Tomei Head Gasket

[OMGGTR]

Hi guys

Quick question, just received my overhaul kit from my mechanic on the list we made we settled on 1.8mm gasket i was told i would need it to push alot of boost into the engine so i agreed since im going for decent power i would need it!

now i got the kit and i noticed the head gasket it 1.5 mm i questioned him about it... he said ( sorry they dont have 1.8mm i talked to my tuner he said its good not to worry)

im asking here coz i know hes full of shit lol standard being 1.2mm is 1.5 big enough to get me 350awkw with good boost or do i need the 1.8 mm ? btw its a Series 3 R33 GTR

cheers.

[89CAL]

Sorry I cant really help, but in order for others to help maybe specify how much is 'alot of boost'

just a thought

[OMGGTR]

he was talking to be about running 28 psi ? look im not an expert so please dont assume i know what im on about lol

[JKR-32]

Standar bottom end? Few engine specs perhaps.

[OMGGTR]

20thou oversized cp pistons eagle rods full tomei gasket kit inc sump baffel, greddy oil pump tomei restrictor , havent got harmonic yet but properly ati ....N1 waterpump.... pritty much good bottom end...top end hasent been decided yet but yeh -5's im happy with so far might change my mind still doing research on what turbos... on and id2000s with a good pump setup also

[BLITZ-26]

who is building the head?

[OMGGTR]

havent decided mate...but not going ported or anything like that just standard valves just chuking in some cams doing a valve grind n so on... simple shit really

Look all i want to know is if i should sell the 1.5 n get the 1.8 is it worth it so cbf having a mass convo about it..

[TiTAN]

lol is all that needs to be said.

-5's on 28psi should push 400kw and can be done on a 1mm standard headgasket, all a 1.8mm one is going to do is make an engine that was already pretty crap off boost even worse.

[OMGGTR]

Titan.. seriously... i love you... some 1 with an ANSWER lol fair enuf so the bigger the gasket the more lag ill get? hmmm so 1.5 should be fine well that made my life a little easier lol ta

[r33_racer]

Well you are increasing the combution chamber capacity when you go a thicker headgasket (unless you have custom pistons that protrude above the deck anymore then normal), which means a lower static compression ratio which means less power in NA form or off boost form. Thats what makes the engine doughier until you start jamming boost in there.

[Beer Baron]

honestly you should be thankful you couldn't get the 1.8mm. it's just not needed and isn't going to make your engine seal any better. as R33 said all it does is increase chamber volume which reduces your compression ratio which means less power/response off boost. you would only need a 1.8mm if you wanted to perhaps run like 40spi or if you had custom pistons that needed that extra bit of clearance.

a 1.2mm would have been fine but since you have the 1.5mm now by all means just use that.

[James_03]

Yeah not required for your build anyway.

Edited September 1, 2011 by James_03

[R31Nismoid]

Headgasket size needs to be decided once everything else is taken into account as r33_racer said.

Depends on the comp ratio the motor is being build too which included the bottom and top ends to "work" together.

You are sorta going it a bit backwards if you don't know whats being done with the head yet.

Even with a 1.8mm you won't be running 28psi on PULP through -5s for a start with a basic head. All for 350rwkw is odd too as you could do that on 18psi with a stock motor

I'd be a little concerned about the build with the 'advice' being given out thus far.

[OMGGTR]

Im building it myself...im an apprentice mech... dont know to much about the smaller details but i do a bit of reconditioning eg head work and bottom end stuff at work so i have a decent idea....

alot of people are scared but look im gona cut my teeth on these engines i love them to death and their all i think about honestly even my misses craks the shits...i bought my manuals from jpnz chassis and engine manuals im gona do alot of reading and build it so dont mention comp ratios yadda yadda im gona get the block honed machined if it needs and balanced and then ima wet and dry it a bit slap the gasket on strip the head clean it up put new seals thu it valve grind so on and slap that on...... simple question was if the 1.5 was ok to use to push high boost into i was just a little curious...

i dont feel like im going bakwards ? the standard head flows fine i think? with a set of cams (custom made not off the shelf) and some gears the right tuner should get me some good results dont u think ?

ill be asking alot more questions so i might make a thred about my build in the overhaul section so i can ask people there aswell

thanks for the help guys