are there upgrades heads for the vg30e.....I am tryin to boast compression

 

Normally when you want to boost compression youy get new pistons. I dont know if VG30DE pistoms would work (I dont see why not, but I dont know for sure) but if they do they have a higher compresion.

 

Nismo makes some race heads, but you will spend more than your car is worth on them.

You can put some NA Z32 pistons and rods in.

 

ty MrGone i will do that

 

has anyone tried shaving their heads before..........i am cautious about trying it because we have interference vg30e motors....what would need to happen to make head shaving an option.......everything is just very expensive hp for our cars

 

Heh... NA Z32 rods = VE rods.
the pistons are almost the same as well.

 

check ebay.. there's a set of VE pistons and rods for like $9 on there right now. the pistons are used, but the rods should be in decent enough shape that you can drop them in. will be much stronger than the VG rods.

 

vg30de pistons should have a .5 higher compression ratio than the ve's... i need to get out and check how much clearance there is between the valves and pistons since the two pistons have different valve reliefs... i wouldn't think it'd be close enough to hit but, i'm not sure.

 

if i put ve pistons inplace of my vg i would lose compression right?

 

you'd gain compression. vg = 9:1, ve= 10:1

 

well the VE has a higher compression than the VG. 9.1 to 8.9 respectively iirc

 

you would gain compression, but I'm not sure how.....

the VE and VG pistons both have flat crowns. VG piston comes to the top of the block, so does the VE.
CR for VG is 9.0 :1
CR for VE is 10.0 :1.

VE and VG rods are the exact same length, but 2mm larger wrist pin diameter on the VE.

Either the VE piston is taller (FSM doesn't list specs so I can't tell you), or the head has a smaller volume in the combustion chamber...

 

Measure from the center of the wrist pin to the top of the piston.
Also measure rod length from the center of the end cap 'hole' to the center of the wrist pin. Thats how the FSM measures them, but they are the same (per Matts post) so it doesn't make a difference that it is 2mm larger on the VE.

It would have to be the combustion chamber*, although I would think the VE's would be larger :-/


* Assuming the pistons for both engines stop at the same distance from the deck.

 

not only do you have to worry about valve clearances, but it will also effect valvetrain timing.

Read some books on engines. It is not even a very effective practice for making more horse power.

 

anyone have any pictures of the ve combustion chamber?

 

Mark, I can get you some later... have a dismantled VE in the attic..

 

My guess is the combustion chamber. Thats a very easy way to up the compression without making dome pistons (which would probably be quite hard to do on a 4 valve head).

 

for comparison to the VG30E and VE, here's a picture of a VG30DE(TT) combustion chamber. the guy cc'd it out to 64.84 cc with a 1.1 mm headgasket and 71.447 cc with a 2 mm headgasket.

1.1 mm headgasket landed him 8.96:1 compression while the 2 mm headgasket got 8.23:1 compression.

i'll try getting out today and seeing if i can't find the cc's of the VG30E's combustion chamber and such (pictures of that below).

here's the picture of the DE(TT) heads:





original link: http://www.twinturbo.net/net/viewmsg...msg_id=1196273

VG30E combustion chamber (i chose the dirty picture from this site so everyone can see the size of the chamber combared to that of the cylinder):



Cleaner so you can see it better



larger pictures for each of those:
http://www.nissanperformancemag.com/...ck_chamber.jpg
http://www.nissanperformancemag.com/...ed_chamber.jpg

originating site: http://www.nissanperformancemag.com/...05/pathfinder/

 

Here's a few pics of the VE:


couple more here:
http://mattblehm.com/pics/engine/100_0266.JPG

you can see the chamber is between 3/8" and 1/2" deep here. no other measurements.. don't have time for it today, and I don't have the equipment to CC the heads.
http://mattblehm.com/pics/engine/100_0267.JPG

 

hmm.... yeah, visually that thing looks smaller than the TT's combustion chamber... that is most likely where the bump in compression comes from so most likely VE pistons in a VG won't help...

i'll see what i can find on the vg30de

 

Here ya go Mark.. flip that puppy over, resize a bit and VOILA!

VE head is nearly identical to VG30DETT head!
http://mattblehm.com/pics/engine/VG_VE_comparison.jpg

Look at the quench pad size and shape (round off the edges of the VE a bit and they'd be nearly identical to the VG in that picture. Also remember the VG valves are 1mm smaller diameter (I & E) than the VE, which explains the additional room between the valves inside the combustion chamber and around the edges). Also check out the water jackets and head gasket outline.. aside from the timing cover, they're almost identical in shape and form..

 

Now that's interesting... another odd thing to note is when I went to JE's website and looked for the specs on their pistons of the VG30DE(TT) is says both engines have the same head volume (49.5 cc) but the difference is the top of the piston. VG30DETT pistons are -4.1 while the VG30DE pistons are 4.8 (which of course is where the compression change is). I'm still trying to find some info on the VE if there is any out there (like what JE has listed).

The odd thing is the head volume, compared to the one I listed above. Either JE is wrong or that guy modded the combustion chambers. I know he included the thickness of the headgasket in the measurement however, for the .9 mm increase in headgasket thickness his combustion chamber volume increased by 6.607 cc. There's no way, not including the gasket, that you could get that down to the 49.5 cc that JE claims without modification. Time for some more searching... yay...

 

subtracting the difference from the 1.1mm headgasket, that comes down to a CC volum of 56.765.. that's 7.265cc more than the stock ones, and from the looks of those heads, there's been quite a bit removed from it. so those numbers are all realistic.

 

ok, did a quick search at z31.com and it looks like the combustion chamber volume of a vg30e is 55 cc. include the gasket and the notches of the 9:1 piston and you get about 61.625 cc total volume (72.549 w/87-89 Turbo pistons).

but to keep things less confusing:

Combustion chamber volumes:
VG30E - 55 cc
VG30DE(TT) - 49.5 cc
VE30DE - using some math equals ~49.34 cc or something like that

 

I think 49.5 is a good round number for the VE as well..

 

http://www.digitalbeta.net/images/Veapart/17.jpg
http://www.digitalbeta.net/images/Veapart/18.jpg

 

i guess with the vg30de pistons you might be able to get pretty close to 10:1 on the vg30e. that really bites that they won't work out as well as most had thought...

 

like i said what a shame it has to cost so much money for hp with maxima's....maybe i should find something else....when i became a die hard maxima i didnt realize the crap involved

 

That was the main reason why I got the Maxima, especially 3rd Gen VG motor. I didn't want anything easy, and sure enough, nothing is easy.

I had plenty of people tell me I should have just gone out and gotten a Honda.

I want a challenge, there's no fun in bolting on something, plugging in a chip and going.

 

WOW, that thing looks like it would bolt on np.....has anyone ever tried to put vd30dett head on or blocks?

 

Read my post in this thread about that..
http://forums.maxima.org/showthread.php?t=383001

 

Did you not read his reply?

Now why would you want do to that?

 

I'm going to start banning idiots, they are bringing the IQ of the 3rd gen section dangerously close to that of the 4th gen section

 

OH god NNNNNNNOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!! Let the ricers stay there please. Do what you have to... Just don't let this place become like the 4th Gen forum

 

didn't he just mean the heads? either way though, VE = timing chain, all VG's = timing belt

the tt valves?? oh well... they're inconel... hold heat much better than stainless does