I have a consulting fee. LMAO...

I do remember this but the cars that did this disappeared like unicorns. If you try and find one running around today you can't. Unlike other platforms you will find older powerful/ fast cars running. This is not the case with 350z/370z. Its really history repeating it self high dyno number vanish into thin air.

This is the frustrating part right here. WTF !!!!!!

The 1/2" headstuds in DEs was the fix until the L19/CA625 made them obsolete and unnecessary hassle. The original ARP2000 material had very low torque specification and was causing headgasket failures in the 500s and 600s. People moved to 1/2" studs (including myself), and the ARP2000 material in that size we could torque to 90-105 or so, and this fixed the issues. Eventually ARP released L19 in stock thread size, and then you could build a DE with adequate clamping load on the headgaskets without the extra hassle of machining for 1/2 studs.

The blocks showed no signs of issues with oversizing for the studs. My block was tapped 9/16 then had thread inserts down to 1/2". The "machine work" for the oversizing was done with a hand drill, and the studs were so crooked that you couldnt install the heads with the studs threaded in (not my work, sent it to a member that allegedly arranged a group batch of this with a machine shop, found out when I got it back that he was doing them by hand), you had to set the head on the gaskets and then thread the studs in. That engine then lasted over 10 years without headgasket failure 600-800hp. Once it was taken to over 900whp, it didnt last much longer... although it was the old fatigued crankshaft which failed and took out the engine.

In summary, the DE 1/2" headstud debacle fixed the issue with blowing headgaskets at 500-600hp. It was made obsolete by the L19s and then CA625+. There is no evidence that a 1/2" headstud would do us any good for what is happening now, which doesnt appear to be a clamping issue, but a cylinder movement/support issue.

So what are your thoughts on the Darton MID sleeves Phunk? Is this the right move. I am still researching on this subject.

If sleeves are the answer, who or what shops to install them? How do we know if they installed correctly?

Oldy but goody. Triples, compound turbos.

Think of yourself as a Mercury astronaut instead. It's more flattering and they got a ton of *****.

Sent from my SM-G955U using Tapatalk

I havent really formed an opinion on wet sleeves in the VQ. For a long time I didnt think they were worth the risk of problems, since nobody was breaking cylinder walls open or running enough power to have issues. In 2003 I did build myself a sleeved block, AEBS did the sleeves and installation. That engine made it about a day or two after tuning to 670whp I think before it blew the headgaskets, but it also had the old m11x1.25 ARP2000 that failed everyone. So who knows which was the culprit, or maybe both. That was when I followed up with the 1/2" headstud build. After that I never really considered them again, and assumed that even if they did hold up for a while, they probably werent the right setup for a long life engine that someone wanted to see like 4+ years out of. I feel like you are setting yourself up with some individually very strong cylinders, but that they are floating around in a compromised chassis (block) that is tweaking and twisting and probably not going to be able to hold those sleeves stationary forever. But what do I know, maybe they are the answer. I would trust them more if they were 1 solid chunk per bank, so each cylinder is supporting its neighbors as they hand off cylinder wall side loads back and forth, but that would be a lot more expensive to produce. What I wanted to do with my wet sleeved VHR was do a half-fill to try and give them more support to the block and to one another. My machinist didnt think he could pour in the epoxy through the small holes in the wet sleeves well enough to do a nice even job.

https://youtu.be/1pV_tLbZY0A

Why y’all drag racers need to find yourself a good tuner and run a stand alone

Is that your first taste of compound turbo charging? It is very common in the diesel world. I was dang close to putting a setup on my truck. LOL

Yeap, that is my question. How long will it last and what will happen over time. Will the sleeves stay put? Will the block yield and crack?

JUst the depth of detail

Yeah, compounds been around a long time. Worked on a few Elliott PAP compressor packages that had 3 of them.

My Titan XD Cummins is a compound turbo setup. Even though Nissan can kiss my a$$.

Some ford super duty's are compounds too. Depending on year.

Damn Spooler so sorry to hear man. I came on here to see what Crazy flywheel/clutch combo you had told me about only to see this. Scares the **** out of me man with the 22psi setting I have on mine. Think even with the built block, closed deck I should keep boost levels low if I want to last. Limiting it to 15psi :( today is a sad day brother. Hope all is well and you’re back again soon!

