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Head Facing When Replacing Head Gasket

kitto

By kitto,
in Engines & Forced Induction

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kitto Mentor

kitto

Posted
Posted

Hello everyone, this may sound like a stupid question to some, but this is a legit question, i'm pretty sure i know which way i'll go but i thought id ask the question.

Engine; RB25 NEO

Head has to come off for the sole fact of fitting restrictors. It hasn't overheated or blown a head gasket that i'm aware of. But to fit the restrictors the head has to come off.

I'll be replacing the head bolts with either factory Nissan ones or some ARP ones if i decide to fit a metal head gasket.

My question is, for a simple gasket change, should the head be faced to ensure a good seal again? Thinking about it myself, using a factory Nissan gasket i dont really see an issue with not facing it. Obviously facing it would give a nice flat surface for sealing.

I'm aware that i fit a metal head gasket i'll have to face the head.

Thanks, Daniel.

kitto Mentor

kitto

Posted
  • Author
Posted

Just grab a straight edge, and see if both the head and block a straight, if within spec whack it back on (when using a standard gasket)

and make sure you clean every last trace of old gasket from the block and head

Yes i'd be doing both of these.

Is it worth going with a metal head gasket? This engine will be flogged to shit. It may some day be asked to make over 300kW, but not any time soon.

zebra Grand Master

zebra

Posted
Posted

imo, no

Standard gasket will be fine.

If you are worried about having to pull the head off at a later date for what ever reason, than don't.

Because if something goes bang and the head needs to come off than a head gasket will be the least of your worries

kitto Mentor

kitto

Posted
  • Author
Posted

imo, no

Standard gasket will be fine.

If you are worried about having to pull the head off at a later date for what ever reason, than don't.

Because if something goes bang and the head needs to come off than a head gasket will be the least of your worries

Yeah ok, cool. I've never had an issue with a factory Nissan gasket.

Does anyone know how many restrictors the NEO has? I'm hearing mixed reports that its two or three. I'm quite green when it comes to NEO's.

JustinP Mentor

JustinP

Posted
Posted

Two.

Yeah ok, cool. I've never had an issue with a factory Nissan gasket.

Does anyone know how many restrictors the NEO has? I'm hearing mixed reports that its two or three. I'm quite green when it comes to NEO's.

kitto Mentor

kitto

Posted
  • Author
Posted

simple solution yes, but a worth while mod?

Doesn't hurt to grind it, but if there is no scratches that will prevent the gasket sealing you should be fine

I also recommend to lightly run a 2nd cut file over the block deck after you've scraped all the gasket off

I've used a fine grinding stone before, works a treat. Just takes that layer of crap off.

JustinP Mentor

JustinP

Posted
Posted

Nope, there is a third unrestricted oil gallery for the VCT towards the front of the block, this should not be restricted at all.

I bought 2 x 1.5mm Tomei restrictors for my Neo which I will put in over the top of the 2 x stock 2mm restrictors. Some people recommend completely blocking the rear restrictor altogether and just using 1 smaller restrictor in the other one, but it depends on your oil pump choice.

By the way I found out that the Neo's come with an N1 oil pump as standard.

So one for the head itself as it has solid lifters. And one for VCT correct?

I shall only need to restrict the main one to the head?

kitto Mentor

kitto

Posted
  • Author
Posted

Yeah I thought it was 3, one for VCT. Obviously you wouldnt block the VCT.

How come the NEO has both restrictors but an RB26 has its rear blocked. The NEO has solid lifters aswell.

It will be used or circuit primarily, so at constant high revs for 20 minute periods.

It will see the occasional drift day and driven on the street from time to time.

I plan on just using the N1 pump.

The Dan Grand Master

The Dan

Posted
Posted

Get to know your engine now, it won't be around for long with that pump on the front of it.

I haven't had an N1 pump survive any type of road use let alone track use in the last 4 we sold and half a dozen failures we saw on customers cars that came in the door with 0 oil pressure due to smashed gears. One of them was a car that was trailer to the dyno and didn't even make it through the tune

kitto Mentor

kitto

Posted
  • Author
Posted

Yes im well aware of N1 pumps being shit.

However that seems to be with the ones manufactured in the last few years.

The ones fitted to engines from factory seem to be ok.

I do have a Tomei pump I could use, but the thr crank has to come out to get a collar fitted.

The Dan Grand Master

The Dan

Posted
Posted

Yes im well aware of N1 pumps being shit.

However that seems to be with the ones manufactured in the last few years.

The ones fitted to engines from factory seem to be ok.

I do have a Tomei pump I could use, but the thr crank has to come out to get a collar fitted.

Yes if you have one from an actual N1 then you should be fine

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