Just got this back (RB26DETT Head)

[CursedGTR]

It as been a while since I posted anything on the progress of my RB26 in S15 project. I decided to get the squish area removed from the head and get the surface shaved. While I was at it all I went ahead and got an Apexi V-Max head system for it. but I will put up pictures of the completed motor and all of the mods in a week or two. The pictures below show the machine work that was recently completed by Nagoya Precision. Removing squish area helps with Knock prevention under high Boost and High RPM, since this motor will be turning right at 9,500 RPM I decided it best to be safe rather than sorry.




Modified by CursedGTR at 7:22 AM 3/4/2007

[Nameless EJ6]

Nice! Looks like they did an awesome job at removing metal and finishing it up.

[RB280SX]

It as been a while since I posted anything on the progress of my RB26 in S15 project. I decided to get the squish area removed from the head and get the surface shaved. While I was at it all I went ahead and got an Apexi V-Max head system for it. but I will put up pictures of the completed motor and all of the mods in a week or two. The pictures below show the machine work that was recently completed by Nagoya Precision. Removing squish area helps with Knock prevention under high Boost and High RPM, since this motor will be turning right at 9,500 RPM I decided it best to be safe rather than sorry.

WOWOWOW ! You better get sound clips ASAP .

[Darius]

WOW! That looks really good. With a turbo motor I was just curious why you were shooting for such high rpms?

[Swedish Mike]

WOW! That looks really good. With a turbo motor I was just curious why you were shooting for such high rpms?

Normally you need high revs to reach big hp with a big turbo and small engine.And yes, 2.6 litres are actually small if we talk crazy hp.

We had the same problem in a 2.3 litre Volvo engine, needed at least 9000 rpm since the turbo woke up at 5000 and gave us full boost at 8500 rpm.

/Mike

[bmadd2402]

I'm sorry, Squish area? I am thinking of pulling my head (out of my *** first) and doing the HG, and some cams, and while I'm at it I figured a valve job etc... So, can you clarify a little? Just want to know what you guys are doing, but I never heard that phraseology before.

[74260zt]

I'm sorry, Squish area? I am thinking of pulling my head (out of my *** first) and doing the HG, and some cams, and while I'm at it I figured a valve job etc... So, can you clarify a little? Just want to know what you guys are doing, but I never heard that phraseology before.

Look at the difference between these two RB26 heads... see the "squish" area?

[CursedGTR]

^^^^ That pretty Much sums it up on what squish area is.

[UK-SRi]

Quick question for you, was it trimmed back that far to lower the compression, or was it to reduce hot spots?Also wouldnt it be better to cut back at 45degrees for minimum surface area if its to reduce hot-spots???

Mike

[jdms13rhd]

Nagoya Precision!!!

I am living in Nagoya now. Can you please hook me up with a number to call them??

Very sexy chamber!!! Looks like lots of fun, I'm looking forward to the new pictures!!!

[bmadd2402]

^^^^ That pretty Much sums it up on what squish area is.

yes. yes it does.

[CursedGTR]

Nagoya Precision!!!

I am living in Nagoya now. Can you please hook me up with a number to call them??

Very sexy chamber!!! Looks like lots of fun, I'm looking forward to the new pictures!!!

Tel: 0426-60-1185

http://www.naprec.co.jp

[jdms13rhd]

domo arigato Mr.Roboto!

I will be giving them a call today!

Thanks a million!

[CursedGTR]

Not a Prob

[CursedGTR]

Just figured I would post up an update on this thing.

Continued working on the motor today. All I have left to do really is put the valve covers on (waiting for paint to be finished), finish painting the throttles (nothing more than spacers now) and do some other stuff here and there. This Weekend I painted the motor mounts, intake manifold, Cam Position Sensor Bracket, Altenator Bracket, Cam Gear Backing, installed the cam gears, set timing and installed the timing belt, Torqued the head down, welded in 1/4 NPT female bungs for use with AN fittings on the valve covers and put on the ATI Damper Pulley with the lower belt shroud (painted in blue ghost flames, which will be about the way the valve covers will be). I also blocked off the water passage under the intake manifold (do not really need it anymore) and started to replace as many bolts as possible with Hex Bolts. We also cleaned the corrossion off of the exhaust manifolds by using a sand blaster with fine sand and a scratchy pad with metal polish, the results were pretty nice looking. All the pictures are below. Hope you likey.



