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EA Sports and EA Supersports engines
#1
As a relative neophyte, I am wondering about the differences between these engines and the standard jetted ones. I know a few things. The blown engines used the mag crankcase and the unblown used coil crankcases. Blocks and heads were Chromidium. Were there water pumps on both blown and unblown? Valve adjustment by shims. I also know the feet are different from the jetted engines. Does that mean a blown or unblown Ulster engine won't fit on a standard chassis with a replica body? I have heard that the early engines(1930) used the same number of head and block studs as the jetted engines, but this increased over the years. Is this the case?

Erich in Seattle
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#2
Erich. You need a copy of Chris Gould's Guide to Building Reproduction Austin Ulsters. Available direct from him and probably a few of the specialists. It's brilliant on the differences.

Charles
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#3
Hi Charles, I've got it but don't recall that he spoke about the stud changes nor how one might fit an Ulster engine in a Replica body. Though he did mention the engine sits lower at the rear(as I recall) to place the starting handle in the correct place through the cowl.Yes, it is an excellent resource.

Erich in Seattle
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#4
Erich, do you think there is a choice of these engines on the used market?
You would be extremely lucky to find one and it would cost you in excess of £20000
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#5
Fair point Erich. Chris Gould only goes some way. Martin Eyre's excellent slender volume on Austin 7 Competition Cars is also worth reading

Only blown engines had water pumps (they drive off the front of the magneto drive shaft).
Crankcase were based on mag and coil crankcase but were different.
10 stud engines arrived in early 1931.
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#6
Erich - I'm more familiar with the unblown engines, which don't have the different gear-train housing across the front of the crankcase with the extra gear for the water pump) and they have different cylinder heads, just for starters.  The actual unblown crankcases are deeper than the standard (at last you can get easily at the oil pressure adjustment, for example).  If you email me on ausevenoz@gmail,com I can send you a sketch with measurements of both crankcases to compare.  Remember too that there are different routes of pipes, cables etc, plus extra oil tank on your body's scuttle for the blown type - most of which are explained in Chris' book.  Good Luck, Cheers,  Bill in Oz
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#7
10 stud blocks and deep sump crankcases  with a moved PRV arrived early 1931 as Charles says.Only works engines ever had more than 14 stud heads.
Unblown engines also had a rev counter drive off the front of a longer camshaft.
The crankcase mounting feet were positioned differently so the drive line suited the lower springs.
Much of the surviving original bits have been or need repair,due to butchery or blow up damage.
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#8
Thank you all. So, if I am reading Dave's and Charles' comment correctly, from 1930-early 1931, the cars had 8 studs. After that, they went to 10. Were these on the head to block or block to crankcase? Sorry if I am misreading this. At some point then, it sounds like 12 and even 14 studs were tried on production cars. I realize that in response to Zeto's comment, these engines are rare. So much of my inquiry is just to educate myself on how the EA Sports and EA Supersports engines evolved.

Erich in Seattle
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#9
Why Austins based the unblown engine on the coil engine and the blown on the mag engine we can only guess.They probably used the mag c/c so they could fit the water pump for better cooling and a convenient way to drive the s/c .
The pressure feed was very similar to the Gordon England Brooklands on these too.
Earlier cars all had 8 studs holding the block down.Austin altered this to 10 stud due to block c/c failures on the works cars of 1930.
Any variations were done later,ie Robin Jackson,private tuners.I know he fitted brackets either end of the block.
My guess is c60 blown engines,c160 unblown.
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#10
Thank you, Dave. This helps greatly. As well, I understand the crank cases had extra webbing to eliminate cracking.Did the 8 stud have this webbing, or did it come later?

Erich in Seattle
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