question about a yella terra head
question about a yella terra head
i went and looked at a motor from ebay today the ad said it had a yeea terra head on it. my question is did yella terra stamp their heads with holden on it the same way holden did. or what markings would i find on a yella terra head. thanks
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mrs ratbox
don't think there's any markings other than on the valves they have yt if they are still the yells terra valves they have the holden markings cause they use the holden castings, on the rear left of the head there is usually an L or a H cast for low comp or high comp yella terra heads usually are blank but this is not on every head
As far as I know Yella Terra heads didn't stamp their heads with any identifying mark as Rat said they had the letters YT on the valve head.
If the inlet manifold is off the engine you will see where they have machined out the inlet port support boss and fitted a thin support sleeve that the head bolt then goes through.Taking this boss out and the fitment of larger valves and combustion chamber valve unshrouding was part of their stage 3 heads process.
From memory their stage 5 "bathurst" heads were the high compression 138/149/161 type head with the inlet boss completely removed and no sleeve or head bolt through the inlet port at all.Head was held down in this part via a very short head bolt at the bottom of the inlet port and the top bolt hole was plugged.This gave a very open inlet port with no airflow obstruction by the head bolt going through.
Yella Terra heads were obviously yellow painted but this alone is not a surefire way of ID ( anyone can spray a head yellow )
There were a fair few head mod places around in the '70's and '80's doing similar mods that Yella Terra did.
I know that Wilkies Engines in Cardiff NSW did a head like Yella Terra as I bought one from them around 1983 or so and it visually looked the same as the YT heads.
If the inlet manifold is off the engine you will see where they have machined out the inlet port support boss and fitted a thin support sleeve that the head bolt then goes through.Taking this boss out and the fitment of larger valves and combustion chamber valve unshrouding was part of their stage 3 heads process.
From memory their stage 5 "bathurst" heads were the high compression 138/149/161 type head with the inlet boss completely removed and no sleeve or head bolt through the inlet port at all.Head was held down in this part via a very short head bolt at the bottom of the inlet port and the top bolt hole was plugged.This gave a very open inlet port with no airflow obstruction by the head bolt going through.
Yella Terra heads were obviously yellow painted but this alone is not a surefire way of ID ( anyone can spray a head yellow )
There were a fair few head mod places around in the '70's and '80's doing similar mods that Yella Terra did.
I know that Wilkies Engines in Cardiff NSW did a head like Yella Terra as I bought one from them around 1983 or so and it visually looked the same as the YT heads.
I can't think what to write here so this will do.
thanks for the info. this is the link to the ebay ad. http://cgi.ebay.com.au/ws/eBayISAPI.dll ... K:MEWAX:IT it doesnt have much time left. i went to check it out cos he was local
Can't tell by the photo unfortunately, if the inlet manifold was off it may be possible to see if it had the inlet boss removed and sleeves fitted.
Looks like it may have a 186S manifold and what appears to be a 350 Holley??
That and the fact that it had extractors might be more indicative of an engine that has some performance work other than external bolt ons, so I'd give it a 50/50 chance that it would have a Yella Terra head ( or similarly modified one ?? ).
Looks like it may have a 186S manifold and what appears to be a 350 Holley??
That and the fact that it had extractors might be more indicative of an engine that has some performance work other than external bolt ons, so I'd give it a 50/50 chance that it would have a Yella Terra head ( or similarly modified one ?? ).
I can't think what to write here so this will do.
Re: question about a yella terra head
Didin't think it was worth opening up a new thread so I dredged up this old one.
Does anyone know what sort of compression ratio you'd expect with a 9 port yella terra on a red 202?
cheers
JK
Does anyone know what sort of compression ratio you'd expect with a 9 port yella terra on a red 202?
cheers
JK
Re: question about a yella terra head
That depends - which head are you using ??? if you have all the bits and you need to determine what to do to get the desired CR - try using this -NZ_EK wrote:Didin't think it was worth opening up a new thread so I dredged up this old one.
Does anyone know what sort of compression ratio you'd expect with a 9 port yella terra on a red 202?
cheers
JK
http://www.csgnetwork.com/compcalc.html
I started with nothing and still have most of it left.
Foundation member #61 of FB/EK Holden club of W.A.
Foundation member #61 of FB/EK Holden club of W.A.