One more MHG Thread - Yikes!

[gottadiesel]

I have spent hours reading through threads and the sticky on mhg selection. I stopped by machine shop, they had to take off .015 off block, minimal off of head, but it had been surfaced once before also, but he said it was still .020 over toyota minimum, tomorrow I will ask for total measurement of head and block, since I have gathered toyota is not always the intended stock of 116mm and 198.5mm from the factory.

So my questions that I want to confirm are the following:

Brand - HKS vs Greddy vs Titan vs xxx is there someone to stay away from?

Bore - so they took off .02 from cylinders, so now should be 83.5mm bore, I am guessing that any gasket between 84mm and 86mm is ok?

Thickness - this is the major item covered in all of the threads and is very understandable that retarded timing and or compression increase are all bad for sure - but lets say my measurements call for a 1.65mm thick hg, would I go down to 1.5 or up to 2.0. This is just an example, I am not sure of that value yet, but I am wondering where to draw the line of going up or down since no one manufactures every possibility.

Sorry to add one more thread - but thank you for additional advice and feedback.

 

[hvyman]

cometic(same as titan) will make custom sized gaskets.

 

[nick88]

I would just go up to 2.0.

Save the cost from having a custom gasket made.

 

[Bri7man]

cometic(same as titan) will make custom sized gaskets.

My cometic was $252 from cometic and I ordered from them. I filled out an order form as well with my dimensions and they answered me with "what they had" and I just chose what the closest dimension was. Don't remember what that was but they totally didn't custom make it for me like I wanted em to. It wasn't as close as I wanted it to be.

Maybe I just got shitty service but that was my experience.

Also if you intend to re-use, cometics new viton will take you at least a couple days of hard scrubbing to get it off. I used everything on the market and the best results I had,(which still sucked) was Lacquer thinner by Valspar.

Just lettin ya know what you're in for!
GL

 

[gaboonviper85]

My cometic was $252 from cometic and I ordered from them. I filled out an order form as well with my dimensions and they answered me with "what they had" and I just chose what the closest dimension was. Don't remember what that was but they totally didn't custom make it for me like I wanted em to. It wasn't as close as I wanted it to be.

Maybe I just got shitty service but that was my experience.

Also if you intend to re-use, cometics new viton will take you at least a couple days of hard scrubbing to get it off. I used everything on the market and the best results I had,(which still sucked) was Lacquer thinner by Valspar.

Just lettin ya know what you're in for!
GL

my cometic cost me $145....

 

[92nsx]

:nono: :nono: :nono:

 

[quake]

I wish the mkiii community would stop using the crappy cometic gasket then make a post about a blown gasket.


1. use the hks stopper.

2. resurface head and block as needed there should be no erosion around the cooling ports and no ring left around the combustion chambers from and old gasket.

3. lap both surfaces untill there are no finish marks (you will know when you do it)

4. measure head and block to see how much has been removed by you or previous owners.

5. spray it or not with copper spray it won't matter.

6. use arp studs

7. never make a post about a blown headgasket again :biglaugh:




at the end of this all you have done is to update your 1980's design motor surfaces to newer technology. Even a crappy 05 corolla has this style gasket and surface finish.

 

[gottadiesel]

Thanks for the info, I will check Cometic, but it appears that what I need will be pretty standard...

Deck to VC sruface - 115.82mm
Deck to MB Saddle - 198.15mm
Bore 83.50

Should net me a 2.00mm (1.90 to be exact, but close) with an 84mm bore... seems pretty typical...

Thanks to all you joined a very over used thread subject, but like I said, There were some grays areas that I could not find covered anywhere else...

Thank You! and HAPPY NEW YEAR :biggrinbo

 

[msimsi10]

you could always check out SIP Racing they make all different sizes of MHGs for 7Ms

 

[quake]

Thanks for the info, I will check Cometic, but it appears that what I need will be pretty standard...

Deck to VC sruface - 115.82mm
Deck to MB Saddle - 198.15mm
Bore 83.50

Should net me a 2.00mm (1.90 to be exact, but close) with an 84mm bore... seems pretty typical...

Thanks to all you joined a very over used thread subject, but like I said, There were some grays areas that I could not find covered anywhere else...

Thank You! and HAPPY NEW YEAR :biggrinbo

you picked cometic because?

 

[gottadiesel]

Lol - ok well I missed the most previous post in regards to cometic...

So there is one that says no don't use it... But others have had good luck with them? A choice I will have to make I reckon...

