The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Fuel Injector Clinic
Please Support STM Tuned

How should i prep my block

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

bNasty

10+ Year Contributor
669
3
Jan 15, 2009
Chantilly, Virginia
Alright well im coming back from college soon for thanksgiving break, i can finally start putting my talon back together (2.3, slowboy stage 2 head, slowboy g60 turbo In blog) and i was wondering how i should prep the block for the head/hg. The block was not decked but was in spec. How should i prep the block surface for the head gasket? Its a cosmetic head gasket, should i use copper seal?

Heres a pic of the block surface
You must be logged in to view this image or video.
 
its a cosmetic multi layer gasket. the cylinder head has been resurfaced but what should i do to the block if anything?
 
The Cometic IS an MLS gasket. It is not going to perform properly on a deck that has not been surfaced to RA50 or finer.

Why was the block not decked while it was apart? That is the first step in machining a block for high perforamance use because it locates the bores perpendicular to the crank.
 
i asked my builder to but he stated that "it was in spec" and didnt need to be decked but i asked him to deck it
should i use a different head gasket or what?
 
its a cosmetic multi layer gasket. the cylinder head has been resurfaced but what should i do to the block if anything?

Do you mean a composite multiple layer graphite steel hg? Or do you have the cometic mls? For the composite your block will have to surfaced however mls requires mirror smooth finishes on both head and block for a perfect seal.
 
I'm no expert by any means but the way I see it you have 2 options. One, you rip the block back apart and have it milled and run the mls, or you buy a composite head gasket and slap it on and call it a good day.

OEM mitsu composite head gasket has been proven to run 30lbs with arp's numerous times. Sounds and looks to me you have some money into the block already. I'd almost rip it apart, get it milled, and run the cometic.
 
if you like pulling your head, spray it with copper and run it. I think it will be fine.

If you plan on running lots of boost.... IDK, it's your call. I'd run it up to 22'ish without concern.
 
If you want to run a Multi-Layer Steel HG then you need to have that block resufaced. Your machinist is a dumb shit if he thinks that surface is in spec. I wont put a head gasket on a surface until 1) it is flat, and 2) its clean enough to eat off of. That is not clean at all. It should have been cleaned at least.
 
if you like pulling your head, spray it with copper and run it. I think it will be fine.

If you plan on running lots of boost.... IDK, it's your call. I'd run it up to 22'ish without concern.

22lbs on a 20g though? Where's the fun in that? LOL


Good luck with whatever you decide to go with man.
 
its a few more hours of work... but I would agree with JAM.. pull the crank and rods out.. mill the block and wash the block then put it back together..
 
If its not warped, having it precisely clean and using Hylomar spray gasket or copper spray, it will seal to a certain extent.

I myself wouldnt have let the block not get decked in the process, but just to save you any headaches down the road, Ben, i would just get it surfaced now while everything is still apart.
 
yea joe i think thats what im going to do. Ill just pull it apart when i get home. Joe you already know i hate my machinist haha
 
FYI, clean that block when you get it back... and then clean it again! You have to clean it really really good! Any metal shavings can work their way into the main/rod bearings and cause issues or wreck and new rebuild. You can't trust that the machine shop will clean it well enough if even at all.

Hose it down, degrease it, wipe it and then do it some more... LOL
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top