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89 Runner Build


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As it stands today the block is at a shop ready to be bored to match a set of oversized pistons in order to get rid of the water marks in cylinders. The pistons are coming as part of a full rebuild kit I ordered just last night from the states for cheaper than the local parts guy could get a gasket kit only. 

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  • 8 months later...

After getting my new parts things really slowed down though. The machine shop I was working with was very slow and I didn’t get my block back until August and the work was subpar at best. So subpar my crank that was in excellent shape was left to rust and had to be reground to match oversize bearings whereas it was bang on factory specs when I pulled it from the motor. The non aluminum parts in the head were even allowed to rust. Long story short after some back and forth I was refunded a large portion of what I paid to have the work done. I picked up a parts engine to scavenge some pieces from and took my heads to a proper shop (Nova Automotive) where the work was done in a very timely manner and done right for a fair price.

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I didn’t bother taking the block to the second shop as it really just needed a good cleaning since it didn’t get hot tanked. I started with wire wheeling all the exterior surfaces. The crank also needed the oil passage ways scrubbed out so I picked up a syphon spray gun and a paint gun cleaner kit to handle this and the inside of the block. I wiped down all the interior surfaces of the block with ATF until the rags wiped clean. It was amazing what came off the surfaces with the ATF even after washing with mineral spirits. 












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The spare motor I bought for parts was also helpful for mocking up my exhaust crossover. From the factory the exhaust ran on the passenger side but since my front axle is a passenger drop and my gas tank is on that side it had to be swapped. I cut up the original crossover to use to build the new one and this is when I confirmed I couldn’t use the transmission that can out of the donor. 3.4Ls have the clutch slave on the driver side because the exhaust runs on the passenger. I thought I could make it clear but there just wasn’t space between my narrow frame rails. Good news is the same transmission came behind the 3.0L engines with a passenger clutch slave and bolts right up to the 3.4L. Luckily a fellow 4runner owner had two he was willing to part with but wanted them both gone so I got a spare in the process. 






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The motor I am “upgrading” to was built in 1998 so I opted to replace many of the “perishables” on it so I wouldn’t go through all the work of the swap and be stopped by a silly piece I should have just replaced. I plan to keep this rig for a long time.


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I plastigauged my crank and oversized bearings to ensure all fit right and it checked out good. Next up was pistons. I tore them all down and installed one new bushing for the wrist pin in one and confirmed they would need to be honed to fit. Took these back to Nova and it was another quick turn around at a fair price. I then proceeded to assemble the pistons, plastic gauged them one at a time as I installed. All bearings got a healthy bit of assembly lube. 








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Next came a bunch of assembly and new parts. Little things like the knock sensor wiring harness, that sits underneath the intake whose plastic clips all broke during tear down, were addressed. A new Aisin oil pump, new timing kit with water pump, new coolant hoses for the oil cooler and the new rear sump oil pan and pickup to clear the solid axle. I also replaced the rubber isolators for the engine since the old ones were delaminated. 











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6 minutes ago, sar4x4 said:

Love this thread.  The garage I use is not mine, so that's my excuse for never doing a job any where near as particular as this!

Good on ya! 

Thank you, it is easier when you can walk away and pick up where you left off days or weeks later!

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With the engine fairly complete I turned my attention back to the exhaust crossover. I replaced the flex as the braid on the outside of the old one had rotted. I was able to make it fairly snug fitting using only the old crossover piping and the new flex. I didn’t fully weld at this point because I wanted to test fit in the engine bay.







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I had reached the point where I couldn’t go much further without fitting a few things in the engine bay so I took my rig, which was fully mobile up until this point, in and pulled the 4 cylinder engine on Dec. 1st. I had also ordered an adapter from advanced adapters to bolt my R150 transmission up to my dual geared t cases. Advance was the only one that offered a coupler that would work without replacing the input to my t case. As per the trend for this swap I couldn’t help but clean things up a bit. I felt like I had scrapped pounds of mud, undercoating and grease off the t cases and transmission by the time I was done. 












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With the 4cyl mounts cut out I dropped the new engine in and bolted up to the transmission which was sitting on a motorcycle jack so it could more forward and back as needed. I located the engine where the exhaust would clear the firewall, where the intake would clear the hood, driveline at the same angle it was and centered between the frame rails. It is common for this swap to have to run a body lift or hood scoop but I planned on making it fit by building my own mounts. Using the old engine mount pads as a template I built some basic mounts that were put in with enough weld to take the weight of the engine to keep fitting things up. 






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One thing I thought I would have a clearance problem with was the alternator. Once the belt was tensioned it was against the steering rag joint. To fix this I shortened the bracket and and bought a shorter belt. The whole driveline had to be moved forward 2” to make everything clear so I also had to modify my transmission crossmember. Instead of making any changes to the frame mounts I just cut the sides off and rewelded them two inches back and things bolted up. Both driveshafts will have to be modified as well so I’ve purchased new tube for the rear and I am working on an appointment with a machinist. 








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1 minute ago, sar4x4 said:

Loooong transmission and transfer-case combination!  Did we discuss this before in the post?  How is it going to work out?


It is almost identical to what I took out in overall length. I had built the crossmember to suit originally and the length with dual t cases is part of the reason why I had to turn my rear pinion up and run a double cardan joint in the rear when I did the lift. 

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I ordered a few more odds and ends to finish things up. Pieces like exhaust heat shields, shifter seat gaskets, shifter boots and a bushing for the transmission as the factory one had turned into crumbs. Moving the driveline 2” forward also meant my shifters didn’t fit the tunnel so I did a little cutting and welding and things fit again. Everything clears and I even get to keep my cupholders!






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  • 4 weeks later...

The charcoal canister/evap system for the new engine is quite a bit bigger than what came out. It also sits on the opposite side of the engine bay, not that there was any more room on the passenger side for it. To make it fit right without interfering with the hood I built a recess into the fender well. I also had to move my fuel return and vapor line on the firewall as they were dangerously close to the exhaust crossover. While bending the lines the vapor line broke with minimal force. I found the line blocked by debris. This explains why my tank built pressure/vacuum when the gas cap was tight! I put a union in and ran the vapor line to the driver side to hook up to the evap box. 




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