H22A_CD5

iTrader: (3)

Bit of a wild hair at the beginning of COVID led me to rebuild my J35A8. The original intent was to toss a J37A4 rotating assembly in and call it a day, but after getting the new short block pulled apart and inspected I just decided to use it whole. Gonna just do a giant dump of info and why I chose the stuff I did incase it helps someone down the road. I pieced and parted info from here and v6p, but had to just hit the I believe button on several things I just couldn't find any confirmed info on. Need to convert the pictures over to embed more, but I'll attach a couple to start.

• The J37A4 shortblock mated up to the 07 Type S manual trans bell housing no problem.
• Factory clutch and release bearing worked, FX250 for the 07 TLS application worked,
• J35A8 oil pump worked on the J37A4 shortblock,
• Didn't have any oiling issues between the J37A4 block and J35A8 heads (the head oil orifices in the block were the same size in both blocks)
• J35A8 crank triggering sensor and wheel works just fine on the J37A8 shortblock with some caveats explained below
• Using the J35 crank trigger and wheel, was able to tune on 07 TLS Flashpro without any issues.

My J35A8 came out with 248k on it, but ran and drove basically fine, Still kept up with my and a buddy's decently modded s2000s, so it wasn't down on power, though it consumed a little too much oil for my liking, per oil change. I tend to engine brake a lot, so that was probably a contributing factor, but either way a refresh wouldn't have hurt it. It had a ton of carbon/oil buildup in the intake runners of the head. When I originally bought the car, it had 114k on it and there was evidence it was abused, not super well kept, or both. Had some pretty heavy, visible varnishing under the valve covers when I adjusted the valves initially, the clutch was toast, and every single wheel was curbed to hell and back. It had a couple mods on the car: tein s-tech lowering springs and a RV6 longtube J-Pipe and there was a junkyard stock intake where an aftermarket intake was replaced. All of that to say, I've put >130k on this engine with it starting out under questionable circumstances, so even if the engine was still relatively healthy, it doesn't really hurt my feelings to go through and give it a good refresh.

in 2016 with 146k on the odo it dyno'd 252/221 on a mustang locally, at about 2,130ft of elevation where I live. (video says J-pipe was stock, but it did have the RV6 Longtube J Pipe with stock precats)

You Tube

Picked up a J37A4 longblock complete with IM and TB, 155k miles on it from an Auto flood car from TX. Wasn't flooded bad at all though, water level barely got into the car and wasn't even above the oil pan, so no engine damage at all. The salvage yard I used specializes in Hondas and does a great job of checking stuff over and making sure advertised condition is accurate.

After tearing down the engine I found it to be in spectacular condition. No varnishing, bearings looked perfect, could have convinced me it was a <50k mile engine had I not laid eyes on it still in the car. Even the oil drains in the block were still clean and not varnished. This engine seems to have been extremely well kept. After seeing how good of condition it was in and after realizing the J37A4 had FRM sleeves I just decided to go ahead and use the entire J37 shortblock, rather than putting the J37 rotating assembly in my J35. I am pretty sure the pistons are compatible with both iron and FRM sleeves, but I keeping the block with fewer miles and in excellent condition seemed like a safer bet either way.

I don't remember exactly where or whether it was here or on the other site, but I found a thread claiming flow bench numbers for the heads from both engines and the J35A8 heads actually flowed a little better. This makes sense as the J37A4 seems to be much more optimized for midrange power and torque to get that big body UA8 moving. I also did a bunch of comparing dyno charts to see what torque plots looked like on the engines and the J35A8 generally torque peaked about 4-500 rpms later. I didn't intend to rev the engine lower than the J35A8, so I decided to keep the J35 heads. Started out porting the manifold, runners, and my J35 heads. I kinda hogged out the manifold but went super conservative on the heads.

In progress porting on the J37 mani

Very mild porting in the heads.

Main and rod bearings looked basically new. I was pretty blown away at how little wear they had.

