3rd gen VQ35DE Full ECU Swap Progress Thread
10-27-2008, 07:58 PM
#81
Yeah. Whenever you replace rings without boring out the cylinder, you are only making things worse unless the rings are in really bad shape, then anything would be better. If all you do is break the glaze with a light hone and use stock rings, it will seal just that much less.
I know what you mean and it make sense in a way that if it's not broken dont touch it. But I think that if the concentricity of the cylinder is within spec ( the maximum out-of round clearance on a VQ30DEK is .015 VQ35 should be similar)
If within spec I would then only polish the cylinder wall in order to only remove the carbon build-up, no need to shave any material. With a new set of stock ring and cleaned cylinder wall, I'm almost sure your compression test for each cylinder will be higher and very close to each other.
I guess my next step is to remove the heads and inspect the cylinder walls. Or do you think I should bother with a leak down test first? I can get a tester pretty cheap. But, I am not willing to spend the money on boring the cylinders right now. I'm already way over my budget because of the, "while you're in there, you might as well", mods.
I know what you mean and it make sense in a way that if it's not broken dont touch it. But I think that if the concentricity of the cylinder is within spec ( the maximum out-of round clearance on a VQ30DEK is .015 VQ35 should be similar)
If within spec I would then only polish the cylinder wall in order to only remove the carbon build-up, no need to shave any material. With a new set of stock ring and cleaned cylinder wall, I'm almost sure your compression test for each cylinder will be higher and very close to each other.
I guess my next step is to remove the heads and inspect the cylinder walls. Or do you think I should bother with a leak down test first? I can get a tester pretty cheap. But, I am not willing to spend the money on boring the cylinders right now. I'm already way over my budget because of the, "while you're in there, you might as well", mods.
10-27-2008, 08:00 PM
#83
I did not rehone and I do not burn any oil. The factory x-hatch hone pattern was still clearly visible on the walls so I just left them.
My leakdown numbers went from about 40% to about 5% on a cold engine. Originally I was leaking air past the rings and through a few of the exhaust valves.
If you are pulling the heads anyways then don't bother doing a leakdown.
My leakdown numbers went from about 40% to about 5% on a cold engine. Originally I was leaking air past the rings and through a few of the exhaust valves.
If you are pulling the heads anyways then don't bother doing a leakdown.
I am guessing that since the engine is so cold, compression or leak down test numbers will vary from one cylinder to another. I will go ahead and yank the heads and inspect everything thoroughly. I will post my findings.
10-27-2008, 08:03 PM
#84
Doing a leak down test is cheap and may tell you something that the guess work wont. Let say the compression is pretty much consistent from one cylinder to another after the test, then there will be no need to investigate further, you know you have a good engine. On the contrary if there is let say one or two cylinder that are off compare to the others, you will then have to investigate further to see what's the cause ( cylinder concentricity, out of spec ring etc.) or anything else.
I can get a leak down test kit for only $30. If you think it will help, then I can do it.
10-28-2008, 12:56 PM
#88
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There were a lot of carbon deposits in the seat area and on the back of the valves. I suspect they were preventing the valves from closing fully. Fortunately none of the valves were burned and there was no seat errosion.
I just cleaned everything up with a brass brush/wire wheel and hand lapped the valves to the seats.
10-28-2008, 01:36 PM
#89
There was no physical damage to any of the valves or seats.
There were a lot of carbon deposits in the seat area and on the back of the valves. I suspect they were preventing the valves from closing fully. Fortunately none of the valves were burned and there was no seat errosion.
I just cleaned everything up with a brass brush/wire wheel and hand lapped the valves to the seats.
There were a lot of carbon deposits in the seat area and on the back of the valves. I suspect they were preventing the valves from closing fully. Fortunately none of the valves were burned and there was no seat errosion.
I just cleaned everything up with a brass brush/wire wheel and hand lapped the valves to the seats.
10-28-2008, 03:21 PM
#90
I know you are getting lots of good advice Aaron but I am on my 3rd 3.5 and haven't pulled a head off yet or modified the stock block and have never got an oil burner. I think I would run it like it is before doing anything and if it gives you problems or doesn't perform then go for it but the old " if it ain't broke don't fix it" comes to mind. I dont like to borrow trouble or do work if it isn't necessary and I hate spending money. So far it has proven to be the best route.
If you have the whole winter with nothing to do, hmmm maybe but I have other stuff I can do that is more fun.
If you have the whole winter with nothing to do, hmmm maybe but I have other stuff I can do that is more fun.
Last edited by Jime; 10-28-2008 at 03:24 PM.
