Well I went down to help a fellow Maxima.Org member put a timing belt on his car down in Cincinati OH. Made it down there just fine. Got 25.4mpg doing it! I was happy! On the interstate at 70-75mph the AFR danced between 14.7 and 15.1 all is good...
I had to fill up at a station somewhere in OH with 92oct. I'm still running 12lbs of boost. I only use one station here in Elkhart that has 94 on the pump and it's normaly cheaper than anywhere else.

Anyway... I get about 4mi from Goshen which is 20min from my house. My wife calls and her truck is broke at the mall. I start rushing to get home and I end up Nukeing the headgasket passing some guy that keeps hitting the brakes going 40mph in a 55zone. Well it's doing the huge white cloud of smoke trick all the way to the gas station there in goshen but runs prity smooth doing so. I didn't want to chance over heating it and warping the head so I stopped there. I got a ride from my folks back to my shop where I got the Dueley and trailer. Got back to goshen and picked up the Max. I got about 4mi out of Goshen and blew the trailer tire. Screw it... Went 15mph alll the way back to the house and drove the Max into the Garage.
Switched the tires around on the trailer and Off to go pick up the broken truck at the Mall... which takes me a hour to ratchet on the trailer. Great.. truck is loaded.. Back to the shop..... Remove completly full gas tank and replace 300.00 fuel pump/sending unit/regulator assembly. Drive truck home go to bed... LOng story but I was up from 3am Saturday morning till 5am Sunday morning..
Moral of the story... Avoid BAD GAS
I'll send Mark pic's of the carnage when I tear it down tomorrow night!
~Scott

 

that sucks man but good luck getting the max back on the road and hopfully everything else in the motor survived

 

You forgot to mention it was a Shell station. Hopefully everything will go smoothly with the headgasket, and maybe the roads around here will be dry when you get done. I'm anxious to see your car in action!

 

man that sucks. the highest octane around here is 91 which definitely compared to have 94 back in bloomington (or 116 if i wanted to go to the speedway downtown )

hopefully there's not too much damage.

 

Man you had a rough day. Sorry to hear that!

 

Yea that Shell station is getting a Mail bomb! Lol..
I know it was the gas with almost 10,000mi getting gas from the same station and the one time I get fuel somewhere else it detonates.. Gota be fuel!

On a more serious note... I'd like to order a thicker headgasket and drop my compression down to around 9-1 or 8.5 if I can get one that thick. What engine application would I order it for? The older 300Z's?(Forget the year) That have the same block as my VG. Hopfully Cometic makes a set for it. ARP headbolts avalb? Studs? I'd realy prefer studs.
Getting into this engine will help me understand more about the limits I might have with it. I've built alot of GN engines but this will be my first time tearing down the top of this VG. I'm interested to see how the headbold configuration is along with port shape and sizes. I'd send the heads up to have them redone but it's not leaking oil or burning oil... Maby I'll have them retouch the valves and seats and new valve seals.. Just depends on what it all looks like when I tear it down. I know there's not going to be much block wear.
If there is .. My parts car has a 120,000 mi motor that's in great shape. I only paid 300.00 for the whole car so Whatever I find it's no big deal.

Thanks for coming over Saturday Brad! Sorry for not being able to take you for a ride.. Have to give you a rain check I've met 3 board members so far!
Hopefully have most of it torn down tonight.. I'll send pics when I'm done!
~Scott

 

actually the engine is already at 9:1 compression... and i probably wouldn't go any lower. the engine i have has 8.3:1 compression and its a dog down low.

3 places that i know of that can make custom head gaskets for our cars:
http://www.cometic.com/
http://www.scegaskets.com/
http://www.paeco.com/gasket.html

i'd probably stay away from paeco myself. they don't have a very good record.

also, you can find a lot of good info the VG's at www.z31.com

 

Well it took me 3hrs to tear her down but I found the culprit. It's the #1 cyl and for as much smoke as it was making it sure didn't do much to the gasket. All the other cyls look great! valves are clean Chambers look good wow.. Very little cyl bore wear too.
I'm sending you a few pic's. I don't think I'm going to do anything with the heads just clean them up and put'm back on.
Maby by friday I can get it back together!
Scott~

 

good luck scott.

sorry to hear about your troubles, but its good that you and brad hooked up.

