HEAD GASKET!!!
29 January 2010, 03:46 AM
#1
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HEAD GASKET!!!
hi all, Head gasket has gone on ma scooby 555 the car is in the garage atm to get the engine striped out to change the head gasket so i just wanted to know that would a standard head gasket from a car part shop be ok ?? also have been told that the heads would be skimmed so does that mean that the head gasket size will change??
thanks.
thanks.
29 January 2010, 07:32 AM
#2
hi all, Head gasket has gone on ma scooby 555 the car is in the garage atm to get the engine striped out to change the head gasket so i just wanted to know that would a standard head gasket from a car part shop be ok ?? also have been told that the heads would be skimmed so does that mean that the head gasket size will change??
thanks.
thanks.
Is it a subaru specialist doing the work or a back street garage????
29 January 2010, 10:13 AM
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If you have the heads skimmed then yes you will need to change the head gasket size to make up for whats been skimmed away. If a garage is doing the work for you then i'd leave it upto them to find the right gaskets as if you get the wrong ones then the compressions could be out and can cause damage to your engine.
Is it a subaru specialist doing the work or a back street garage????
Is it a subaru specialist doing the work or a back street garage????
hi mate i was told by the guy to get a head gasket myself, the guy has worked on subarus before and does know how to the gasket on the scooby. so the standard gasket is no good then??
29 January 2010, 01:38 PM
#4
As above: not if the heads have been skimmed, no.
Think about it: you are removing material from the head surface by skimming, so if you use the standard thickness gasket, the heads are now that much, (whatever was removed), closer to the pistons. You have effectively RAISED the compression ratio, NOT good.
However, the standard head gasket IS ok if you are doing a standard rebuild, unless you are going for quite a bit more power.
Think about it: you are removing material from the head surface by skimming, so if you use the standard thickness gasket, the heads are now that much, (whatever was removed), closer to the pistons. You have effectively RAISED the compression ratio, NOT good.
However, the standard head gasket IS ok if you are doing a standard rebuild, unless you are going for quite a bit more power.
29 January 2010, 01:55 PM
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As above: not if the heads have been skimmed, no.
Think about it: you are removing material from the head surface by skimming, so if you use the standard thickness gasket, the heads are now that much, (whatever was removed), closer to the pistons. You have effectively RAISED the compression ratio, NOT good.
However, the standard head gasket IS ok if you are doing a standard rebuild, unless you are going for quite a bit more power.
Think about it: you are removing material from the head surface by skimming, so if you use the standard thickness gasket, the heads are now that much, (whatever was removed), closer to the pistons. You have effectively RAISED the compression ratio, NOT good.
However, the standard head gasket IS ok if you are doing a standard rebuild, unless you are going for quite a bit more power.
what is the thickness size for the standard head gasket ?? and what thickness head gasket should i be looking to get now!!
29 January 2010, 10:08 PM
#7
What you buy will be influenced by how MUCH was skimmed off the heads. The idea is to end up with the cr exactly the same as it was before the heads were removed.
Decent tuners will know gasket thicknesses and can advise. Back-street garages tend NOT to know, fit standard gaskets and the result is an engine gone pop.
Been there, done that
Decent tuners will know gasket thicknesses and can advise. Back-street garages tend NOT to know, fit standard gaskets and the result is an engine gone pop.
Been there, done that
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29 January 2010, 10:23 PM
#8
It's the garage's responsibilty to source a suitable thickness pair of HGs as it's them that (should) know how much thou is coming off the heads; you don't! But from what you've posted I don't like what I hear i.e. them telling you to get a pair etc. Who is the garage - is it a proper Impreza specialist that has intimate knowledge of the marque?!?!
FTR, the 555 is effectively a v.2 STi (I think), so the std HG thickness, I believe, is 1.6mm. I stand to be corrected though...
Are you sure the garage is doing a proper 'skim' off of metal, or just a polish to clean off the crud to make true? (they don't normally suffer from warp). If the latter, then the OEM thickness is all that's required, - and to that end make sure you fit multi layer steel (MLS) HG's e.g. STi v.3/4 ones (if 1.6mm), or Cosworth, Cometic, etc. of correct thickness....
