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^^ Yup what he said. I did my swap 6mo ago. Found a 70k RL motor J35A8 from a local wrecking yard. They delivered it free to the shop for $650, motor was super clean, mechanic was like the timing belt and tensioner look so new he almost was trying to convince me not to change it out. Also, with the RL motor you get the better cams, and finned oil pan.
Borescope is pretty definitive. Given how generally robust the J35 engine is, I'd love to know how those cylinder walls got scored; unfortunately that is something we'll probably never figure out.
What do you think about theory that cylinder walls were scored by failed precat debris back flowing in to engine?
New plan. Started disassembling engine. Will eventually bring short block to machinist to rebuild. Current plan is to bore 10 over and install new set of Honda +25mm pistons. Machinist mentioned possibility of slight bump in compression. Then back to garage to reassemble, with maybe some intake and exhaust improvements. Thx again. will keep you posted and assume will have more questions in next couple of weeks.
right .25mm. which as I understand is the metric equivalent to 10 over? We are not near the short block yet, but eventually when I bring it over to machinist, the initial plan is bore it 10 over (.25mm?) then fit new +.25mm pistons. Cast pistons from Honda rather than forged pistons costing 3x more?
thx. TL-S engine would have been the easier. And after some more input swapping RL engine would have been easiest, but for various reasons we decided to have an adventure and rebuild
That should never happen unless the timing was all screwed up (which presents its own failure modes).
Still not down to the cylinders yet, but still thinking about possible cause for this scoring in order to try to prevent any repeat problems.
Is it really not possible for any metal shavings from oil pan to make it past the oil filter?
What are you thoughts on water through the CAI causing this? After Hurricaine Matthew was driving 2mph on only road through 2"-3" of standing water without issue. Fire truck approaching at something like 30mph generated a huge bow wake that stalled out my car and another. We pushed cars up a driveway, removed spark plugs, turned over engine, shot water out of couple cylinders. Engine started, drove home, changed oil. Ran great for another 16 months/25K miles until abruptly stopped in Jan.
right .25mm. which as I understand is the metric equivalent to 10 over? We are not near the short block yet, but eventually when I bring it over to machinist, the initial plan is bore it 10 over (.25mm?) then fit new +.25mm pistons. Cast pistons from Honda rather than forged pistons costing 3x more?
I've never dabbled with engine internals but from the info I've read over the years, it's best to purchase your pistons ahead of time & have your machinist do his thing.
As for OEM vs custom, depends on what your goals are with this rebuild.
With that said, might as well get the machinist to bore it out to 90mm & get a J37 rotating assembly...
I've never dabbled with engine internals but from the info I've read over the years, it's best to purchase your pistons ahead of time & have your machinist do his thing.
As for OEM vs custom, depends on what your goals are with this rebuild.
With that said, might as well get the machinist to bore it out to 90mm & get a J37 rotating assembly...
Does it matter which 3.7 rotating assembly? I would assume the 07-10 MDX would be best fit?
I've never dabbled with engine internals but from the info I've read over the years, it's best to purchase your pistons ahead of time & have your machinist do his thing.<br /><br />As for OEM vs custom, depends on what your goals are with this rebuild.<br /><br />With that said, might as well get the machinist to bore it out to 90mm & get a J37 rotating assembly...<br /><br /><br />The main goal is to have a durable engine that will go 200K miles mostly on the highway. The secondary goal is to build in as much power and performance that does not diminish engine endurance.<br /><br />The last time I talked to one of the guys at the machine shop about ordering Pistons now, he said they usually like to wait until they see the short block. The initial findings on cost is $366 for a set of cast Honda +.25mm pistons. Forged Pistons they said would be $1,250.<br /><br />Regarding how much to be bored or can be bored I do not know enough yet. If the J35A8 is 89mm x 93mm with 3mm cast iron sleeve, it seems a prudent option to have cylinders bored 10 over and install OEM +.25mm pistons. But, if it is possible to bore existing sleeves to 90mm and this can add power without reducing durability or substantially increasing cost then that would be intriguing.<br /><br /><br /><br /><br /><br />
Here are 2 pictures of MTylers rear (bank 1) precat. All bank 1 cylinder walls show signs of scoring though cylinder 5 looked to be the worst from the borescope. Funny because cylinder 5 is the straightest shot out or possibly back in of the cylinder head. Also these are the original precats (230k) and were reused after the original engine failure . There had been a p0420 (bank 1 converter efficiency below threshold) but was turned off some time ago with hondata.