 

definitely not that bad at all:

 

Well. after tearing one head down at the shop and porting the intake and exhaust runners I'm still very impressed by the engineering job done by nissan. I'm also betting that this VG will hold more power than a 3.8L buick before huring a headgasket. The combustion chamber design and having 13 head bolts VS the GN 3.8L having 8 is a huge clamping force for the nissan head. Stage 2 buick's have 14 bolt pattern which holds up to 1200hp and above.

There's also a flaw in the fuel rail design on this engine. I'll send Mark a picture of the completed mods to the stock fuel rail and a writeup about it for boosed applications. You N/A guys don't need to worry but the Boosted VG guys will need to do this fuel rail modifaction or you'll lean out the back three cyl like I did. Don't care what Injectors you've got it won't get enough fuel back there. Combustion chamber's on my car prove it. I'll get into that later.
The Exhaust mainfolds on the car are a great design for turbocharging... Very thick flanges.. wraped with fiberglass and a heatshield. The inside of the mainfold definatly needed porting.. Rough ends where pipes were welded and overhaning neeed to be trimed out badly.. Once smoothed and matched they look great!
These changes I'm making will definatly help.. I'll send pic's over as I go along.
If the Headgasket would not have failed the intake gasket would have for sure.. It was so brittle it fell apart in my hands... So one way or the other these gaskets needed to be replaced for sure.
~Scott
You can't hardly tell where it blew the gasket.. very small track there on the top left where the small hole is looks more like the coolant passage gasket failed then detonation to me.. But it could have been a combo of both.
It won't happen again that's for sure.

 

how does the diameter of our head bolts compare to the GN's?

 

They are smaller by a little bit I'd have to mic them to tell you the difference for sure. It'd be only one size smaller. But it's maby a half size because of the american to metric differences.. I'd guess.
~Scott

 

That right there is a quality post. Informative, and apparently breaching new territory that hasn't been posted here before, at least that I have seen.

 

yeah, i'm definitely interested in the fuel fail issue. i never really liked the design but never really thought up any ways to help it out.

 

I agree Neal, this is very informative stuff.

I've always wondered about the fuel rails on even 4th gens. Sorry to steal your thunder but couldn't there be a possible pressure difference between the entrance to the rail and exit? Is it possible that cyl 5 is always slightly richer than 6? I think having a dual entrance and exit setup would relieve this. This is of course not needed if you've upsized the injectors, MAF and such to return to near stock FP. Is this similar to the VG rail?

I can't believe you guys have gas stations that sell 116 or even 94 octane for that mater.

 

what's even weirder about them selling 116 is the closest drag strip is a crappy 1/8 mile track in the middle of nowhere. closest 1/4 mile is about an hour away. i guess guys do race a lot at that 1/8 though... and there are some very fast cars there as well. must have been a lot of requests to that station for race gas.

 

when i lived in PA, i only filled up with sunoco 94

 

Thanks alot for that comment Nealoc!
Broaner: That's what I'm going to make for the 3gen guys a duel inlet duel outlet system for the stock fuel rail. It's realy going to be a simple mod but I believe it'll make all the difference in the world with the design of the fuel rail. I'll try and get the fittings rounded up at the begining of this next week.
I contacted Isky about camshafts.
I need Head studs for sure. Trying to find a sorce for that.
I need springs for the newly ground camshafts.
I'm also going to make the mods on the combustion chamber that I read about in Popular Science that swirls the charge when the piston is rising before combustion.
From what was stated there it makes a great difference with reducing detoniation. In Inda where the guy who found this method they have very poor fuel and he started to find ways to get around the detonation and he found this as a solution.
More later,
Scott~

 

scott, is there any way that, once you have this fuel mod done, i could drive down and we could try to adapt it to the 4th gen?

i have 5 370cc injectors and will be installing them soon.

