Black_1985_SR5

iTrader: (1)

exhaust wont help all that much 2.5 inch can support 500hp

JPL

It sure helped plus being at 7K feet elevation makes is makes it hard for my little rig to breath. I don't plan on pumping out 500hp but I'd be happy with 200hp.

I'm also going to regear it to help pull a light trailer with a 400 lb motorcycle. If I can pull up hill without losing serious momentum I'll be happy.

JPL

Everything is still doing great after 6K miles and I'm planning a trip to the Southern California coast end of May.

I had a quiet muffler installed and it sounds much better to me (quiet!). I did have an exhaust leak and found that one of the exhaust studs came out of the head but it's at the shop now getting taken care of.

The engine is holding up and seems to have no issues. Still waiting on my core $$ but it looks like I'm getting the runaround... I just hope this isn't the issue if/when I start having engine issues. Oh well, all I care about is having a reliable engine.

I really want to regear and was told that the tacoma e-locker diffs are the way to go. I'll need to do more research on that for what years work and if I need the axles too.

Before my Cali trip I plan on having the windsheild replaced and all windows tinted so I can enjoy my Air Conditioning.

JPL

The ticking noise couldn't be fixed so I started a thread on it. Here: https://www.yotatech.com/forums/f120...ystery-252808/

JPL

Update December 2012: A lot has happened since my last "build" thread update. I have sence replaced the built engine due to poor machining and had my local machine shop start over on a new block.

The KB pistons were still good so we used them along with new rings and bearings.

Today the 4runner is running great with only 10 miles on the new engine. Compression test at 6 miles show:
#1: 149psi (at 6,400 feet or 180psi at sea level)
#2: 151psi (at 6,400 feet or 182psi at sea level)
#3: 140psi (at 6,400 feet or 169psi at sea level)
#4: 139psi (at 6,400 feet or 168psi at sea level)
{engine has 9.7:1 KB pistons and 272 degree cam}

I plan on having it tuned in the near future. Already had valves re-adjusted at 5 miles. Also plan on re-torquing the head and re-re-adjusting the valves after my Colorado trip in two weeks.

The Vehicle ODO shows 267,590 miles.. I plan on seeing all 9's.

More upgrades to follow:
Tint windows.
front and rear lockers.
gear change to slightly lower range for 32's.
Stereo system.
Rock crawler bumpers, step rails, and skid plate.
2-3" lift.
Fender flairs to cover 1" of tire extending past body on front and back.

It's so nice to have my rig back on the road.

Thanks to Yotatech helping me on the way. Here are a few pictures of my build:

JPL

UPDATE 12-27-2012: After putting 2K miles on the new rebuild this happened...


Needless to say I no longer trust Keith Black pistons. I suspected that carbon got sucked into cylinder #4 and did this but there is a strong possibility that the piston came apart under pressure. See link for issue details: https://www.yotatech.com/forums/f120...ooting-263069/

Edit: The cause was likely pre-detonation due to a combonation of factors: Ignition timing was off, KB pistons are strong yet brittle, and pre-detonation is more noticable and more likely to cause damage at lower elevation.

mYnAmEiSmUd

Sorry to hear man. I cant see pic but i fear for the worst...

I believe i am in the same boat. Maybe our shared misfortune can offer solace... =D

My motor has yet to completely grenade but the oil consumption is absurd enough to figure it out. Going to leakdown test to verify head is in good shape.

CitrusTheDragon

Have you contacted the manufacturer to find out if they will warranty the piston? Those Zuk guys seem pretty solid behind what they sell

JPL

UPDATE 1-19-2013:

The new engine is installed now (rebuild #3) and running good. This time I went with stock pistons at .040" over and it seems to have just as much or possibly more power than the KB pistons.

I managed to get everything done in just 2 weeks (removed old engine, have it machined, and installed). I did run into a few minor set backs such as: Coolant leak from coolant pipe under lower plenum (took 3 tries to get it right because the propler gasket wasn't included in my kit). Then a fuel leak from the injectors, since I had to remove all the injectors I took the time to clean them and install new seals and O-rings (I took the upper plenum off 3 times before doing it right. I think injector #3 was leaking from the body, I replaced it and no more leak).