Blocked off water passage for intake manifold underside

Engine as it sits now

[sparksta]

looking good man and i was wondering with the "GT" head cooling system as some call it do you also get rid of the balance tube. If so what do you do to feed air into the air chamber with IACV? Thanks

[CursedGTR]

Since it is a mod that goes with big throttle set ups you end up with a system similar to that of the greddy intake manifold on the RB25DET. I will hook it all up in the next couple of days and show pictures of how it all works.

[sparksta]

yeah i'll prolly be doing it but having the ports on the underside. I want to keep the stock intake and itb's so that'll prolly be the only way to do it.

[CursedGTR]

I thought about doing it on the underside, buut you have to fab up some kind of flange deals to go over the water jackets, it was just a little easier to do it this way for me. I might try it on another one I am going to do for a friend in the future.

[RBMonster]

Cursed, I would really like to discuss the squish area mod with you. can you shoot me an email? [email protected]

[CursedGTR]

E-Mail sent

[74260zt]

Any new pics to share...??

[CursedGTR]

I put the finished motor pics up a while back under a different thread. I am still in Iraq for the time being but I promise sensory overload via .jpg when I get back to work in February.



Just to jog the memory

[CursedGTR]

I put the finished motor pics up a while back under a different thread. I am still in Iraq for the time being but I promise sensory overload via .jpg when I get back to work in February.

[johnzm]

maybe im missing something.

the edges that protrude into the chamber, prevent knock by doing 2 things-creating alot of turburlence thus atomising the fuel more efficiently, and concentating the best mixture of air/fuel into the center of the chamber, where coincidentally, the spark plug is also located. not to mention the fact that the piston itself is designed very carefully with that chamber design. it prevents raw fuel from collecting at the corners of the chamber, which (i previously mentioned) creates detonation b/c of unevenly distributed air fuel misture in the combustion chamber...

[CursedGTR]

^^^^^ Is this a statement or a question??

The benefits of this mod have been discussed in detail in this thread. read over it carefully and you will answer your own questions if you have any after that.

But in Short, My primary reason for doing it was Big Boost + High RPM = High Chance for detonation. This mod helps me reduce risk of detonation.

[74260zt]

^^^^^ Is this a statement or a question??

The benefits of this mod have been discussed in detail in this thread. read over it carefully and you will answer your own questions if you have any after that.

But in Short, My primary reason for doing it was Big Boost + High RPM = High Chance for detonation. This mod helps me reduce risk of detonation.

^^= well known fact......

[johnzm]

^^^^^ Is this a statement or a question??

The benefits of this mod have been discussed in detail in this thread. read over it carefully and you will answer your own questions if you have any after that.

But in Short, My primary reason for doing it was Big Boost + High RPM = High Chance for detonation. This mod helps me reduce risk of detonation.

im just curious, where you got this info that removing squish prevents detonation.. ive seen in many many places where adding squish rasies the knock threshold..

http://kb-silvolite.com/articl...id=35

http://www.techworkseng.com/Pr...s.htm

http://theoldone.com/archive/quench-area.htm

just looking for some insight..

[CursedGTR]

I got the information from a few sources. I DID NOT GET THIS INFO FROM A WEBSITE.

1) Motorworx Race Systems in Okinawa Japan. A very small operation, pretty much owned and operated by one guy who is also very experienced with the RB advised me that ti would be in my best interest given my choice in turbines. He is an American and is very reputable.

2) Speed Factory in Okinawa Japan.

3) Techno Sports (912 AWHP GTR used to be number 3 in Japan) in Okinawa Japan advised me to do it.

4) Nagoya precision advised it over the phone when I called them about shaving the head.

Basically, I got my information from guys that have tried it and proven it to work. I did not put alot of stock into internet write ups and other things so all of my information on major modifications came from guys that were able to explain it to me and tell me why I should or should not do it.

[jrb92se]

i saw another thread recently , i believe in general chat , that covered the removal of squish area when getting the head done. it had a link to another companies site that explained why you should do it in detail i just cant find it now to link it.