Reassembled with the basic refresh/rebuild stuff. OEM Rings, bearings, seals, gaskets, water pump, new J35A8 oil pump (didn't take the chance on the old one being still good or the J37 one, since that engine has a lower rev limit). All the replaced shortblock stuff was replaced with OEM J37 stuff except the oil pump and all the head stuff I replaced with OEM J35 stuff. This is where all the heartache happens. Lots of shipping delays due to COVID parts availability and had several backordered bearings that still had to be reordered again from arriving damaged. All in all it took about six months to get everything ordered and the engine reassembled after getting it torn down and inspected. Really wanted it to be more in the lines of 2 months, but is what it is. Couple key differences I ran into: The J35A8 and the J37A4 use different crank triggering. Since I'm tuning on flashpro, I needed to retain the J35 crank sensor and timing gear trigger wheel. The J37 has an in crank wheel where the crank sensor is in the oil pan. I left the J37 trigger wheel on the crank for balance reasons, but I swapped back to the J35 oil pan and retained all the J35 trigger hardware. I used the J37 timing covers since they were cleaner, but I had to notch the J37 lower cover to have room for the crank sensor wire to come through where it did on the J35. There was not an accommodation for it on the block since it didn't run there on the J37. Not a huge deal, but something to keep in mind.


Going together for final assembly. (Pictured with the J35 crank pulley, but the J37 was used once buttoned up)

Had a big ordeal around trans stuff. The clutch that was in the car is a Luk/OEM with an Aasco single mass flywheel that has been in since about 150k and for about the last 20k it's been grabbing fine, but it was binding real bad at high rpm and had some noise when the clutch was disengaged. I'd previously changed out the clutch master and slave, so at this point I'd assumed the clutch was bad and the noise was release bearing related. After getting it out and taking a look at it there looked like the release bearing may have been binding a little bit so I cleaned it up, threw in a new release bearing, and crossed my fingers on the clutch. Long story short, pressure plate was bad and it had to come back out for a clutchmasters FX250. Put that in but kept the recently new OEM release bearing since it only had a couple thousand miles on it and had to pull it all again since the clutchmasters kit had an extended release bearing. After all that, the noise wasn't clutch related, it's a bearing. I think it's on the countershaft though. No play on the input shaft and it's a lot louder on decel than accel. Oh well, what's just pulling the trans again lol.

In summary:
J37A4 bottom end, refreshed
J35A8 heads ported myself
J37A4 Intake mani and TB, ported myself
RV6 Cat Deletes and longtube midpipe
Clutch masters FX250 clutch
Aasco lightweight single mass flywheel
ATLP 2.5” exhaust
AFE Takeda short ram intake
Hondata Flashpro, tuned myself

Dyno map is in the attachments and I'll have a video uploaded soon.

Tuning was a bit of a challenge. It was pretty warm that day and I was using a new dyno I'd never used before. It was in a much smaller space than I'd seen in the past and was a 2wd dyno optimized for a bunch of RWD LS boys. So my car was about 6 feet off the wall with not enough fan. I struggled super hard with heatsoak on all the highcam pulls. Was able to get a ton of low cam pulls in without too much trouble. So I was able to get the low cam dialed about as good as I think it's going to be and made around 260/270 on the low cam. However, when I started making high cam pulls, even with 3 bags of ice and all the fans I could muster, I would only get a single decent pull after cooling the car for a half hour and making a second pull would be 20hp down and only got worse from there. All in all, I just left the high cam basically where it was roughed in at on the street since it wasn't having any problems there. My hope is that I can get it retuned in cooler weather down at sea level at a buddy's shop this fall. I'm pretty confident in better conditions and a little bit more work on the high cam tune and it'll find some better pull on the big end.

300/278 - 84F ambient with about 30% humidity, at ~2,130ft of elevation.

You Tube

The torque this motor has now is absolutely righteous. It legitimately pulls up hills in the mountains in sixth now, like it did on flat ground before. Highway driving and city driving is effortless with this kind of torque. The car has been getting around 25mpg tuned a bit on the rich side. I've got a renewed love for this car again and am really looking forward to doing some more tuning on the high cam at some point. Hope all this helps someone. Let me know if you've got any questions about anything.

truonghthe

Nice write up, the only thing that make me hesitant about this swap is that some 3.7 notorious for the oil burning issue. I drove couple SH-AWD TL back then and yes the torque came earlier and stronger than J35A8 despite being AWD.

