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MG MGB Technical - Oil thermostat

Following on from the recent thread, fitting an oil stat seems the way to go. My oil cooler spends most of its life blanked off.

Does anyone know the inside diameter of the pipes to the cooler on a '77B?

Also, the 'standard' Mocal stat in the Moss catalogue (no ID pipe size quoted for it, although Mocal do it in at least two sizes) is a lot cheaper than the other, full flow, they offer (two ID sizes quoted). Would the extra expense (three times the price) be justified?

http://www.moss-europe.co.uk/Shop/ViewProducts.aspx?PlateIndexID=9567
John Bilham

as mentioned to you before
you need to understand your oil flow completley befpre attempting this
the two hose unit on a b is no good as it will completley block off all oil flow

even with the four hose full flow unit you have to understand which direction oil is flowing in each hose
before you start
willy
its not hard but you need to get into how it all operates
first
William Revit

As William says you can't use the two hose unit as the oil cooler is part of the complete oil circulation, and the two hose unit will block it completely. I'm amazed Moss are showing it. You need a four hose unit and Mocal make one that looks just like the two hose unit shown on that Moss page, only with four arms. As I remember it, the unit has arrows cast into the arms to show the oil flow direction, and I expect there was an instruction sheet with it, but it's years since I had one. I do remember it was blo*dy difficult to get the cut pipes over the arms, and once tightened up with Jubilee clips, it never leaked. This is the sort of thing
http://www.ebay.co.uk/itm/MOCAL-OT-1-1-2-REMOTE-OIL-COOLER-THERMOSTAT-CIVIC-VTEC-TYPE-R-S2000-CRX-SQ-/400662044842?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5d4951a0aa

You then need to figure out the oil flow on your engine - does it come out of the block and return to the filter or out of the filter and return to the block. For the life of me I can't remember. However, once all connected up properly it will work well. The oil will flow up one pipe to the stat and if it's not warm enough, will simply double back down the other pipe.

Pipe size? Dunno. Might have done once, but the little grey cells aren't what they used to be!
Mike Howlett

ok
oil flow mgb
oil is drawn up into the pump and runs along the gallery on the left hand side of the engine towards the rear
oil then crosses accross behind no4 cylinder to the rh side of the engine
all oil then comes out the fitting where the cooler hose screws on
out the hose to the cooler and back to the oil filter housing where it is filtered and then allowed to enter the main oil gallery
oil pressure is regulated at the rear of the main gallery
with excess oil being dumped back in the pan


willy
William Revit

I think the picture in the Moss link that I posted is wrong. There's no way that Moss would sell something that patently wouldn't work.

I used the Moss page simply to illustrate the two different types of stat available. There's no way I would buy one from them (they want to charge me £15 p&p!), when I can get one cheaper (and delivered for £3.50) from a seller on ebay, who also shows the correct picture with the four pipes visible.

Discerning flow direction should be simple enough, just disconnect the cooler pipes at the filter and turn the engine over with the plugs disconnected.

Aside from the price and function difference, my main concern is the pipe ID, since I don't want to order the wrong one. If necessary I can cut one of my pipes in a suitable place in anticipation of the stat's position, I just wondered if anyone could confirm the ½" or greater.
John Bilham

Oil comes from the block port just in front of the engine back-plate, through the cooler and into the filter head.

The relief valve is between the pump and the main oil outlet to the cooler/filter, not in the main gallery.

What's more important is making sure the four ports on the thermostat are understood and connected correctly.

Another gadget to solve a non-existant problem, and to go wrong.
Paul Hunt

Answering my own question, the OD is ¾", so allowing for the walls to be ¼" total, the ID is ½".
John Bilham

>Another gadget to solve a non-existant problem, and to go wrong.

I'd make the same claim for the cooler itself! ;-)

Just remove it and be done with it!
Rob Edwards

>>Another gadget to solve a non-existant problem, and to go wrong<<

Rob beat me to it, did Paul mean stat or cooler :D

mind you I don't expect it gets as hot in North Carolina as it does in the West Midlands, record(?) temperature 29C, over three days in 2011 ! ;)

John,
as you already answered your own question, yes I think it's half inch but don't rely on my memory

note the Mocol linked to is for 80C, I think someone put something about 85C in the other thread(?)
Nigel Atkins

>West Midlands, record(?) temperature 29C,

:-) That's about 84ºF. I've seen that here at 7am...
Rob Edwards

I've been running the 4 port Mocal unit for over a decade and the car reaches operating temperature in only a few minutes all year round. It's a great unit that controls oil temperature and prevents oil contamination by keeping the oil hot, but not too hot. RAY
rjm RAY

Rob,
you're welcome to that, personally I'm not happy with over 77F (25C)

which is a shame as we generally get it warmer here -
"Northamptonshire held the UK's highest temperature record from 1911 to 1990.

