Not really. It does have a larger stroke and bore, but the VQ30 block is closed vs. VQ35's open deck, and the heads on the VQ35 are vastly improved over the VQ30.

I am sure there are other difference too....maybe someone else can chime in.

 

Do you have any plans to build up your engine? If so, please post pics of your bearings once your tear open your engine. I think your bearings would provide some interesting information.

BTW, the stock pulley doesn't do any balancing, it just absorbs torsional vibration.

--
Jeff

 

If this motor goes then yes, I will be tearing it apart... And about the" balancing" I guess I just worded it wrong.. The motors are internally balanced...anyway, back on subject, I guess time will tell with my motor. We have been running it around 400whp @ 7lbs for the past 8000 miles but will be uping it to about 10lbs over the next week or two to get it ready for the racing season.. As someone else spoke about the tolerances, I would also consider it a possibility.... It seems to me, but I am not certain, that the oil pressure is controlled by a piston with a hole in it, and a spring behind that. If the hole in the piston along with the clearance around the piston is too much, then oil leaks passed it instead of moving it against the spring. When this piston moves back it uncovers a port which relieves the oil pressure back to the pump instead of the rest of the motor.. We have noticed major oil pressure differnces from Z to Z.. Luckily my car is one that seems to have a "controlled" range of pressure, but I have seen Z's that pin the guage... I guess time will tell....

 

Actually the VQ30DE is an open deck design just like the VQ35DE. The only changes to the VQ35DE from the VQ30DE are the upped displacement, CVTC, much better flowing heads, different accessory drivebelt layout, and other minor improvements. It's like an LS1 vs. an LS2.

I "think" what you're reffering to is the VG30DE that came in the 300ZX, that motor was iron block , closed deck and shares nothing with the current VQ35.

 

Bri, your are correct. I was refering to the 300zx motor, which has a solid cast iron block and closed deck.

 

Here is what may be a stupid idea:

The amount of power the factory rods can handle has always been a matter of conjecture - would it be possible to take a rod and put it in some type of hydraulic press and apply pressure on it until it breaks and translate that pressure to a relative hp or torque value? I realize you may have to sample several rods to get a base line value. With all the people getting forged internals there may be some extra rods around that could be donors.

 

I'd be willing to donate a stock rod. Not sure if we will find any takers to destroy a new forged Pauter rod.

 

You guys do realize that the stock rods are forged pieces...although not extremely beefy...they are far from the weakest rods I've seen. (Finally got to take a look at some stock rods over the weekend) I would say the weak part of the stock set up is the short, and small rod bolts.

 

Definitely appreciate that opinion - however what i am suggesting is that we need to start to remove opinions and conjecture from the equation to truly determine what the engines are capable of. I am not Mechanical engineer but it seemed to me that applying pressure to a rod until it snaps and measuring the pressure is one possible way to determine a range of hp levels and tq levels that the Rods are good for.

If through some type of pressure testing of the rods independently (remove the other variables such as rod bolts and detonation and oil starvation) someone can make conclusive claims tha rods break around 400-450 hp then at least we know. If through testing rods are capable of sustaining 600-650 hp then we know the problems with the engine blowing is due to something else.

I have been reading these forums avidly for nearly two years now and there are just to many variables when examining the blown engines - most initially were blamed on bad tuning. Now the current widly accepted mindset is that rods and internals are a problem. there is a newer theory that the oil issue is a problem.

All i am suggesting is that we eliminate as many variables to establish baseline tolenrances for some of these parts.

i dont have the knowledge of what is available to perform this type of testing since it is not really my field but i was just guessing that you could try to snap one inside some sort of contained hydraulic press.

 

I think you're right about that and I'm 99.99% sure that oil starvation is the main cause of big end bearing failure............I spoke with a friend overseas last night and he's seen 3 VQ engines in Dubai with broken rods over the lasy month.

This guy has built engines for world championship rally cars and british 2 litre touring cars so he has enormous experience with high performance engines (race engines).