10-28-2008, 08:23 PM
#91
I know you are getting lots of good advice Aaron but I am on my 3rd 3.5 and haven't pulled a head off yet or modified the stock block and have never got an oil burner. I think I would run it like it is before doing anything and if it gives you problems or doesn't perform then go for it but the old " if it ain't broke don't fix it" comes to mind. I dont like to borrow trouble or do work if it isn't necessary and I hate spending money. So far it has proven to be the best route.
If you have the whole winter with nothing to do, hmmm maybe but I have other stuff I can do that is more fun.
If you have the whole winter with nothing to do, hmmm maybe but I have other stuff I can do that is more fun.
Today, I did a brief leak down test with results of 13-15% pressure loss. I plan to conduct a much better test tomorrow to see if anything differs between cylinders with regards to the valves. That will give me a better idea of which cylinders I need to pay closer attention to once the heads are removed. But at the moment, it does not appear that I will need to touch any of the rings.
10-28-2008, 09:55 PM
#93
Yes, VQ30 is a return style setup. The rail won't work with the VQ35 LIM, though. So to use the VQ30 fuel rail, you'd need a VQ30 LIM, which only matches up perfectly with the Pathfinder VQ35 heads (or VQ30 heads obviously).
As has been said, it's a trivial thing to convert the VQ35 to a return style fuel setup. Many aftermarket companies make return systems for this motor.
Of course, you could always look into the 4th gen VQ35 swap threads, there are instructions there for cobbling together a return system.
As has been said, it's a trivial thing to convert the VQ35 to a return style fuel setup. Many aftermarket companies make return systems for this motor.
Of course, you could always look into the 4th gen VQ35 swap threads, there are instructions there for cobbling together a return system.
BTW, my 3.5 has 30K+ miles on it and has yet to consume any oil at all. (knocks on fake wood)
Good luck man, I like the Gen 3 Maxima the most!
10-29-2008, 06:51 AM
#94
Not sure if someone mentioned this previously, but if you are using the A33B ECU then you need to convert to a BYPASS fuel system, not "return" setup. Most A32 guys switched over to return systems because they were able to utilize the stock style return system that has variable fuel pressure. The A33B likes the FP to remain at 51 PSI. You are better off using the stock VQ35 fuel rail with a bypass style FPR, just bypass the bleed off pressure to your return line and set the static FP to 51 PSI. No need to change out fuel rails or such.
BTW, my 3.5 has 30K+ miles on it and has yet to consume any oil at all. (knocks on fake wood)
Good luck man, I like the Gen 3 Maxima the most!
BTW, my 3.5 has 30K+ miles on it and has yet to consume any oil at all. (knocks on fake wood)
Good luck man, I like the Gen 3 Maxima the most!
10-29-2008, 02:47 PM
#95
I did some further leak down testing today.
Here are the average results with over 5 tests per cylinder:
1: 16%
3: 15%
5: 16%
2: 15%
4: 16%
6: 16%
I'm guessing that since this engine hasn't ran in a while, that's why the first dry compression test was erratic between cylinders. But, now that I've turned this engine over so many times by hand and with the starter, the numbers have now gotten better.
Also, during the leak down test, I paid close attention to where the air was leaking out. In all cylinders, a good rush of air could be heard in the crankcase (air slipping by rings). And the same exact amount of air was coming from the intake ports, exhaust ports, and coolant housing. I could not tell any difference between any of the cylinders.
Here are the average results with over 5 tests per cylinder:
1: 16%
3: 15%
5: 16%
2: 15%
4: 16%
6: 16%
I'm guessing that since this engine hasn't ran in a while, that's why the first dry compression test was erratic between cylinders. But, now that I've turned this engine over so many times by hand and with the starter, the numbers have now gotten better.
Also, during the leak down test, I paid close attention to where the air was leaking out. In all cylinders, a good rush of air could be heard in the crankcase (air slipping by rings). And the same exact amount of air was coming from the intake ports, exhaust ports, and coolant housing. I could not tell any difference between any of the cylinders.
10-29-2008, 07:45 PM
#97
I am mainly happy that all the cylinders are close to one another with valve and head gasket leakage that is consistent. But, 15% is doable. If it were under 10%, that would be a pretty good race motor. But, considering how most VQ35s have sub par rings, I am happy with it. Some motors can still be just fine as high as 20%. But when you start to get over that, you really need to think about a complete rebuild.
10-29-2008, 07:49 PM
#98
I am mainly happy that all the cylinders are close to one another with valve and head gasket leakage that is consistent. But, 15% is doable. If it were under 10%, that would be a pretty good race motor. But, considering how most VQ35s have sub par rings, I am happy with it. Some motors can still be just fine as high as 20%. But when you start to get over that, you really need to think about a complete rebuild.
10-29-2008, 07:53 PM
#100
11-01-2008, 08:06 AM
#106
I am mainly happy that all the cylinders are close to one another with valve and head gasket leakage that is consistent. But, 15% is doable. If it were under 10%, that would be a pretty good race motor. But, considering how most VQ35s have sub par rings, I am happy with it. Some motors can still be just fine as high as 20%. But when you start to get over that, you really need to think about a complete rebuild.
