CGA3 to CG13 head

[Skinner_87]

Hi All,

This may be a right daft question but i thought id seen this before.... CG3A short block onto a CG13 head is this a straight swop? Does this give the same 1348cc? or more/less?

Will the CGA3 take the CG13 box also?

Thanks guys

 

[frank]

aye, straight swap its just an overbored and stroked 1275 basically, same headgasket and bellhousing pattern too

 

[Skinner_87]

aye, straight swap its just an overbored and stroked 1275 basically, same headgasket and bellhousing pattern too

Thats a pint i owe you frank, id have to post it though i was hoping i could use my head on it that makes it a 1348?

Need all the cc i can get to try & beat the bigger coopers next year!

 

[frank]

yes mate, 1348, tho the pistons have a humdinger dish, the flat top 72.5mm corsa pistons have showed great promise in my low comp 1367cc turbo engine, and would have been fine in my high comp decked N/A engine (if i had,nt had it underbored too much )

 

[hoopdub]

whats the downside to this then? what would be the expected power increase?

 

[Skinner_87]

Sorry to hear that mate, you've got me thinking now! (not to steal your idea)

CGA3 Block with a light skim
Corsa pistons (should be ok to get hold of here with there being alot of rallying)
Lighten flywheel
Gas flowed head
Meaty cams on carbs

And the cheaper the better!!

 

[frank]

be my guest
mine had a 2.5mm block skim iirc, and 2mm headskim to allow for the shorter compression height of the corsa pistons and shortened chain.
it ran sweet (apart from the diesel-esque excessive c/r) but the 20" thou underbore meant that the rings did,nt seat properly , the 5" thou underbore on the 2nd attempt/engine was far better.
i will probably source some more pistons, and get it bored to the same as the 2nd one, but with a CG13 crank this time

 

[frank]

whats the downside to this then? what would be the expected power increase?

its just a bit more cc hoopdub, the CGA3 k11 has 85hp eh, tho some of the gain may be from the more sophisticated/precise crank sensor and coiloverplug system