Flat Top Pistons And Tu3S Head ?

[batespeed 0]

hi folks, ive got a tu3s engine and box in my mini

 

but the engine is burning a lot of oil after i roasted it,(it always smoked a bit, i dont know how many miles it had done)

but i have an early saxo 1.4 sx engine and box,and i want to put the tu3s head/carb on it. but ive noticed the pistons from the multi point injection engine are flat topped , whereas the tu3s ones are dished,

is this a good thing ? obviously it will increase the compression ratio a bit but its only about 9 to 1 to start with isnt it ? or will it be too high?

 

 

i also have a 205xt (single point) that i converted to tu3s head/carb a couple of years ago, and it goes realy well,

it is an iron block tu3m . it just occured to me that meaby it has the flat topped pistons as well and thats why it goes so good............................any one know?

[trogboy 17]

I think you'll find that the pistons from TU3 engine that you took from the XT will be dished as per the TU3S. From memory the dishes in the TU3S pistons are 3-4cc so you'll see a slight increase in CR from using flat topped pistons (if they are the same height as the TU3S ones) It shouldn't cause you any clearance issues in any case so I'd just give it a go.

 

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[batespeed 0]

I think you'll find that the pistons from TU3 engine that you took from the XT will be dished as per the TU3S. From memory the dishes in the TU3S pistons are 3-4cc so you'll see a slight increase in CR from using flat topped pistons (if they are the same height as the TU3S ones) It shouldn't cause you any clearance issues in any case so I'd just give it a go.

 

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cheers, according to "carfolio" tu3s has 9.3 to 1 compression ratio, and saxo multi point has 10.2 to 1 so it should go even better with the flat tops........... just wondering if i should put the saxo gearbox in too, as the mini runs 12 inch wheels. lowering the gearing even more than the ax gt,s 18.2 mh per 1000 revs in top

 

what mph per 1000 revs does the saxo 1.4 pull ? something like 22 point something from memory, dont know what diff is in it ? could be 3.444

Edited September 20, 2011 by batespeed

[welshpug 1,661]

probably want a diesel box if you've got 12" wheels and small tyres

 

not sure on the ratios though, the 16v boxes are quite long, as is the UK rallye box off the 75 bhp engine.

[batespeed 0]

i found a list of ma gearbox ratios on this site

http://www.suzukituning.com/PSA/MA5%20Gearbox/ma5gearratio.htm

unfortunatley the sticker is off mine but it does have "20CC51" stamped onto the casing in the same place, but it doesnt seem to cross refer............

[batespeed 0]

I think you'll find that the pistons from TU3 engine that you took from the XT will be dished as per the TU3S. From memory the dishes in the TU3S pistons are 3-4cc so you'll see a slight increase in CR from using flat topped pistons (if they are the same height as the TU3S ones) It shouldn't cause you any clearance issues in any case so I'd just give it a go.

 

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i found an old thread of yours, trogboy .where your engine was burning oil after instalation, what was the problem in the end ? mines seems similar.......

[trogboy 17]

i found an old thread of yours, trogboy .where your engine was burning oil after instalation, what was the problem in the end ? mines seems similar.......

 

Ar - that's a well old thread from 2006! Your really have been digging. I can't remember what the solution was in the end! I definitly cured it though without replacing the rings. Think that it may have been valve stem oil seals....