Stock(never change, never blown) Head Gasklet replacement

[sylquebec]

Hi all, as title said, i'm doing a head gasket replacement while changing timing belt on my 7m. Its still the original headgasket, never overheated. But since i'm doing my timing belt i know it would be a good idea to change it since i want to upgrade the engine a little bit.(300-350hp max) Head will be deck to the best RA possible in the best shop here in Quebec. I will use a Cometic Head Gasket (thickness will depend how much materiel will be removed from the head to get the RA). I will not remove the block (50 000miles on it). I plan sanding it with 1000 to 2000 sand paper.
My question is : can i use the cometic head gasket? What do you think about it considering everything i said.
Yes i will use ARP head stud.

 

[xzeror]

Didnt read it well, thought it was going to be a metal one ><

 

[mk3-4-me]

if its just a Cometic HG than it isnt necessary to deck the block. Although it would deff help. You would need to for a metal HG of course because its, well metal and it needs to have a smooth surface.

as long as the head isnt warped to much, it should be fine.

 

[radiod]

Last I checked Cometic is a metal head gasket. I have one on my vehicle, and I put it on :icon_razz. You don't need it as smooth as an HKS one, but I have no idea what stock RA is on a factory block.

 

[IJ.]

Last I checked Cometic is a metal head gasket. I have one on my vehicle, and I put it on :icon_razz. You don't need it as smooth as an HKS one, but I have no idea what stock RA is on a factory block.

Correct!

Some people just shouldn't be posting in Tech... :nono:

OP: 20 year old I-6 engine there's about 0.000% chance of the Deck being in any condition to use even with a Composite HG let alone a MLS, save yourself some heartache and pain and just Deck it properly.

 

[mk3-4-me]

Oh my bad... I guess I was wrong, n shouldn't of posted... Lol

I was just tryin to help out... But I guess it isn't helpin if it's wrong...

 

[IJ.]

Oh my bad... I guess I was wrong, n shouldn't of posted... Lol

I was just tryin to help out... But I guess it isn't helpin if it's wrong...

Well no it's actually the opposite of helping

 

[sylquebec]

ok, so i guess i'm better using a stock composite head gasket instead of a cometic metal one. I dont want to get the engine out for many reason. First : money. Second : everything is ok on that engine, there is no leak, ac is working, etc.

I read on multiple search on the board that many peeps use a cometic metal head gasket without decking the block. But they were properly preping it by smoothing the surface with some fine sandpaper. YES, the deck need to be straight edge before anything, but dont forget it never blown, never overheat.

..............> I understand one thing : I know we are in the tech section, and people here can't say; ''Yes, try it! it should work without any proplem if you check the block for starightness and deck the head to a proper RA''. Because i could get a BHG after this for any reason and responsability could be your bad advice. ( not really a bad advice but a not 100% sure advice)

Thanks!

 

[Poodles]

Timing belt is a very easy job compared to a headgasket job. If you're trying to save money, doing it right the first time will save you a LOT of money (trust me on this, I know).

May sound like a dumb question, but why are you changing the timing belt?

 

[sylquebec]

Timing belt is a very easy job compared to a headgasket job. If you're trying to save money, doing it right the first time will save you a LOT of money (trust me on this, I know).

May sound like a dumb question, but why are you changing the timing belt?

Because the timing belt is 20 years old and is made from rubber...The belt doesnt look crack but it have some wear on top of it my beeing a little loose, look like it touch something.
Ok now, i wil ask you a question too ; Why are you asking why i'm changing the timing belt? Is there anything with the supra i dont know about timing belt. Like a maintenance free belt or anything else? I was simply thinking that like many engine, you better change it.

 

[Poodles]

Well, if the timing belt snaps, it will leave you stranded, but won't do internal damage (engine is non-interferance). My point is, if you want to save money, save up to do everything right all at once instead of doing each part multiple times.

Also, I doubt it's 20 years old, more than likely it's been replaced at least once.

 

[sylquebec]

Also, I doubt it's 20 years old, more than likely it's been replaced at least once.

Everything is original on the engine, no bolt was ever removed, every belt are the original one. Thats why i decide to change every of those, and putting arp stud with a new headgasdket could be a good idea too.

 

[Poodles]

No way :aigo:

Always had belts fall apart after 5 years or so...