Cometic headgasket; Feedback

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Satan

Supramania Contributor
Mar 31, 2005
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Yes, I have searched and read everything I could find.... here's my situation and plan.

I need to get a BHGed 7M swapped and running ASAP. While it is out, I am replacing bearings, seals, gaskets, timing belt, etc (basically a rebuild). I will be using ARP bolts.

I do not know the condition of the head yet, but if it all looks okay (no warpage, etc), I will likely clean it up VERY good and slap it in there with a Cometic MHG and torque to 80ft/lbs.

Seems like the Cometic is a "forgiving" MHG and will work fine in this situation, keeping the HP/boost at stock levels. If the head/block requires machining, it will add too much time to what I'm needing to do. I will do it "right," if it's absolutely necessary, but am trying to avoid the delay with the machine shop.

Where can I get the Cometic 1.2mm? I want to order from someplace that stocks them and not have to wait on it. Also, I saw something about drilling out a rivet... what's that about?

Also, feedback on the above? I will accept machining if it's bad enuff to need it anyways, but just looking to speed things up. Thanx!
 
GrimJack

GrimJack

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I have to say that every BHG I've helped to repair ended up taking long enough to get everything machined properly. You'll end up waiting a day here and a day there for little parts that you hadn't anticipated replacing anyhow.
 
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Satan

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Paradise will ship the MHG out to me today... THANK YOU! I want to machine everything that needs machining, but am in the process of contacting the shops. I need to get a "firm" commitment from them and not get the run-around, or still be waiting for the stuff to be returned, 3 weeks later.
 
Reign_Maker

Reign_Maker

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Aug 31, 2005
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Satan, good call! *that sounded wierd in my head* Anyway, Louis at paradise is a great guy, very helpful... When I built my last Supra, I got a Cometic 1.3 from him and it fit perfect, no rivets in the way or anything... He also set me up with a great gasket kit for a great price and a set of ARPs... I totally recommend him when people are looking...

Isnms: how much do you thnk they'll take off when they machine it? :) 1.3 is fine for straight replacement... I havent had that much shaved off, but I have a 2.0mm... There isnt THAT much difference in the compression in a .XXmm difference... He'll be fine...
 
Justin727

Justin727

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Cometic is a more forgiving MHG then say the hks or greddy. Let's say he cleaned up the head and block surface up really well and it has no warps or pitting he can use the Cometic with arp's and it not blow. Thats why there are alot of people running cometic. Cometic isn't a bad mhg. So if everything is fine with his head and block he would not need machining therefore he would be alright using the 1.3mm
 
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Satan

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Mar 31, 2005
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...thanx guys. I am ordering things based on the idea that if there's any machining needed, it will only be enuff to make the surfaces smooth enuff for the MHG (quick turnaround?).

If things turn out worse and more machinework/time is necessary, then I have to bite the bullet and re-order what I need (thicker MHG). However, if things are "good enuff," then I will have everything on hand to quickly put it all back together. I can always re-sell or get rid of the extras which aren't needed/used. If I have everything on hand, then the only thing I'd be waiting on, is me.....

Make sense?
 
MDCmotorsports

MDCmotorsports

Offical SM Expert: Turbochargers
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Mar 31, 2005
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Cometic is the best in my opinion.

I have ran them for years in the high horsepower cars and they have never failed me yet.

I have one on my supra now, and I was the first to have commetic build one for the 7m (or so they told me). Turns out they had 2 holes in the wrong place. I am running the 2mm and it works great.

Only thing is though with any steel head gasket, is to make sure the block and head are very well prepaired and prepped / surfaced!
 
shaeff

shaeff

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i run a cometic too. though, i do highly recommend getting the head lapped...

-shaeff
 
S

Satan

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Mar 31, 2005
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shaeff said:
i run a cometic too. though, i do highly recommend getting the head lapped...

-shaeff
Click to expand...


Yep, I plan to get the head and block prepped. I just don't want them keeping everything for weeks, like I've seen in the past. I'm just hoping that no other machinework will be necessary...
 
S

Satan

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Here's the Cometic I received. There are maybe 5 rivets tho, I understood that there'd only be one that would be necessary to remove.
cometic.JPG

cometicrivet.JPG


Should I remove them all?
 
S

Satan

Supramania Contributor
Mar 31, 2005
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Very kewl....

Now... Why is it that only that 1 rivet gets removed? Will the others "crush" into place and allow the gasket to fully seal/seat?

Also,
I've heard different methods used for installing. What is the real-deal for using the copper spray stuff? Is that only when you re-use the gasket? For the 1st use/install, nothing else is needed, right? Just place the headgasket "as-is" on the prepped block/surface and put the head on... no extra sealant, etc.... Right?
 
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