[qaz393]

CAM LOBE HEIGHT MEASUREMENT CHART for J37A4
INTAKE EXHAUST
PRI 34 299 mm (1 3504 in) 36 734 mm (1 4462 in)
SEC 35 932 mm (1 4146 in) 37 370 mm (1 4713 m)

doesnt seem that great. for the same price i rather get billet cams. killer vtak style

 

[Sonnick]

CAM LOBE HEIGHT MEASUREMENT CHART for J37A4
INTAKE EXHAUST
PRI 34 299 mm (1 3504 in) 36 734 mm (1 4462 in)
SEC 35 932 mm (1 4146 in) 37 370 mm (1 4713 m)

doesnt seem that great. for the same price i rather get billet cams. killer vtak style

Where did you get this info? And are there specs for other J engines there?

 

[qaz393]

Mitchell on demand aka from a factory manual. What other one do u want

 

[qaz393]

2012 MDX 34.299 + 35.932 intake and 36.760 exhaust 4 lobe
07 MDX 35.112 + 36.394 intake and 36.389 exhaust 5 lobe
07 RL same as 07 mdx
04-08 Tl 3.3 35.041/35.284 + 36.445 intake and 36.326 exhaust 5 lobe
05 av6 35.041/35.284 + 36.445 intake and 36.326 exhaust

 

[qaz393]

So TLS is 35.112 + 36.394 intake and 36.389

 

[00suprchrgdAV6]

E requires 30% more fuel. With a walbro 255 and 440cc injectors at almost 500hp i still have more fuel capability. I did the math and a 750cc will work at 700-750. If 1000cc make you feel more confortable the price is the same i think, but under boost tunning may be challenging.

E is becoming very hard to find in the Northwest so make sure you research availability in your area.

 

[Jasmine6-6]

Jasmine, to be honest I'm not 100% sure if they work or not, no one has done the swap and with my current set up, I am now a little gun shy till the part is in front of me. From what I understand you can swap a J37a4 into our AV6 as long as you get the 07-08 6spd trans (bell housing), or 08+ AV6 (no LSD). The Dual Vtec still operates on a single solenoid as our cars, so then you just tune on Pro.

With that said, again no one has swapped Dual Vtec heads onto a none dual Vtec vehicle. I would assume the oil passages would be different, maybe coolant, and just an overall different design of the head in general.

Here's a thread to read up on. I'm not interested in swapping those heads, so you gotta do the digging yourself
My $.02, just get a J37A4 long block, no porting needed, Best stroke, largest pistons,etc and build off that. Then get a TLS trans to bolt up to it.

http://www.v6performance.net/forums...-performance-discussion/214580-j37a4-rocker-swap-j30a4-vtec-intake-exhaust.html

The j37a4 heads will line up to the J32A3 Block. Oil and coolant passages all workout to be a direct fit. The VTEC I currently have on my j32 also works with the j37 heads because they're are still controlled by one single controller. Buying the j37 block outright is costing me wayyyy more otherwise I would go that route

E requires 30% more fuel. With a walbro 255 and 440cc injectors at almost 500hp i still have more fuel capability. I did the math and a 750cc will work at 700-750. If 1000cc make you feel more confortable the price is the same i think, but under boost tunning may be challenging.

E is becoming very hard to find in the Northwest so make sure you research availability in your area.

I have researched the availability and I am glad to say its readily available in many locations! Could you tell me how you were able to calculate all of that?

 

[screaminz28]

I'd be interested in the fueling calcs as well. For E, and 700 crank HP, in a turbo app, I was calculating closer to 1200cc injectors, and that would be at 90% DC.

 

[accord325]

Good luck with the build. Looking forward to seeing the j37a4's on your block.

 

[00suprchrgdAV6]

No crazy math wizardry on it from me. Just from experience and what i have today. Currently I am at 82% +/- duty cycle with my setup and have been looking into running a flex fuel setup due to availability of E85 (which is really E60 mostly). Based off what i have now vs. desired 700hp knowing E requires 30% more fuel consumption i arrived at 750cc required. If you use online calculators with my current setup it will say i can achieve a max of 350whp at 90% duty. I have far surpased that.

