Engine Head Question

What year MGB or ??? engine head is in the picture below? The hubby doesn't think it is the correct one for Bandit (the 79) since it doesn't have the air port holes. It is the engine in the car though.

He does think the engine is a 79 due to the serial number. The reason for the question is I know I have to order a water pump now and I recon I need all the info on this engine for other parts when those times come.


Your turn :)

You're right, the head is an earlier head, but that won't matter. Just get the pump for the 18V block (water pump doesn't attach to the head).

Joe - that's what I thought too - BUT it has the water port on the rear for the water choke on the Z/S carb! It is a VERY strange head and "may" have come from a UK spec car.

But I don't think the home market cars ever had a water choke...did they? For that matter I wonder if any MGB (maybe for some other market) was ever equipped with a water choke from the factory...but not an air pump? Or possibly some other BL vehicle that used the B-series engine?

Naomi...you may have a priceless one-of-a-kind collector's item head - or at least that's how you should list it on Ebay! :D

Wanna buy that "priceless one-of-a-kind collector's item head" Joe)

By the way Eric did get a hands on close up look at it and he can tell ya all about it :)

I can't see the water choke outlet... looks like an early head.. Wonder what your compression #s are with that head???

I agree - it looks like an early head, but it definately has the water choke outlet (I checked) and no air injection ports. At first I thought somebody had plugged the ports and then filled the holes, but the casting is completely different. It could possibly be a head from a UK spec Marina, but I'm not sure.

It does have "18" cast into the rear, and there are part and/or casting numbers at the front.

That's an earlier head from before the days of ZS carbs (started in 75), and before the days of air pumps (started ? - well before 75). It will work - it's what I have on my 80, you just hav to do a little re-plumbing because the rear hose connection is not here. I piped my heater straight to the lower radiator hose and put 71 HS4 SU's on it. Works fine.

Sorry Jack - this head does have the water choke port on the rear of the head!

Water choke port and "maybe" a better picture of the head :)

I can't recognize it if it is, from this photo. They can be added. The air pumps were added long before the water chokes, so to my knowledge, the factory never made an MGB head with the water spout and without the air ports. My next question is: Is this an MGB engine? Looking at the engine #, I cannot reconcile it with NAMGBR's listings for engine codes. 18V(883AE)L036779. The part I entered in parentheses is not defined by NAMGBR that I can see.

Jack I do think you are on to something. This engine, with the ZS, has much more power than my 80 with the Weber. I've also mentioned this several times on the forum but I suppose pictures are better.

This should be interesting :)

Naomi,

The engine number is correct for Bandit. The head is from something pre 1968. If the hubby or you does not mind taking the rocker cover off and letting us know what the "12H****" number is between the rear two rocker pedestals it would let us know what car the head is from.

Most likely its an early head modified with water outlet. This would also mean that the engine would have 7:1 compression which is lower than the stock 8:1. This would mean less power than your 1980 MGB. I think the engine must have been rebuilt in the past with high compression pistons which would make the car have 8:8:1 compression. Ask the hubby to run a compression test and report the numbers for us if its not too much to ask.

Hopefully we can determine what makes Bandit faster than your 1980 B.

David the hubby said I should order a valve cover gasket when I order the water pump so he can do as you suggested. I'll send you the info once he does so :) :)

Naomi, if you're still looking for the water pump:

http://bhive.tierranet.com/00MGWEEKLYwebspecial.htm

I agree with David. I have done this. Drilled a hole in an early head and tapped it for a fitting to use the water choke on a Stromberg carb. I had to because I couldn't find a water choke head that wasn't cracked at the time.

David Kiehna Wrote:

Jack,

Early MGB 1962-1971 : 8.8:1 compression (42cc chamber and 6cc pistons)
Late MGB 1972-1980 : 8.0:1 compression (39cc chamber and 16cc pistons)

Using a late head on a 42cc head with 16cc pistons will achieve a figure close to 7:1 compression. If you want to raise your compression to 9.4:1 use a Late MGB head with early 6cc pistons.

Clausager's book lists the 18V 883 AE L**** as correct for a 1976-1980 MGB. The "AE" designation means single carburetor with emission equipment.

To really know what you have you need to know the casting number as David stated. If its a 62 to 67 head the number will be 12H906. There are two other possibilities and they are 12H2709 which has 43cc combustion chambers and 12H4736 which has 39cc. I got this information here: http://www.mgbmga.com/tech/mgb25.htm

I had a head with casting 12H2709, it didn't have holes for the air rail. According to this web site the head was for non North American market engines and was equivalent to 68-71 NA 12H2389 heads.
http://www.mgbmga.com/tech/mgb25.htm
The head had 43cc chambers and would lower the compression on a stock later model engine.

Clifton