 

hmm interesting idea for the fuel found this bilelt fuel rail for a 4th gen a while back
http://www.eautoworks.com/html/ORD-A...e-no-24122.htm
i dont know if anyone ever used it or installed it to review but i have a 4th gen and was wondering to create a 2 inlet/outline fuel rail system wouldn't this jsut involve weling/fitting a 2 line adapter to the fpr to split to both inlet of the say the rail in the link, and use the same fitting to reconnect the 2 serperate outlet on the other side of the rail to merge agin as one, and then its jsut a matter of running that return line to where the stock was? or is it more complicated than that? dont look like it but i could be wrong


Kinda like this(please excuss my ms paint sketch):
http://pg.photos.yahoo.com/ph/bintan...f1.jpg&.src=ph

 

the only thing you need to change on that sketch is the fpr location. its actually on the return side so that it can basically block the fuel flow to increase the pressure.

fuel pump -> fuel filter -> fuel rail -> fuel pressure regulator -> gas tank

other than that that's probably the right way to do the dual inlet/outlet setup.

would there be any benefits of using ss braided hose on the fuel lines? say for instance like on the brakes... could it help level out pressure or anything? make the fuel pump not work as hard? etc. etc.

 

oops i knew it was somethign like that but i foudn this stuff too

http://www.russellperformance.com/au...l_manage.shtml
maybe that can be used for the y adapter
SS lines would be nice, but doesnt the injector need special fuel injection hose??? or the high psi type?

give it a try let me know how it turns out since you got the engine out and all lol, i wish i had a 2nd car so i can play with mine more

 

most ss braided lines are fine for fuel

 

If your running new lines from the tank to the rail I'd suggest the same hose as a nitrous feed hose. Nylon on the inside and Stainless on the outside.
There's a big fuel flow difference between the rubber hose that has a stainless wrap and the nylon style N2o hose. The nylon just allows the fuel to flow easier and it's also alot more durable.
I'll be using the braided rubber hose for the small runs I'll be using on my car since you can't just put a clamp on the Nylon hose.
Anyone know a place called Nissan Motorsports out of Gerdina CA? I guess they have alot of valve springs.. cams other parts I'll be needing
Thanks for the help! Scott~

 

i have two inlet ports on my aem fpr, so the y return would not be necessary.

is there any way to adapt the hard line that comes out of and back to the tank (the one that runs underneath the car) to accept AN fittings? or is it basically a cut and flare procedure?

Scott, I have heard of it, but dont know too much about it.

Have you tried courtesy or jerry rome?

 

Wow! This is turning into a really good idea. The easy way would be to do away with the stock tank. Moving to a fuel cell would eliminate all clamped fittings. It would also be quite a bit of work.

 

where did anyone say fuel cell?

 

Nobody said anything about fuel cell. I'm suggesting it since people are suggesting these low expansion fuel lines. Believe me I'm not about to up and buy a fuel cell. But it would illiminate all issues asscociated with clamping fuel lines.

 

I had to do this procedure with my wife's T-Type.. It's the stock Fuel tank with a -8 fuel feed and a -6 return line to the tank. I had to use a fitting similar to how you splice brake line but it has a AN fitting on the other end. It crimps onto the steel line on one side and has -6 or -8 or what ever on the other. I have those fittings on the tank side and just before the fuel rail up by the engine. Not a problem with stock tank. Fuel cell won't be a issue eather but no fun loosing trunk space for fuel.
Or you could sump your stock tank by adding a lower pickup with AN fittings.
I've got my rail here at home and stuff here to do pictures. I'll send the info over to Mark and let him post on a new thread...
~Scott
Oh.. Also.. That popular Science article had to be in June,July or August "ish" 2004 I know it was in the summer because I did the mods to the boys motorcycle and it worked!

 

scott-what are you doing the weekend after valentines?