Rb25 Head Rebuild

[AlpineFreak]

Goodmorning,

I seek your advice with my RB25det head rebuild.

Its been too long since I have been able to drive my car, approx 4 years since I cracked a few pistons, and decided to move onto new projects. But the time has come to bring her back to life.

I'm currently looking at doing a full head overhaul using the following equipment:

Tomei Procams:

1418270102 ( Nengun $315.20 )

Nissan - RB20DET/RB25DET - Exhaust - High Type - 270deg 10.25mm Lift - Solid Lifters

1417270102 ( Nengun $315.20 )

Nissan - RB20DET/RB25DET - Intake - High Type - 270deg 10.25mm Lift - Solid Lifters

Tomei solid lifters:

163006 ( Nengun $521.69 )

Nissan - Skyline RB25DET - (24x 161008)

Tomei valve springs:

163022 ( Nengun $521.69 )

Nissan - Skyline - ECR33 - RB25DET - Type B - Lift 10.25 - Solid Use Only

Valve guides:

TOMEI Valve Guide - Exhaust RB25DE(T) ( RHDJapan $19.00 each = $456.00 )

Stem seals:

Ferrea

VS1022 Exhaust 6.00 mm valve stem. Viton rubber compound. Hi Temp.

Ferrea

VS1023 Intake 6.00 mm valve stem. Viton rubber compound. Hi Temp.

Valves:

Ferrea Exhaust Comp+ ( Ebay America $501.00 set of 12 )

F2150P E 30.6 mm 21º Flo. + 1mmoversize. Super Alloy. Turbo Application

Ferrea Intake Comp+ ( Ebay America $365.00 set of 12 )

F2152P I 35.12 mm 15º Super Flo. +1 mm o/s. Special Alloy

Tomei Adjustable cam gears:

152009 ( Nengun $154.61 )

Nissan RB26DETT, RB25DET, RB20DET Intake Pulley

152010 ( Nengun $154.61 )

Nissan RB26DETT, RB25DET, RB20DET Exhaust Pulley

Not really after any particular goal, just gonna see what it turns out to be really with an attached T04Z or T51R.

Now the few questions I pose are:

1. Do you think this is too overkill for a head job?? Looking at high HP applications.

2. What size shims do you normally require?

3. Does the head need machining to fit these size cams?

4. Is there any one shop I can seek all these parts from, rather than buying around the world.

5. Any other input with branding or recommendations would be much appreciated..

Thanking you in advance..

[KiwiRS4T]

Define what you mean by high horsepower: 270kw? 300? 450?

People seem to suggest that with poncams you don't need adjustable cam gears.

[Harey]

Interested to hear this too, geeze it doesnt look cheap!

[AlpineFreak]

Would love to see anything above 380rwkw above out of it.

Going with Procams with solid lifter conversion not Poncams.

[R31Nismoid]

Thats a lot of money for only 380rwkw mate.

IMO you are going way overboard. Especially if its a street car.

Outright race car, different story.

[AlpineFreak]

Thats a lot of money for only 380rwkw mate.

IMO you are going way overboard. Especially if its a street car.

Outright race car, different story.

Hmmm, perhaps your right. But like I was saying I'll be happy with anything above that, hell the more the better right

I wasn't planning to drive this as a streeter, as I'm moving down the coast later this year to get into the car scene/action.

I work in the mines, so money wasn't really an issue, just damn availabilty of parts.....

Can you suggest things to remove or perhaps change then?

[r33cruiser]

You are in the same position i was in 6months ago. FYI Tomei also offer a 260d range with 9.25 and 10.25mm lift.

Be very weary of the 10.25mm lift cams mate. As my motor was being built a friend was finishing up his build and put in the 270d, 10.25mm lift cams. He ended up breaking 3 of the tomei type b 10.25mm springs .

So we decided to put the 260 9.25's in my car with the tybe b springs. So far no worries. Things I can tell you from building my head;

Yes get oversized valves

yes machine the head

Yes you will need the type B springs

yes you will NEED solid conversion

unsure of shims (left that to the boys at the shop)

Yes you will need intake and exhaust cam gears. (From memory you cant get procams with VCT? I couldn't at the time)

Figure in ATLEAST $5000 for labour + parts

Dont forget to run the camshafts in properly too. Instructions will be in the Tomei instructions manual

Edited January 5, 2011 by r33cruiser

[AlpineFreak]

Thanks mate, will definately keep that in mind regarding lift/duration.

How has yours turnt out so far? Turbo/power/happiness factor??

[r33cruiser]

350hp at 12psi with a 5000rpm limit, run in tune.

Very happy with it 

[Rolls]

rebuild it stock and put the $5k towards something that will net better returns.

or just get a second hand head and save even more money, that is what I would do.

hell you could get your entire car resprayed for that cost, proper jap forged rims with semi slicks etc.

[AlpineFreak]

Does anyone know where you can source the other 12 retainers ( exhaust ) needed when using the tomei type B springs??

The only ones I can find are for the RB26. Are these retainers interchangeable with the RB25??

Edited January 5, 2011 by AlpineFreak

[DR 32R]

Suggest you do a comparison on oversized valves and supertec springs from fabre australia, www.fabre.com.au

[AlpineFreak]

Was speaking to Daniel from ERD today. He has recommended going with supertech.

Have been doing a little research on them and have found a whole valve train kit ( 1mm oversize etc )

Has anyone else purchased one of these kits?

Did the kit come with everything for a pure swap in solution ( keeping in mind machining )..

cheers..

[DR 32R]

Was speaking to Daniel from ERD today. He has recommended going with supertech.

Have been doing a little research on them and have found a whole valve train kit ( 1mm oversize etc )

Has anyone else purchased one of these kits?

Did the kit come with everything for a pure swap in solution ( keeping in mind machining )..

cheers..

I'm doing the whole super tec thing, seems less complicated than the Tomei build you outlined. And more advocacy from full house RB builder

[Rolls]

i would seriously consider my suggestion unless you think youll be aiming for 400kw+ in the future, below that it helps but the money would be much better spent elsewhere.

[FineLine]

Dan supplied my supertech solid conversion kit. Its a good setup. I couldnt be happier with the result. I am running the 10.25 lift tomei cams as well.

As far as the High price jap products like tomei etc, I now try to avoid them where ever possible. Its taken a while but I have slowly come to the conclusion that the japs make sweet f**kall, They source components elsewhere, Whack their branding on it then jack the price stupid.

Other than a few specific items like the greddy plenum I run non jap stuff throughout my engine now, No chinese shit though, theres good quality stuff available for rb's by the truck load if you want to search for it.

[bigmikespec]

Rolls stop being boring; if you have the money to spend on the head do it! If you have money to waste on the head... buy Ferrea over Supertech. FYI, Tomei valves are not made by Tomei... can't speak for their springs though?

[Rolls]

I would argue $5k spent on awesome semi slicks and rims would be less boring!

[FineLine]

I would argue $5k spent on awesome semi slicks and rims would be less boring!

I would argue that money spent on a cylinder head should be the priority of everybody seeking big power.

Sure you can make some very respectable numbers on standard rb heads by virtue of a pretty good design to begin with but real power gains come from correctly modified heads. Getting the engines breathing characteristics to suit the other mods is the key to unleashing the true potential of your build.

Every performance category be it, drags, marine, Tractor pulls, circuit,N/A Forced induction or whatever has had countless hours of time and money poured in to developing cylinder heads simply because that is where Real horsepower benefits and torque characteristics to suit the application can be found.

[Rolls]

he is aiming for 380kw though, certainly not low, but not some 500kw monster that needs it to get the power.