I asked him what he thought the cause of the broken rods was, to my greatest surprise he answered immedaitely with............oil starvation to the big end bearings, I'm designing a baffled oil pan as we speak.

I have a very high respect for this guy so now I'm very sure we are on the right trail as to one of the main reasons of con rod failure.

Thanks

Peter

 

Most performance, and even Honda rods are all forged. But they are a very lightweight, cheap designs, and not nearly as strong as forged aftermarket rods.

 

I picture from my archives. Stock rod vs. Pauter rod.

 

While I most certainly agree that oil starvation could in fact be a cause of the failures seen I do see some discrepencies that I would like to point out. First off it was mentioned that there exists a possibility of oil running away from the pickup during acceleration. Based on what I have seen in regards to the location of the pickup I find that hard to believe. Attatched is a picture of the stock oil pick up with the lower pan removed. As you can see the oil pickup is angeld to the back of the car. This is the only place if any that the oil would "run" during accelartion. This in and of itself should alleviate the theory on oil starvation during acceleration. Furthermore should oil starvation be my concern it would be more concerning during cornering when the oil could slosh away from the pickup. Unfortunately on neither pan I have seen available is there I believe suffcient baffling for side to side slosh. Yes the baffling is there and should help some but from the looks of the primary baffles it is more intended to prevent front to back slosh.

Now I know I have been branded as an APS hater. And I will agree to an extent I do have my questions as to the motives in which they have when they post. For example their deep care and regard for the community in bringing to light the CAS wire issue. Although it did seem rather intriguing that it was only brought up by phunk and that even he was asked not to disclose it by APS. (I do not have proof as the thread has since been deleted although some may remember the post). My ultimate point is that like others have said everyone needs to make an informed decision prior to going F/I. However I must say that the statements constantly stressing a well baflled oil pan (with gratuitous plugs to the APS pan) focusing on even straight line acceraltion are IMHO overblown. Yes I believe its an issue. No I don't think its an issue during regualr acceleration and honeslty unless you are running a road course I do not believe it is as serious an issue as tuning and timing. I myself am working with another board member to design our own pan based on a stock pan with baffling welded on by him. I will be coupling this with an JWT pan spacer for added volume. No I am not plugging this and it is entirely possible this will be the only one ever built. I did not like the way the baffling was designed on the other pans as I said it looks as though by design or by general space restrictions they were designed primarily to prevent front to back slosh. Being that I do plan to track my car side to side is a far more serious issue for me. I will have a front to back baffle but the majority is designed to prevent side to side... Enough retoric from me... Oh and here is pic of the stock pickup. Note the angle it has pointing to the rear of the car. This should allevaite the percieved issue of oil "running" from the pick up tube under acceleration..

 

I didn't mean to infer that the stock rods are anywhere NEAR as strong as the aftermarket forged pieces. Those pauter rods are probably good for over 1000whp with the right set-up....all I'm saying is that the stock rods aren't as weak as some people want to make them out to be.

 

Not to totally punch a hole in your argument , but the additional "side to side" capacity added by the APS pan design should guard against lateral starvation considerably. That extra ~1/2qt per side has to go somewere during a cornering event. The result is deeper oil around the pickup area during lateral and fore/aft Gs..

 

Actually you didn't my main argument was that you did not need a baffled oil pan to prevent against slosh front to back during acceleration due to the angle of the pick up tube. The reason I am welding side to side baffles in the oil pan I am using is that it is a stock lower pan. Because my setup is simply increasing volume vertically it will not have the same effect as their pan does, not that their pans baffles actaully decrease the slosh as the increased amount of oil is the principle reason for the negated starvation efect. It is not becuase their baffles are helping in side to side slosh but rather that the increased oil capacity provids more oil thus somewhat reducing the possible effect

 

What a great thread! It's just soo long, I put off reading it.

The oil idea is a good idea, as are the wires, as is con rod failure, as is bad tuning, as is fuel system failure, etc.

There are too many variables and too few blown engines in our knowledge base.

