Gtx3071 Install

[Sunkist]

L19 why not get good ones and know its not your weakest link anymore..

and it looks like youve made up your mind!

[scotty nm35]

Yep, I figure there is no point getting another engine for it to just lift the head again. This way with the L19's I know the head studs are good for 1500hp or more.

It looks like VQ25's have the same head bolts as the VQ3.5de hence the same head lift issues at around 500whp. Anyone pushing for over 300kw would have to consider these L19's at some point.

[Daleo]

Yep, I figure there is no point getting another engine for it to just lift the head again. This way with the L19's I know the head studs are good for 1500hp or more.

It looks like VQ25's have the same head bolts as the VQ3.5de hence the same head lift issues at around 500whp. Anyone pushing for over 300kw would have to consider these L19's at some point.

This is your new target; kgo.

[Sunkist]

my point exactly! i didnt know of any other ways to tell you its a waste of time and money to be fishing for a new engine with no history of it.

[scotty nm35]

Its easy, twin gt40's sticking out the bonnet should get me there. lol.

Thanks Dale but im more than happy with the powah it has now, It looks like I will have to do open heart surgery on my poor engine though, and Gleeson's.

[scotty nm35]

my point exactly! i didnt know of any other ways to tell you its a waste of time and money to be fishing for a new engine with no history of it.

What can you do, no-one could have predicted I would stretch head bolts. Looks like the little 25 is not as tough as I thought. Hopefully its just the studs though.

Anyway, we can rebuild it, we have the technology... lol.

[Daleo]

Its easy, twin gt40's sticking out the bonnet should get me there. lol.

Thanks Dale but im more than happy with the powah it has now, It looks like I will have to do open heart surgery on my poor engine though, and Gleeson's.

Lol, only joking...

It'll be interesting to have a proper look with the heads off, to see how bores, piston crowns & heads look after the number of km's you've done at your elevared power level.

[iamhe77]

What can you do, no-one could have predicted I would stretch head bolts. Looks like the little 25 is not as tough as I thought. Hopefully its just the studs though.

Anyway, we can rebuild it, we have the technology... lol.

Just how tough did you think it was?

It did overheat prior to this problem due to a radiator issue and has been pushing over 300awkw for a while now.

Not bad for an unopened 2.5.

[scotty nm35]

Just how tough did you think it was?

It did overheat prior to this problem due to a radiator issue and has been pushing over 300awkw for a while now.

Not bad for an unopened 2.5.

Agreed, but if the head studs are all that need changing (and that's understandable at probably 600 flywheel hp) then lets do it and get on with tuning. Its not expensive in the scheme of things just inconvenient. Looks like i succeeded in finding the limits of the unopened engine anyway. lol.

I have never seen the temp gauge much over half way, not sure if it overheated or what. I always seemed to catch it in time, lucky I have the informeter... I think it's just the combustion pressure and that is what the VQ35 guys are saying too. Weak ass 3.5 bolts.

[iamhe77]

Agreed although it might pay to look into custom head gaskets while waiting for the studs to arrive.

Might as well do it while the top is off.

[slippylotion]

Id say you proven the stock vq25 to be very strong so far. I consider the head gasket and bolts the fusible link in an engine and your just tripped.

Yours is still testament to the strength of the factory bottom end. Good job and look forward to the finished result of the 76.

[scotty nm35]

Agreed although it might pay to look into custom head gaskets while waiting for the studs to arrive.

Might as well do it while the top is off.

I can't find any, do you mean copper gaskets or Cometic, apparently the Cometic ones are crap and I doubt they make them for the smaller bore. At least they come in different thicknesses for the VQ35de's though. I have just ordered the stock head gaskets from Nissan but I have to rebuild 2 engines so if you can find a stronger hg option i'm all for it.

[Daleo]

Frankly, if the head bolts stretch; even a million dollar gasket won't save you.

At least the Nissan gasket is a known quantity; sort the clamping issue and the problem will likely be gone.

[scotty nm35]

I agree Dale. I don't want to go down the larger bolt route, the L19's look like they will do the job nicely and the stock hg should hold fine with 100 foot pounds of torque. lol.

[Sunkist]

Agree with dale, the cometic ones won't be any better than the stock metal one from Nissan, they are both multi layer gaskets, once shit gets in between them they need to be changed.. The L19's and some new head gaskets from Nissan and it should definitely not be the weakest part in your engine

Scott should shave the head while theyre off

[ARTZ]

Scott should shave the head while theyre off

higher comp with the 3071 and smaller rear housing would of been sweet and punchy as to drive around the street, but limited to 330-350

but try telling that to these damn horsepower junkies

Thing is if you get a bigger (3 or 3.5lt) engine chances are your going to need a bigger turbo then as well, I mean a 3076 is often considered just big enough for an rb30 and nearly all go bigger Gt35s...I think be best just to get a 2.5 up and running again, maybe slightly higher comp for kicks..most importantly sort out the overheating issues...

[scotty nm35]

I may have to get the head decked anyway but they wouldn't be taking much off. I'm keeping the 2.5 for now.

I ordered the oem head gaskets today, and ended up getting the ARP L19 head studs for $399us. They should all be here in two weeks so that's how long I have to get the engine out and disassemble/check it. All going well it should be back on the dyno within a month or so, just got to learn how the pull a VQ down and reassemble it now.

[ARTZ]

well you got plenty of engines to practice on...its just a head job, how hard can it be..

just dont strip any bolts/threads..ended up costing me 130$ to get that little m6 retapped and helicoiled.. but i had it running 2 hours later

[scotty nm35]

Ouch, not too bad considering you hacked at it with drill bits for hours though.

Thread doctor good to you? He didn't want a bar of my snapped thread with an easy out snapped off in it... I managed it by myself though.

[ironpaw]

So...under 300awkw should be find right? RIGHT?!?!?!?? no stud stretching for me yeah?

I ask because I plan to flog the hell out of the car in 61 days time....well at least for the 1st month anyway!!!

After a visit to Cihan that is...

Edited May 30, 2012 by ironpaw