Worst case you can always tap in a 7th injector if you run out of fuel.

Hope someone schools me on this so i can change my thought process and start looking for 1000cc injectors .

 

[yungone501]

Trust me when I say that j37a4 heads are compatible with the j32a3 as well as the j35a8. The only other "issue" I've encountered so far when doing this swap is ensuring that the oil pump is capable of putting out at least 70 psi above 3000 rpms when running these heads. As they do require a much greater amount of oil to activate the rocker locks due to the added quantity of parts involved. I'm sure some of you know that stock Honda oil pumps can be shimmed on the pressure relief valves to modify the pressure at which they begin to bypass oil which means that simply modding your stock oil pump should suffice in supplying adequate amounts of oil during VTEC engagement. Other than that, I've found no other issues or reason for concern.

Aside from this, OP, I'm in total agreement with the compression ratio dispute. If this were a NA build I'd say go for it but when you raise the compression of a boosted engine, you do effectively lower the max amount of boost it can take by increasing its effective compression ratio (ECR) which is basically a formula that factors boost and compression to determine a safe area for an engine in keeping it out of detonation. I'm aware of the few people that say that keeping the compression high means nothing as long as your tune is spot on...and technically they are correct to an extent. However, the fact still remains that when you add compression (which is basically kept for low end response on a boosted engine), you bring the detonation point MUCH closer and the only way to offset this is by running higher octane which can get very expensive in time.

 

[bdbconcepts]

Question....

Robert...


how much for what is pictured?



Do your work on Hondata installation?


:up:

 

[jiga21]

Trust me when I say that j37a4 heads are compatible with the j32a3 as well as the j35a8. The only other "issue" I've encountered so far when doing this swap is ensuring that the oil pump is capable of putting out at least 70 psi above 3000 rpms when running these heads. As they do require a much greater amount of oil to activate the rocker locks due to the added quantity of parts involved. I'm sure some of you know that stock Honda oil pumps can be shimmed on the pressure relief valves to modify the pressure at which they begin to bypass oil which means that simply modding your stock oil pump should suffice in supplying adequate amounts of oil during VTEC engagement. Other than that, I've found no other issues or reason for concern.

Aside from this, OP, I'm in total agreement with the compression ratio dispute. If this were a NA build I'd say go for it but when you raise the compression of a boosted engine, you do effectively lower the max amount of boost it can take by increasing its effective compression ratio (ECR) which is basically a formula that factors boost and compression to determine a safe area for an engine in keeping it out of detonation. I'm aware of the few people that say that keeping the compression high means nothing as long as your tune is spot on...and technically they are correct to an extent. However, the fact still remains that when you add compression (which is basically kept for low end response on a boosted engine), you bring the detonation point MUCH closer and the only way to offset this is by running higher octane which can get very expensive in time.

Oh Wow so we would have Vtec on the intake & exhaust side...hondata dyno tuned numbers would be ravaging.

 

[yungone501]

Robert...

how much for what is pictured?

Do your work on Hondata installation?

:up:

This setup isn't for sale but the j37a4 heads alone (even used) are pretty damn expensive. I've sold a few sets already including the complete single head I had and I don't keep them for very long when I do get them. The pictured engine is my personal engine that's about to be installed in my AV6 that's running boost and methanol injection and FlashPro tuned on the stock j35a8 ECM.

As for your Hondata question, it was a bit vague but I'll answer it to the best of my ability. Assuming you mean the harness conversion that must be done (since this is mainly an Accord oriented forum) when using the j35a8 ECM on the j30...I can do them but they a pretty labor intensive and because I'm busy up at the shop almost year round, its difficult for me to perform such a service for anyone here. I'm an automotive electrical technician (12 years now in the electrical aspect of cars) and because I do so many repairs that involve fixing or cleaning up someone else's shoddy electrical work, I've became OCD with my electrical work. LMAO...

