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Guys,

I have noticed in the RB25 Workshop manual it says to first Torque the head down to a small number... like 25-30pounds all round...

Then torque to 70-75 (100Nm) and then back to 0!!? then back to 101Nm??

Why?

Doesnt this create unnessacery stretch on the head bolts, and doesnt the gasket loose its "mojo" (tensile)

Do you guys tension the head a diffrent way?

Cheers,

Trev

Hi Trev

If you are using a standard Nissan head gasket, then use the standard Nissan method as you have described above....

a little off topic , just curious

i am a firm believer that nissan is best , in terms of quality of parts etc

i have always used nissan head gaskets in mine and other vlt's

in comparison , what are hks and tomei gaskets like etc? any of the hipo skylines use them , mario etc?

Hey guys ! I wonder if you can help me with head ID for my RB30 conversion.I got two heads. Ones a RB20 turbo(i think). I think its a turbo head by the valve sizes and individual port runners for each intake valve. Now heres the problem i got another head brand new, totaly bare. The valve sizes seems the same , maybe slightly larger but the bottom of the heads are different. There are more water jacket slots around the combustion chamber on the brand new one (which looks exactly like the head pictured with 62.2cc marked, in the Rb30 fact sheet) So which head is it ???? Im stumped ! Any help would be apreciated

Thanks Guys.

RB31det in car! :)

got the car back today.. just got home from runing it in :D

oh boy so good the torque is amazing - half throtle and the car dosnt eaven feel like its working but its pulling like anything.

probaly working the hell out of the stock turbo :(

One of the things that was done to my block that I didnt know about was that they bored it out 10though and i was running standard rings when i put it together

I'm running 87mm pistons.

Some of the Calais turbo boys I have been talking to said not to go anything over .020" (86.5mm) for 600hp+.

Not sure how much my pistons weigh. Compared to the stockers they had much less skirt material.

Can anyone shed some light on the weight  of the std RB30 rod, and also the std piston.

I haven't got the wieght of the factory RB30 rod, but should do in the next couple of weeks. Same for factory pistons and forged 86mm Arias - will have weights in the next couple of weeks. I do have the weight of my forged RB30 rods though: 688g. Pics posted on my "RB25DET casuality" thread in the WA forum.

Bosch also make a timing belt to suit. Its part number is VB-T866....this has been used on an RB30/25 withno problems.

any other mods required to the tensioners etc?? or just straight on with everything in the std position?

PS ima gunna die if sydneykid doesnt empty his pm in box soon :bonk:

I'm running 87mm pistons.

 

Some of the Calais turbo boys I have been talking to said not to go anything over .020" (86.5mm) for 600hp+.  

 

Not sure how much my pistons weigh. Compared to the stockers they had much less skirt material.

it is best to keep the machining of the cyl walls to a minimum if ur planning running high boost , 20psi plus.

though there are plenty of chaps out there with 1mm overbore and are running high boost.

Can anyone shed some light on the weight  of the std RB30 rod, and also the std piston.  And if you can post the weight of your forged pistons if your running them, oh and whether your forged pistons are 86 or 87 mm... thanks !!!!

roy

i weighed a rod , endcap , rod bolts , piston , gudgeon and c clips all as one unit , and the weight was 1.25kg.

if u want i will seperate them , and just do the rod and piston alone.

cheers

Hi GTR-Ben,

Are you able to post the actual Garrett part numbers for your GT3040 so everyone knows what is going on for comparison. As far as I can determine, there is not really any such thing as a Garrett GT3040 officially, only various components that make some sort of hybrid. This has led to a great deal of confusion, for me personally and I assume many others, by salespeople that persist on applying HKS nomenclature to off-the-shelf Garrett componentry. Thanks.

Im going mad here guys..

I had a dayco belt.. but all they could give me here was the 94470.. which has 152 teeth..?

With the tensioner in the idler postion this seems much to slack!!?

I was looking at getting the belt with 150 teeth?

Whats the deal?

Ben,

U mean 94407? not 94470?!? (I did have a typo (94470) in an old RB30det guide)

The 94407 belt was way to tight with just an idler down low and a tensioner above the waterpump.

We used 2 tensioners to get the correct 20kg belt tension.

Oh thats what it would have been, the typo thay mixed me up :)

I was talking about using the two tensioners in the low position, i have a 150 tooth belt that is 23mm wide, GATES was quoted earlier in the forum. I am going to use that with the 2 tensioners mounted beside each other so I don't have to drill and tap the block and can get the right tension..

Is this going to work? I thought thats how you did it?

Here's another couple of pics ben.

Having two tensioners allows for quite a bit of adjustment.

Drilling and tapping is dead easy.

The bloke who built up the engine said there wouldn't be enough adjustment with the two tensioners in the low position with the belts we sourced.

Powergrip told us the belt number I gave them didn't exist so who knows maybe the bloke on the phone was lazy.

I see thanks for that mate, Just had a read over the guide again.

I think with the 150 tooth belt and the two lower tensioners it will have the right adjustment as it says in the second setup in the guide.

They found the belt I need here and I can get it on monday.. it's a lot more expensive.. but I can get it for about $100 or so, the dayco one was about $30.

It's 2mm thinner but that shouldn't cause any trouble.

I have a few questions you guys might be able to answer.

1. when will boost come on when using a Gt3040 (475 hp) with 9:1 comp, power fc with boost controller.

2. For the guys with over 300rwkw, did you use the standard rb25 sump?, are these baffled?. -I know they have crank scrapers which need to be removed with the rb30.

3. another one for the 300rwkw club. Are their any problems with the standard manifold?.

Ive heard that air is not distrubuted evenly into all cylinders, people have made some mods to the inside of the manifld to fix this problem.

4. Are aftermarket manifolds worth it?.

5.Will the rb26 manifold complete with throttle bodies fit onto the 25 head?.

6. attached is a pic of a modified rb25 manifold.

What do you think of this?.

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