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Yella Terra head

Started by r2160 , Jun 21 2012 10:02 AM

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9 replies to this topic

#1 r2160

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Name:Glenn
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Car:2/71 LC GTR, 4/71 LC 4 'S'
Joined: 20-May 09

Posted 21 June 2012 - 10:02 AM

Hi all

There have been a few yella terra heads pop up for sale recently and to that end, I was wondering if somebody could tell me the best way to tell if its a genuine yella terra head, rather than just a standard head that has been painted yellow

cheers
Glenn

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#2 TerrA LX

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Posted 21 June 2012 - 10:33 AM

I presume you mean cast iron head?
The later ones had YT on the valves but there is no way to tell earlier ones that i know of from stock or for that matter a head modified by another shop.
Unless the head is still new(reco) i would buy solely on parts quality.
ie, is the head fit for service?
Does it have oversized (serviceable) valves?
Are the springs good?
Etc etc.

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#3 _stretchlc_

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Posted 21 June 2012 - 12:52 PM

I thought Bennett stamped the heads on the flat pad on the rear of the heads with date stamps or something??..........Yella Terras Porting was always pretty "machined looking" compared to a head shops hand porting effort. But like Terra says above..the easiest way to tell is the YT cast into the valve heads, double valve springs and the obvious porting and inlet ports posted!!....Most Tella terra heads also run valve sizes of 1.74" inlet valve size, and 1.55" exhaust valve sizes!

Edited by stretchlc, 21 June 2012 - 12:59 PM.

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#4 _qik64_

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Posted 21 June 2012 - 06:44 PM

Not all yella terra heads are yellow,bathhurst 6000 heads are painted red.

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#5 greens nice

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Name:Kevin
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Posted 21 June 2012 - 07:13 PM

1.74" inlet valve size, and 1.55" exhaust valve sizes!

never seen one like that before.
all the one's ive seen are 1.65 & 1.44 and 1.68 & 1.49 valves.
maybe only the Bathurst 6000 heads had those valve's.

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#6 TerrA LX

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Posted 22 June 2012 - 05:08 AM

YT heads did have specific cnc machining but nothing stopped a regular engine or head shop from replicating that work on a good head cutting machine.

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#7 _Ned Loh_

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Posted 26 June 2012 - 04:26 PM

Double Post

Edited by Ned Loh, 26 June 2012 - 04:29 PM.

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#8 _Ned Loh_

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Posted 26 June 2012 - 04:28 PM

For what it's worth - Iron Open Chamber YT 12 port on the bench has 1.74" inlet.

Edited by Ned Loh, 26 June 2012 - 04:30 PM.

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#9 _stretchlc_

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Posted 26 June 2012 - 06:33 PM

My 9 port has the same sized valves...but its bolted to "Klunker" and I cant measure them to prove it!

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#10 _judgelj_

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Posted 26 June 2012 - 06:51 PM

My research indicates that the earliest YT heads were standard holden castings modified with performance in mind. Yes there should be a stamping on the rear, which is true in most cases but i have not, nor have i figured out how to decipher this code (it could mean anything). Later YT did have the initials stamped onto the valves but in the absence of this, double valve springs and porting is not a solid indicator as it could easily be replicated. As suggested, go by parts value and quality as YT and other shops essentially did the same things to these heads.