What about GReddy, any votes yea or nay? The HKS, looks like perhaps the best, but they seem to be about $300 also, maybe for a reason??? I do not plan to push more than 15psi boost, do I need that kind of safety factor or is a GReddy or Cometic going to work for my application...

Any and all opinions are appreciated, as I know we all have them and have a reasons for having them...

Thanks

 

[CyFi6]

Check out FRSPORT.com they have some different thicknesses i couldnt find anywhere else. It seems the person making the post about the Cometic gaskets being crappy has little to no backing so i dont think you should believe that, there are supposedly many people using them with no problems.

 

[GrimJack]

I wish the mkiii community would stop using the crappy cometic gasket then make a post about a blown gasket.


1. use the hks stopper.

2. resurface head and block as needed there should be no erosion around the cooling ports and no ring left around the combustion chambers from and old gasket.

3. lap both surfaces untill there are no finish marks (you will know when you do it)

4. measure head and block to see how much has been removed by you or previous owners.

5. spray it or not with copper spray it won't matter.

6. use arp studs

7. never make a post about a blown headgasket again :biglaugh:




at the end of this all you have done is to update your 1980's design motor surfaces to newer technology. Even a crappy 05 corolla has this style gasket and surface finish.

QFT.

I've blown a Cometic. Titan / SIP are the same thing.

I've never blown an HKS, and the one on my car has already taken *WAY* more abuse than the cometic did before it let go. The only difference was the gasket, both times the surface prep and everything else were exactly the same.

Hell, my first HKS survived detonation that destroyed the pistons in three cylinders. I re-used that gasket, ended up selling it when my head got too thin for the 2mm gasket, and the guy who bought it put it in an engine and it's still going strong there!

IMO the HKS gaskets cost more for a reason. Admittedly, it's probably not worth double the cost, some of what you are paying for is the HKS name, but who cares? Any extra insurance on these engines is a good thing.

 

[Bri7man]

I wasn't advertising not to use cometic, I was just saying the total was $252 for a gasket I wanted custom made and they gave me a premade one that was not as close as I wanted it to be. $212 for the gasket, $40 for shipping.

The quality is perfect from what I hear 20+ psi easily along with hks, titan and greddy. HKS stopper being the most superior for the extra bead.

I'm just saying I got shit service and cometic ripped me off hardcore, though the product is quality even though the thicknes is not as close and I wanted them to give me. I could have gotten it half price from HPF if I had known better.

If you can try to find a premade one off HPF or something and if you do decide to order from cometic. Make certain they are custom making it to your specs and don't let them over charge you. I swear it was like talking to Apu from the Kwik-E-Mart....

 

[IJ.]

QFT.

I've blown a Cometic. Titan / SIP are the same thing.

I've never blown an HKS, and the one on my car has already taken *WAY* more abuse than the cometic did before it let go. The only difference was the gasket, both times the surface prep and everything else were exactly the same.

Hell, my first HKS survived detonation that destroyed the pistons in three cylinders. I re-used that gasket, ended up selling it when my head got too thin for the 2mm gasket, and the guy who bought it put it in an engine and it's still going strong there!

IMO the HKS gaskets cost more for a reason. Admittedly, it's probably not worth double the cost, some of what you are paying for is the HKS name, but who cares? Any extra insurance on these engines is a good thing.

Blown both you just need to try harder Dave

 

[GrimJack]

Hey, what you do in the privacy of your own bedroom is none of our business. Unless you have pics, in which case, GIMME.

 

[jetjock]

What about GReddy, any votes yea or nay?

I ran a Greddy at 14 psi for twelve years with zero problems...

 

[gottadiesel]

Appreciate everyone's feedback... haven't been on in a few days.. damn virus hit all 3 of my computers... deep one, had to format everything :: angry ::

So anyway the one and only question that I am not clear on is the following:

How large is too large on the bore? It is hard to find a 2.0mm by 84mm in any brand. Is 85mm or 86mm too large on an 83.5mm bore. What does this really affect, other than there is a lip with micro vacant space just above and around cylinder. Am I thinking straight on this?

Thanks!

 

[GrimJack]

I put in pistons at 20 over in my build, and still went with the stock bore. I'm not sure about stock pistons, but my JE pistons never come all the way up out of the block anyway.

 

[Bri7man]

I put in pistons at 20 over in my build, and still went with the stock bore. I'm not sure about stock pistons, but my JE pistons never come all the way up out of the block anyway.

The hg material didn't "shelf" over the bore?