11-03-2008, 04:50 PM
#108
I used whatever rings that came with the 11:1 JE pistons I bought. I think I remmeber hearing Total Seal during my discussions with the machine shop. I just told them to put something in there they'd be willing to stick their name on. He said he'd use good stuff.
When the rings didn't seat after 10k miles, I called the machine shop back and talked to them. He mentioned they were Chrome rings and it's not uncommon for them not to seat due to the nissan cyl walls being so hard as well as the rings. neither of them wear enough to seat properly. DOH.
(I had them build the bottom end since I didn't have the time, tools, or experience to deal with mic'ing the crank and bearings and etc. Plus I had them balance the bottom end, so no point in me building it for the $100 they charged to assemble the shortblock.)
fortunately the guy said he'd stand behind it too. bring the engine back in anytime and they'd go through it and install new rings for only the parts cost. sweeeet.
Cyls were bored 0.5mm over. (87.5mm)
When the rings didn't seat after 10k miles, I called the machine shop back and talked to them. He mentioned they were Chrome rings and it's not uncommon for them not to seat due to the nissan cyl walls being so hard as well as the rings. neither of them wear enough to seat properly. DOH.
(I had them build the bottom end since I didn't have the time, tools, or experience to deal with mic'ing the crank and bearings and etc. Plus I had them balance the bottom end, so no point in me building it for the $100 they charged to assemble the shortblock.)
fortunately the guy said he'd stand behind it too. bring the engine back in anytime and they'd go through it and install new rings for only the parts cost. sweeeet.
Cyls were bored 0.5mm over. (87.5mm)
11-03-2008, 04:59 PM
#109
I used whatever rings that came with the 11:1 JE pistons I bought. I think I remmeber hearing Total Seal during my discussions with the machine shop. I just told them to put something in there they'd be willing to stick their name on. He said he'd use good stuff.
When the rings didn't seat after 10k miles, I called the machine shop back and talked to them. He mentioned they were Chrome rings and it's not uncommon for them not to seat due to the nissan cyl walls being so hard as well as the rings. neither of them wear enough to seat properly. DOH.
(I had them build the bottom end since I didn't have the time, tools, or experience to deal with mic'ing the crank and bearings and etc. Plus I had them balance the bottom end, so no point in me building it for the $100 they charged to assemble the shortblock.)
fortunately the guy said he'd stand behind it too. bring the engine back in anytime and they'd go through it and install new rings for only the parts cost. sweeeet.
Cyls were bored 0.5mm over. (87.5mm)
When the rings didn't seat after 10k miles, I called the machine shop back and talked to them. He mentioned they were Chrome rings and it's not uncommon for them not to seat due to the nissan cyl walls being so hard as well as the rings. neither of them wear enough to seat properly. DOH.
(I had them build the bottom end since I didn't have the time, tools, or experience to deal with mic'ing the crank and bearings and etc. Plus I had them balance the bottom end, so no point in me building it for the $100 they charged to assemble the shortblock.)
fortunately the guy said he'd stand behind it too. bring the engine back in anytime and they'd go through it and install new rings for only the parts cost. sweeeet.
Cyls were bored 0.5mm over. (87.5mm)
It's quite a good setup you have there!
11-04-2008, 06:39 PM
#111
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damn took me a while to read all this useful information that all you guys have posted about Aarons motor swap. Aaron, i hope you finish this damn swap already so that the 3rd gen community can finally leave the 160+hp range and step up into the 200+ N/A. i think i will just pick up a 3.5 along with all the parts that you will use for yours and do the same to my 3rd gen. Aaron finish this swap buddy and good luck.
11-04-2008, 07:09 PM
#112
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Posts: 2,208
Amazing Aaron. Subscribed!
The Raleigh guys haven't been out to the track in years, but I'll keep up with your progress and maybe we can meet up in the future.
I've got to get my 328i running again
Jon (JMAXIMA) now has an Infiniti I35
Will (KINGMAX) wrecked his 97 maxima, and recently got a 99 maxima
and Brandon (Ladeesman) now has a 04 Audi S4
The Raleigh guys haven't been out to the track in years, but I'll keep up with your progress and maybe we can meet up in the future.
I've got to get my 328i running again
Jon (JMAXIMA) now has an Infiniti I35
Will (KINGMAX) wrecked his 97 maxima, and recently got a 99 maxima
and Brandon (Ladeesman) now has a 04 Audi S4
11-05-2008, 08:30 AM
#113
Thanks.
I'm stepping up from the 170whp VE to 260whp 3.5! 