One issue I overlooked was a surging idle after the engine warms up. It was doing this a week before the piston came apart but I forgot to address the issue while I had everything taken apart. I did research today and found that I might have a bad (clogged) Idle Air Control Valve.. The engine would idle high at ~2K RPM and drop 500 RPM every couple seconds, when I press the brakes the idle would drop to ~1K RPM and surge faster.

I plan on putting some miles on the 4runner tomorrow before going on any trips. Here are a few pictures and videos of my progress. >>>









Turn down your volume. >>>

sc87yota

WOW, so sorry about all your engine troubles. These engines seem to have a mind of their own some times, hope you dial it in soon!

JPL

Just got the 4runner back from the shop where they did 3 hours worth of work. They adjusted the idle, ignition timing, and valves.. They also inspected all my work (all good except the three items that needed to be adjusted). The check engine light was on so they pulled the codes and found codes for the O2 sensor, EGR valve, and starter signal.. all these codes were cleared and they didn't see a need to replace anything.

So it runs a little better now, it idles at 1K RPM and not 1,500 RPM. It doesn't surge at idle anymore so I'm guessing he cleared out the Idle Air Control Valve, I have yet to ask him exactly how he fixed it. To me it seems well worth the $280.00 in labor for a smoother running engine and peace of mind. By the way the work was done at a new shop that is well known for their Diesel truck work but the owner actually use to work for the Toyota Dealership. I'm glad I stopped going to my old mechanic.

For now I'm happy with my rig how it is.. but in the near future I hope to change my front and rear differential from 4.10 gearing to 4.88 with lockers. I think I'll stick with the IFS since I don't plan on doing any serious wheeling but I'd like something that can roll through the mud and snow with ease.

This is how she sits. >

gillesdetrail

iTrader: (1)

Wow you have been having many problems it's crazy!
I think that with a bigger cam and higher compression tuning is the most important for reliability, performance and MPG. With all that bigger airflow and compression the original EFI can't accurately adjust timing and airfuel for everything to work together efficiently.

Now it seems better because you went back to original pistons, KB pistons might be crap but with higher compression reliability comes down to tuning, and I'm sure a lot of problems people have had with them were because of detonation and lean mixture. Proper break-in is also very important for ring seal, but you don't seem to have a problem with that. Good luck with the 3rd motor!

JPL

I'm sure not having it tuned properly was the main cause of Rebuid #2 (last engine) going bad and damaging the KB piston.
As for the first rebuild it was gutless because the block was overbored (larger than they should have been for the KB pistons that were installed) from the beginning. So I actually only made one mistake and that was not getting it properly tuned on my first rebuild (engine #2), the first engine was pure bad luck and laziness on the builders behalf.. He should have double checked his machine shops work and made a few quick measurements.. That would have saved me half a year of being down a vehicle and roughly $5,000.00 dollars.

I can just dream about all the stuff I could have done to my rig for that much $$... I could have done my gearing and lockers, maybe get a winch, front and rear cusom bumpers, tinted windows, SAS, 3" lift, intake kit, etc. Wow! amazing the difference a couple minutes makes... just a couple minutes to measure the bore of the block and pistons... The time it would take to have the timing set properly on the second engine. That's why I say that the 3 hours of labor I just paid was well worth it.

This whole process has been quite a learning experience for me.. a $5K learning experience to be exact. Serously I have gained much more from this time and money than most people will gain in years of lessons. I have learned to slow down, be patient, do things in order, what to do, what not to do, how to disassemble my entire engine and put it back together myself, spending $5.00 on a cluch alignment tool is well worth the money, taking the extra time and money to clean parts (i.e. injectors), torquing everything, checking everything 3 times, etc. I wish this didn't happen to me in the first place but looking back it was a lesson money couldn't buy. I delt with friends and family telling me to give up. I had regret to the point of wanting to call it a total loss and start with a whole new truck. My inital goal was to build up a junker and that is exactly what I did and am still doing. So for all you naysayers.. I don't regret making the decisions I have made over the past year and a half since I purchased my 4runner.