"Stage x" heads?

[Ed]

Just a question...

Always seem to see ppl describing cylinder heads as a Stage x, y, or z head.

I remember reading old mags and seeing certain companies building up heads to a particular spec and then calling them stage 1, 2, 3, for ease of selling a "package".. however

Does Stage 1, 2, 3, heads have any real relevance or meaning?

personally Id prefer to know what work has been performed to the head in question rather than see a Stage number placed on it.



Exit... stage left.

Cheers

Ed

[57fewagon]

Hi, it all relates to the extent of work done to the head- its similar to the way they rate stage 1,2,3 etc... cams, stage 1 is almost stock, stage 2 is getting warmer, stage 3 is hot street etc...
So a stage 1 head may have larger valves and double springs, stage 2 could be stage 1 plus port and polish, whilst stage 3 could be 1+2 plus shaved etcc...

[Ed]

specs still remain a mystery tho...?

[Blown_FC]

Ed....I think 57fewagon explained it pretty well.   Use the stages as a guide, as I think people can get specific about a lot of things....When my kid is in grade 3, it won't tell me what he actually knows, but should give me a guide, that he should be able to read and spell, and when he's in grade 7, he should be teaching me about the world ! ( lol ).

It is an interesting topic you posted though, as I recently had my head recond.   It already had the dividers cut out ( holden red 6 ), it had larger valves, and that's about all I knew about it.   Since the recon, I found it was a Yella terra exchanged head, but needed new valve guides, decking, k-line, and general clean and service....I then aksed the guy what stage the head was, and he really couldn't answer.  he said they don;t talk like that anymore, and rather told me what specs my head now was, then he ended by saying, it could be compared to say a stage 2 or 3 head.

A bit like air conditioners now.....You used to be able to be a 2 hp or 3 or 3.5 hp air conditioner for your house, but now the are 6.2kw or 7000w or 8300 w......what the hell ?

I guess it's just a sign of how in todays world, we have to know everything and aren;t happy anymore being told...yeah mate, your head is a stage 2 and your kid is in grade 3, whilst you have a 3hp air con in your lounge room....

Aahh.....how simple ( and great ) life was !

Cheers

Mark

[Dave_EH]

The bloke i bought my head from claimed it was a "stage 3"

When i got it recond the bloke said he could't say exactly what stage it was other than "mid range"

Yella Terra used to make 5 stages i think.  Stage 5 had the bolt posts removed, although some people believe stage 3s had them removed too.

the thing with yella terra heads is that you could option all sorts of spring tensions depending on what you intended to do with the engine.

Mine had enlarged valves, double springs and a port and polish...other than that who knows?  I had it shaved down a little with some valves and valve guides replaced (as well as acid dipped, crack and pressure tested) and it cost bugger all - $200 cash.

Dave

[Dr_Terry]

Hi Guys.

Ed's question is a legitimate one.

The various 'stages' are only meaningful if you're compararing 'apples with apples'. What I mean by that is, with one brand say 'Yella Terra' if they have 5 stages of modified head available, then stage 1 is mild & stage 5 is radical then the other 3 are in between these.

If you then look at another brand (say brand X) if they have 3 stages available, then a stage 3 brand X head is going to be totally different to a stage 3 Yella Terra head.

Stages of head (& cam) modification had relevance many years ago, but today they are meaningless. You need to know what the mods actually are. With cams for instance the lift & duration are what matter & with heads it's overall head flow & RPM capability are important. Technology in these areas has changed so much over time that the old stage 1 & stage 3 bit now means nothing in real terms.

Dr Terry