I have a 3.7 turbo now but want more power. Looking at a doing forged internals in a 3.6. Every thread I've read comments about using stock J37 rods/crank, concerned they are not going to hold up to high boost (15+psi). What aftermarket rod do I use? Are the j35 rods going to fit on the crank journels?

 

I have been looking for the same info as well. inline pro makes j37 rods, so does pauter. Unfortunately Carrillo doesn't make them, they would have to be custom. I've actually been trying to find out if they make upgraded rid bolts for the j37 rod, nothing yet

 

I ordered the 3.7 Pauter rods. Read somewhere the rod journals are 58mm on the 3.5 and 60mm on the 3.7 but maybe I'm not remembering correctly. I saw those inline pro rods too, never heard of them before my search so a little hesitant to take that route. Also, decided to sleeve the 3.7 block instead of the 3.5. This is an expensive venture...

 

Is the engine a stock J37 or a stroked motor?

 

I'm building a stock stroke/bore 3.7.

 

The 3.7 is a very expensive venture indeed. I'm sure you will like the results. Also if your planning on building heads, p2r has valve springs that fit the j37 head, and so does inline pro. Inline pro is very popular on east coast they did a lot of work for F series motors. . Super tech doesn't make j37 springs. Btw where did you find the info on the rod bolts, that would help. Thanks.


I wish wish there was more info on the j37. I've only seen 1 person build it. One is Yungone, I tried to message him, no avail. He got really far with the j37, think he even went to get camshaft regrinded by Web and Gude. I emailed both not getting straight answer. GL with the build, post pics

 

Cost of 3.7 vs 3.5 will be very close either way. I don't have any info on the rod bolts specifically. ARP2000 bolts will come with my new Pauters. Not sure why you'd want to go away from OEM bolts quite frankly, suspect rod would fail way before any bolt. Searching for ARP head studs now, not sure they exist but if not new OEM will go back in along with p2r springs, etc. Sticking with stock cams. Big question currently is whether to pick up a 2007-9 J37A1 or a 2010+ J37A1, bunch of different parts in the lower end between the 2. Need to make sure my flywheel will bolt to crank (manual trans, this is not going back into a street car). Current stock engine has a 6266 Precision turbo and does 390whp but it's a conservative tune, running AEM. Shooting for over 600whp this time... Also, had a supercharger on this engine and it was a complete slug even after dyno tune. No way would I go supercharged again...

 

I've read somewhere that the rod bolts are very weak. Also I've heard of people using h23 headstuds, though there is a arp J series head stud kit. Best of luck with the build

 

Rod bearing subject is driving me nuts. I can't find the bearing chart for J37 but have seen many references to charts online and in threads that are obviously not J37 because the alphabet characters only go to "D". My crank has "E" and "F" rod journals. Compared my new Pauter rods to oem #2 and #3 stamped rods (difference between OEM rod stamps appears to be .00025" increments), so I'd say my new rods are closest to #4 oem.
Pauter: 2.3631" bore
OEM #2: 2.3626
OEM #3: 2.36285

Where the heck is a bearing chart for J37 and what to use for a high boost motor (20psi) is the question. Would like to know what others have done. ???

 

Ok, of course I finally found it right after posting

 

Finding bearing information is a pain staking process. Certainly I'm not the first average Joe to build one of these and I've scoured forums looking for dimensions of bearing thickness for J37 or any J series for that matter. Called an Acura dealer tonight only to be shocked at $15.xx for 1/2 a bearing! Ridiculous! Would be really helpful if someone could tell me what thickness each color is. Suspect they're roughly .0001" increments.
Here's what I can share about rod stamps and measuring:
#1 (this is a guess) 2.3623"
#2 measures 2.3626"
#3 measures 2.36295"
#4 (taken from Pauter rod where they most likely hone to the largest size) measures 2.3631"

Machinist who sleeved my block said "just go with the thinnest bearing available for max clearance. Thinking he's correct. It'll be hard to get too much clearance with any of these bearings. Shooting for .0025" for this application due to boost, planning on running 40w oil or something significantly heavier than stock. Anyone want to chime in??

 

http://www.laskeyracing.com/shop/bearingthickness.htm

 

Thanks KN. I have seen the B series charts several times but have never heard anyone say they're the same thickness codes for J series. Did measure a one of my used bearings and it appears the same as B but was with a cheap .001" micrometer.

 

B series mains are NOT the same as J series, add .02" approx for J. Still not sure if colors are same increments in B vs J. BTW, King sells a j35 main at .0986" max thickness (not sure what min tolerance), only 1 option available.

Another note is that references to bearing mix and match say not to skip sizes. The stock J37 skipped 4 sizes. Red and green were mixed in 5 of 6 rods, so apparently Honda doesn't agree with the statement completely.

 

How is this project coming along...

 

Project got put on hold for the moment unfortunately. Going too many directions over the summer so this is hopefully a winter project. Did come to the same conclusion my machinist mentioned (he sleeved the 3.7 block), just go with the sloppiest Honda bearing available. Completely agree that for big boost it'll be thick oil and .003+" clearance if I can get that much. Will post updates as project progresses...

 

Sleeved block sounds good... I'll be paying attention to your progress...... Whats the compression ratio your going for and whats your WHP goal...

 

10:1 CP pistons, would like to see 500whp. At 390whp now w stock internals and conservative tune.

 

You should be able to do this with the stock internals I have seen at lease 2 cars doing 500whp and 700whp respectively on stock J internals.

 

Yes, I've seen crazy numbers with stock engines too. They'll do it a couple times... most likely. Suspect many high hp stock setups don't mention the part where they grenade the whole thing a couple thousand miles later. Shooting for reliability

 

lol very true.... How much compression you going to run?

 

bear in mind this picture is printed in the firing order 142536.
also, I came across this info when I was doing my j36 research, they are j35 numbers, but atleast it's something for bearing thickness.

 

Sleeved block
JE Pistons
Pauter rods
ARP head studs
GTR injectors
Supertech springs/retainers J32 cotters
Precision turbos
Tial bov, and waste gates
AEM Series 2

Tuner thought 500whp was ridiculously conservative and had no problem hitting goal in a couple pulls. Needs custom injectors to get 600+hp, we are at 90% duty cycle now.

 

Oh wow, that is beautiful. That has to be a blast to drive. Do you have a full pic of it?

 

Yeah, nice build OP. Would love to see some full pics of this thing. Any videos? Must be hella fun!