The main goal is to have a durable engine that will go 200K miles mostly on the highway. The secondary goal is to build in as much power and performance that does not diminish engine endurance. The last time I talked to one of the guys at the machine shop about ordering Pistons now, he said they usually like to wait until they see the short block. The initial findings on cost is $366 for a set of cast Honda +.25mm pistons. Forged Pistons they said would be $1,250. Regarding how much to be bored or can be bored I do not know enough yet. If the J35A8 is 89mm x 93mm with 3mm cast iron sleeve, it seems a prudent option to have cylinders bored 10 over and install OEM +.25mm pistons. But, if it is possible to bore existing sleeves to 90mm and this can add power without reducing durability or substantially increasing cost then that would be intriguing.
Well that was a mind fuck but I managed to clean it up..
The factory limit for J-series blocks is 90mm. That is the farthest you can go without cracking sleeves.
There's no reason why you can't have reliability and power with the J37 rotating assembly. The only wild card is whoever is doing the machine work/engine assembly.
Doesn't matter. Whichever you can get a better deal on..
Ok i was just checking... I had seen somewhere of someone having fitment issues with a J32a3 block and J37a4 crank.The crank physically wouldn't fit into the block. I didn't know if that would be the case with the J35a8.
teh CL
Thx for fixing that combined monster paragraph post. Make someone crossed eyed trying to read that.
Regarding getting a 3.7 short block, we did talk about that also but moved away from it because of the oil consumption issues with some/many of the aluminum sleeves in the 3.7s.
This Thread Should Be Retitled. WHY YOU SHOULD
SWAP YOUR J35A8 ENGINE NOT REBUILD IT
Heads were taken apart and cam shafts and journals were found to be scored. Hoping cam shafts can be polished. Assuming journals too badly damaged and will need to buy a used rear head. I have front head still from my first J35A8.
Taking short block, heads and cam shafts to machinist to get his assessment and determine if it is still worth it to me to fix or replace this growing list of damaged goods.
Expecting that it will be either too expensive or time consuming or impractical and I will return to the swap option.
I have a couple J35A8s available for good price and with 115k miles and realize that would be the smart option.
However in the pursuit of unnecessarily complicating things, in our local auto salvage yard there are two 2014 base TLs with J35Z6s with ridiculously low mileage. Anyone know of any fitment concerns swapping a J35Z6 into an 08 TL-S 6MT?
I'm certainly no expert, but that damage seems consistent with either low oil, dirty old high mileage oil, or oil starvation due to sludge build up from dirty old high mileage oil. Once the damage is done, there is no turning back. I think you said the engine had 75K on it when you got it (or something like that). Who knows what neglect that motor went through early on?
I'm certainly no expert, but that damage seems consistent with either low oil, dirty old high mileage oil, or oil starvation due to sludge build up from dirty old high mileage oil. Once the damage is done, there is no turning back. I think you said the engine had 75K on it when you got it (or something like that). Who knows what neglect that motor went through early on?
You could be right that there was pre existing damage on the swapped in engine. I never ran it with low or old oil for the 80k miles I put on it.
Definitely hearing more and more instances of Honda engines with cats directly adjacent to the exhaust manifolds failing and causing severe engine damage. Also not an expert on the issue but it seems like it would have been better design to not have these two cats that run so hot located in the engine bay and immediately next to the engine so that if they do fall apart they cannot cause such significant damage.
which as I understand is the metric equivalent to 10 over? We are not near the short block yet, but eventually when I bring it over to machinist, the initial plan is bore it 10 over (.25mm?) then fit new +.25mm pistons. Cast pistons from Honda rather than forged pistons costing 3x more?
