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Yella Terra Head ID

Started by red6 , Feb 18 2006 04:46 PM

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12 replies to this topic

#1 red6

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Posted 18 February 2006 - 04:46 PM

Bought this head today for my 186 i was told it was a stage 3 or Bathurst 6000 and was purchased new in 1991 by the person i bought it off who had it on his 179 bored to 186 in his eh and covered approx 5000 miles as he was interstate and the car sat untouched for years. Pulled the following numbers off the head:

7438296
J110
6H

and the following part number off the rockers:
YT5007

all valves have the YT stamping and the valves measure approx:
4.4mm Inlet
3.8mm Exhaust

So What can u guys tell me about the head? are those rollers Yella Terra or Street Terra? what compression ratio am i looking at on a stock 186 block? what was the head originally off? what stage is the head? anything else? what is the proper yellow paint for these heads as it is currently painted blue?

also i realise that i need a bigger/ more carbys for optimal performance, but will it run with the single stromberg without any hassels?

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#2 _CHOPPER_

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Posted 18 February 2006 - 04:55 PM

It may not be a Bathurst 6000 head, they are different to the "stage 3" head. The numbers off the head were put there by GMH. It has the valve size I would expect in a "stage 3" YT head, whether they have the same size valve in the Bathurst 6000 head, I'm unsure. It's a high compresion head, as the normal size chamber has a kidney shaped combustion chamber. The 5007 part number is for the Yella Terra roller rockers. I had them myself. The Street Terrors have a different part number.

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#3 red6

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Posted 18 February 2006 - 05:26 PM

cheers chop so who can tell me what to look for to see if its a stage 3 or a bathurst 6000?

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#4 _CHOPPER_

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Posted 18 February 2006 - 05:37 PM

Might be best to contact Perfectune 03 9555 5522 or http://www.yellaterra.com.au

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#5 FastEHHolden

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Posted 18 February 2006 - 06:32 PM

to quote the YT site:

"How can I identify a Yella Terra head already fitted to a vehicle?
Once fitted, a Yella Terra head is very difficult to identify except alloy V8 heads which have a part no. engraved on the ends. All heads are stamped with a coded production date, but there are no distinguishing features to date."

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#6 _CHOPPER_

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Posted 18 February 2006 - 07:01 PM

But judging by the pics, the head isn't fitted to a vehicle. Does the Bathurst 6000 have bigger valves? More port work? Stronger springs? All of the above?

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#7 _Yella SLuR_

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Posted 18 February 2006 - 10:02 PM

It's obviously a later YT head to have YT stamped on the valves. Earlier ones didn't.

As FastEH has quoted off the YT site, there are no obvious signs to identify a Yella Terra head, they weren't even painted yellow, just a bit of clever advertising in the print media, where they were yellow. But in real life they are just a modified Holden head.

I'm not familiar with the 202 heads, however it has similar characteristics to the 308 Stage 3 heads:- 60% larger valves, metal removed to provide improved combustion chamber for the bigger valves, tuft-rided (black coating) to the valve stems. In the inlet/exhaust ports, the porting is minimal, all they virtually do is remove the sharp casting edges (where the moulds meet), with minimal removal of metal.

Easiest way is to grab an old 202 head from somewhere (a head machiner will prolly give you an old cracked one), and sit them side by side to see the difference.

Have NFI on the roller rockers sorry.

Mods, we need the old Identifying YT heads off the old forum back.

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#8 _CHOPPER_

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Posted 18 February 2006 - 10:27 PM

Two things Pat.

#1 The $175 spent on retrieving the lost data appeares to have been a waste, as the data appears to be corrupt.

#2 If you read my post, I answered the question about the roller rockers and a few tips on I.D.ing a YT head. As I said, it may not be a Bathurst 6000 head, but it does look like a "stage 3" YT head.

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#9 _Yella SLuR_

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Posted 18 February 2006 - 11:35 PM

No worries, yeah, I don't doubt you on the rockers. I don't know anything of them or the Bathurst 6000 heads. What were they? Just pointing out that they have similar characteristics to the 308 Y/T's.

Would be happy to learn what Bathurst 6000's are.

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#10 _CHOPPER_

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Posted 18 February 2006 - 11:42 PM

The Bathurst 6000 heads were made to the same spec as the 73 Bathurst XU-1 heads. For those that didn't know, Perfectune modified castings that came straight from Fishermans Bend via Harry Firth.

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#11 red6

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Posted 19 February 2006 - 02:51 PM

reasonably confident that have got what i paid for now and it is a stage 3 YT head with the YT rollers still curiouse what the diffrences are between a stage 3 and a bathurst 6000 head... started to prep it up today and discovered that the studs for the roller rocker retaining bolts also have some sort of retaining pin tapped into them thru the head to prevent them from comming out is this standard YT?

so all i need to know now is will my standard stromberg be able to supply enough fuel to make the engine drivable or will i have to hold off putting the head on untill i have a better carby set up?

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#12 FastEHHolden

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Posted 19 February 2006 - 02:57 PM

if you don't fit some massive cam the single strommy will be fine....I think you will find a little extra power and some economy too...these heads are the way they all should be.

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#13 red6

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Posted 19 February 2006 - 03:14 PM

cam is a dynotec stage 2 30/70 so i should be fine really need to get onto a better carby set up tho, this came up in the local trading post and i couldn't resist.