Grey Motor Head Advice

[Jolls]

Hi Team,

I came across this head on FB yesterday.
(Pictures have been removed as it keeps telling me it is forbidden for some reason - I will post the pictures separately; touch wood)

I reached out to the seller and he doesn't have a great deal of information. His father had it modified for ULP a few years back and passed prior to fitting it. Since then the paperwork has been misplaced - probably thrown out as no one knew what it was. The previous owner was from around Grafton; someone may know who it was.

From my conversations with the seller he understands that it has been crack tested, had hardened seats fitted and all up the work cost about $900 around 2020/2021. I assume from the 1411 marking on the exhaust valve that it is 1.411" probably making the valves 186 red motor. Given I haven't modified one of these girls since 1982 am I likely to get in trouble if I was to grab this (priced at $750) to save me the hassle of getting the work done? Do red motor valves change the rocker/pushrod/am follower geometry or is it a simple bolt on replacement. I understand that most run 202 valves - on a mild grey does the 202 valve upgrade add significantly more than the 186?

Keeping my current head as a spare isn't a bad thing. I have looked into getting my head done and it costs around $900 plus shipping - given I get a head plus the work for $750 it seems like a good buy. I don't want to get stuck with a lemon though.

Your advice and recommendations would be greatly appreciated.

[Jolls]

[Jolls]

[Errol62]

I saw the add too Craig. I don’t think there is any difference between 186 and 202 red valve sizes. Could be blue motor spec, but I don’t know that is any different either. Dr Terry will say, no doubt. If not I can look it up, but a bit cold to venture to the shed just now.

Probably a bit more than $900 now to do one up anyway I should think, but without knowing the specs it is a gamble. Can you see how much thumbprint it has?


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[RET]

Those mods aren't anything too unusual in unleaded conversions. My car had much the same done when the engine was reconditioned. That's about 15 years ago now. Still going strong - didn't miss a beat Sydney to Broken Hill and back again last year.

cheers
RET

[ardiesse]

Craig,

Late grey motor valves are 1.345" inlet and 1.219" exhaust.
Red motor valves are 1.493" inlet and 1.276" exhaust.
Tolerance is +/- 0.005".
Source: EJ/EH workshop manual.
HQ shop manual says all red motors have the same size valves as EH.

The exhaust valves in the photos are original Holden, but Holden-made red and grey exhaust valves look very similar.  I don't recognise the inlet valves.  Given that the combustion chambers have their original surface finish and the valve heads have a fair clearance to the combustion chambers . . . and looking a little more closely . . . the inlet valves aren't that much larger than the exhausts, I'd say the head has grey inlet valves and red exhaust valves.  You could always ask the seller to run a vernier caliper over the valve heads.

It's a "two-outlet" head, so it's FB or later.

Apart from the different head diameters, red motor valves are a drop-in replacement for grey motor valves (and yes, I have a grey motor with red exhaust valves sitting on grey-size exhaust valve seats).  The main source of uncertainty will be the valve seat height and how much the head's been machined.  But that's what the valve lash adjusters are for.

As always, caveat emptor, but I think you'd probably be safe buying this head.

Rob

[Jolls]

Thank you all for your input,

I searched high and low for a 1.411 reference and could only find one on the net referring to a 186 valve. Clearly an erroneous entry - got to love the internet! I have asked a few more questions and taken the punt so I will find out in due course exactly what I have spent my hard earned on. I was aware it was a later model head but was not aware that the red valves were a straight changeover - another piece of information learned. Worst case is a learning expereince as I can sell it on and do use the funds to do up the FB or FC head I have in the shed.

Cheers n Beers
Craig

[Jolls]

The head arrived today. It does not appear to have been shaved at all - a full thumb print and evidence of old gasket being scraped off with a screwdriver aometime over the last 60 odd years. Although I can't be 100% sure because my verniers are a little short, it appears to be a new set of standard grey motor valves. No work on the ports or combustion chambers. I expect that the work done was new valves, guides and seats. If I have read the casting correctly (M200) it is an FB head manufactured in December 1960.

This will serve my purposes; although I would have preferred to go the larger valves and had it ported. I may still do this with the other FB head down the track.

[Errol62]

Believe it or not the FB head was a slight performance upgrade…..


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[Jolls]

Believe it or not the FB head was a slight performance upgrade…..


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Once I clean up the Speco alloy rocker cover, that was being used as wall art for the last 40 years, it should be good for an extra 50 horses! haha