Disclaimer: This is based on fact and this thread was not created as defamation or slander toward the builder or Keith Black brand.





1991 Toyota 4Runner 22RE (rebuilt engine with Keith Black pistons and only 5K miles).



My story: The end of November 2011 I purchased and had installed a new rebuilt engine with Keith Black pistons from a builder who will not be named. After the purchase and install of this engine I was informed on this forum that Keith Black has a poor repution due to piston/ring failure.



The engine has been though the proper "break in" procedures using the recommended oil, RPM varried at first 2K miles, not exceding 4.5K RPM for the first 1.2K miles, valve adjustment after 3 or 4K miles, and changing oil with oil filter every 2-3K miles.



I have noticed a loss in power from the beginning but didn't think much of it due to being at 7K feet elevation, having the stock intake and exhaust system. I noticed more loss of power over time. I then decided to replace the exhaust system and upgrade to a LCE header hoping for some power gain. I suspected a problem after the exhaust system was installed and I could hear a ticking noise between 2-3.5K PRM. I checked the compression and found each cylinder between 130psi up to 145psi. I called the builder to ask about the noise and power loss, he mentioned that it's most likely an exhaust leak. I also asked for the specs on the engine including cylinder compression.. he mentioned that anything under 160psi is questionable and likely bad. I then decided to bring it to the shop where they said I had compression leaking past the rings, they found air rushing out of the oil cap (with cap open) when checking each cylinder.



I emailed the builder with the shops results and he replied saying that he can check and inspect the engine for free and possibly rebuild the engine for free. Since the core return I have been inquiring about my core fee hoping to be refunded my $250.. after multiple emails and excuses I have given up. I'm told he's way too busy to check the core, then I was told the check would be mailed out, and last told that the check would be re-sent.. the last core fee email well over a month ago so I just gave up on getting my money. I doubt he'd have the time to check my engine let alone have the time to rebuild it.



My question: What should I do? Can I replace the KB pistons with stock 22RE pistons?



I plan on keeping the 4runner and fixing the failed engine. I don't want to pay the shop to remove the engine again and install another possible bad rebuilt engine with parts that can easily fail.. I plan on removing the engine myself and possibly rebuilding or replacing the failed engine.



Also, you don't have to say "I told you so" because I purchased this rebuilt engine before knowing about KB piston history of piston/ring failure.



I plan on updating this thread with more information as it comes and pictures of my findings. This is a NON-biased thread.. I'm not bashing the product or builder. This is simply a public service to advise people of the potential dangers in buying a rebuilt engine.

 

Might I suggest that when you do the rebuild, look into Probe Performance Pistons, and sorry about your luck with KB.
http://www.probeindustries.com/Probe...stons_s/20.htm

 

I've heard of people having problems with KB pistons. Alot of the problems coming from "rebuilt" motors they bought from someone. I'm going to be putting together a motor for a circle track racing application in the next few weeks. I'll be using KB pistons (I'm assuming were talking about their "9.7:1 hyperueutectic") with the head milled as much as mine is and depending on the head gasket I use and the piston deck height my motor will be between 10.5:1 and 11:1 compression. I'll keep you posted on the result as well as my build techniques. I really feel these pistons (rings) get a bad rap because of careless engine building practices. BUT I have never used these pistons and rings before, so I may end up back on this thread wishing I had never bought them. Like I said I'll keep you posted. Sorry about your luck.

 

Another thing: you might just be able to replace the rings with stock replacements. I dont have the KB rings or stock rings in front of me to measure the widths but they are the same height. You'll also have to set the ring gap to KB specs if you do. Pistons dont cause oil loss or blowby (unless they have holes in the tops of them). Just a low cost idea, as long as your cyl walls look good.

 

Thanks for the info.. I'll look into this when it comes time to rebuild.

Same pistons. I'm not saying that these pistons are crap.. it's still under investigation but if I had to do it all over again I would probably spend a little more and go with forged pistons.. or even stock. I'll be looking for your build and progress.. good luck.

The builder stated that he used high quality Japanese piston rings. At this point I can't blame the engine fail on the pistons, rings, or builder.

Also I found this: http://www.kb-silvolite.com/article....n=read&A_id=32
I plan on making sure everything is within spec.

 

I was waiting on this one…

Well here is what my builder told me about the KB pistons. They use a moly plating on the Piston rings, which is fine to use. The problem is, that is a very hard metal and a special process is needed to get those to seal. A builder should apply a torque plate to the block to replicate the twisting that happens when a head is torqued to the block. He didn't tell me what type of finish is required (micro or coarse), but it should be noted in the specs on the pistons. Then you hone the cylinders with this torque plate on and that will give a perfectly round and straight starting point.

