head gasket install

[daneyan]

hey i just bought a motor with no bhg and i also purchased a titan 1.4mm mhg and arp headbolts to put on. my question is if the car doesn't have a bhg the head wouldn't need ne resurfacing or ne thing due to the motor not having a bhg right?. if so when i install the 1.4mm hg and rod bolts torqued to 90ftlbs, how much boost can i possibly run safely?

 

[supra90turbo]

It's not a matter of whether the Headgasket has failed or not, it's how many heat cycles it's been through. Aluminum and steel expand at diffent rates.

When you install a MHG, you must at least have the head machined, and check straightness of the block.

 

[shaeff]

also, considering that the titan MHG is nearly identical to the HKS MHG, it requires an RA (roughness average) of less than 10RA, if i remember correctly. the stock cut on the block is NOT that smooth, which means there's a larger chance that even if you DO get the head machined (which you ALWAYS should) that it still wont seal to the block correctly.

if the block is true, (read: straight) not pitted or damaged in any way, you could probably get away with using a Cometic MHG, as it only requires an RA of less than 50RA. that's what i did. i checked the block for straightness, had the head machined, and cleaned up the block til it was shiny, and used Permatex brake quiet to coat the headgasket and help it seal. i havent had a problem yet at 15psi on the stock CT-26, and 1k miles.

you can get the writeup for the brake quiet in my build thread, the link is in my sig.

if you're hell bent on using the titan headgasket, you'd best get that block machined.

-shaeff

 

[soontohavesupra]

do your arp bolts tell you that you can run them at 120ft lbs too? cause you will be able to pump a few mor psi into the motor with that dont also, just a suggestion for more boost

 

[kwnate]

do your arp bolts tell you that you can run them at 120ft lbs too? cause you will be able to pump a few mor psi into the motor with that dont also, just a suggestion for more boost

That is way too tight. I've read, that 90 is about the max you want to run although some are running 100. IJ has posted on this, with pictures about how fragile the head is inside. Search and read before you go messing up your head, or deforming your block.

 

[Stretch]

He's probably referring to 120lbs/ft with engine oil. ARP's torque ratings are higher for when you use regular oil instead of the supplied lube.
eric

 

[Joel W.]

http://www.supramania.com/forums/showthread.php?t=9119

 

[daneyan]

i'm just probably gonna stick with 90ftlbs, thanks for the quick responses guys.

 

[shaeff]

do your arp bolts tell you that you can run them at 120ft lbs too? cause you will be able to pump a few mor psi into the motor with that dont also, just a suggestion for more boost

as kwnate also stated, that's WAY too tight, AND it'd be dumb not to use the moly lube that comes with the ARP's. dont go above 90ft lbs with the moly lube. some go to 100ft lbs, but that's a bit tight, in my opinion.

-shaeff