valve and spring dimensions

[tortron]

Hi guys

wondering if someone has a few spare valve springs laying around and could measure them for me.
The manual lists the expected pressures but no mention of diameter or uncompressed/compressed hight

would like to order some uprated replacements to be waiting for when i get back home

also, the same goes for valve length. I have head and stem diameters listed. But no mention of lengths

cheers

[mike.perry]

I have stronger springs fitted to my Series MM, good for 6000rpm apparently, not that I have ever tried. I think that doubles were available once. I will measure some standard springs

[tortron]

Cheers. I read that the double valve springs that were available for the 100e had a tendancy to ahift and not sit right. Due to the collet arangement. I assume it would be similar for a minor. Perhaps not. But will go.the simple route and stick with single springs.

Will post any part numbers i come up with

[mike.perry]

Standard spring length 48-50mm

[katy]

BMC manual AKD 530 lists free length at 1.75" (44-45mm) on page "General data 12"

[tortron]

How about diameter?

Cheers

[mike.perry]

Measured uncompressed length 49mm
Fully compressed length in vice 23mm
Diameter 23 mm
My springs were made by Paul Savage, Reddich

[tortron]

Thanks for that

a quick seach tells me that finding a spring weak enough to not be 5-10 times stronger than the originals may be the hardest part.

But perhaps this wont be a problem, the originals are pretty much pudding it seems, and i cant think of any reason a "modern" spring pressure would cause excessive wear on anything. If anything the direct motion of the cam-tappets-valve would be less stressful than the leverage eated by apush rod and arm arrangement. I will contact a guy i know who works at a local cam company and see what he thinks anyway.

Just noticed i cant post from many ip addresses in peru. Must be why theres no members from there! Though i did see a few minors on the road in colombia

[katy]

If anything the direct motion of the cam-tappets-valve

Does this mean that you're working on a side valve engine and not an OHV (A series)?

[mike.perry]

Correct, This is the Series MM Register Message Board

[tortron]

so I sorted this out by finding a box of unused smm Terrys aero valve springs. will measure them up and give the specs when I get around to fitting them

[BLOWNMM]

Measurements of standard spring - free length 47.6 OD 20.7 wire dia. 2.67 installed length 38.3 (19 lbs) open length 30.84 (37 lbs) when compressed to 28.65 48.4 lbs. Standard valve LOA 92.48
Bob

[BLOWNMM]

I suspect that the MM motor internals are constructed in a very similar manner to the Morris 10 motor from which I believe the MG TD motor was derived, even to the 12 X 1.5 threads in the crank nose and camshaft nose. The TD spring tensions are installed - 93 lbs. valve open 123 lbs. Although I am not saying these tensions can be applied to the MM I do believe it leaves the way open for considerable pressure increases to be applied.
Bob
http://www.mg-cars.org.uk/mgtd/mgtd_general_data.htm

[RobThomas]

If I get the Alta head off I'll try to get the dimensions for you from that. Might give some guide for experimentation. Oh, and I measured an LP917 today at 4.5 inches between the faces as per the correct measuring method. I didn't have a camera handy at the time. I also picked up some 15 inch rims for the MM today and will get some pics and dimensions for your friend during the week.

Cheers

Rob