Acura TL Builder

Great work!

H22A_CD5

iTrader: (3)

I'm always hesitant to blindly accept folks complaints of oil burning being a common thing on engines. So much of that is PCV or emissions stuff functioning as intended and people misdiagnose as a real problem. Not aiming that at you, I'm just a little skeptical. Can you point me in the right direction to some info on that being a systemic issue? I'm always happy to learn.
Thanks. Was bummed it took so long to come full circle, but it definitely feels worth it now.

Acura TL Builder

I have a J37 in my 2012 MDX. It burns a quart every 1200 miles. But there isn’t any smell ect. Kind of odd.

Acura has said this is ‘normal’.


Why Do Acura Engines Use an Excessive Amount of Oil?

https://www.carproblemzoo.com/acura/...l-problems.php

https://forums.edmunds.com/discussio...dx-burning-oil

https://www.700r4transmissionhq.com/...x-burning-oil/

https://mechanics.stackexchange.com/...ong-can-it-run

csmeance

ALL THE MDX'S 2010-2013 having engine replacements/rebuilds done and same with 09-14 TL and some years of RL; if acura is dishing out thousands of dollars vs a PCV then they must know better than us!

There's J37 with iron liners and then there's one with the AluSil (aluminium silicon) liners that have the oil burning issues. The issue isn't the liner, but the piston rings getting clogged with carbon and eventually scoring the block (if left bad enough), lots of oil consumption (more than a quart every 1K miles) is the first sign the carbon is building up. From there it'll only get worse. Some folks here have posted pics of the failed cams due to lack of lubrication from so much oil being burnt off.

2 solutions:
1. New pistons and rings if the block is in good shape
2. Use heavy cleaners to try to dissolve the carbon. Folks have had results with DMSO, BG engine cleaner service and other products but do use with caution!

Euro-R_Spec_TSX

All versions of J37 blocks lack iron cyl liners. That's the trade-off that Honda engineers made by increasing the bore diameter.
And maybe they wanted to reduce the weight a bit. Honda changed the pistons and rings to reduce the oil consumption. I saw
a write-up on a MDX forum by a dealer tech that showed the old and new parts. As someone mentioned, the carbon build-up
seems to be the problem with the initial piston design.

The later cyl head design flows notably better than the J35A8 heads. The information you found is flat out wrong. But the later
heads have a slightly different bolt pattern for the exhaust port, so you would need later style pre-cats. By any chance, do you
want to sell the J37A4 cylinder heads?

Bense

Looks like you're just up the road from me! Now you just need one of my transmissions :P

rockstar143

iTrader: (6)

What a badass thread...thanks for sharing pictures and writing in complete sentences.
Very very cool.

Dr. Honda

The nicest engine for the 3G TL is the J37A2 from an '09-'10 RL as the sensor layout is the most similar to the 3G TL and it doesn't have a known, potential, oil consumption issue like other J37s. Other J37s can be used but it's more work and you might have to deal with a potential oil consumption issue. Although it might be possible to find a used engine with the updated pistons and rings that were replaced by the dealer in decent shape.

The dual VTEC J37A2/A4 heads should definitely be left on. The powerband is worse without them and peak power as well. People struggle to make 300+whp with other combos (including J37 bottom ends) but there are multiple J37A2/A4 engines making easily over 300whp with just bolt ons and tuning. Also the J37 oil pump should be used with a J37, the specs are different for a reason.


^^318 whp and it doesn't even have all bolt ons...

Bense

Can you please provide more details about the specifics of the sensor layout differences and why the 09-10 version of this engine does not have oil consumption issues? What did Honda change?

These IB forums get indexed by all the search engines, and you might be surprised as to how eternal and visible these threads end up becoming in a few years.

If the sensor layout of the 2011+ J37A2 / J37A4 is different, what changed? I would assume that if someone were to pick up a 2013 J37 for the purpose of installing it in their 3g TL, that usually implies that whichever sensor that doesn't match up might be able to be swapped over.

​​

Dr. Honda

You're correct that they are indexed, which is why I'm glad Euro mentioned something.

The crankshaft position sensor and other related parts to the sensor, are different. Parts could be swapped but you could just avoid the headache with getting an engine that is more specific for the application.

