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MG MGA - 1622 valve clearance - hot or cold?

The MGA Workshop Manual says 0.015" measured when Cold for the Mark II 1622 engine (as it does for the 1600/1588 engine).

The tag on my engine says Hot - see image.

Help!

I think I go through this each time, but nowadays I have trouble remembering breakfast :)

Thanks!

- Ken


KR Doris

I posted the same question some years ago
https://mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&access=&mode=archiveth&subject=6&subjectar=6&thread=201002282316037126


Graham V

Hi Graham,

So that thread basically says hot or cold is not a real worry.

Since cold is easier, and more consistent, I'll go with that.

Thanks!

- Ken
KR Doris

I saw posts in the old thread by Fletcher R Millmore, who could be relied on for sound advice.

I hadn't realised that the "mechanic specializing in classic foreign cars" had died a couple of years ago.
https://garrettfuneralhomeinc.com/tribute/details/1778/Fletcher-Millmore/obituary.html
R G Everitt

I have a highly modified MGA with a 1950 cc engine and high lift race cam. Cam supplier advised clearance to be set at 0.017” hot but because I have high ratio roller rockers 1.625:1 compared to standard ratio clearance has to be increase by quotient of ratios meaning clearance needs to be set at 0.021” hot. This shows clearance is dependent on cam profile ramps as well expansion. Still doesn’t answer the hot/cold question. My gut feeling is it doesn’t make a lot of difference to a standard cam.
Mike
Mike Ellsmore

Ken
That engine plate is for a MK1 1600

valve clearances differ for the MGA.
The 1500, 15GB and 15GD, engine is 17 thou (hot). The 1600, 16GA, engine is 15 thou (hot),
and the 1622, 16GC, engine is 15 thou (cold),
all according to the original workshop manual.

My personal opinion which is worth about 3cents is that setting them cold equally will give differing clearances hot with the exhausts closing up as they get hot and the inlets opening up
I've run an MGB up the road and got it nice and toasty, pulled the cover and set No1 cylinder at 15 while it was nice and stinky then left it overnight to cool right off and then remeasured them-
14 inlet--16exh was the result ---COLD
did the same to one with SS valves and the result was 14I-17E---COLD

I like doing them cold as you can take your time and recheck---doing them hot usually means the engine will cool while you're doing it and by the time you get around them and recheck the first pair they will have changed
willy
William Revit

RG, thanks for the info on FRM, no surprise about his thoughts on a funeral service and good on him for contributions.

"Per Fletcher’s wishes, no funeral services will be held. For those who wish to honor his memory, memorial contributions may be made to The Nature Conservancy, to recognize his love for nature."
Nigel Atkins

I was really sad to hear that FRM had passed, we have some great conversations over the years and he always had some really accurate, practical and interesting things to say on the forums.
He is sorely missed.

Quite a few years ago FRM and I found ourselves on the receiving end of some quite abusive comments from a Canadian member who took great offense at a couple our (intended to be humorous) replies to his post asking about Chrome Plating SU dashpots.
(It was all sorted out in the end though and there were no hard feelings)

See https://mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&access=&mode=archiveth&subject=6&subjectar=6&thread=2011032303030721953

FRM and I have had some fun remembering this conversation over the last 10 years.

RIP FRM

Colyn
Colyn Firth

FRM always had incredibly correct details - we lost a great one!

Colyn - I see nothing but a clever “reflection “ and good advice in that thread.

Glad to see by the final posts the author realized he over reacted.

- Ken
KR Doris

Thanks Ken,
I just tried to open the link I put in to the post and it just took me back to this current thread instead of the archived one I mentioned.
Here's another link which may work
http://mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&access=&mode=archiveth&subject=6&subjectar=6&thread=2011032303030721953

If not, you can find it if you search in the MGA Archive under Chrome Plated SU's

Cheers
Colyn
Colyn Firth

Colyn,
just to let you know, both links take me to the other thread (both link address look the same to me but don't go by my eyes).

I might have this wrong but the link might be an open access, i.e. within a logged in rather than non-logged in public access (if that makes sense) using - 71427636207095 - within the link address.

Giving -
(-------) mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&access=&mode=archiveth&subject=6&subjectar=6&thread=2011032303030721953

instead of -
(-------) mg-cars.org.uk/cgi-bin/or17?
runprog=mgbbs&access=
&mode=archiveth&subject=6&subjectar=6&thread=2011032303030721953

The addresses automatically form themselves despite me putting in spaces and square brackets.


Nigel Atkins

I run out of edit time, I see the presentation here is because I'm logged in to the site which must throw in the numbers (code) 7----------- but excludes them if viewing logged out as 'public'.

Nigel Atkins

I just tried it again Nigel and both links now work fine for me once I am logged into the site, I didn't realise that you have to be logged into the MG Enthusiasts website for them to open correctly.

The second time I posted the link, I had taken out the letter (s) in the https part of the web address, which usually fixes the problem.

Cheers
Colyn
Colyn Firth

Colyn,
I made a right hash of explaining it as I was trying to get the examples without them being hyperlinked (fully or partly) but some automatic things beat me.

Basically you'd have to be signed in as a member to access the Archives - but the thread might also have open access via a search engine.

I might be wrong (again) but I don't think the 's' matters so much now generally (perhaps, maybe IIRC) but best not to rely on for that - or much else - what the wheel nut torque is for a 1275 Spridget and what page it's quoted on in the good book is a different matter.

Then of course the early books for the earlier models had different nuts and different torque figures . . . zzzzzzzzzzzzz
Nigel Atkins

This thread was discussed between 13/05/2021 and 15/05/2021

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