Has anyone here actually built a VG34?

[Magic Carpet 510]

I am interested in the build but it is very hard to find anyone that has actually built one.
An internet mag. built one for a Pathfinder and that made for interesting reading.

No HP figures but they go through what they did pretty well.
http://www.motoiq.com/magazine_articles ... vg30e.aspx


A poster on another board brought up this problem:
The problem with the pistons is cutting the valve reliefs. It requires assembling and disassembling the heads from the block over and over to check clearances. The piston tops are not thick enough to just cut super deep reliefs that are guaranteed to clear, so you have to slowly make the cuts deeper and check to see if they clear. This is even more of a PITA if using higher lift cams. The shop that built Nissan Performance Mags vg34 (I think it was JWT) would not give out the specs they used either. If the hight from the wrist pin to the piston flat were the same on vg33 and vh45 were the same you could just make them the same as stock but they are not.
http://forums.nicoclub.com/vg34e-t270909.html

If you have built a VG34 what problems did you run into and do you have some idea of what amount of power you are making?

What did you do different?

Thank you!

[yellowdatsun]

I'm looking into building the same thing. It's our assumption that the big dishes in the stock VG33 pistons are to make the engine non-interference. I mean, think about it............the crank/cam timing can't be so vastly different than the VG30 to have the valves open when the pistons are at TDC. The engine wouldn't run if this was the case. Also, in conjunction with the timing, there's no way the VG33 cams can have an extra HALF-INCH of lift to necessitate the cutouts. So we're guessing that you'd be fine with flat tops like a stock VG30.

[jonesmechanical]

I am doing it right now. I was out at Miller Motorsports park chasing porsche's with the local PCA chapter. The smurf was doing great, perfect. I was using mostly 3rd gear, but to stay out of 4th, I was revving it out at 6900 to 7000 rpm's for too long. Hydraulic lifters didn't like it too much. Valve collided in the 200SX VG30 and shattered on of the pistons and sent the valve through the liner.

So, the block was shot. What to do?

$450 got me a 200,000 mile VG33 out of a Pathfinder from LKQ
$180 for Infiniti Q45 Pistons
$160 for Rings
$100 for VG30de Rods (they link my VG30 Crank to the wrist pins of the V8 pistons).

I have the motor up at American Machine in Salt Lake City. Clark is an old school machinist that is really into anything that goes fast. His shop is amazing. He came highly recommended from multiple trusted sources. Also, he was first machinist to actually tell me he would clearance the V8 pistons for me.

Today he measured the "flat top" V8 pistons. They have 4 valve reliefs in them already from the infinity 4 valve motor. Looking at the VG33 stock pistons that came out of the Pathfinder, they have massive reliefs (I think that motor may be non interference and the pistons were built up around the valves to maintain the compression ratio), and at least gives a good template. The depth of the table of the pistons was between 220 and 280 thousandths depending on if you are at the center of the piston or out towards the perimeter of the piston (deeper at that point). Clark mentioned that there should be plenty of material there. This is one thing that was not ever documented online.


Another factor: I will be using the upgraded JWT cams I installed in the my broken VG30 into the VG33 heads. I imagine that the clearance to the pistons is also dependent on the spec of the cams, and the duration.

I will be using my Crank from my broken VG30 to maintain the stock drive pulley.

This VG34e project is something that has been talked about a lot, but not documented. Especially the end results and small important details.

I will be limiting the RPM's to 6500 to control the valve float. JWT will be tuning the whole setup to 91 pump. In all, I hope to be into the entire rebuild with tuning for about $1500. At this altitude (4500 ft) I hope to dyno 200 wheel (200sx intake manifold, headers, tuning, possibly cam gears and the 3.4 liter 9.? :1 compression ratio). If its more, then great. Clark will also be doing detailed measurements to actually calculate the net compression ratio after the valve relief cuts and any other machine work we do.

I imagine that machine work will take some time, the getting it back together should be quick.

I have been so pleased with the VG30 in my 510, even with my 510 being a bit heavier with all the things Rick and Kelvin did to make it a great street car. I think this upgrade, with all of the other things that this car has seen will really make a great improvement.


