the cylinder walls sonic tested to make sure the thickness at a water jacket wouldnt get too close and cause an eventual blow out... I would think going 25 over would be the best if the cylinders are in good shape and do need machining...go the smallest you can in case you ever need to do this again the block isnt trashed b/c you cant bore it over any more... Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted August 20, 2007 Author Share Posted August 20, 2007 (edited) A guy said, it's not worth boring the block and said I should just get another block find one that's already rebuilt... I find it hard to call it quits. Like you said, I'll have to take it a reputable shop and get their opinion. Here's #4 piston. You can see where the edge of it hit the ground when it rolled off: [image]http://i2.photobucket.com/albums/y5/cuongnutz/VG33/DSC01372.jpg[/image] There' some pitting in cylinders 4 and 6 but more than i like in number 3. #3: #4: funky wear in #5: I checked with Nissan and it seems they have 0.25 and 0.5 OS rings along with the standard size. I scratched either #4 or #3 bearings and journal. Not too worried about it since I plan on using a new 3.0 crank and bearings....if the cylinders and pistons check out right. I don't have calipers or micrometers to do the measurements so I'll be taking it to a shop, if I can find a reputable one back on the border. I'll need to move onto the heads and check them out. I noticed that the rear passenger side head has a tendency have oil baked on the rocker assembly: Edited August 20, 2007 by Cuong Nguyen Link to comment Share on other sites More sharing options...
unccpathfinder Posted August 20, 2007 Share Posted August 20, 2007 a lot of people say its not worth it to bore the block...it just depends on if you will run the risk of blowing out an oil/water jacket... yea I think you made the right choice by tearing it down completely...do make sure you get a good set of ring expanders and the intaller sleeve(not sure what its called) I would also make sure that the rings are easy to get I have noticed that sometimes you can get 1 with a bad spot and if you go to expand the ring to install it, it will snap in half and if they are hard to get, that means more waiting...if there are some napa's around you should check them out they can usually get anything pertaining to rebuilds...and if you do a good bit of business there you can try to see if they will throw it on 1 of their business accounts to save you some $ (i knew a manager back home and got most things at cost then i got to know the guys in charlotte and they gave me about 10-25 % savings on most things) Link to comment Share on other sites More sharing options...
Casey.T Posted August 20, 2007 Share Posted August 20, 2007 Now that you have it in pieces Have everything hot tanked and cleaned up real good... Thorough inspection of all parts being reused... If your going this far on the block, how far do you want to go on the Heads??? Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted August 20, 2007 Author Share Posted August 20, 2007 (edited) our local club sponsor is Napa back on the border! hehe I"ll have to hit them up. Is it safe to hot tank the heads? Is it bad for aluminum? I don't know anything about hot tanking... I have the stage 1 cams on order and they'll be going into the heads after I have it checked out. I plan on tearing everything down on the heads. I have to find a place that will do a port and polish and valve job. I'm sure my valves need some lapping done with all the crud on it. Things being reused: block, pistons, connecting rods, heads, valve springs and retainers. Everything else is coming off my current motor or brand spanking new parts. that is if the blocks and heads check out. This is my first time doing a full rebuild on an engine. Definitely an experience! Edited August 20, 2007 by Cuong Nguyen Link to comment Share on other sites More sharing options...
SnowSurfLax Posted August 20, 2007 Share Posted August 20, 2007 Honestly, I say get the 91 Q pistons and have that good machine shop you find put the indents for the valve clearance and find a cheap pair of DETT rods and have yourself a merry little VG34! You're already down to the block. Go the extra inch. Put in a new cam and port your heads and you're looking at 240+ hp (give or take) Link to comment Share on other sites More sharing options...
Slick Posted August 20, 2007 Share Posted August 20, 2007 just an FYI if yer gunna keep it stock (or go no more than 2 sizes up on pistons). parts dinosaur quoted me $235 for a complete piston set (rings/bearings included).... Link to comment Share on other sites More sharing options...
Casey.T Posted August 20, 2007 Share Posted August 20, 2007 If your going to completely rebuild the heads(Seals/Guides/Laping/Valves/ P&P) Hot tank em after you strip it down.... If your using them as is, its careful cleaning by hand... Link to comment Share on other sites More sharing options...
jj big shoe Posted August 20, 2007 Share Posted August 20, 2007 I'll need to move onto the heads and check them out. I noticed that the rear passenger side head has a tendency have oil baked on the rocker assembly:Mine had that symptom, must be a VG thing. I'm in the process of porting heads from a 25k JDM motor right now and it's really not too hard, just takes time. Once I disassembled them I cleaned them up with Purple Power degreaser and a parts brush. Get a low plastic tub to set each head in and keep brushing the degreaser on them then hose them off. Worked great even on the carbon deposits on the valves, just let them soak overnight. Those JWT cams are a bit pricey for me, so I'm getting a regrind from Schneider Cams. Maybe its something you would like to look into as well if your block starts eating too much of your cash.Depending on when you need them (and when I get to it) I plan on porting my old heads after the swap and possibly selling them to recoup some of my motor fundage. Prolly won't be done untill October sometime, though. Here's the thread with pics showing my progress so far. Good luck with it. Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted August 30, 2007 Author Share Posted August 30, 2007 Block and heads are at machine shop. They're going to resurface the heads and blocks. The shop doesn't do any performance work on the heads, so I might just attempt the DIY PnP. I'll know more about the cylinders' condition tomorrow when they start working on it. S1 cams came in last week, BTW... Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted September 1, 2007 Author Share Posted September 1, 2007 (edited) Does this look right to yall (those that know about machining/milling/shaving VG heads)? It would seem that the shop took too much off but I don't know how much is too much since I have nothing to use as a reference. Are the combustion chambers suppose to oblong and not symmetrically round? Found some great informative sites as well: http://www.redz31.com/ http://www.z31performance.com/ http://www.vg30et.com/ Edited September 1, 2007 by Cuong Nguyen Link to comment Share on other sites More sharing options...
Casey.T Posted September 1, 2007 Share Posted September 1, 2007 From looking at my heads.... Yes... but that looks like they took off more than the .002... Wheres the dam book... Lots of notes, and warning in the chiltons... Bore alignment on the cam, milling valve seats.... maybe im having some bleed through on the DE stuff.... Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted October 26, 2007 Author Share Posted October 26, 2007 well damn, looks like I'll need a new block... the shop didn't hold up to his words about the rust and pitting in the cylinders..... wasted my time and money... Link to comment Share on other sites More sharing options...
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