Greetings comrades. It's the Russian guy with the Honda Inspire. I very recently blew my J35 a second time, and my search for the answer as to why this could've happened has brought me back to this forum after such a long time. My engine is a J35 block with J35A1 rods and crank, J32A2 pistons, heads and cams, and the first time around it suffered catastrophic failure in October of 2022, after it lasted for about 40 thousand kilometers. The assumptions were that it could've been caused by my lightweight crankshaft pulley, or by detonation inside the engine. After the engine was rebuilt I fitted a stock pulley to it, and a new knock sensor. Fast forward to April of 2024, 10 thousand kilometers later - I was doing a hard third gear pull, and at the top of third gear I could hear a knock coming from inside the engine.
My engine builder insists (and he wasn't the only one) that this was caused by low oil pressure due to the oil overheating. I highly doubt it. Yes, I was really going for it that evening, but - temperature outside was around freezing. I've done plenty of highway driving with frequent VTEC activation in much hotter conditions, with no issues, but for some reason both times the engine went when it was fairly cold outside. Also prior to that hard pull I was driving fairly conservatively for about five minutes, I'd imagine the oil is not the issue. I'm more inclined to think that the engine was either improperly assembled, or the old 3.5 units weren't built to be wrung out like a J32A2. I used to scratch my head wondering why in third gear in automatic mode the gearbox would short shift, as in go into fourth at about 160 km/h, when in manual mode you can go all the way to 180 in third. Now I'm thinking that Honda might've built that in for protection, because some component of the powertrain does not like the combination of third gear, VTEC and engine speed close to the rev limiter.
Anyway, nothing like this has ever happened to me throughout the numerous years I was running a J32A2 (I had one in my Honda Prelude for 150 thousand kilometers, and a different unit in my Inspire for another 120-130 thousand k's). I used to rev the balls off of those engines, thankfully they never let me down quite as spectacularly as this built 3.5. As I have no idea why this would've happened - I'm reluctant to go down the 3.5 liter route once again, as that might lead to catastrophic failure for the third time, so in the meantime I'll be swapping a J32A2 back in (turns out it's not even much slower than the 3.5, it's literally tenths of a second from 120 to 180 km/h, at least that's the difference I saw when comparing my own acceleration videos).
My question to anyone who cared to read this far into my post would be the one I used to headline it - is the J35A1 crank any weaker than the one used in the J35A3/4? I suspect it might be. The engine itself was used in the Honda Lagreat (that's the Japanese version of the Odyssey), while the A3/A4 was used, well, everybody on this forum knows where they were used. The part numbers are definitely different, but I don't know whether there's an actual difference in durability or anything like that. Thanks.

 

Another forum member and I did some research on early j35s a few months back trying to find more information on the j35a2. From what I recall the j35a1 came in the U.S spec oddyssey and pilot. Hondapartsnow shows the part number as 13310PGKA00. Cross referencing acurapartswarehouse the j35a3 crank as found in the 01-02 mdx is the same part number.

As someone who has tuned fuel and ign maps from datalogs of j35 and j36 stroker motors, I can tell you that knocking often occurs when running lean. This is especially prevalent in vtec on wide open throttle. Reason being on W.O.T. the ecu runs in open loop and also disables the EGR. Meaning the computer runs off the default stored fuel settings, without closed loop o2 feedback, while also not feeding any exhaust into the cylinders as when cruising. Thus, unless you have an tunable aftermarket fuel computer, or bigger injectors the ecu is spraying whatever the factory specified for a 3.2, not.3.5.

Out of curiousity why do you suspect the crank, and what exactly shows damage on your engine?

 

Just to be clear - by knock I don't mean pinging, like in a detonation situation. I mean the sort of knock you get when you spin a bearing, which doesn't go away after it appears. I'll go ahead and post a video link, no need to watch the whole thing, just from about 0:31 -
After the first time my engine failed I had the crank examined at a specialized shop (with a defectoscope, I don't know if that's a word in English), they found microscopic cracks in it. It's not exactly clear the sequence of events - whether the crank was contorted under heavy load and crushed the bearing, or the bearing was the first to let go with the crank following (as a result of there being play between the journal and the bearings). I suspect it was the former, as the journals in the middle of the crank were the ones to suffer damage, which is consistent with the crank getting bent out of shape. I suspect the it'll be the same picture this time as well. I'll have the crank examined once I fit the new motor and pull this one apart, but I have a feeling that this will be a repeat of the first situation.

