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Building an engine for the Turbocharged Pathfinder


snowboard419
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So as some of you may know I recently purchased a new to me 95 Pathfinder that another member on this forum '2milehi' had installed a turbocharger on. The guy I purchased it from did not do the build but he did manage to blow the motor up. So here I go building an engine to get her back on the road. I was just getting ready to rebuild an engine for my 91 but that is going to take a back burner now.

It is going to be a budget build no forged pistons or anything but as long as I don't screw up the tuning and don't get greedy with the boost :crossedwires: it should be just fine. And to be clear I cannot take any credit whatsoever for the turbo build, that was all 2milehi. And thanks to his excellent build thread I wont be in the dark as to what he did.

http://www.nissanpathfinders.net/forum/topic/29646-adding-a-turbointercooler-to-my-95-pathfinder/

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The block and pistons are at the machine shop getting cleaned bored and honed. Ill fit my rings and adjust end gap when I get it back. I just got the crank back, in good shape except for the harmonic keyway i need to do a small repair. I pulled the best parts out of the 2 engines I have torn down currently residing in my garadge. crank, cams, heads, rods, etc.

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I am doing the headwork myself, they are getting freshly cut valve faces, a fresh 3 angle valve job. I am going to try and install 10mm exhaust studs. And I may do some very minor port work/unshroud the valves, also smooth out any surfaces that could create a hot spot in the combustion chamber.

 

Here is the valve work.

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I'm curious as to how it "blew up". Lots of blow by? Broken connecting rod? These engines have forged internals from the factory as they were designed to be boosted. (originally in the 300zx)

 

It would be worth building a vg33 for it.

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Just had a bunch of parts show up today. New Lifters, Crank and Rod bearings and gasket set. Water pump and timing kit are in the mail. I need to check out the oil pump to see if it can be rebuilt or needs replaced. Now just need to get the block back from the machine shop and I can start going together with the bottom end. :wiggle:

I still need to get some speedi sleeve's for the crank rear main and the camshafts, both cranks i have and both sets of cams all have HUGE grooves worn in the seal surfaces.

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I'm curious as to how it "blew up". Lots of blow by? Broken connecting rod? These engines have forged internals from the factory as they were designed to be boosted. (originally in the 300zx)

 

It would be worth building a vg33 for it.

 

 

The guy I got it from said he was trying to get it unstuck off a rock while wheeling and it let loose and sounded like @!*% when it happened. They towed it down the hill, tried to start it and all they got was some bad noises until it locked up, all I get is a solid CLUNK when I hit the starter. Im thinking low oil + extreme slope+boost+dip@!*% = broken rod or something of the like.

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I had to rebuild my engine a few years back. I would adjust the timing and a few hundred miles down the road it would be way out again. Tearing into it I found that crank shaft keyway was chewed up and it was allowing the crank timing sprocket to slip out of the keyway.

 

I had a mechanic change the timing belt and water pump shortly before that and it was the first time the belt had ever been changed, so I assumed they messed it up.

 

I'm curious if this is a common thing with this or maybe there are a lot of people out there taking channel locks to their Crankshafts.

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I'm curious as to how it "blew up". Lots of blow by? Broken connecting rod? These engines have forged internals from the factory as they were designed to be boosted. (originally in the 300zx)

 

It would be worth building a vg33 for it.

 

the NA vg30's aren't as stout. They can still make some decent power though.

 

 

 

The guy I got it from said he was trying to get it unstuck off a rock while wheeling and it let loose and sounded like @!*% when it happened. They towed it down the hill, tried to start it and all they got was some bad noises until it locked up, all I get is a solid CLUNK when I hit the starter. Im thinking low oil + extreme slope+boost+dip@!*% = broken rod or something of the like.

 

I'm betting the crank girdle broke.

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I had to rebuild my engine a few years back. I would adjust the timing and a few hundred miles down the road it would be way out again. Tearing into it I found that crank shaft keyway was chewed up and it was allowing the crank timing sprocket to slip out of the keyway.

 

I had a mechanic change the timing belt and water pump shortly before that and it was the first time the belt had ever been changed, so I assumed they messed it up.

 

I'm curious if this is a common thing with this or maybe there are a lot of people out there taking channel locks to their Crankshafts.

 

I have not herd of that being an issue but that being said my harmonic ballancer pulley keyway is a little buggered on my crank I am going to have to do something about.

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Alright I got a little more work done on the lower end the last couple of days, I installed the new pistons on the old rods. I fitted the rings to there respective bore, I did have to file the end gap open a touch to get the clearance I was looking for, top ring--.017 second ring .019. also checked the crankshaft main bearing clearance with plasitguage and have run into a small issue. Main clearance is .0011-.0022 with a service limit of .0035. I measured .003?ish. I found a spec sheet that lists different bearing thicknesses from nissan, I dont know if they are even available or not. I also have another crank that may or may not be in better shape. What do you guys think. Run it or find better crank, bearings etc.Any pros/con's. About the only thing that would worry me is maintaining proper oil pressure. :shrug:

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The turbo that is in the pathfinder right now I am almost certain is the ebay unit, no real branding I can see but I have not done any teardown on that one yet. Im going to pull it soon to inspect it and also see whats in the oil/filter to see what may have gone through it and then decide to use it or upgrade.

 

I think I am going to source some undersize bearings just for the peace of mind, Ill check the clearance on the connecting rods before I order so I can get it all at once.

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Yeah in the original build he says he used an ebay turbo, was just curious if that scared someone enough to change it lol. Ebay units are very hit or miss from what I've heard. Like many before me have said, I'm thinking eventually I want to do some sort of turbo build or maybe a VG33E+R if I can get my hands on a cheap donor, just looking to see what people are actually running specifically for parts in these builds. Any idea how many miles were put on that turbo set up before it blew?

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Yeah in the original build he says he used an ebay turbo, was just curious if that scared someone enough to change it lol. Ebay units are very hit or miss from what I've heard. Like many before me have said, I'm thinking eventually I want to do some sort of turbo build or maybe a VG33E+R if I can get my hands on a cheap donor, just looking to see what people are actually running specifically for parts in these builds. Any idea how many miles were put on that turbo set up before it blew?

 

 

He finished the build in 2011 sometime, sold it in 2015 and according to the title the guy he sold it to had about 10k on it. So not really sure about the mileage of the setup. but at least 10-15k .

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You can get undersize bearings. Usually in .001 increments. Most auto parts stores should be able to order a set.

 

Last night I searched the internet high and low for a .001 oversize bearing for the vg30e. Today I called my machine shop, and two other auto parts stores and I cant find them anywhere, they exist for other engines but not ours. If someone knows where to source please let me know.

 

I am going to call nissan tomorrow and see if they still offer different bearings if not I think I will install an oil pressure guage and run it with an oil closer to 15w40 or 15w50

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Try a bearing and drive shop. I have had good luck with McGuire bearing in Tacoma. Alaska Bearing and Drive is good in Anchorage. Those are the only two I have experience with.

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Well I got part #'s from nissan but no parts they are discontinued, so ill search around a bit. Im going to measure my other crank tomorrow and see if its any better but most likely will just go ahead and run it, not sure yet. :scratchhead:

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The crank is installed in the block, I went ahead and used it even though the clearance was a bit on the loose side. Pistons rods and rings are all put together, so far I have 3 out of six pistons installed in the block and hope to get the rest installed later tonight. The rod clearance plastiguaged at .002ish so im happy with that. Today on my lunch break I did a little bit of head work. Some very minor porting, opened up the spark plug drain channels, and also installed 10mm exhaust studs :aok:

 

The 10mm Looks a little better than stock

 

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