High temperatures are common in the summer as the county does not benefit from the cooling effect of the sea.

In August 1911 temperatures of 36.7C were recorded at Raunds.

At Pitsford (weather station) an average 1,624 hours of bright sunshine is recorded during the year. This is typical for inland areas in lowland Britain but high for the UK as a whole."


Ray,
for the majority of standard Bs over here IF the Bs were actually driven all year round I bet the majority of the days the stat wouldn't even open and if it did, without a blanking plate in front of the oil cooler, much of the year the stat would soon close again - spirited drivers perhaps being the exception on occasions
Nigel Atkins

John,

"My oil cooler spends most of its life blanked off."

And presumably the car runs fine....

Last year I forgot to remove the blanking plate (a rally plaque!)till half way thru the summer!
Michael Beswick

Curiously enough, oil temp is one of the many things that the trip computer on my Passat can display. It reached 99C on the way to York this morning.
Dave O'Neill2

you got a B-series engine in your Passat Dave ! :D

when I had cars with 'analogue' oil temp gauges they used to worry me as normally they showed so low, bit like having a wide range oil pressure gauge on the RV8 engined cars that hardly moves from the start at tickover

where would the ideal place be to take the oil temperature reading from on the B-series engine?
Nigel Atkins

Anyone with doubts about oil temperature should feel their oil filter/measure it with an infra-red or thermometer/put an LCD temperature strip on it.
Paul Hunt

Should have read:

Either or both. I wouldn't add a cooler if it didn't have it, neither will I fit a thermostat. People seem to forget that these cars have been running for 50 years, in most cases with coolers, and for quite a number of years will have been used in all weathers. I'd say the take-up of thermostats was pretty minimal, if 'overcooling' was a problem we would know about it by now. My V8 was used through cold winters for several years, kept outside, has now done over 200k on the original engine. I've nearly done 100k with it, decided I'd better check the big ends and main bearings. They were the original size hence crank not reground, and they were all at or just inside the tolerance for new bearings with no visible wear on the crank bar a few faint scratches on the first main bearing, probably from incomplete removal of debris following the rebore it did had for some reason, before my time. The V8 may well get hotter, but then I don't use the roadster in temperatures as low as I used the V8, even if we had them these days.

There's too much Fear, Uncertainty and Doubt spread around http://www.kenrockwell.com/business/fud.htm. Anyone with doubts about oil temperature should feel their oil filter/measure it with an infra-red thermometer/put an LCD temperature strip on it.
Paul Hunt

yes you have a good point about use but we really need testimonial from the owner of a standard 1800 B in this country say, who has the oil cooler fitted but no thermostat and who uses the car all the year round

as with respect your V8 is a different engine

then from a B owner in much hotter climes that never had an oil cooler fitted

I'm with Paul and John in that I'd not choose to have an oil cooler so obviously wouldn't need the stat but when I had an 1800 B it was used all year round and all my car sit outside 24/, 365/6 so if I had another I'd add the stat to the cooler

btw we had -16C here a couple of winters back and I think the record here was about 25 years before that at -19C, but no until the winter two and three back we hadn't had a proper cold winter for about 30 years that I can recall

fear has been used for centuries to control people and not just for sales/marketing
Nigel Atkins

Well this thread has got rather profound with talk of fear :)

The simple facts are that the coolant has a stat to keep the engine hot and my oil cooler seems to do its best to defeat that, with its rad (and the 2 metres plus of additional external pipes, so blanking off the cooler only partially cures the problem).

I appreciate that the B runs well in the heat of say, California, but I have to admit when I'm lumbering up the side of a mountain either here or more especially in Spain in 35°C+, the cursed cooler is exposed and does provide me with some reassurance, justified or otherwise. I also have a mildly tuned cylinder head, although whether that makes a difference I doubt I shall ever find out.

Nevertheless, I thank everyone for their comments, especially from those who patently know a lot more about the B and its engine than I ever shall.

John
John Bilham

John,
whether you have an oil cooler with or without out stat the main thing is to have the whole of your 'water' coolant system in good and clean condition condition with all the components fully functioning and the coolant regularly change (well before the antifreeze part of it wears)

I've put my very simple but thorough cleaning system in other threads so won't repeat here but the B engine particular seems to need the engine block draining, flushing and scraping clear

the secondary oil cooling system also needs to be in good and clean condition obviously and the use of good quality oils and thorough oil (& filter) changes will help

then you need not have fear of the Spanish 35C+ mountain climbs :)

and if you're lumbering up them then attack them at, and maintain, higher speeds :)

being serious the altitude makes a difference to performance too

good luck, get the right stat and fit it the right way round
Nigel Atkins

This thread was discussed between 12/03/2014 and 14/03/2014

MG MGB Technical index

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