enjoyer;1720974 said:
1mm = 40 thou
.4mm = 15 thou
55 thou = 1.39mm, you add this to 1.37 to get 2.76mm, closest you'll find is a 3mm MHG, never seen a 2.8mm.
Head Gasket thickness selection
- Thread starter IJ.
- Start date
1mm = 40 thou
.4mm = 15 thou
55 thou = 1.39mm, you add this to 1.37 to get 2.76mm, closest you'll find is a 3mm MHG, never seen a 2.8mm.
So, i actualy calculated corectly. Just wanted another opinion from the supra god, i mean IJ. So, i milled everything to fit a 3mm HG. OK,now the next question. I've red a lot of different discusions about HG manufacturers and still i'm not sure witch manufacturer is a better choise. I've got an option of custom made HG, but that's a bit expensive. If any of you have bought 3mm HG, could you give me any feedback, and where to look for them(with links for buying). I found some myself, but i just want some second opinions.IJ.;1720979 said:
I've searched Cometic site more than once and i can't find what i'm looking for. They give only kits without any info on HG thickness.IJ.;1721236 said:
Awesome thread, great information. I am in the process of building another motor due to BHG.
Is there a prefered material? I.e copper or MLS? That's assuming anyone does a Copper head gasket.
Is adding a sealing agent a no no? I heard spray-on holymar was a good thing, anyone had experience with it?
I'm yet to get the machining place to measure the head and block heights but have to wait until I get the pistons so they can do the boring and surfacing at once, before they can measure it for me
Is there a prefered material? I.e copper or MLS? That's assuming anyone does a Copper head gasket.
Is adding a sealing agent a no no? I heard spray-on holymar was a good thing, anyone had experience with it?
I'm yet to get the machining place to measure the head and block heights but have to wait until I get the pistons so they can do the boring and surfacing at once, before they can measure it for me
Use MLS - copper would have to be wired around the cylinder for a seal. Way too much work for zero gain.
Never, ever use any kind of spray on sealer on a new MLS HG. It already has a viton coating - the spray sealer will destroy it.
Never, ever use any kind of spray on sealer on a new MLS HG. It already has a viton coating - the spray sealer will destroy it.
Chello;1748643 said:
Usually a Copper HG is used with "O-Rings"
These are a stainless steel wire that sits in a groove machined into the deck surface, there isn't enough room to do this on a 7M due to the close bore spacing.
Where in VIC are you?
(Central here)
Thanks for the reply IJ.
Half the problem with mine was, the last owner, who did the head gasket put a 1.2mm HKS gasket on it which would have bumped the comrpession up a fair bit and then machined the head ontop of that, they didn't get the block surafced either.
Just trying to make it reliable as humanly possible as it's in a Hilux 4x4 ute, so don't really want to be stuck in the middle of nowhere with a BHG
Mildura, North West Vic here
Half the problem with mine was, the last owner, who did the head gasket put a 1.2mm HKS gasket on it which would have bumped the comrpession up a fair bit and then machined the head ontop of that, they didn't get the block surafced either.
Just trying to make it reliable as humanly possible as it's in a Hilux 4x4 ute, so don't really want to be stuck in the middle of nowhere with a BHG
Mildura, North West Vic here
Chello;1748899 said:
If you haven't got around to measuring it by early October let me know as I have to go to Berri in SA and intended going through Mildura so it's no probs to bring my big Digi Vernier along!
I will let you know, thanks for the offer. Much appreciated
With any luck they should have it measured this week, just thought it would be easier for the machine shop to measure it seeing they have to bore and surface the block and port and surface the head.
Is it acceptable to go a little lower in the thickness of the gasket? Just to get a little more compression without going over-board. Obviously not to the extreme that was in it initially, more say the thickness of the gasket was to be 1.8mm to bring it back up to standard specs, how low could I go before it would start to cause problems? 1.6mm be ok? I know it's a bit of a how long is a bit of string question until I know exactly what size I need, was just curious about it for now.
With any luck they should have it measured this week, just thought it would be easier for the machine shop to measure it seeing they have to bore and surface the block and port and surface the head.
Is it acceptable to go a little lower in the thickness of the gasket? Just to get a little more compression without going over-board. Obviously not to the extreme that was in it initially, more say the thickness of the gasket was to be 1.8mm to bring it back up to standard specs, how low could I go before it would start to cause problems? 1.6mm be ok? I know it's a bit of a how long is a bit of string question until I know exactly what size I need, was just curious about it for now.
great sticky here! just saved me a hunt over on sf.
i have a question about the titan headgaskets...are they still just cometic rebranded?
will a cometic gasket hold up as well as an hks when shooting for 500+?
i have a question about the titan headgaskets...are they still just cometic rebranded?
will a cometic gasket hold up as well as an hks when shooting for 500+?
Okies, got back from the machine shop, they seem to think there will be around 40 thou all up removed from the block and head over time, will have to wait until they measure it properly, they are still porting the head before they deck it
As far as I know Cometic make the Titan MHG, 500 is well within it's limits, keep it out of detonation and make sure it's torqued down correctly and retorqued and that the surfaces are flat and smooth.suprajztwenty;1749433 said:
I see a 3mm MHG in your futureChello;1749606 said:
What sort of HP are you aiming for on this motor?
Not a great deal of HP, it's in a hilux 4x4, so more building it more for torque than straight out power. So getting them to port the head out a bit, has .50 mm over pistons.
They took 10 thou off of the block, the head has been milled 20 thou previously and they estimate maybe another 10 thou has to come off of it to make it flush.
So.. I guess I will be looking at around a 2.4mm, depending how much ends up coming off of the head, which I can't see it being 10 thou, but they said it as more of a safe guard I think
They took 10 thou off of the block, the head has been milled 20 thou previously and they estimate maybe another 10 thou has to come off of it to make it flush.
So.. I guess I will be looking at around a 2.4mm, depending how much ends up coming off of the head, which I can't see it being 10 thou, but they said it as more of a safe guard I think