1uz head seal vs 2uz iron block strength @ 30+PSI

[Full-Race Geoff]

Im keeping the boost down for now until I procure a larger turbo. Other than that Ive got things under control for now, new design MLS gaskets, new threads in the block and the use of much more head stud torque, - 100lbs. No problems so far at the 20psi level. Hope to hear more about your project, lets keep in touch.

no problem feel free to email me at geoff [at] full-race.com ill also supply you compressor maps and any information you may need for your next turbocharger purchase. We have two setup options we are considering at the moment, not sure which path we will follow until the cyl heads are finished and we flow them.

what MLS gaskets did you get? also are you using the L19 ARP studs? hit me back on email since i dont get on here too often. thanks

 

[M3TURBO]

I take it your 7/8" is a typo. I used 7/16 ARP studs for this motor. I have 1/2" ARP's ready for the next build.

IMO, 75 - 80lb is about the safe limit for 10mm ARP and the block threads

 

[stevechumo]

Hey M3, I rebuild my heads and used std size 10mm arp head studs. I torqued to 75lb, did you use 7/8'' studs for that torque?

Yep. I think 75 lb/ft is the safe side. 60 lb/ft as recommended is too little, I barely feel much resistance with the torque. And more than 80 lb/ft is too much that can warp the aluminum heads.

 

[Hennie Marais]

Sorry, bit offtopic, where did you get that short runner manifolds from?

 

[XR8tt]

I tend to torque to 30Lb then 60* then 60* turn..
Both surfaces MUST be machined flat [as in mirror smooth surface] with MLS / Cometic gaskets..

 

[spf_lexus]

It sucks because my head studs/HG's are 5k old but once the new block is ready to drop in I will have to do this all over again. I don't know if a resurface is totally required but i'm moving over to iron on aluminum, dissimilar metals. Would the surface still be prepped the same? Mirror finish? Or should it need it to "bite" down on the block since it's iron?

 

[cribbj]

I like Larry Carley's tech articles a lot. Here's his advise on head gaskets and surface finishes:

http://www.babcox.com/editorial/cm/cm100178.htm

http://www.enginebuildermag.com/Article/2587/the_fit_is_in_the_finish.aspx

 

[Full-Race Geoff]

we build a lot of 900+hp hondas, they use a 7/16 stud tq to 80-82. we dont have head gasket problems very often. weve built 1/2" stud motors they are usually more of a hassle than its worth. you got to drill all your head gaskets, youve got to get a custom socket made (i machine a socket on the lathe) etc.

i recommend using L19s (treat them like they are glass until you put them in the car) and tq to ~80+, unless you reall are trying to make over 1500

 

[M3TURBO]

Sorry, bit offtopic, where did you get that short runner manifolds from?

I purchased the short runners from Damian at a1turbos in NZ

www.a1turbos.co.nz

Though I will need to fabricate the plenum section myself.

 

[Hennie Marais]

Thanks. That's what I want to do, I've got a custom plenum on the stock lower part but want to improve on that. Thought about getting manifolds cnc cut but that's way too expensive.

 

[marlew]

Just been reading this thread as well
What i have found after playing with the 1jz motors is that what ever pressure you are running into the intake should be the same as what you have in the snail of the turbo.
In doing this i have never had a head lift
Also the 1jz is a cast block
I will find out soon enough with the 1uz iam building
I also use a sealant on the head gaskets (Cometic)
Three bond 1211 It does help.
I have found that some other guys have been using engine oil on the ARP studs and nuts when assembly is being done and some of them have had issues
I do recommend to use the lub that ARP supplies
also when tightening the heads down on the 1jz and 1uz I do it 3 times before the cams go in
eg; tighten then to spec then back them off and do it again 3 times
this will pull the stud up in the thread of the block and allow it to sit in the correct position also it allows any slight streach in the stud to happen
well guys thats how i do it any way.
cheers
Lew

 

[scotturnot]

Please repost the updates on this thread. I missed it!

 

[rdm20fan]

This is a great thread.
I wish you lots of luck M3
Are the head lifting issues really that serious? I had a HG fail, but I was running stock timing, and I think that was the major issue.
I have only head bad things about Comitec, now I have never used then, but I have only heard bad things.
I ended up using the MLS head gaskets from the GS400.

 

[XR8tt]

Head gasket issues can be a result of bad tune !!
Especially with steel gaskets..

 

[Fasteddie]

M3Turbo,

what intake manifold are you using ?....got a nice picture ?
Thx !

 

[M3TURBO]

The Intake manufold is still under constuction, might be at least a few more weeks.

 

[JBrady]

The Intake manufold is still under constuction, might be at least a few more weeks.

PLEASE repost your updates and dyno chart. Your post was lost in a server glitch. Thanks.

 

[M3TURBO]

For JBrady, re-post of dyno pull notes.

Notes about this run:
Not a particularly good pull, we had a tire slipping problem, can be seen on torque sharp dips after 4.9K. Damaged a tire on the dyno so could not do further runs at this session.
Having to use a high gear, Dyno speed limit was 290kmh hence graph cuts of at 6.5K, normally run to 8K
26psi peak, GT45R with 102/76 comp wheel, anti-surge port deleted.
880HP @ 5.4K
1179NM (870FtLb) @ 5.0K
AFR = 10.8:1 on boost – still rich
4” Down-pipe with electric valve opened to vent exhaust at front of car.
Comp wheel getting near its limit of puff and turbine on the small side.
Stock 1UZ intake and runners manifold, stock throttle body apart from removing the Trac butterfly.


Other updates:
With new tires fitted I have done some further tuning on the street since this dyno pull, (middle of the night) basically leaned it out even ran up to 30PSI. Power increase yes, though difficulties because of traction limits, even with drag radials fully heated, 5th & 6th gear runs. Traction control switched on would mess up AFR readings.
This motor is taking a lot of hard driving and now seems to be holding up.

Coming soon:
New short runner intake and plenum, 100mm TB.
108/80 mm compressor wheel – or a bigger turbo such as S488 or Y2K88
Even bigger stickier tires. Rear down-force spoiler etc.

Hope to have some decent new dyno charts after that.

 

[Fasteddie]

Stock 1UZ intake and runners manifold

That's surprising !...what cam profile are you using ?...
Again...great numbers !:arms:

 

[M3TURBO]

Fasteddie,

Cams are 272/272.

Re: stock intake, why surprising? Torque curve or peak torque? Though I am pretty sure a short runner new plenum will keep VE and torque up above the 6K point. Fueling requiement is down above 6.5K on this boost level but that also could be due to the small turbine.