Awesome! Thanks for the update. I hope we can do another track meet next Spring.
damn took me a while to read all this useful information that all you guys have posted about Aarons motor swap. Aaron, i hope you finish this damn swap already so that the 3rd gen community can finally leave the 160+hp range and step up into the 200+ N/A. i think i will just pick up a 3.5 along with all the parts that you will use for yours and do the same to my 3rd gen. Aaron finish this swap buddy and good luck.
Amazing Aaron. Subscribed!
The Raleigh guys haven't been out to the track in years, but I'll keep up with your progress and maybe we can meet up in the future.
I've got to get my 328i running again
Jon (JMAXIMA) now has an Infiniti I35
Will (KINGMAX) wrecked his 97 maxima, and recently got a 99 maxima
and Brandon (Ladeesman) now has a 04 Audi S4
The Raleigh guys haven't been out to the track in years, but I'll keep up with your progress and maybe we can meet up in the future.
I've got to get my 328i running again
Jon (JMAXIMA) now has an Infiniti I35
Will (KINGMAX) wrecked his 97 maxima, and recently got a 99 maxima
and Brandon (Ladeesman) now has a 04 Audi S4
11-05-2008, 06:17 PM
#114
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11-05-2008, 06:36 PM
#115
yes, please step up with this cuz today i found out my friend who use to work for my local Nissan dealer has a '03 3.5L VQ from an I30 with less 60K miles on it willing to sell it to me for $400. what do you think? i think will get it off of him so i can start my build along with yours.
11-05-2008, 08:17 PM
#116
yes, please step up with this cuz today i found out my friend who use to work for my local Nissan dealer has a '03 3.5L VQ from an I30 with less 60K miles on it willing to sell it to me for $400. what do you think? i think will get it off of him so i can start my build along with yours.
But, if you are really interested in doing the swap, I will be more than happy to help you out. Also, I will be posting as much information as I can in this thread about the details of my swap.
11-06-2008, 05:54 PM
#118
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That engine will work great. Does the engine run right now? Can you warm it up and test compression before you purchase it? If not, is he trustworthy and can vouch for where the engine has been? Can he guarantee it hasn't been run without oil or anything?
But, if you are really interested in doing the swap, I will be more than happy to help you out. Also, I will be posting as much information as I can in this thread about the details of my swap.
But, if you are really interested in doing the swap, I will be more than happy to help you out. Also, I will be posting as much information as I can in this thread about the details of my swap.
11-06-2008, 06:06 PM
#119
well, he told me that he has had the engine for almost a year now and that it came out of an '03 I30 that was involved in a crash. he was gonna swap it into his 240 but i guess he just bailed out and doesn't want to do it anymore. so he offered to sell me the engine for $400 and for me to swap it into my 3rd gen. but i will get more info from him about it before the accident to that I30. and trust me, i really want to swap it into my car.
11-06-2008, 06:17 PM
#120
I finally got this dang crank pulley off!!
Since the engine is on the stand, I was scared of tipping the entire thing over with the cheater bar. I first locked the engine with the "suitable tool" (cough, screwdriver) in the driveplate teeth. It was tough holding the screwdriver while lifting on the huge cheater bar. And my impact wrench wasn't nearly strong enough. So I borrowed a friend's 675 ft-lbs max impact wrench and it didn't even phase it! And I've been soaking this thing in PB Blaster for the past 36 hours.
And I was about to take out the torch to heat it up, but just a little while ago, KRRZ350 gave me an idea to lock the engine in place. On the 3.5, there is a stud that sticks out of the timing cover used for the lowest nut on the front engine mount. Simply wrap a belt around the crank pulley and fold it under itself. The stud will keep the engine from turning. This pic is for illustrative purposes only. It's best to wrap the belt around the inside rib since it's closer to the stud. Then put a 3 foot cheater bar on that crank pulley bolt and that's it!
Thanks Kevin for the idea!
Since the engine is on the stand, I was scared of tipping the entire thing over with the cheater bar. I first locked the engine with the "suitable tool" (cough, screwdriver) in the driveplate teeth. It was tough holding the screwdriver while lifting on the huge cheater bar. And my impact wrench wasn't nearly strong enough. So I borrowed a friend's 675 ft-lbs max impact wrench and it didn't even phase it! And I've been soaking this thing in PB Blaster for the past 36 hours.
And I was about to take out the torch to heat it up, but just a little while ago, KRRZ350 gave me an idea to lock the engine in place. On the 3.5, there is a stud that sticks out of the timing cover used for the lowest nut on the front engine mount. Simply wrap a belt around the crank pulley and fold it under itself. The stud will keep the engine from turning. This pic is for illustrative purposes only. It's best to wrap the belt around the inside rib since it's closer to the stud. Then put a 3 foot cheater bar on that crank pulley bolt and that's it!
Thanks Kevin for the idea!