That being said, its tough for me to find the time for harness conversions. I definitely don't mind helping anyone in need of assistance, diagrams, connector views, pin outs, general technical help or even text/email communication to help with any technical issues or questions. The honda j-series has become my passion and always find time to help those out in need.

Oh Wow so we would have Vtec on the intake & exhaust side...hondata dyno tuned numbers would be ravaging.

Yes, dual VTEC. The sound is much more "throatier" when the big lobes hit and I foresee some very exciting gains and tuning advantages coming from this if and when j-series enthusiasts pick up on the j37a4 & j37a2 heads.

No dyno tuning has been done yet as I do all my tuning on the street. I'm not one for max power as much as I am for streetability and reliability. Most tuners on the dyno, to my knowledge, tune to the edge of knock by taking a boosted engine to detonation and then pulling back a few degrees. Most will call this a "conservative tune" but to me that's not ideal to a person who's looking to daily drive their car and get the most they can out of their motor while having a little fun at the same time.

 

[Jasmine6-6]

This setup isn't for sale but the j37a4 heads alone (even used) are pretty damn expensive. I've sold a few sets already including the complete single head I had and I don't keep them for very long when I do get them. The pictured engine is my personal engine that's about to be installed in my AV6 that's running boost and methanol injection and FlashPro tuned on the stock j35a8 ECM.

As for your Hondata question, it was a bit vague but I'll answer it to the best of my ability. Assuming you mean the harness conversion that must be done (since this is mainly an Accord oriented forum) when using the j35a8 ECM on the j30...I can do them but they a pretty labor intensive and because I'm busy up at the shop almost year round, its difficult for me to perform such a service for anyone here. I'm an automotive electrical technician (12 years now in the electrical aspect of cars) and because I do so many repairs that involve fixing or cleaning up someone else's shoddy electrical work, I've became OCD with my electrical work. LMAO...

That being said, its tough for me to find the time for harness conversions. I definitely don't mind helping anyone in need of assistance, diagrams, connector views, pin outs, general technical help or even text/email communication to help with any technical issues or questions. The honda j-series has become my passion and always find time to help those out in need.



Yes, dual VTEC. The sound is much more "throatier" when the big lobes hit and I foresee some very exciting gains and tuning advantages coming from this if and when j-series enthusiasts pick up on the j37a4 & j37a2 heads.

No dyno tuning has been done yet as I do all my tuning on the street. I'm not one for max power as much as I am for streetability and reliability. Most tuners on the dyno, to my knowledge, tune to the edge of knock by taking a boosted engine to detonation and then pulling back a few degrees. Most will call this a "conservative tune" but to me that's not ideal to a person who's looking to daily drive their car and get the most they can out of their motor while having a little fun at the same time.

I just want to take a second to thank Robert. I bought the J32A3 engine that i'm working with from him and he has been doing nothing but helping me with this build by answering all my questions. I can't say this enough but I really appreciate all your help! I can't wait for the J37 to crank come in! Paul has also been helping me tons on this build too. Without these two I'd be lost. These are just two of the names that come into mind at the moment but their are many more! This forum is awesome

 

[00suprchrgdAV6]

The guys are right on compression. My shop always says lower compression and add boost. Same power, but you get the safety aspect of avoiding detonation. They have explained it a few times to me, but it goes over my head. Basically they use a safe compression zone piston and then during tuning add advancement. Once you stop producing around 1% power per degree they back it off 2 degrees, which in theory will reduce your chamber pressure by half. Now techs you will probably be able to explain that much better then me.

I am looking into the same stuff for my next step and I am going to stay at low compression and throw boost at it.

 

[Sonnick]

You don't always have to go low compression with boost, though. Look at the K20...it makes tons of power on 11:1 compression. TUNING IS EVERYTHING.

 

[accord325]

^ It's just safer. High octane or E is usually ran on high compression, boosted set ups

 

[thisaznboi88]

for the J you should definitely go with low CR. The J is prone to knocking with fluctuation of temperature. k20/24 have VTC, and can change the cam phasing to suppress knocking in addition to ignition timing.

 

[Sonnick]

True. I wasn't necessarily saying bump the compression to 11:1, but he should be fine with 10:1.