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best 1098 motor to rebuild

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M

mightymidget

Jedi Knight
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I have just purchased another Midget, this time for parts, don't even know what year except it is an early one-No door handles-vehicle is two hours away and have purchased it over the phone with out seeing it in person. Typical mold covered neglected yard car.

Anyway the last Midget I purchased has a light knock in engine so needs to be rebuilt. If the motor is no good in the one I have just bought is there a preference on an early 1098 or later 1098 to build?
 
The later 10 CC engine has bigger 2" crank journals, redesigned intake with a more positive attachment to the head, bigger intake valves and higher horsepower (59 instead of 56 for the 10cg).

If the parts car you bought has the original engine in it it will be a 10CG engine with the smaller 1.75" inch crank. The 10CC didn't come along until Feb 64 when the MKII Midget/MKIII Sprite debut.

The 10CC is probably the better engine, but there's not much wrong with the 10CG. I don't race by any means, but mine takes all I give it without any problems.

I would say the best 1098 to rebuild is the best one you have. :thumbsup:
 
There ya go, in a nutshell.
 
MM-
I agree with ScoutII, the best to rebuild is what you have. But to add something that might be helpful, the early and late 1098's do have different cylinder heads. The early 1098's had the 12G206 heads while the later have the 12G295 heads. The intake ports on the 295 heads are bigger as well as the intake valve itself. These heads will flow a good bit better in stock form than the 206. Exhaust port shapes and valve sizes are the same between the 206 and 295 heads. The 295 head also has the carb manifold locating ring. Not a problem using an earlier manifold, but does allow use of later manifolds too. The later 1098's also have less of a chance of having the dreaded aluminum rocker pedestals.

HTH,
Mike
 
How do you ID a head?
 
For all A-Series engines, 99% of the time the casting number will be cast into the head some where inside the valve cover area. The casting numbers for 948 heads seem to move around the most inside the valve cover area depending upon who cast the head. I have see a few times where the heads had very little of the number visible. Sometimes the factory actually stamped the part number (not casting number) on the head as well. This is mostly on the 1275 heads.

For 1098 heads, the casting number is usually between the #2 and #3 rocker pillar, counting from the front of the engine and under the rocker shaft. With a flashlight or other kind of helpful illlumination, you can see the casting number.

Vizard's books cover the common UK casting numbers pretty well. The US had some different heads for the 948 that aren't really discussed much. The 12G206 is much more common in the US as it was used on most of the 10CG engines. There are many more nuances of the various cylinder head castings, but mainly if you are planning for a full race port job and not stock or hot street use.

HTH
Mike
 
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