 

I think that very same forum member sent me a DM asking what I know about the J35A2 (because he had reason to suspect it might me Russia specific). I was just as puzzled as he was.
And you know what, I just thought about it - after the first engine failure back in 2022 I had to replace the crankshaft, and the one we fitted was actually for an MDX, not a Lagreat, so this whole topic is sort of moot now. The reason for the engine failing probably wasn't due to the crankshaft itself. That leaves improper assembly, or bad bearings, maybe. Has there been anybody on this forum who has had these problems? Say, someone who swapped in a J35A3 and fitted it with J32A2 cams?

 

Thanks for clarifying the knocking noise and posting a video. It definitely sounds like a bad bearing or a motor with no oil.

When you had j35 crankshaft installed, what bearings where used? Did the engine builder match up the letters on the crankshaft and engine block to find the proper honda bearing halves as illustrated below?

 

The bearings used were made by a company called "King", as for whether the bearings were matched according to the illustration - I honestly have no idea. I'd like to think they know what they're doing, the guy has been running an engine just like mine in a Honda S2000 for quite a number of years now.

 

Not that I am aware of or at least have come accross in the many 2G CL/TL j35 conversions on this site. Although, this may be due to most people opting to swap the whole engine block as an assembly (not just the crankshaft) then installing j32 heads or cams.

I myself installed a j35a8 crank in a factory new j32a2 block and had no similar issues revving to 7200rpm repeatedly. Although, to be fair I opted not use OEM honda/acura bearings or connecting rods.

 

King is good. I use their XP line of bearings (i.e. MB4508XP)


However, unlike factory bearings which come in different thicknesses, aftermarket bearings are produced as one size. So, you may end up with uneven clearances from one journal to the next. Which I am starting to suspect as the culprit in your situation. A wobble in the crank, compounded by high load, high rpm.

 

I think the ones in my motor are of some regular series, not a special line (XP is like a heavy duty variant, correct?). As for the uneven clearances - honestly this is something I'm not aware of, and while going over your replies I still can't quite wrap my head around the whole thing, but I'll try to process it. But on the surface it does seem to make a lot of sense. My builder says his S2000 has been running the same engine and on King bearings for years upon years upon years, but there is a caveat - his crankshaft has been reground. In that case I'd imagine it would be much easier to get the journals and the bearings to match, when you're machining your crank.
BTW I forgot to mention that the King bearings were only used in the current iteration of my motor that recently failed. Before that, prior to the previous failure that happened 1.5 years ago - I was running the bearings that the engine came with. I bought a fully assembled junkyard J35A1 for the rods and the crank, the engine came apart. The rods were disconnected from the crank, my builder told me that the old bearings look really good, that we should reuse them, and so they were reused and the engine was put back together using the bearings that were already in there. I suspect that this might be something you wouldn't want to do. Even so, that engine did last way longer the first time than after the second repair.

 

Yes, the XP line is intended for racing applications. There are a lot of proprietary features highlighted in their website and on youtube. However, the XP line essentially uses better quality materials and larger oil grooves and drain passages in comparison to standard bearings.

https://www.kingbearings.com/products/racing/

 

Alright, well, hopefully we can get to the bottom of my issue. Thanks for the input!

 

^
Hello InspireJ32A, good to see you back here on the forums, although, not quite under the engine circumstances that you currently present.
Good Luck with the J32 rebuild efforts.
P.S. I was hoping @619rcr would pop in & contribute with his vast knowledge on these engines.

 

Hello zeta! It's nice to see you too. It's been a while, yeah. I don't even post on Drive2 all that much anymore, as I haven't been driving my car a lot lately.
The engine failure is unfortunate, but it has happened before, I'll soon be on my fourth engine, and my sixth transmission, so these situations are sort of par for the course and don't really upset me all that much
The only thing I was worried about was making it home once the engine started knocking, but I did, the car drove for another 30 kilometers, the noise wasn't even getting any worse.