FTR, the 555 is effectively a v.2 STi (I think), so the std HG thickness, I believe, is 1.6mm. I stand to be corrected though...
Are you sure the garage is doing a proper 'skim' off of metal, or just a polish to clean off the crud to make true? (they don't normally suffer from warp). If the latter, then the OEM thickness is all that's required, - and to that end make sure you fit multi layer steel (MLS) HG's e.g. STi v.3/4 ones (if 1.6mm), or Cosworth, Cometic, etc. of correct thickness....
Last edited by joz8968; 29 January 2010 at 10:41 PM.
29 January 2010, 10:27 PM
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Back-street garages tend NOT to know, fit standard gaskets and the result is an engine gone pop. Been there, done that
Been there, done that
Not good.
29 January 2010, 10:38 PM
#10
Again, exactly. I'd be a little concerned at a customer being advised to go out and buy the "right" gasket. It sounds as though the garage doesn't know what to do and is effectively trying to offload responsibility for any resultant problems by having the ability to say that they're just using what they were given.
Not good.
Not good.
Totally my train of thought too.
Not at all filled with confidence by this outfit. Pull out if it's not too late and flatbed it to your nearest PROPER IMPREZA specialist nearest to you i.e. any of the ones that post on this board.
30 January 2010, 09:36 AM
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It's the garage's responsibilty to source a suitable thickness pair of HGs as it's them that (should) know how much thou is coming off the heads; you don't! But from what you've posted I don't like what I hear i.e. them telling you to get a pair etc. Who is the garage - is it a proper Impreza specialist that has intimate knowledge of the marque?!?!
FTR, the 555 is effectively a v.2 STi (I think), so the std HG thickness, I believe, is 1.6mm. I stand to be corrected though...
Are you sure the garage is doing a proper 'skim' off of metal, or just a polish to clean off the crud to make true? (they don't normally suffer from warp). If the latter, then the OEM thickness is all that's required, - and to that end make sure you fit multi layer steel (MLS) HG's e.g. STi v.3/4 ones (if 1.6mm), or Cosworth, Cometic, etc. of correct thickness....
FTR, the 555 is effectively a v.2 STi (I think), so the std HG thickness, I believe, is 1.6mm. I stand to be corrected though...
Are you sure the garage is doing a proper 'skim' off of metal, or just a polish to clean off the crud to make true? (they don't normally suffer from warp). If the latter, then the OEM thickness is all that's required, - and to that end make sure you fit multi layer steel (MLS) HG's e.g. STi v.3/4 ones (if 1.6mm), or Cosworth, Cometic, etc. of correct thickness....
yes mate it is a sti ver 2 redtop so if the heads are going to be skimmed should i be looking to get a 2.0mm head gasket ??
im not sure if they are going to be doing a skim off of metal but i will find out and keep you guys updated.
btw thanks alot for all ur help so far!!
30 January 2010, 09:40 AM
#12
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Again, exactly. I'd be a little concerned at a customer being advised to go out and buy the "right" gasket. It sounds as though the garage doesn't know what to do and is effectively trying to offload responsibility for any resultant problems by having the ability to say that they're just using what they were given.
Not good.[/QUOTE]
that is quiet true mate !! im in 2 minds now!!
Not good.[/QUOTE]
that is quiet true mate !! im in 2 minds now!!
30 January 2010, 09:41 AM
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im based in birmingham mate you wouldn't happen to know any around here would you??
30 January 2010, 10:14 AM
#14
Most heads need only 0.002" to 0.005" to clean them up, this will make next to no difference to the compression ratio.
You will have more than that figure with built up carbon deposits on pistons & heads. This head gasket thickness issue is blown out of all proportion.
You will have more than that figure with built up carbon deposits on pistons & heads. This head gasket thickness issue is blown out of all proportion.
30 January 2010, 10:37 AM
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Most heads need only 0.002" to 0.005" to clean them up, this will make next to no difference to the compression ratio.
You will have more than that figure with built up carbon deposits on pistons & heads. This head gasket thickness issue is blown out of all proportion.