Crap happens, you should be good to 17psi if you have ARP 625 head studs and a close deck block. I have a couple of options I am looking at. Nobody knows how long anything will last due to the fact that they don't drive them for whatever reason. I may be back sooner than you think I hope.

Spooler whats your compression ratio? I have 10:1 and even with that 27psi spike I had no evidence of problems. That whole day of running hard at Wannagofast I was running 18psi and since Seb fixed my duty cycle on the boost solenoid I've had it at 21psi and hammered the crap out of it. Seb made a big deal on confirming L19s but I'm thinking the way the torque hits is going to play a big part along with compression making a difference. I also know Matt DiPaolo made his power at a ridiculous psi with the Stage 4 IPP block but a closed deck RJM block.

Do you have boost limit protection? Seb set my limited my psi to 15 and when I was having issues with the bolts backing out on the waste gate my boost would spike and it would cut throttle and reduce the rpms 5500 to protect the motor.

Pioneering **** as an individual sucks. Thanks for sharing your findings thus far.

I was running fine also until I wasn't. LOL I was at 11:1 compression. Matt already blew his headgaskets from what I was told. Can't use him as an example. Besides, his car is a mall crawler anyway.

Wow, sorry to hear about Matt! As far as I know mine will be 11:1 as well. I know Seb's is 11:1 also.

Sent from my SM-G965U using Tapatalk

Seb's got your back. He knows what he can and can't do.

That happened a while back when his car was first completed. He is back up and running now.

Copy that! Okay thanks for the clarification.

Sent from my SM-G965U using Tapatalk

That was the 9XXwhp car Forged Perforamance did, right? I was wondering whatever happened to that car, but I guess that's what yall have been saying. Laid it down on the dyno once and then radio silence...

Yes, that is the car. Laid it down, blew the headgaskets, got it fixed, and then doesn't drive it hard anymore. Same thing with CarbonZ.

I learned a good amount of information researching my 2nd motor build before my first one cut loose. I was lucky I had already started that project. I think I know what I am going to do. We shall see. Getting closer.

He is scared to run it autocorrected. Then I asked why build a damn near 1000 hp car. Silence.

I might join you guys in this wonderful service to the community :P

I might be sending my extra block to Mazworx to have it Darton sleeves, then swap over all my engine components. Based on what I've seen in this thread so far, it seems that simple sleeves won't fix the HG issues.

There is more to it than just the Darton MID sleeves. You will need to get a complete motor built to get his knowledge.
He is holding some information very close. He is smarter than the average bear, eh booboo.

Maybe he is going for best 370Z gas mileage... a high hp engine build and having to keep a light throttle should work out pretty well for him :ugh2:

Details have been worked out. I will let you know when it is time to reveal.

Trying to figure out few things. When the head gasket(s) let go. What was the conditions for everyone who had this happened? High boost, high in the rev range, hard on the gas, high traction, boost spike, just cruising around, etc?

Think Spooler hit on something a few pages back with the billet block. Talked about the 350 block breaking during launch, and the cure was the billet block. So the block was distorting enough to break. The 370 block is stronger, but it will still distort. Not enough to break, but cause other problems. When you combine the things I listed above. You'll have the head gasket issue. The block is distorting enough to release the clamping pressure off the gasket. The distortion could be the cylinders walking, the outer part of the block, the galley area. If the area that is distorting is around a few head studs. A few will pull tighter, and others will loosen up. Also need to know which head gasket, left or right side. Which cylinder? The inside or outside of the gasket? If we get this info. Maybe we can map out which area is being distorted the most. The other thing is. Is the head being distorted? Is it doing it's own thing, separate from the block, or with the block?

First, I would like to say thanks for the plethora of information in this thread. Truly appreciated. VQ35HR ('08) here with BP kit just installed on stock block so planning my engine build next and am looking to possibly go VQ37 bottom end. What bolt/gasket setup was this running?

My car? Not sure what they put in it. I would have to take it apart to see.

The VQ35DE block was yielding between the Head studs and Main studs. If you didn't catch it in the videos the tell tell sign was the main caps would just fall out during disassembly. The car took 1200hp before they had an issue launching the car at the drag strip. We may be going to a billet block down the road. We shall see. Right at this moment, I am pissed off to the point I might let the car sit for a while. I don't want to spend every dollar I have trying to get it back together only to have other people copy what I have done and it cost them nothing. F that.

What did you think was gonna happen? :rolleyes:

I have control over that. I am done with this thread.