Identifying a true yella terra head?
#1
Posted 15 March 2009 - 12:58 PM
Looks like a date code? 05B92
Are there any other markings to be found besides valves etc?
The other head is stock 202 for comparison.
#2 _NZ Toranaman_
Posted 15 March 2009 - 01:04 PM
#3
Posted 22 March 2009 - 02:43 PM
Rob, could you get a few photos of the rocker setup on this head for me? Even if you just e-mail it, I would appreciate it greatly I want to confirm what the rockers are from, in addition to a few other things
#5
Posted 22 March 2009 - 02:55 PM
#6 _Drag lc_
Posted 23 March 2009 - 07:20 AM
you might be onto somthing here i am not interested in y/t heads but have come in contact with a few over the years and i have 2 what look to be genuine y/t 9 port type the classic unforgetable "stage 3" style with y/t valves they both have a stamping in the same area one has 12 82 and the other 7 82 and i have another one that has had vey simalar treatment but did not have y/t valves in it it did not have any code in that area.
Thanks Hayden
#7
Posted 23 March 2009 - 08:11 AM
#8
Posted 23 March 2009 - 09:29 AM
#9 _Drag lc_
Posted 23 March 2009 - 05:20 PM
Thanks Hayden
#10
Posted 23 March 2009 - 10:54 PM
what does it all mean
#11
Posted 23 March 2009 - 11:17 PM
Mine reads 05 B 92 (though hard to see in pic) which might interpret as 5/2/92?
(B being February like Holden?)
It would appear going by others pics that perhaps, somewhere in time, they decided to unify their stamping methods?
Your second pic might be the reason for unification?
#12 _NZ Toranaman_
Posted 24 March 2009 - 04:30 AM
Heres a couple
what does it all mean
It looks like you have 2 totally different number stamps...
One says 2/80
One says 1/767 (maybe he got the year wrong as was is the first month of 77)
#13 _clubspClubsportr8ortr8_
Posted 25 March 2009 - 10:55 AM
Jeff
#14 _Drag lc_
Posted 25 March 2009 - 11:24 AM
what he said^^^^they were chev valves hey not 308 ones. yeah i thought you might have seen them before hehe. so you have some y/t ones that have the simalar stampins on them.we are running a 930 head on our lc and it is open chamber.
Thanks Hayden
#15 _SableMet7/73_
Posted 25 March 2009 - 10:32 PM
Whats a 9937263, 4J9, Hi comp head off?
Were they graded in stages by the amount of work
done & the equipment fitted?
If so then whats this one.
Cheers Jono
Attached Files
#16
Posted 26 March 2009 - 12:28 AM
Were they graded in stages by the amount of work
done & the equipment fitted?
I'm begining to think that.
And i'm also thinking (from memory) that early YT valves didn't have YT on them.
Stage 1 ?
Stage 2 ?
Stage 3 ? in the early days?
This is coming from buying a YT head for my HK Monaro back in 1977ish?
#17 _HQ SS_
Posted 26 March 2009 - 09:21 PM
I have a 9937263 head listed has a 173/2850 ADR27A head
4J9 means it was cast on the 4th of September 1979 so off a VB commodore I would think ( HR's and HQ are more my thing ).
If you can all bare with me on this I have been trying to sort a head ID guide out for red heads and we appreciate any comments and corrections
on what I have so far.
On the stage 1, 2 and 3 thing.
There is always a lot of different views to that one but if you have a look at this picture
http://gallery.oldho...ageViewsIndex=1
and this one
http://gallery.oldho...ageViewsIndex=1
That is what perfectune (Y/T) called a stage three back then.
Interesting to note in this advert stage 1, 2 and 3 heads which are listed as hand finished items and Yella Terra as a separate item and is listed as machine modified.
Rodomo I was also told that the early Y/T heads did not have Y/T on the valves and looking at that picture those valves do not have the Y/T on them.
I was told years ago a stage one had slighty over size valves and it had been throated to suit those valves. With basically minor port work done.
stage two was std inlet post removed and a insert post fitted with both inlet and exhaust ports were ported and match ported to the inlet gasket with slight larger than stage 1 valves fitted.
Stage 3 I always thought looked like this.
Where the inlet posts had been removed totally and a Hex head bolt was used instead of a std head bolt.
they also had duel springs, larger that stage 2 valves and had been decked.
But after looking back through my old magazines and finding the adverts in the links above I know that is not right.
