cg10 cg13 cga3 moding question

[Paul Smith]

Ok,

The cg10 has flat top pistons which are good and you can put 1.3 pistons in to lower compression - correct?

The cg13 has dished pistons and you can fit 1 litre pistons to raise compression - Correct?


So does the same logic work on the cga3 1 litre and 1.3 litre engines?

 

[frank]

Ok,

The cg10 has flat top pistons which are good and you can put 1.3 pistons in to lower compression - correct?

The cg13 has dished pistons and you can fit 1 litre pistons to raise compression - Correct?


So does the same logic work on the cga3 1 litre and 1.3 litre engines?

no, cga3 has a bigger bore

 

[Paul Smith]

is there anything along the lines of inter changing parts that would work with the cga3?

 

[frank]

is there anything along the lines of inter changing parts that would work with the cga3?

just matts oversize ones i think paul (the CR (k12) is a very similar design to the CG,s tho)

 

[Alienfish360]

Does anybody know the depth and diameter of the dish in the CG13 pistons?

 

[frank]

Does anybody know the depth and diameter of the dish in the CG13 pistons?

you can work it out mathematically phil , 1.0 = 249.5 cc (1 cylinder)
1.3 = 318.75 cc (1 cylinder) both have a C/R of 9.5:1

 

[Alienfish360]

are you suggesting that the dish in the CG13 piston has a volume of 69.25cc?

 

[Alienfish360]

Even though the piston has nothing to do with the engine capacity?

 

[frank]

are you suggesting that the dish in the CG13 piston has a volume of 69.25cc?

noooo 249.5 + the dish, gasket and combustion chamber divided by 9.5 will give you the cc of the dish, gasket and combustion chamber.
and the difference in cc between the 1.0 and 1.3 figures will give you the cc of the dish *geek*

 

[Alienfish360]

by my very rough calculations, I get that the CG10 with CG13 pistons will give a compression ratio around 7.7:1 ish?

 

[frank]

by my very rough calculations, I get that the CG10 with CG13 pistons will give a compression ratio around 7.7:1 ish?

yeh, i get it to.... chamber + gasket = 30cc (1.0)
and ..................chamber + gasket + dish = 38cc (1.3)
so 288 divided by 38 = 7.6 : 1 ish, a bit low really (laggy ?)
i still favour opening up the combustion chambers (4 or 5 cc availiable with ease imo)

 

[Alienfish360]

It may be worth testing still, I believe the ST had a compression ratio of 7.7:1 but then again, that does have a supercharger too.