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MG Midget and Sprite Technical - 1500 compression changes

from what i have read, i may have lucked out and got the 9.0:1 compression ratio. since the two motors i have are both from a 76 car, is there any way to tell without taking the top end off or is it a definite yes for an 86?

basically just wanting to know if i should hunt down the better pistons or not.
CAPTAIN AWESOME

'76 should have been 9.0:1, you can always shine a flashlight down a spark plug hole & see if the piston is flat topped, the lower 7.5:1 were dished...see attached photo.

Dave :)



Dave Rhine ('78 1500)

is there a good link to tuning these motors for more performance other than the random google find?
CAPTAIN AWESOME

Besides checking for flat top pistons as Dave said, look at the top of the head opposite the #3 spark plug for TKC 2748 stamped on the flat part. This head is physically shorter. Flat topped pistons alone won't get you to 9.0:1. You need both. Home market (UK) engines are marked TKC 1155 and will work also. All others are 7.5:1.
Lee

Lee Fox

aww shucks...

i just read the tag on the motor i know to only have 30k on and it is a 79. the other motor with unknown internals is the 76 with the codes TKC 2748 on the head like you mentioned. so i should be able to swap pistons and head to get the right hp? i noticed the intakes look different between them as well.
CAPTAIN AWESOME

<< is there a good link to tuning these motors for more performance other than the random google find?
>>

http://www.totallytriumph.net/spitfire/engine_building.shtml

One of many.

HTH, Richard
R J Reeves

This thread was discussed between 28/04/2010 and 29/04/2010

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