Hopefully everything goes as planned, and it really proves to be a great performance/value. In reality, not much more money than just rebuilding a stock vg30. In my case, having to get a new block really pushed this project into motion.

[benz-tech]

If you are having valve float issues, you need upgraded springs, which you may already have. If not, get them. If your lifters are collapsing at higher RPM, there is a write-up on Z31performance.com about hybrid/solid lifters. I will be getting around to doing this one of these days, also. And, since this is a pretty small community I might assume that you have read that as well. I've bounced my VG of its rev-limiter (7.3k) more than a few times and never had valve float. Cooked rod bearings, yes. But valve float, no.

[jonesmechanical]

The solid lifter fix is something that I have just recently explored. I didn't know there was a write up over at z31. I'll have to check it out. I have also hit the rev limiter many time, and have even had it at the track. At Miller, I was literally running the car over 6500-7000 for minutes at a time. It is possible that I had an oiling issue, but I don't think so.

I have purchased the z31 turbo automatic oil pump for good measure for the build. I am also considering doing an accusump, which would help with startup and starvation under most any condition. We'll see. As far as the lifters, I just noticed that all of the links online referred to the Z32 twin cam conversions.

[benz-tech]

VG's have high rpm oil issues. The cranks, I'm told, counteract oil pump pressure when they're spun beyond 6.5k. A turbo A/T pump will help. Check out how your oil passages line up, esp at your oil filter area. Its as if the guy who drilled the longitudinal hole didn't talk to the guy who drilled the side hole and they don't meet up very well. I opened that junction up on my block while it was apart. I also ported the pressure side of the oil pump and radiused every 90deg bend in the entire oiling system. This is mainly for the lower end oiling issues. It sounds like you may have just had a bad lifter or two. I put the pics in as links so they can be seen full-sized. Feel free to peruse the entire album.

http://i383.photobucket.com/albums/oo27 ... CF2961.jpg

http://i383.photobucket.com/albums/oo27 ... CF2962.jpg

http://i383.photobucket.com/albums/oo27 ... CF2963.jpg

even the coolant passages needed a little help:

http://i383.photobucket.com/albums/oo27 ... CF2965.jpg

[510rob]

What about the crankshaft itself? Did you do anything to the oil passages inside the crank, like drill them out a bit more to get a bit more capacity to the rods? It's tedious work for sure, but every little bit helps...

[benz-tech]

What about the crankshaft itself? Did you do anything to the oil passages inside the crank, like drill them out a bit more to get a bit more capacity to the rods? It's tedious work for sure, but every little bit helps...

Nope. Running a stock crank. If for some reason every step I have taken is not enough for daily duty and maybe be light track use, I will prep a crankshaft and start over. The Eagle rods do not have oil squirters either, so all oil is devoted to lubing the bearing. Maybe that will help, who knows.

[jonesmechanical]

Thanks for the input. Would it be a good idea of replacing all of the lifters? Do they fail very often or "wear out"?

I didn't see any threads on z31 performance about solid lifters, just a thread started by "satan" that seems to know his stuff, he designed a partial solid lifer setup. I'm not sure what the benefit of what that would actually do.

Seems to me, that the VG is a motor that either likes to be boosted, and resists being revved. I think my approach to this one is to enjoy the new found displacement and compression, and keep the revs to 6500. I really don't know how much more power is gained by revving further than that, especially with the 200sx intake manifold.

I never had an issue on the street rapping it out to 7K, and of course, I really never kept it loaded at that rpm for any amount of time. Maybe I'll keep the redline at 7K, and be a bit more judicious about sustained revs on the track.

I'll be sure to look at the oil filter location and casting/drilling to make sure they line up good. As far as the oil pump, I need to look further into what exactly "porting" is.

The hydraulic lifters on my new vg33/4 motor are the stock 200K ones from the vg33, but the valve springs and cam would be transfered over from my vg30. Does anyone know if the lifters of the vg33 are any different, have different limitations, or are better/worse?

[jonesmechanical]

Wow, this forum is weak, I am not used to this. I can't believe that its been days that any topics in this forum have not been commented on. Has this forum died? Any sign of a heart beat? Shoot, I am bumping this entire sub forum, and I was the last one to post. Come on guys.

