[Apex1]

Well my concern was when I bought the 2010 was if it would burn oil. And it looks like those concerns are validated. I did an oil change right after I bought it. It was at the top of the hash marks. After 1700 miles it is just above the bottom of the hash marks. I added a bit less than a quart today.

So maybe a quart about every 2k?

I also drove pretty hard so far, taking advantage of the 300hp/275tq fairly often. I also sea foamed it when I bought it and the oil came out pretty black. I noticed it looks pretty dirty on the stick already. Much darker than my Ridgeline with 186k on it.

So clearly the rings are carboned up, which is not uncommon for some Hondas. I plan on changing the oil at 3k and hitting it with the seafoam again. Maybe try some different oil although I am already on 5w30.

The good news is it runs awesome. If it never gets any better... so be it. However I will see what some ring cleaning will do.

Stay tuned....

 

[skirmich]

You will burn oil when driving hard the 3.7L, as the engine has been tuned to hell to reach the 300HP mark... Is not uncommon for normal production cars to burn oil when you push them. The abnormal behavior is when you have to pour 1 quart every 1K and drive like a grandma.

 

[TrouserTrout]

That's what I burn. Acura claims anything over a quart per 1000 miles is excessive. Luckily I have the AcuraCare warranty for another 40 thousand miles if it gets worse.

Outside of oil consumption the MDX has been rock solid.

 

[Apex1]

Well, glad it's not uncommon. My experience with the j35 in the Ridgeline is that it does not use a bit of oil. So it's a bit new to me. If I can't improve it, I'll just live with it.

Otherwise it runs like a beast!

 

[skirmich]

The J35 is quite un-tuned, It was based on the J32 so it isn´t in the same ball park.
The J37 on the other hand is the most savage J-Series Honda has ever built, It wasn´t based on anything but built from scratch. Even compared to newer Direct Injection Engines the J37 is still the most powerful J ever made, and most powerful V6 N/A Honda ever made! Yeah even better than the C32B from the NSX.

 

[Apex1]

Did not know that. I just figured it was a stroked version of a 3.5 with some more compression. I guess not...

I am a big fan of Honda engines. The F20C in my S2000 is ridiculous. I almost bought a NSX with a C30A, another award wining engine.

The J37 is a blast. It rips, plain and simple. I have been having so much fun with X, the S2k has barely been out of the garage this year!

 

[qqzj]

The J35 is quite un-tuned, It was based on the J32 so it isn´t in the same ball park.
The J37 on the other hand is the most savage J-Series Honda has ever built, It wasn´t based on anything but built from scratch. Even compared to newer Direct Injection Engines the J37 is still the most powerful J ever made, and most powerful V6 N/A Honda ever made! Yeah even better than the C32B from the NSX.

are you sure? j37 is just j35 with fancy and thinner cylinder lines. So lighter and more displacement. Better than J35, but no way from scratch and not that much better.

https://en.wikipedia.org/wiki/Honda_J_engine#J37

 

[qqzj]

You can also see that the compression ratio of the 07-09 MDX is 11:1. For the 10-13 MDX it is 11.2:1. To increase the compression ratio slightly, Honda used stronger inner components etc, but also caused the oil burning issue. I really don't get why Honda would bother to create J37A1-A5 all these seemingly the same engines. Why not just make one engine and make it better. I cannot even tell the benefit of the increase from 11:1 to 11.2:1. Maybe max torque comes early? It is so trivial that they should not have done it at all.

 

[skirmich]

The J35 is the stroked version of the J32..
The J37 has a larger stroke and bored out cylinders but the whole block is Unique to the J37. The cylinders are also Unique (Size wise they have to) and the rods are specific to the J37..

There was a good read from SAE on how they built the J37 somewhere around here and tells all specifics on the journey for 300HP which no other J has reached to this day.

 

[skirmich]

The main difference between the J37s are the introduction to Dual VTEC on a V6 which is state of the art.. This changed the power band delivery not so much the power output, The idea was to have better Low End Torque since the J37 like most Honda Engines was tuned for the High End..

I think Dual VTEC coupled with the 6 Speed delivers the most OOMP on the low end and that is why there wasn't a big difference in total power output

But I think the MDX didn't have Dual VTEC though that is why there is little difference on it.
The J37 was also used in the TL and RL.

 

[qqzj]

The J35 is the stroked version of the J32..
The J37 has a larger stroke and bored out cylinders but the whole block is Unique to the J37. The cylinders are also Unique (Size wise they have to) and the rods are specific to the J37..

There was a good read from SAE on how they built the J37 somewhere around here and tells all specifics on the journey for 300HP which no other J has reached to this day.

Need to see the real article to be convinced. From temple of vetc,

The Temple of VTEC - Honda and Acura Enthusiasts Online - Articles - I agree Jeff!: New Hardware

This engine is essentially a bored and stroked version of the 3.5L, but there are some key differences, starting with the cylinder liners. The 3.5L engine features an aluminum block with cast-in iron cylinder liners, but due to the relatively close bore spacing of the J-series V6 design, the 3.7L version uses high-silicon aluminum cylinder liners for improved cooling. During the block machining process, a mechanical etching process exposes silicon particles embedded within the aluminum sleeves, creating a hard piston ring sealing surface. A side benefit of the aluminum cylinder liners is that the overall engine weight of the J37 is actually less than the J35.

 

[skirmich]

Found it.. Jesus it was an ordeal:
Article of Honda R&D Technical Review　Vol.19 No.2
"Development of Aluminum Liner in Die-cast Cylinder Block for High-power and High-displacement V6 Engine"

Now its just a matter of finding a free sample hahahaha.

