L_U_D_I_AMaxima

iTrader: (3)

Hello everyone.
Long story short we end up a small project on our hands. Our new to us Murano had a blown head gasket. After a few night of wrenching and removing various harnesses, connections, hoses and what not I had the entire cradle assembly sitting on 4 jack stands. Separating the engine from the tranny was yet another trick since the transfer case had to be disconnected so the engine will clear it and come.
Anyhow with the engine being free and standing on the engine stand I now had the time to get to the actual problem. After removing both heads i did confirm that the head gasket was bad on cylinder 2 directly next to the inlet where the water jacket is. After researching the various options it looks like using the hr head gaskets are actually an upgrade to the problem? I found a pretty interesting article about the upgrade the gaskets. Here is the link http://5523motorsports.com/the-three...n-just-3-days/

Has anyone done this upgrade in their vq35? Any feed back? Looks like there is also a need to upgrade the headbolts as well

Crusher103

iTrader: (10)

Just use stock gaskets. You have to mod the block to run HR headgaskets. not worth it if you do not track the car.

grey99max

iTrader: (12)

Here is a web link to JWT (best darn Nissan racing parts supplier in the universe) which shows you details of using the HR head gasket, including the minor mod to get improved water flow thru the heads. The HR gasket has the latest in sealing technology, including a new fire ring sealer built into the gasket.

http://www.jimwolftechnology.com/wol...BOLTS_juke.pdf

A little work with a Dremel tool or other small grinder will remove the small amount of aluminum needed to increase the water flow thru the block up into the heads. This is easy compared to all the work you did to get the engine out - I'm impressed.

Pay attention to the comments about the head bolts in the JWT download.

At the moment, I'm building my third engine using the HR gasket and JWT c11 cams.

L_U_D_I_AMaxima

iTrader: (3)

gary99max,
that is exactly the article i found about the upgrade. I am also leaning towards the hr gaskets due to the added fire ring. When I look closely at the HR gasket it is very simple to understand that it offers much better flow than the vq gasket. Granted the OEM lasted 170,000 miles before it had a problem. Also which head bolts are you using? The 2 dot hr bolts or the Juke bolts? The article you posted has the extra bolt juke bolt which was not mentioned in the article I found.
At this point we are going to do small modifications to the engine such as bench flow test the heads and and see if we can pick some more flow. Polish the crank and replace all bearings, ultrasonic clean the pistons and replace all bearings/rings. I am going to keep this as stock as possible since I am dealing with a cvt transmission and it will be a very easy daily driver for her. Not building a rocket ship lol.
I am adding pictures of where the gaskets was weak and developed the leak. Cylinder 2 directly next to the water inlet.

L_U_D_I_AMaxima

iTrader: (3)

We are not going to track the Murano, but i just want to build it and eliminate the positional failure of the head gasket again. Like I said removing a vq35 form a Murano is a timely and tedious process. If i can make it better and forget about it it will be worth the mod.

Crusher103

iTrader: (10)

And my question would be what about the rest of the cooling system? The status of your cylinder head on your engine? Blown head gaskets are not common problems with the VQ, yea it does happen but its not common, you have a couple of scenarios that would cause the HG to blow. Most of them involve a part failing that in turn fubars the HG, like a thermostat, lifting the head, a blockage, even a rad cap. The HR gasket will cause the heat to transfer faster thus improving cooling but is not any stronger than the stock gasket. So if there is any underlying problem that has not been addressed your just going to pop the HR gasket as well. That's why I'm saying just pop a stock gasket back on, look at other things that could have caused the head to overheat/warp/lift.

grey99max

iTrader: (12)

Looking at your photo, maybe there was overpressure in the cooling system and water was pushed thru the head gasket. Crusher has good points about the cooling system, and you should replace the thermostat and hoses to be safe. However, the HR gasket has better sealing than the OEM gasket you have today. I use ARP head studs (202-4701 from ARP or eBay) because they aren't one-shot bolts, but can be tightened many times with no stretch. You can install and remove the heads over and over. They use a moly assembly lube and install and torque down much easier than OEM - and I know you know which end of a torque wrench to pull on.

The Juke bolts suddenly became popular when people discovered that the present Nissan inventory of HR bolts contains a lot of defective bolts - soft and weak. You can use the Juke - once - and I would grind off the ends of the Juke bolts to match the length of the originals. Put a 10.9 nut on the bolt before grinding then take it off - cleans up the threads.

Since you've come this far, I would replace anything in the cooling system you can, install ARP studs, and install HR gaskets under the heads. FWIW, there isn't much point in porting the VQ35DE heads, with stock cams, intake, and exhaust. Just touch up the valve seats and replace the valve seals - either lap the valves of have a machine shop do it. Just be careful about how much material you remove, because the valve lash is dependent on the height of the valve stem and there's only 3-4 thousands tolerance there.