Sorry to hear about your troubles. If I was you, do what I did. Find a block that does not need boring out, just a hone to bring it back to square. Then get OEM Pistons, Rings, and Bearings etc. and rebuild like the factory did 20 years ago. Toyota does not sell larger pistons and bearings, just OEM spec units. Mine 22re has been trouble free and great power wise. But everything is factory again, with the exception of an early 22r steel backed timing guide, I think for a 1982 22r. But even that is OEM.

Edit:

Is the engine still running? What I gather is the engine is still running, you just have low compression. Have you done a leak down test to see if it is really your pistons? Bad compression could also be a bad head gasket. Do a leak down to be sure it's your rings before you get drastic.

 

The engine is still running fine except for the lack of power and slight ticking (exhaust leak type) noise at mid range. The shop did a leak down test and found the air coming out of the oil fill cap (with cap removed). I'm guessing the pistons are still okay and I just need to re-hone the cylinder walls and replace the piston rings. I'm curious to see what's causing this. I would like to go to OEM pistons and rings..

 

Update: Since my last post I have removed the engine and had both the pistons and block inspected by a machine shop as well as the pistons inspected by the builder and manufacture.

The block was found to be machined correctly and the pistons were within tolerance...
Conclusion: The block was machined for the standard KB piston size and the pistons were not the standard piston size eventhough they were within tolerance. In other words the pistons and piston wall clearance/difference should be between 0.0015" to 0.0020"... mine were 0.0040" to 0.0050". Thus causing the pistons to have more of a gap than acceptable. (the guys at the machine shop said with that much of a difference I should have been able to hear a tapping noise from the engine... so that explains the noise I was hearing.. "exhaust/valve noise").

I just got the engine back from the machine shop (whole new block with same KB pistons) and I'm waiting for a copy of each measurment to show the builder and see how he plans on compensating me for the small mistake that turned into a long, expensive headache. I might need to ship out the block to the builder but I really don't want to pay shipping for something that might become a total loss. I will update this thread on the outcome of the new rebuild and more.

 

Don't give up. That's what they want. If you paid by credit card, use the emails as evidence for the charge back.

 

first off check ur cam timing the nosie maybe a bad tentisoner or a halfway broken chain rail. me and my dad have used kb piston in dozens of builds without problems like the guy befor said the builders that have issues dont torque plate there blocks. u can just go to rock auto and get a set of ring and stick them on ur kb pistons if thats what u know is the problem but check those things first. also when u got the new engine did they start with a new head or did they rebuild a oem head? is ur valve adjustment staying true?

 

I paid with my debit card almost exactly a year ago.. I doubt I can dispute the charges at this point especially when I'm still using some of the parts from the rebuilt engine. I don't plan on simply letting it go. I deserve more than a sorry from the builder.

The noise ended up being the pistons hitting the side walls due to a slight over-bore with my KB pistons. The pistons are still good and I ended up using them in my other "new" short block. I have all new rings, gaskets, and bearings. The tensioiner is new but I'll keep that in mind if I get another stange noise from the engine. The head was new so I'm re-using that as well.. it has a slightly larger cam for the higher compression KB pistons. The valves were adjusted twice before removing the engine and they didn't change much but did need slight adjustments.
Also, I got an adjustable cam gear.. I plan on messing with the timing later. This weekend I hope to have the new rebuilt engine back in the 4Runner.

 

If you have an adjustable timing gear and the head has been milled or if the block has been decked use a degree wheel and a dial indicator to position the intake centerline at the proper crankshaft degree. Ex) if the cam has an intake centerline of 110° the maximum intake valve lift should be at 110° ATDC. Tune for your driving from there. Advance will help bottom end, retard will help top end. Too much advance Or retard and it is possible to run into piston-valve clearance issues but I doubt that will be a problem. If you install it set at 0 and the head our block have had material removed it will most likely be retarded a couple degrees. Head gasket thickness will also affect cam timing. Or just play around with it until you find something you like.

 

if u havent put the head back on id have it shaved down to the markers lol have it make 10:1 or 10:5 22rs scream at that compression. what cam did u put in ur engine. and btw kb dont make more compression if u cc them there same a stock but they seem to hlep the motors run better. and ya i didnt see u had posted about the piston slap til later

 

^^^ adjustable cam sprockets are to DEGREE the cam.
that is to find true tdc with a piston stop,
and adjust the cam timing precisely.

this makes the cam timing exact instead of "within tolerances" like assembly line engines.

it will make more of a difference when you mill the head or deck the cylinder.

 

@ celica, i used to have a 85 celica GT.
great car, bought for 12 trans for 3, sold it for 25... a couple years later.
blew off a 5.0 on the mountain roads (corners NOT HP) lol...