 

[qqzj]

Found the summary. It doesn't bode well for your cause. hahaha ....

https://www.hondarandd.jp/point.php?pid=233&lang=en

 

[skirmich]

It doesn't hold weld for yours either.. You said it was just a stroked J35 when it clearly isn't.. The block is unique to the J37 like I said... I am lost on what is your point now.

 

[skirmich]

The J35 is a simple stroked J32 it so that the early MDX J35 used the SAME block (Part Number) that the J32A1/2..

Found a correlation between the J35 block and the J37 if you can?

 

[Apex1]

Obviously the J35 and J37 share lots of technology. But clearly the J37 starts with an all new block. One that is unique to the 3.7L.

This is from the 2007 MDX Tech papers:

ENGINE ARCHITECTURE

The 3.7-liter VTEC® V-6 in the MDX is the largest and most powerful production engine in Acura’s history and incorporates many of the refinements and improvements that have been developed in other Acura powerplants. The MDX engine has a smooth-firing 60-degree V-angle, compact overall dimensions, and actually weighs 17.2 pounds less than the smaller displacement engine it replaces. Aluminum alloy construction including aluminum cylinder sleeves saves weight and improves cooling, while VTEC® cylinder heads operate four valves per cylinder for maximum power development.

A high flow intake system, high compression ratio, close-coupled catalytic converters and high flow exhaust make the MDX engine the most powerful normally aspirated 6-cylinder engine in its class.

ENGINE BLOCK

The MDX’s lightweight, heat-treated die-cast aluminum-alloy block has cast-in-place aluminum cylinder liners. These high-silicon sleeves dissipate heat better than iron liners. The aluminum sleeves also allow a closer piston-to-cylinder clearance for less operating noise. A new mechanical etching process during manufacturing exposes silicone particles embedded in the aluminum sleeves, which provide a hard piston-ring sealing surface. The block also incorporates a deep-skirt design for rigid crankshaft support and minimized noise and vibration.

CRANKSHAFT/PISTONS/CONNECTING RODS

The MDX uses a forged steel crankshaft for high strength with minimum weight. With their raised crowns, the MDX pistons raise the compression ratio (relative to the previous MDX) from 10.0:1 to 11.0:1. This elevated compression ratio is possible due to an oil jet system that sprays cooling oil on the underside of the piston crowns to keep temperatures in check. New steel connecting rods are forged in one piece and then the crankshaft ends are “crack separated,” creating a lighter and stronger rod with a perfectly fitted bearing cap.

CYLINDER HEADS / VALVETRAIN

Like other current Acura V-6 engines, the MDX powerplant uses overhead camshaft cylinder heads. These lightweight components are made of pressure-cast, low-porosity aluminum, and improve overall packaging, enhance exhaust flow and allow the optimal positioning of a primary close-coupled catalytic converter on each cylinder bank. To save weight and reduce parts count, an exhaust manifold is an integral part of each cylinder head casting. Magnesium cylinder head covers save a total of 2.6 pounds.

Special new camshafts are 25% lighter than the camshafts they replace. Assembled from tubular steel shafts with splined steel lobes and journals that are pressed in place, the MDX’s camshafts are a first for Acura.

 

[qqzj]

I must be blind. I read this paragraph several times, cannot find anything like 'all new'.

ENGINE BLOCK

The MDX’s lightweight, heat-treated die-cast aluminum-alloy block has cast-in-place aluminum cylinder liners. These high-silicon sleeves dissipate heat better than iron liners. The aluminum sleeves also allow a closer piston-to-cylinder clearance for less operating noise. A new mechanical etching process during manufacturing exposes silicone particles embedded in the aluminum sleeves, which provide a hard piston-ring sealing surface. The block also incorporates a deep-skirt design for rigid crankshaft support and minimized noise and vibration.

 

[Apex1]

Well maybe not "all new"...

However the block is new. It has a new cylinder liners and new bore. It is not the same block as the J35.

I originally thought it was. I expected the same block with a bigger crank. Nope... the J37 block was built especially for 3.7 L of displacement.

 

[qqzj]

Having a larger bore is not surprising. The liner is thinner so the bore has to get larger. What is surprising is that the stroke is 96mm, a 3mm increase from the 1st gen MDX. Maybe the stroke is increased to match the increase in bore? I do not know. Also I do not know why sharing the same block is important and why we are arguing ... I really do not care b/c it seems I have no interest in this topic.

However, looking wiki closely, this is interesting.

Power; torque: 300 hp (220 kW) @ 6000 rpm; 275 lb·ft (373 N·m) @ 5000 rpm (2007-2009)
Power; torque: 300 hp (220 kW) @ 6300 rpm; 270 lb·ft (370 N·m) @ 4500 rpm (2010-2013)

So Honda increased compression ratio so that max hp comes later, and the only benefit is max torque, a smaller one, comes 500 rpm earlier? What the heck, nobody is racing MDX, who cares.

 

[Apex1]

I agree the difference in blocks is not as interesting as the power specs you listed...

Initially you would say the engine took a step backward in 2010 losing 5ft/lb of torque. However look at the RPM spread. in 2010 Peak torque to peak power lasts 800 rpms longer than the 07-09. The older motor is slightly peakier.

I have driven both recently and because of the change in transmission, you can't tell any difference in the engine. They could be the exact same.

Trans wise, I actually like driving the 5AT around town more. However under WOT, I would take the 6AT because its a little quicker through the gears. Both drive trains have their pluses and minuses. I can live with burning a quart every 2k. Anymore than that and I say the 07-09 wins just because it doesn't burn as much oil.