vh45 improvements

[omgshawn]

So, finally got my vh and going to be rebuilding it soon. I've already come across some great info on improvements, mainly oil related. I'm going to be getting all new gaskets, bearings, timing kit, etc full rebuild. Heads look pretty good so probably just a deck and valve stem seals. I know nissan runs tight tolerances from the factory, and I do plan on beating on this engine so I'm going on having the machinist open it up a little, I think I read around 2thou is good correct?

I also plan on doing a oil cooler setup and relocate the filter. I'm most likely going to run a line to the front of the main oil gallery as well.

I've heard some talk of how a redesigned oil pan and pick up could help as well. I still need to check out the stock setup more but I would like to make a new oil pan/pick up and move the sump to the rear if there's room. I would eventually like to go dry sump but not going that extreme yet.

This engine will be NA(for now ) and will be in my s13, which is not a daily driver so it's not going to have any emissions/iacv/etc. I AM going to keep the PCV setup, I've been thinking up a way to redo the whole system yet keep it functioning properly. I'll have to make another post for that, lol

Is there anything else oil/block related I should look into doing while everything's apart?

[omgshawn]

So about the pcv...



Looking at the stock setup, if I'm correct, fresh air comes from before the TB, after the maf, and runs through the middle(green) lines under the rocker cover. The rear lines(red) vent from the crankcase to the rockers, and of course the actual pcv valve and lines(blue) which run from the front fittings, to the valve, to the intake manifold.

Now, it looks like maybe the rear(?) lines branch off(yellow) and connect to the actual lines for the PCV, is that correct?

So, I want to run a catch can on the pcv side(blue) inbetween the valve and the manifold. How much vapor/oil/etc comes out of the crankcase and into the rockers? Would it be beneficial to install one there as well?

Hope this thread doesn't give anyone a headache

[omgshawn]

No one?

[newbissan-tech]

i'm curious to learn about your oiling improvements. you said that they run a line to the front oil galley plug? i would like to see some pics or info on this? very interesting!

[omgshawn]

This is a very good thread.. bad-weekend-discussion-about-running-be ... 65-40.html

The plan is to run a line from the filter to the front of the oil gallery to balance out the flow, and also maybe rework/add drains to the head. I also want to run a accusump setup for pre-start lubing and incase of oil pressure lose

[elwesso]

Considering that Q45s can go 300k miles pretty easy with good maintenance, I am not sure that the VH45 has, per se, oiling issues.. Its when people re-design the sump, either with lower capacities or just differences in general..

It appears that pressure loss is the biggest cause of VH45 bearing failure.. I think for most people that the accusump is probably the most cost effective solution for many people... all you need is compressed air to recharge..

[omgshawn]

Well yeah, that's why I didn't say issues, I said improvements

[speedeast]

An oil cooler is about the best oil related improvement you can make aside from the accusump. And just to toss this out there: my motor has been in my car and there's no way you can run a rear-sump. Do you plan on breaking the block down? I would recommend replacing all bearings (go to the dealer with the engine code so they can match your main bearings - Clevite sent me the wrong ones before I realized this). Also, replace your rod bearings and piston rings. I got my rod bearings and piston rings for 30 some dollars through my local machinist. The part numbers for both are in my build thread. When you get the relocation kit, play around with it before you install it and make sure it flows without obstruction, etc. Just inspect the hell out of it. And like Wes said, most issues with the VH are because of improper maintenance and custom "improvements."

[omgshawn]

Everything will be well thought out, I don't half a** stuff

I'm going to tear the whole thing down so yeah new bearing and rings. How much did the mains cost if you don't mind me asking?

I didn't think the rear sump would fit, just an idea. I will probably end up still making a new pan, but bring it slightly up and make it wider..maybe some trap doors. I'm definitely going to look into an accusump.

[speedeast]

Call a dealer with your engine code and ask for the part number of what you need. I have a new set of OEM main bearings you can have $15 to your door if they fit. I don't remember what they cost me originally.

Be careful with the pan clearance, mine sits only a half inch or something behind the sway bar. Also, you can't shorten the pan depth as the pick-up sits right down by the bottom of the pan. I have an OEM oil pump in mine, nothing more. If my oil pressure drops off, I'll just park it and tow it home.

[omgshawn]

Well I plan on reworking the whole thing including the pick up. And I want the accusump because if I lose oil pressure at say 6K+rpms I want there to be atleast some chance of it surviving lol

[darinz]

In the thread above we went over the bearing issues and they are very definitely related to high performance so in a dd you'll probably never have an issue. BUT if you are going to pull g's then open clearances etc would be top of my list. Read the above thread as there was a lot of good tech in there.

[omgshawn]

Well this car will not be anywhere close to a DD lol, and will probably spend most of it's time getting beat on

[Geoffs89Pathy]

daily driving mine in a pathfinder and some occasional 4wheeling/rock crawling should be ok for a stock setup yes?

[elwesso]

From what Ive seen, if you leave VH45s pretty much stock, maybe just a retune, you can do about whatever you want to them...

In your case, I would defintely run an accusump, the factory oil pan is known to have oil starvation issues on high angles..

[Geoffs89Pathy]

crap. i don't even know anything about accusump. and how much is it? can you point me to a good starting point for this topic?

[omgshawn]

Think it would be worth it to fab up some external drains for the heads?

[speedeast]

IMO, no.

[Infinitiguy19]

Think it would be worth it to fab up some external drains for the heads?

I am not a engineer but if you make a oil pan that holds more oil then you wouldn't have worry about bottom end oil starvation, right?

I am guessing the original VH45DE engineers were more concerned about keeping the HLA's lubricated VS the bottom end since gravity will pull the oil down. Provided oil is changed EVERY 90 days to prevent varnish which would clog holes or worse sludge.

[elwesso]

Think it would be worth it to fab up some external drains for the heads?

I am not a engineer but if you make a oil pan that holds more oil then you wouldn't have worry about bottom end oil starvation, right?

How does the amount of oil the oil pan holds have any affect of what the bottom end of the engine?

[Infinitiguy19]

The way he made it sound with the drains on the heads I thought that he thought that the top end was holding too much oil with its many narrow drain passages that get clogged easily.

If the pan holds more oil then there will be more oil for the pickup because from what I understand the oil doesn't get to the pan fast enough. I don't know thats why I am not an engineer.

[omgshawn]

From my understanding, the pump empties the sump faster then it can get the oil back to the pan, because of a 'maze like' pathway. I'm thinking of fabbing up some -12an drains for each head, but was wondering just how much oil actually gets stuck up there. It wouldn't be too hard to do but I don't want to do it if it won't really do anything lol, -12an fittings are expensive..I will be increasing pan capacity though

[speedeast]

How about a dry sump?

[omgshawn]

To do it the way I want would cost around $1500, and I'm not looking to spend that much on it right now lol. The drains would only cost me the price of fittings, the rest of the oil system will be -12an so I'll have ss line left over.

[Geoffs89Pathy]

Tmorgan4 is doing dry sump.
Keep us posted on what u do.