You will have more than that figure with built up carbon deposits on pistons & heads. This head gasket thickness issue is blown out of all proportion.
so mate what your trying to say is that the standard head gasket would do the job??
30 January 2010, 10:53 AM
#16
NO!
NOT if the heads have been SKIMMED and not just cleaned up/polished. MOTORS S GT posts about how much metal is removed when the heads are cleaned up/polished.
YOU on the other hand, posted that your guy said skimmed. There is a world of difference.
Have you asked him how he KNOWS they need to be skimmed? Impreza heads don't, normally, and I'd be MORE THAN wary of someone who reckons to know this even before the heads are off the car
AGAIN: the thickness of the NEW headgasket will need to be:
Thickness of old headgasket + amount skimmed off heads
NOT if the heads have been SKIMMED and not just cleaned up/polished. MOTORS S GT posts about how much metal is removed when the heads are cleaned up/polished.
YOU on the other hand, posted that your guy said skimmed. There is a world of difference.
Have you asked him how he KNOWS they need to be skimmed? Impreza heads don't, normally, and I'd be MORE THAN wary of someone who reckons to know this even before the heads are off the car
AGAIN: the thickness of the NEW headgasket will need to be:
Thickness of old headgasket + amount skimmed off heads
30 January 2010, 11:03 AM
#17
Carbon Composite gaskets - no, MLS STi 3~4 head gaskets are a better option.
Just bear in mind that the maximum surface grind is 0.012" before the heads are scrap if they havent been skimmed before.
Standard head height is 127.50mm so get them to measure the heads before they attempt to skim the heads.
Mick
Just bear in mind that the maximum surface grind is 0.012" before the heads are scrap if they havent been skimmed before.
Standard head height is 127.50mm so get them to measure the heads before they attempt to skim the heads.
Mick
30 January 2010, 11:06 AM
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NO!
NOT if the heads have been SKIMMED and not just cleaned up/polished. MOTORS S GT posts about how much metal is removed when the heads are cleaned up/polished.
YOU on the other hand, posted that your guy said skimmed. There is a world of difference.
Have you asked him how he KNOWS they need to be skimmed? Impreza heads don't, normally, and I'd be MORE THAN wary of someone who reckons to know this even before the heads are off the car
AGAIN: the thickness of the NEW headgasket will need to be:
Thickness of old headgasket + amount skimmed off heads
NOT if the heads have been SKIMMED and not just cleaned up/polished. MOTORS S GT posts about how much metal is removed when the heads are cleaned up/polished.
YOU on the other hand, posted that your guy said skimmed. There is a world of difference.
Have you asked him how he KNOWS they need to be skimmed? Impreza heads don't, normally, and I'd be MORE THAN wary of someone who reckons to know this even before the heads are off the car
AGAIN: the thickness of the NEW headgasket will need to be:
Thickness of old headgasket + amount skimmed off heads
30 January 2010, 12:08 PM
#19
subaru 555 - is it not too late to stop the job from going ahead? How far are you away from API in Warks (they have a Coventry CV postcode)?
API's current set menu price for head removal, clean/polish (NOT skim - unless actually needed!) and same thickness uprated MLS 1.6mm STi v.3/4 HGs (if no skim) is, IIRC, £800+VAT. Obviously if there are other issues while the engine's apart then Dave would advise as appropriate and proffer a suitable course of action within your budget.
If you can get the car to him, then you're in one of the safest pair of hands in the country. You'd give it to him and just forget about the car until it's fixed! And properly! None of this, "I'll do this.. you research/buy that..." bollox...
API's current set menu price for head removal, clean/polish (NOT skim - unless actually needed!) and same thickness uprated MLS 1.6mm STi v.3/4 HGs (if no skim) is, IIRC, £800+VAT. Obviously if there are other issues while the engine's apart then Dave would advise as appropriate and proffer a suitable course of action within your budget.
If you can get the car to him, then you're in one of the safest pair of hands in the country. You'd give it to him and just forget about the car until it's fixed! And properly! None of this, "I'll do this.. you research/buy that..." bollox...
