is their any particular place that s best to measure on a 4x4 cos cylinder head with the verniers ,or is it just a matter of where they fit on ?

depth wise were they 139.12 from new ?

and whats the minimum thats of use ?

and anywhere else on the head i should examine for defects/problems

sorry for all the questions but im off to look at one

 

bump

 

https://passionford.com/forum/techni...thickness.html

 

cheers for that matey ,i did have a search around this morning and never came across this

you can almost tell the thickness of the head from the valve seat to the head surface

 

No problem James . Its nice having enough material left to see

 

im off to have a look at the head at today mate ,it was a spare head the guy bought 13 year ago and never used so hopefully should be a good one

 

Good luck with it ,I take it its 4x4 .
Mike

 

well i bought it mikeand yes a 4x4 one ,what do you reckon





guess the thickness lol?

 

138.8-139......

 

Looks skimmed to death.

Im going for 138.3

 

it measures 138.86,

heres something i found out whilst doing a bit of digging which surprised me

 

Nice purchase then and seems to be unskimmed maybe.

 

Looks close to the valves to me. Do you measure both sides to ensure its been cut straight?

My 2wd head is as New and it visibly has more meat around the valve seats. I don't have a 4x4 to compare the two.

 

their different heads mate ,you will notice from the pic that their is more meat at the exhaust side of the head as this was deemed the weakpoint for gasket failure .

but like i said im no expert

 

i hope so mike

 

that seems a very good head imo normally you see them less the a papers width from the valve seats to squish area

 

^^^^ +1

 

Just had another look between the valve seats is that ok as it does look suspect minor hairline in the picture the more i look .Hopefully its just a blemish in the cast ?

 

Which picture and where do you mean?

Could you circle it and re upload perhaps?

 

The last pic chip between the exhaust valve seats, could just be a blemish in the casting hard to tell from a pic really

 

At 6 o'clock from the plug between the valves .Im sure its nothing to worry about but it caught my eye Chip.

 

Thats way too big to be a hairline crack, just a surface imperfection I would have said.

 

that little blemish is in the casting mike ,as its in the same place on all four cylinders mate

 

spot on chip


what do you make of what karl said ,that was news to me tbh as i always thought new heads were 139.12/139.2

i found it on the turbosport forum

 

Ive not got karls experience of new cossie heads (in fact never even owned ONE let alone many) so I cant comment.

My opinion is that clearance on the valve seats is the key thing.

 

As chip said, and ignore the min needing to be 138.68 max as people have run them with less plus you can compensate for it by doing other things to get the comp ratio right