This link will take you toward the end of a long thread about a couple of my engine builds. Try and stay awake !


https://maxima.org/forums/nitrous/61...-doing-44.html

6spd_Hayes

iTrader: (3)

Modifying the block for the HR gasket isn't too hard....


Here is some good pictures and info if you care...

https://maxima.org/forums/all-motor/...ld-thread.html

L_U_D_I_AMaxima

iTrader: (3)

Well the coolant system was semi overhauled. The previous owner took the Murano to a shop and they decided that it had a bad thermostat so they replaced it. Little to their surprise that did not fix the problem. They replaced the radiator, both hosed and radiator cap and had a very hard time bleeding the coolant system because it constantly had small bubbles. Surprised? What the engine was doing was actually pushing combustion gases into the coolant system. I test the coolant system with block tester and was able to confirm pretty quick that the coolant system was being over pressurized with the exhaust gases. Long story short once I start putting everything together the only used part will be the new radiator that his mechanic put on the Murano which has less than 15miles all together with the thermostat and radiator cap. Call me crazy but I am replacing those with OEM nissan parts. Basically once i am done putting everything back together the engine will have a new water pump, thermostat, every single gasket located on it, all new timing chains, tensioners, pads, main bearings, rod bearing, valve regrind and seals and so on. I am even going to replace the heater core hoses simply due to the fact that with the engine in the bay those are impossible to get to... modifying the block looks pretty simple. What I really was hoping to find out with this thread was if people had issues withe the HR head gaskets? Since the last post that Gary99max posted it looks like JWT also tested the juke head bolts with the HR gaskets. My main idea behind the upgrade of the head gaskets is that the HR offers the 3 firing ring which is nice and kind of offers that extra piece of mind.

vernk

sounds like you have it under control, couple notes, when having the valves done you might want to jump up the HR buckets they are the same price but DLC on them to reduce friction, the Juke bolts would be more work then they are worth since you would have to have the holes tapped to the bottom, and with that much time and effort you might as well spend the money on ARP studs

L_U_D_I_AMaxima

iTrader: (3)

UPDATE
Well after about an hour on the phone with JWT it was pretty clear what path I am taking. Hands down those guys are experts and know what they are talking about. I cannot remember who I spoke to when I called but we had pretty good conversation about the hr vs vq head gaskets. The reason why they decided to use the Juke bolts was due to bad batches of the vq 2 dot head bolts from Japan. Something about a tsunami and the factory falling behind schedule resulted in a very inconsistent batches of bolts. What JWT recommends is actually using washers out of the SR20 head bolts to space the bolt and thus no need to actually tap the block any further. They have been using the Juke bolts in numerous engine builds so far with no problems. Pretty much they said that with the engine being used for a daily driver and not racing the set up should give us many more years without problems. For some reason they do not like using the studs on the vq engines. So tomorrow I am heading back to the shop to prep the block for the hr gaskets and order parts on Monday. So far we have measured and polished the crank and based on all the numbers we will be using the standard size bearings. I still need to measure the cylinders and pistons but i have a feeling all the new rings will be standard size as well. I will try to keep everyone posted with the "OEM" build and once i am finished i promise to post pictures of everything, tear down, cleaning and reassembly...

grey99max

iTrader: (12)

I'm glad that you got good information from JWT. They are among the best resources for all racing things Nissan. The tsunami wiped out nuclear reactor power plants in 2011, and many companies that made hardware for Nissan (head bolts included) lost power for many months and substitutions were lacking, hence the crappy head bolts that showed up later.

" North Pacific Coast, Japan - 11 March 2011

A powerful tsunami travelling 800km per hour with 10m-high waves swept over the east coast of Japan, killing more than 18,000 people. The tsunami was spawned by an 9.0 magnitude earthquake that reached depths of 24.4km- making it the fourth-largest earthquake ever recorded. Approximately 452,000 people were relocated to shelters, and still remain displaced from their destroyed homes. The violent shaking resulted in a nuclear emergency, in which the Fukushima Daiichi nuclear power plant began leaking radioactive steam. The World Bank estimates that it could take Japan up to five years to financially overcome the $235 billion damages."

You Tube

You Tube

So, much more than HR head bolts were affected...

We would appreciate any photos and details of your repairs - thanks in advance.

grey99max

iTrader: (12)

Just noticed this quote in yesterday's issue of Car Craft magazine (January 2017 - page 43), from a long-time expert on turbocharging, Corky Bell... The magazine is building a Ford 460 with future turbocharging.

"A head bolt is an accountant's decision. A head stud is an engineer's decision".

Something else I recently read, but can't locate, was to the effect that using head studs gives a much higher clamping force than conventional head bolts, because of the use of special lubricants such as what ARP uses. Most drag racers use ARP head and mains studs, to keep engines healthy.

Since we discussed head studs earlier, I thought this was relevant.