The bulletin shows which J37s have higher potential for oil consumption issues. Note the '09-'10 RL are absent as they are different and are not prone to developing said issue. As mentioned in my previous post, the pistons and rings are different. Honda has updated parts which some dealers are installing to alleviate the issue. You might be able to find a used J37 with the updated parts but that would require extra diligence to make sure it was actually done and the oil consumption issue was resolved. I would trust the Honda plant that assembles engines more than a person working for a dealer on flat rate (no offense to them).

Also something worth mentioning is the older style oil pressure switch needs to be used with the J37. The J37 oil pump (which is what you want to use on a J37), has different threads. The old oil pressure switch will need to be rethreaded and installed with appropriate sealing measures taken so it doesn't leak.

Bense

Are you referring to item #16 listed here:
37500-RCA-A01 Sensor Assembly, Crank (1-2)

It almost appears that 2011+ doesn't even have this? Seeing that this part number is also found in all 3g TL, just as you indicated, it leads me to believe that one might be able to transfer this part over. My next question about this would be whether or not threads for the sensor need to be drilled and tapped.

89mm bore - J32, J35
90mm bore - J37A* -

I don't think that there are any other 90mm pistons that can be used to adjust the compression, and IIRC, FRM sleeves require pistons with some sort of coating (don't quote me on this). So that it would seem that the only feasible pistons are the

Specific to 2009-2010
https://www.acuraoemparts.com/oem-pa...td-13010rkg000
https://www.acuraoemparts.com/oem-pa...td-13011rkga01

Is it possible to use these piston rings on the 2011+ pistons?

Are the J37A2 / J37A4 valves the same diameter as J35A8 ?

Dr. Honda

It is possible to swap over the older style sensor setup onto the J37A4. The OP goes into some detail on how it's done:



As far as pistons and rings are concerned, I would just run the updated parts if I were going to go with one of the engines listed in the bulletin.

You can see the updated parts in this video for a MDX (not a J37A4) as well as the overall repair process:
Valve size is 36mm and 30mm on the J37.

rockstar143

iTrader: (6)

That's very cool information.
320hp to the wheels on a TSX must feel quite nice.

Legend2TL

What awesome projects, both builds are very impressive!!
How much extra space do you have in the TSX engine bay with that J37?

ohnoitspiter

Nice job! This is something that I've been meaning to do but loosing hope in doing. After failed attempts at keeping a J35 alive, I went and dropped a J37a4 into my type s and boosted it. I was excited to run that because of dual vtec however, to my surprise, the engine tapped out at 6300rpm peaking at 460whp and dropping to 425whp by the time I hit 6800 rpm. On a j35a8, I made power all the way to redline. After talking to p2r, they mentioned that the j35a8 heads flow better than the J37a4 heads.

Dr. Honda

Basically none:
That's interesting. I've seen J37A2/A4 engines make peak power at higher RPMs. It might have something to do with your setup.

Euro-R_Spec_TSX

So much misinformation on the internet. I had some heads flow tested and the later style heads (RKG and R70 castings)
flowed about 7% more than the J35A8 heads (RJA casting). The J37A2 and J37A4 heads are RKG castings.

Marsalis Simms

Nice work. Good to see other TL-S' in NC.

H22A_CD5

iTrader: (3)

j35a8 crank sensor and crank trigger wheel are behind the crank pulley and the wire comes out of the timing cover where pictured. The J37a8 crank sensor and trigger wheel are in the oil pan and the harness comes up behind the vtec solenoid.

Kelvin Williams

There’s a big difference in the readings from a mustang dyno and a dynojet.

H22A_CD5

iTrader: (3)

The ring pack I used was the 13011-RKG-305, which is the same ring pack called for in the TSB for the oil consumption, so I guess I’ve got that going for me. Good thing Honda keeps the estore website updated when they supersede parts.

Also, I can’t recall whether I rescued my j35 oil pressure switch or the J37 one. Seems I must have used the J35 one as it threaded fine. Good info though.

mikejones23345

The OP said the J35A8 heads flowed better than the J37A4 heads. His comparison was specific to those two types of heads.