58 Nash Metropolitan valve clearance?

[doc50]

Question for those more knowledgable: My book says valve clearance for my 1500 is .021
In another place it says valve clearance is .015

Anyone have the right clearance?

Thanks,

Thom
73 Midget
58 Metro

 

[dklawson]

The MGA documentation I looked at says that the clearance on a cold 1500 should be 0.015".

Perhaps the Nash application is a little different but if you have standard rocker arms I cannot see why the clearance would jump to 0.021".

 

[doc50]

Thanks for the input, Doug. Is the MGA 1500 the same engine? I didn't know that! I was also surprised that the 58 metro (1500) has a bigger engine than my 73 Midget (1275).

Yes, I think the 021. is a misprint. I'll go with .015.

Thom

 

[dklawson]

The later Nash, MGA, and MGB all have "B-Series" engines. Your Spridget will have an "A-Series" engine.

I don't know a lot about the Nash but it is my understanding that they used engines shared with the Austin marque. Towards the end of production they were using BMC B-series engines of 1500cc. These were probably tuned differently than the MGA but shared a lot with it.

 

[doc50]

Thanks, good info. So the way I know the Met has a 1500 engine....It says 1500 in a big plate that's part of the casting at the front left side down low. They REALLY wanted people to know that it is a 1500!

I'm thinking of swapping out the nice HS2s I just put on the Midget and putting them on the Met. IMO, 1500 needs more fuel than 1275.

Lastly, so even though the Midget is 73, it has an earlier model engine?

Thom

 

[dklawson]

Lastly, so even though the Midget is 73, it has an earlier model engine?

If you are thinking A- and B-Series are sequential... I don't think they are but I am not a historian on Austin and BMC engines. It is my understanding that both A- and B-Series engines started in the early to mid-1950s. The A-series started with a small 803cc displacement while the B-Series was larger and started with 1200cc. Both grew and evolved. The A-Series continued as the A+ engine all the way up to the year 2000.

Your 1275 Spridget engine was introduced shortly after the 1275 transverse A-Series was used in the Mini.

I doubt you can "just" put the HS2s on the Metro B-Series. I am confident the port spacing is too wide to take the A-Series parts. I anticipate you will find that MGA and MGB manifolds would fit the head better. The MGA would have used H4 carbs while the MGB (up to the early '70s) used twin HS4 carbs. The H4 and HS4 are bigger than the HS2s on your Spridget. While dual HS2 carbs may help the Metro, the larger HS4s may help more.

Message boards more focused on the Metro may have a lot more information on what parts are interchangeable and what upgrades/swaps work best to improve performance.

 

[doc50]

Doug, thanks again for all your input. I will check out the differences noted in your post.

Thom