I mean, really, yea a vg34 is really kinda of a unicorn as far as good documentation, so I can understand the neglect of this thread, but the entire sub forum? It reminds me of communicating with my high school girl friend when I couldn't afford to call her by land line, and had to rely on mail, yea, mail (not the e kind). Intermittent communication that eventually led to the end of the relationship.

So, update here, to get back on topic with my self (since no one else is around). I will be visiting the engine builder tomorrow (or today, its damn late) and will get some pics to spice it up a bit around here.

[vgwagon]

Wow, this forum is weak, I am not used to this. I can't believe that its been days that any topics in this forum have not been commented on. Has this forum died? Any sign of a heart beat? Shoot, I am bumping this entire sub forum, and I was the last one to post. Come on guys.

I mean, really, yea a vg34 is really kinda of a unicorn as far as good documentation, so I can understand the neglect of this thread, but the entire sub forum? It reminds me of communicating with my high school girl friend when I couldn't afford to call her by land line, and had to rely on mail, yea, mail (not the e kind). Intermittent communication that eventually led to the end of the relationship.

So, update here, to get back on topic with my self (since no one else is around). I will be visiting the engine builder tomorrow (or today, its damn late) and will get some pics to spice it up a bit around here.

There is a good start, very encouraging tone for people to want to reply.

Only a few members have VG's in there car, mostly L-series, then KA24's and SR20's....VG's are not the popular choice anymore.

Having said that, I have a VG30e in my wagon, it put down 191rwhp and 207ft/lbs, I am currently building a 3.3 for it.
Discussion on the valve reliefs has been thrown around.
I am of the belief that the valve reliefs do not need to be cut into the Q45 pistons and that the reason the reliefs are so deep on the stock 3.3 pistons was to accommodate Ford with a non-interference motor. None of this is confirmed as I have been busy repairing the rust on my wagon but eventually I will get there. Maybe you can measure up and see if there are even truly needed and report back.

Also you may want to venture out and get NiStune for your tuning.
Good luck!

[hang_510]

Wow, this forum is weak, I am not used to this. I can't believe that its been days

I mean, really, yea a vg34 is really kinda of a unicorn as far as good documentation, so I can understand the neglect of this thread

everybody else took a step back, so you have now volunteered to go first
take lots of pictures and document everything!




mmmmm VG unicorns... tasty

[Magic Carpet 510]

I started this thread and it sat for a very long time before you came and said that you were going to put a VG34 into the Smirf. I have admired that car for many years and I am one of the few on the East Coast that has actually seen it.

I have a VG33 that I want to put in my car over the winter, I have a VG30 in there now.
I wanted to build the VG34 but I am now thinking of going turbo. It sounds like you are coming along quickly so please do post the details. Do you know what the ending compression ratio will be? Would it be too high to turbo?

I would love to see a discussion on Nistune Vs Meagsquirt.

Good luck with your build and please keep us posted.

[510rob]

Wow, this forum is weak, I am not used to this. I can't believe that its been days that any topics in this forum have not been commented on. Has this forum died? Any sign of a heart beat? Shoot, I am bumping this entire sub forum, and I was the last one to post. Come on guys.

I mean, really, yea a vg34 is really kinda of a unicorn as far as good documentation, so I can understand the neglect of this thread, but the entire sub forum? It reminds me of communicating with my high school girl friend when I couldn't afford to call her by land line, and had to rely on mail, yea, mail (not the e kind). Intermittent communication that eventually led to the end of the relationship.

So, update here, to get back on topic with my self (since no one else is around). I will be visiting the engine builder tomorrow (or today, its damn late) and will get some pics to spice it up a bit around here.

An increase from 3.3L to 3.4L will net you about 3% more displacement.

[okayfine]

Wow, this forum is weak, I am not used to this. I can't believe that its been days that any topics in this forum have not been commented on. Has this forum died? Any sign of a heart beat? Shoot, I am bumping this entire sub forum, and I was the last one to post. Come on guys.

Number of members, much less of regular posters here versus something like Z31 has to be orders of magnitude smaller. On top of that you're in a topic that has very, very few knowledable participants (in that they have build a VG34). So, yeah.

Would love to document a VG34 build for DQ.