I think APS has the most thorough kit on the market, but as others have said: 1. There aren't that many out there 2. They haven't been running for long (other than the test cars) and 3. They have to be professionally installed due to the unichip.

Time will tell. Most blown engines have been ATI (no timing control) or Greddy (mult variables in boost, timing, A/F, tuner etc). Very few stillen failures (lowest boost) and Very few Vortech failures. (Booger knows he went low on the timing )

What we need is some solid evidence. Solid testing. IE what is the strength of a cold coined vanadium stock connecting rod? things like that. Until then, only time will tell.

That being said, I'm sure my Vortech will blow up tomorrow on my way home.

 

There's been some more talk on the other board.

Here's some of the convo...

Although...the APS oil pan has more space for the oil to go, if you don't fill the oil up to account for that 1.25 extra quarts of oil...then it does have space to go, otherwise it will work like the stock one...other than better cooling (and obviously more oil capacity), and it has the oil return for the turbo already in place. So does the JWT...and it increases oil capacity by 1 quart...but won't cool better. So...IMHO, unless you are going to be tracking the car where the cooling would be needed, it would be better to go with JWT, 1.) cost ($350 less than APS I believe), 2.) increases oil capacity, 3.) has oil return lines already in place for the turbo as well.

 

Not sure why you find this issue difficult to understand, if you look closely at the oil pickup it's located at the front of the engine, given the stock oil pan has no baffling if you accelerate quickly which direction do you feel the oil is going to travel? The answer is very obvious.



I don't follow your logic, where the oil runs to under accellartion had zero to do with the angle of the main oil pick up................if the oil runs away fom the pickup in any direction the engine may well be starved of vital engine oil supply and lead to premature engine damage.



I'm sure it's possible that oil may run away from the pickup under cornering forces though looking at the original pan design and the loacation of the pickup I'd be a lot more worried about the oil running away from the pickup under extreme acceleration on a fast twin turbocharged engine.

I only raised this issue oil starvation in the first place as I now believe that oil starvation may be a very real cause of many stock con rod failures (not all though certainly some rod failures for sure imho), to date the only real explanation offered by many is that the stock con rod is weak, which I do not believe from the testing we have concluded to date and at reasonable/sane power levels.

It may well be that some of the engines with failed big end bearings/damaged rods were running low on engine oil (some early engines have experienced engine oil consumption problems) hence the starvation of vital engine oil supply, in any event it best that the guys are aware of this potential problem and keep a very close eye on the engine oil level at all times.

I have no other interest in this issue other than trying to help shine some light on some recent big end bearing/con rod failures for the guys. These bearing/rod failures were not in any way related to APS TT systems so it's easy to see that my motive was simply to help the guys with some interesting information and to try to eliminate the chane of another forum member suffering unnecessary engine damage, if this information saves just one engine then the entire thread has ben very worthwhile imho.

I'd be more than pleased if the guys want to design and make their own well baffled hi volume oil pan as feel this will help to reduce/eliminate the oil starvation problem and further reduce this risk of bearing/rod failure.

Thanks

Peter

 

One other thing to consider is the exact height of the pickup. When you remove the lower oil pan, the pickup is clearly visble and is actually at the same height as the bottom of the upper oil pan. The stock oil pan holds barely any oil....my guess is slightly more than 1 qt. The vast majority of the oil is located in the UPPER oil pan, which is the location of the pickup. So it seems highly unlikely that that pickup would EVER be exposed to something other than OIL.....unless the oil level was horribly low. In which case...nothing would save you.

Again, I'd like to say that I like the concept of a baffled and increased volume oil pan...and the APS unit is very nice. I am probably putting one on my car...as soon as I can find one in stock!

But I really dont think the oil pan has any bearing on oil starvation. My bearings showed little signs of wear and tear after 14000 miles of 8.5psi of boost. And I beat the crap out of my car...certainly didnt babe it. I did 10 or more 1/4 mile passes, and one road coarse track day.