Rb2630 head help

[Griffin]

I'm after help please, I need a head gasket to suit rb26 / rb30.

I'd prefer genuine Nissan but can't get any from Nissan parts. 

The only options are mls gaskets or durapro.

NOT using an mls gasket. Are the durapro any good or does anyone have a Nissan one for sale?

The block is a low km rb30 and the head is from r34 GT-R rb26. How do I tell how much has been machined from the face? Are there marks on the head to use as a reference.

I know it's been surfaced previously. Also the more compression I can get the better. There is a .8 mm durapro gasket available . Does that sound correct?

[KiwiRS4T]

Get a metal Tomei gasket. I think  it will be 1.2mm but they may do a thinner one.

[Griffin]

Ok are the a mls? Do you know who stocks them?

[iruvyouskyrine]

Don't have to go into it if you don't want but why do you not want a MLS gasket? And why is it you think you can't get parts from Nissan? They have a warehouse in Sydney and I'm very sure you would be able to get an RB30 gasket from them.

Places like repco would also have standard fibrous non-MLS gaskets in stock for RB30

[Griffin]

Nissan said they have nothing showing in stock. 

I'll try just Jap.

The surface of the block is probably not up to a mls gasket standard. I've got one I could re-use but rather just get  a genuine one.

 

 

[r32-25t]

Why don't you just ask nisssn for an rb26 gasket? Seeing as they are the same as the head surface 

[Griffin]

I gave them the vin. They looked it up and said none in stock.

[GTSBoy]

Or there's one of the many different ways to get OE Nissan stuff from overseas.  Amayama for example.

[Griffin]

Does anyone know how to measure the amount of material that's been shaved from the head?

[GTSBoy]

1. Turn it upside down.  (make sure that there's a spark plug and the valves in one chamber but without springs)
2. Make it level.
3. Coat the back of the valves in one chamber with vaseline.
4. Put a light smear of vaseline around the head face around that chamber.
5. Place a sheet of clear perspex/acrylic with a 10mm hole in the middle of it over the chamber.
6. Set up the burette in a retort stand over the hole in the acrylic sheet.
7. Fill burette with water.
8. Titrate water into the chamber until it just fills the chamber, leaving no bubbles against the acrylic sheet.  May have to wiggle the head a little to encourage the bubbles to come to the hole in the centre.  Do not fill until the hole in the centre is full.  Fill until the meniscus of the water is just into the bottom of the hole.
   1. The chamber volume will be more than the capacity of a 50cc burette.  So run 50cc in, then refill the burette and run the rest in.  Add the total volume.
   2. If you do not have a burette and can get hold of some decently accurate syringes, you can use those.  Not as precise as using a burette.
9. When you have the total volume of water that went into the chamber, you can calculate the chamber height difference required to give you this answer instead of the well know "stock" chamber volume for the head in question.
   1. Get the diameter of the chamber at the head face and calculate the cross sectional area.  If the chamber is not round, then you will have to work out the cross sectional area via other means.  Putting ink onto the head face and making a print of the chamber could be the first step that would allow yo to use precise scales or a scanner and some software or any of a range of other techniques to get the cross sectional area.
   2. The cross sectional area, multiplied by a small vertical distance, will give you a volume equal to the missing chamber volume.  This might be as little as 0.1mm or it might be 1mm, or any other number.  Either do it via trial and error or rearrange the equations to solve for the height difference exactly.

Edited October 4, 2017 by GTSBoy

[Komdotkom]

http://justjap.com/manufacturers/oem/332/534/genuine-nissan-head-gasket-nissan-rb26dett.html

or $51US on Amayama for a genuine RB26 gasket.

 

I agree with no MLS gasket if you can't be certain of the RA on the block deck.

Are you worried about PTV clearance or static compression? I wouldn't worry too much about the static comp, dummy assemble and measure the crown clearance with pasticine to work out PTV and your cam timing options.

[Griffin]

Just Jap don't have them in stock and don't know when they will be. 

Nissan have zero listed in the country.

I managed to find an old stock vl vrs kit locally for $80 . Pick up tomorrow.

I was more curious how much meat has been skimmed off my head. 

Thanks guys for input on working out compression. 

It's going in this old banger I picked up. Aiming for 350rwkw with bits I have laying around

[Griffin]

I'm just assembling the timing belt and not sure about the belt tension.

It seems taught enough without any load on the tensioner. It seemed as though the belt could of been a tooth longer as it wasn't easy to get on. ( Using gates 152 tooth belt.)

The timing marks line up, belt seems tight enough. Should I tighten the tensioner as is or get more load.

Is this common? Will the belt free a little now it's under load? 

I've attached pics if anyone can assist.

 

[iruvyouskyrine]

Impossible to tell from photos. It all depends on where the tensioner stud is tapped into the block as to how hard the belt it so get on. On my car its pretty tight a to get the belt on and doesn't require much tension adjustment to get it to correct. I have done heaps of timing belts and my rough gauge is you shouldn't be able to turn it more than 45 degrees with a decent amount of hand pressure line in your pic.

[Griffin]

Ok that's about as far as it will go. You think I should just tighten it as it sits?