But to add to that I have now been told that they tried the removal of the post altogether as in the picture and they had problems with the heads cracking so then they went to the insert post design instead.
Like in Jono's no 3 picture.
If you have a look here
http://gallery.oldho...ines/red heads/
I have a selection of pictures which now have to be renamed showing a std head, a slightly modified head (stage 1)and a more modified head (Stage 2 which is actually possibly really a stage 3 head)
Since doing these pictures I have been doing a pictorial record of casting numbers verse chamber designs which is here.
http://gallery.oldho...yl Casting ids/
The only problem is that I have came across one casting number with two designs.
Both of these heads are modified with larger valves and the second picture is a possible Y/T head where as I am not so sure if the first one is a Y/T or not.
Both are 7429477 casting number heads one with a B97 9 2 67 date code and the other with a B237 23 2 67 date code but as you can see totally different chamber designs.
Any ideas on this anyone
So from this I am interested in any pictures I can come across of any other chamber/casting pictures that I do not have.
Cheers Paul.
#18
Posted 26 March 2009 - 09:34 PM
Thanks Paul, links saved.
VitcLJ has a head like this one and might be able to shed some light on it's origin?
Edited by rodomo, 26 March 2009 - 09:35 PM.
#19 _HQ SS_
Posted 26 March 2009 - 10:38 PM
So to come up with a stage rating will be hard to do I think.
I myself have had heads that have had far more work done to them than any I have now and any I have seen pictures of lately.
Some of the speed way and racing heads I have had were right on the limit of what you could do to a red head and would possible
rate up to the mythical stage 5 etc.
Something interesting with the date codes on these heads so far is that they are all from the early eighties which I would have thought would have been the real peak of when the red heads were being modified on a regular basis.
It may end up being that this was something they did on later heads maybe at the same sort of time they started using valves with Y/T on them.
In the colour ad of the red head (in with the other pictures in my shed) which is from the late 70's early 80's it still shows flat un embossed valves.
Cheers Paul.
#20
Posted 26 March 2009 - 10:47 PM
Its in between high and lo comp
Cast # 7420109 possibly 149 EH
#21
Posted 26 March 2009 - 11:40 PM
Some of the speed way and racing heads I have had were right on the limit of what you could do to a red head and would possible rate up to the mythical stage 5 etc.
VitcLJ's head is like an egg shell in places
#22 _TRRANA_
Posted 27 March 2009 - 12:30 AM
first is the number "7" then theres stamped "?87 8" with "YT" stamped on the valves
yt_stamp7.JPG 35.65K 14 downloads yt_stamp.JPG 24.65K 11 downloads yt_valve.JPG 48.82K 18 downloads ports_yt.JPG 46.94K 15 downloads
7420105 H244
yt_top.JPG 59.74K 16 downloads
#23 _HQ SS_
Posted 27 March 2009 - 10:53 PM
I would be interested to know a date code on that one and also if it is a a H or a L cast head.
Also if the L or H is at the front of the head as the 7420109 head I have is a H high comp head with the H at the front of the head
and it looks like this.
So another case of two chamber designs to one cast number.
TRRANA
H244 means the 24th of 8th 1964 and are the other numbers on the rear face of the head.
You have listed your head as a 7420105 not a 7420109 and by the looks of the picture that is what it says as well. (So is it actually a 109 or a 105 head )
It has the same open chamber design as Ferg's head and not the same as the 7420109 I have and also the the picture I posted above
with the inlet post cut out is a 7420109 head with the same chamber design as the picture in this post.
I wonder if they are actually 105 heads for one and 109's for the others.
I have been told that the same casting numbers were used for different chamber designs and this may actually be the case.
I have also been told that early on Y/T just used new and second hand red heads and then modified them to there specs.
Then later on they bought the molds from holden and cast there own heads from these molds.
I am wondering if that is what we are seeing here same cast number but different chamber designs.
I would be interested to see if anyone has std un modified versions of these cast numbers (and any others) to see what the chamber designs are
like compared to these Y/T type heads.
Cheers Paul.
#24 _HQ SS_
Posted 27 March 2009 - 11:04 PM
As you see the same basic design as the std 7420109 head in the above post, when you take in to account that it has been
shaved enough to remove the thumb print in the actual chamber.
#25 _Drag lc_
Posted 03 April 2009 - 04:39 PM
Hayden
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