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MGB UK vs. USA Rubber Bumper MGBs?

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Bret

Bret

Yoda
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Hey Gents,

Question. Besides the obvious differences between the North American & UK MGBs. Namely Single Zenith Stromberg (w/Emissions equipment) for us over here vs. the UK B’s – Twin SU HIF4s. Are there any other things different between the two engines that one might need to consider should he want to change things over?

The question is asked because I was doing some reading of my MGB and MGC book written by Jonathan Edwards. And in his book (obviously written for a “home” market) the only references to the differences in the specs (page 50) are the above mentioned carburetion setups and performance numbers.

UK:
Peak Power 95BHP(net) @ 5,400rpm
Peak Torque 110lb.ft. @ 3,000rpm

North American:
Peak Power 65BHP(DIN) @ 4,600rpm
Peak Torque 92lb.ft. @ 2,500rpm

Now I don’t know what the DIN means in the NA Horse Power ratting but what I do know for sure is that I could live with the UK numbers and not feel shot-changed.

[ 02-03-2004: Message edited by: Bret ]</p>
 
The heads were different. The UK head did not have the air injection ports and was a high compression unit. The US smog head was about 8 to 1 compression. The advance curve on the distributor was also different. Overall the UK models were tuned more like the original MK1 models. Dash boards were different. The transmissions and rear end were the same as were the brakes.
 
The heads would & dizzy make sense. I’ve heard about Euro-spec heads available from various sources but not really sure what that description means.

If I had to guess I would think that the Euro-spec head would involve the higher compression ratio of 8.8:1 as described in my Edwards book. But I seem to remember reading that the Euro-spec heads also had larger diameter intake valves (1.563” vs. 1.625”).

What about the UK pistons? Dished or flat?
 
UK spec engines are almost identical to the early US 5 main bearing MGB engines.

The US spec RB Bs were set up to provide a sense of power off the line to about 3500 rpm and would not breath at all past 4500 rpm.

Installing a set of SU's, 270 grind cam, high compression pistons, adjustible timing sprocket, and a euro-spec dizzy with get you back to 90-95 hp.

DIN - is the european measure of horsepower. I believe you would subtract 10 from that figure.

[ 02-03-2004: Message edited by: David Kiehna ]</p>
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Jim 67B:
The heads were different. The UK head did not have the air injection ports and was a high compression unit. The US smog head was about 8 to 1 compression. The advance curve on the distributor was also different. Overall the UK models were tuned more like the original MK1 models. Dash boards were different. The transmissions and rear end were the same as were the brakes.<hr></blockquote>

There is a set of higher compression pistons available too. 8.7:1 vs 8.0:1 They still have a dish in the top but it is not as deep. I changed to those when I rebuilt in 1987. Regular gas will diesel at times but mid grade and high test work fine.
Bob
 
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