Last edited by joz8968; 30 January 2010 at 12:15 PM.
30 January 2010, 06:17 PM
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subaru 555 - is it not too late to stop the job from going ahead? How far are you away from API in Warks (they have a Coventry CV postcode)?
API's current set menu price for head removal, clean/polish (NOT skim - unless actually needed!) and same thickness uprated MLS 1.6mm STi v.3/4 HGs (if no skim) is, IIRC, £800+VAT. Obviously if there are other issues while the engine's apart then Dave would advise as appropriate and proffer a suitable course of action within your budget.
If you can get the car to him, then you're in one of the safest pair of hands in the country. You'd give it to him and just forget about the car until it's fixed! And properly! None of this, "I'll do this.. you research/buy that..." bollox...
API's current set menu price for head removal, clean/polish (NOT skim - unless actually needed!) and same thickness uprated MLS 1.6mm STi v.3/4 HGs (if no skim) is, IIRC, £800+VAT. Obviously if there are other issues while the engine's apart then Dave would advise as appropriate and proffer a suitable course of action within your budget.
If you can get the car to him, then you're in one of the safest pair of hands in the country. You'd give it to him and just forget about the car until it's fixed! And properly! None of this, "I'll do this.. you research/buy that..." bollox...
yes mate got the car back of the guy 2day and have spoke to a friend of mine who is very good with scoobyz, pulsars and the skylines and said that if i can wait till next month he will do the head gasket for me .
also can i ask a random question i was told by someone that the 555 sti come with a forged bottom end is that true?? i know its a bit off topic but just wanted to know.
thanks
30 January 2010, 07:04 PM
#21
As said, the 555 is an STi v.2 and I believe it does have nominally forged pistons... but standard rods and crank (I stand to corrected though). OEM cranks are very good; but the rods not so - hopefully okay up to 350lb ft. Anything more, and at that age, you'd prob be on borrowed time.
FTR, even though it has 'forged' pistons, the afore mentioned specialist doesn't rate 'em in the grand scheme of things. But if only your rods were up to it, then the pistons should be able to see off this side of c.<400lb ft of torque...
FTR, even though it has 'forged' pistons, the afore mentioned specialist doesn't rate 'em in the grand scheme of things. But if only your rods were up to it, then the pistons should be able to see off this side of c.<400lb ft of torque...
Last edited by joz8968; 30 January 2010 at 08:10 PM.
30 January 2010, 07:49 PM
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As said, the 555 is an STi v.2 and I believe it does have nominally forged pistons... but standard rods and crank (I stand to corrected though). OEM cranks are very good; but the rods not so - hopefully okay up to 350lb ft. Anything more, and at that age, you'd prob be on borrowed time.
FTR, even though it has 'forged' pistons, the afore mentioned specialist doesn't rate 'em in the grand scheme of things. But if only your rods were up to it, then the pistons should be able to see off this side of c.<400lb ft of torque...
FTR, even though it has 'forged' pistons, the afore mentioned specialist doesn't rate 'em in the grand scheme of things. But if only your rods were up to it, then the pistons should be able to see off this side of c.<400lb ft of torque...
also thanks for all ur help mate.
30 January 2010, 08:47 PM
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i know that im going way way way off the head gasket topic now !
but do all the ver 2 sti 555 have forged pistons or is it just the 555 the reason i asked is a mate of mine has a ver 2 engine but is not sure what car it is off. he said it is deffo off a ver 2 sti but not sure which model,
is the normal ver2 sti engine the same as the 555 ver 2 engine?? i.e power internals and so on....
30 January 2010, 08:57 PM
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if youre near birmingham, these guys are deffinatley worth a visit
POLE POSITION UK LTD 01902 605037 Pole Position UK - Subaru Specialist
POLE POSITION UK LTD 01902 605037 Pole Position UK - Subaru Specialist
30 January 2010, 09:10 PM
#26
The 555 v.2 STi is no different mechanically to any other v.2 STi.
