Rebuild or swap?

[Earth1]

Hey it's been a while since I've posted. Unfortunately my truck has become ill.

 

At 189k, my engine is progressively burning more oil, and the oil gets dirtier between each oil change. I have lost a lot of power and gas mileage gets worse by the day. Oh, and the valve chatter. Results of compression test aren't good. I had a mechanic friend look at it and he says it needs more than top end work. Major engine work is way over my head. I am considering a rebuild over a lowmile vg30-vg30 swap. Rebuild would include headers and cams. If I have to have the engine pulled I want to spend some extra $ and upgrade to performance parts. Might as well, right?

 

As an alternative, I'm considering a vg30-vg33 swap. I have checked all over, and haven't seen much discussion on replacing a 3.0 with a 3.3. Sorry if I missed it somewhere. On the NissanPerformanceMag.com Project Pathfinder they used a 3.3 block with slight mods and rebuilt 3.0 heads. What would be the advantage of using the older heads on the newer block? Why not just use the whole vg33? I know the difference in HP between the 2 engines isn't substaintial but if I can find a deal on a VG33 I may want to try it.

 

So I have a few ?s, and I want some of you gurus to elaborate. I want to keep it Nissan, and cost effective, so don't even mention putting a chevy engine. I won't do it.

 

1. What model and years have a VG33? I need to start shopping.

2. Any advantage to keeping the top vg30 if I did swap to a VG33? Is it an ECU/MAF issue?

3. Would adding performance cams & headers to the vg33 project add extra labor cost? They have to remove and replace all that anyway, right?

4. What is the HP/torque in both engines stock?

5. What is a guestimate of the HP/torque in both engines with cams/headers? It seems the 3.3 benefits more from these mods.

EDIT:

6. Any special fabrication needed for putting a 3.3 in a 92? (mounting, etc?)

 

I'm sure I'll have a lot more questions later.

Edited February 11, 2006 by Earth1

[94extreme]

1. 96 and on i think, all Xs

2. i think you get a little better compression but don't quote me on that. (you'd probably need a new ecu too) not sure about the room.

3. shouldn't on labor

4. search?

5. i think the HP gain is pretty minimal... the biggest jumo seems to be with a supercharger.. read eaxpensive though since you have to run on high octane.

[br2an]

Sounds interesting. I have followed Project Pathfinder for quite some time now and find his results very informative. One of the things that I noticed was that he seemed to get his best engine performance gains when he installed the headers/camshafts combination. At the same time he also mentions a big gain in gas mileage.

 

If you look again after the switch to the 3.3L block (and the mods made there were not minor) he gained again in power but went backwards in gas mileage. Oh, and having the heads ported/polished and shaved to increase compression would have added some hp besides the increase in displacement.

 

If you can get the 3.3 for the same price, go for it and you should see some gain. But if the difference in price is substancial, I would probably try to add the cams/headers to a 3.0 and then you will know what the gains will be.

 

Re if the heads will fit or not, try asking morepower2 on his thread on the other forum (hope this doesn't get me banished here). I think he did use the 3.3L heads as he mentions getting the heads that "came out of a wrecked Xterra with only a few hundred miles on it" checked and it came out fine. But later on it seems like he used the older ones. Wouldn't hurt to ask.

 

Good luck and keep us posted.

 

Brian

[Slick]

sssh this gives me ideas when i begin to rebuild my motor...... sly

[Earth1]

Well I have decided to get a used engine and I'll attempt the swap myself. I want to try a 3.3 but this will be my first engine pull, so I'm getting a JDM type vg30 to keep it simple. I have enough learning to do without throwing a different engine into the equation. I have some help, a FSM, and a lot of will. I just got my new headers, and NISMO cams are on the way that I will be installing as well.

 

I was inspired after reading about some of the engine projects on here. I NEVER thought a year ago I would even think of this but the thought of saving at least $1000 and learning how to do that kind of work myself has made this idea a reality. I will have many questions throughout this saga, and I'm sure if I get stuck the crowd here will help me out.