It's just a special edtion with contemporary WRC dark blue paint, roof vent, (optional WRC style "555/Repsol/Pirelli" yellow/white vinyl body decal graphics and optional WRC style Safari 8-spoke gold alloys) and, I think, "555" monogrammed seats, tailgate enamel roundel badge and interior numbered plaque.
Other than that, it's stock v.2 STi. So yours and your mate's engine should have v.2 STi pistons in and basically share exactly the same mechanicals (assuming they're both bone stock...)
It's just a special edtion with contemporary WRC dark blue paint, roof vent, (optional WRC style "555/Repsol/Pirelli" yellow/white vinyl body decal graphics and optional WRC style Safari 8-spoke gold alloys) and, I think, "555" monogrammed seats, tailgate enamel roundel badge and interior numbered plaque.
Other than that, it's stock v.2 STi. So yours and your mate's engine should have v.2 STi pistons in and basically share exactly the same mechanicals (assuming they're both bone stock...)
Last edited by joz8968; 30 January 2010 at 09:16 PM.
30 January 2010, 09:25 PM
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The 555 v.2 STi is no different mechanically to any other v.2 STi.
It's just a special edtion with contemporary WRC dark blue paint, roof vent, (optional WRC style "555/Repsol/Pirelli" yellow/white vinyl body decal graphics and optional WRC style Safari 8-spoke gold alloys) and, I think, "555" monogrammed seats, tailgate enamel roundel badge and interior numbered plaque.
Other than that, it's stock v.2 STi. So yours and your mate's engine should have v.2 STi pistons in and basically share exactly the same mechanicals (assuming they're both bone stock...)
It's just a special edtion with contemporary WRC dark blue paint, roof vent, (optional WRC style "555/Repsol/Pirelli" yellow/white vinyl body decal graphics and optional WRC style Safari 8-spoke gold alloys) and, I think, "555" monogrammed seats, tailgate enamel roundel badge and interior numbered plaque.
Other than that, it's stock v.2 STi. So yours and your mate's engine should have v.2 STi pistons in and basically share exactly the same mechanicals (assuming they're both bone stock...)
and 1 other thing is that i have looked at my engine and his engine and on my engine on the heads its self it says " 4cam16valve " and on his it doest say nothing at all like that his is just blank so what is the reason for that??
also he wanted to know what sort of value is his engine worth as he wanted to sell it and doesn't know what sort of value they are??
it is a fully working red top ver 2 !!
30 January 2010, 09:40 PM
#28
His has probably got different heads on or something (from a Legacy maybe?). Or it just might be the covers.
Has your heads got the coilpack held in by a single bolt and his has 2 bolts - if so, then yeah, yours are Impreza ones at least lol... and his are from a Legacy.
If so, that'd probably devalue his lump, as I think, the STi v.2 heads are appreciably better than the v.2 WRX heads... let alone Legacy heads!
Has your heads got the coilpack held in by a single bolt and his has 2 bolts - if so, then yeah, yours are Impreza ones at least lol... and his are from a Legacy.
If so, that'd probably devalue his lump, as I think, the STi v.2 heads are appreciably better than the v.2 WRX heads... let alone Legacy heads!
Last edited by joz8968; 30 January 2010 at 09:49 PM.
30 January 2010, 10:04 PM
#30
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His has probably got different heads on or something (from a Legacy maybe?). Or it just might be the covers.
Has your heads got the coilpack held in by a single bolt and his has 2 bolts - if so, then yeah, yours are Impreza ones at least lol... and his are from a Legacy.
If so, that'd probably devalue his lump, as I think, the STi v.2 heads are appreciably better than the v.2 WRX heads... let alone Legacy heads!
Has your heads got the coilpack held in by a single bolt and his has 2 bolts - if so, then yeah, yours are Impreza ones at least lol... and his are from a Legacy.
If so, that'd probably devalue his lump, as I think, the STi v.2 heads are appreciably better than the v.2 WRX heads... let alone Legacy heads!
so if his is help on with 1 screw that means its a impreza heads and if its held on with 2 then a legacy heads.
but what if his are held on with 1 both does that mean the cover could be different you said the engines ate 100% the same so the covers should be the same right??