Standard Cylinderhead thickness

[Skinner_87]

Can anyone tell me the factory height of the CG cylinder head?

Cheers

Paul

 

[SuperUno]

Planning a skim job / porting/ build ? I am planning on this in the summer, hopefully found a CGA13 up north collecting it in July if it all works out.

 

[Skinner_87]

Planning a skim job / porting/ build ? I am planning on this in the summer, hopefully found a CGA13 up north collecting it in July if it all works out.

Planning a slightly higher compression build mate yeh.

Have a polished & ported CG head at the minute just not sure how much (if at all) its been skimmed in the past. Hopefully il be the owner of a CGA3 as well from tomorrow if all works out

 

[frank]

121mm paul

 

[Skinner_87]

121mm paul

I should have put "Can Frank tell me....." in the opening post! Cheers bud

 

[frank]

a 1mm skim should be level with that square stump underneath paul, and a 2mm skim will shave the top off it

 

[Skinner_87]

a 1mm skim should be level with that square stump underneath paul, and a 2mm skim will shave the top off it

Ta Frank any idea what sort of compression you can expect with those sorts of skims?

 

[frank]

i think a 2mm skim is about 11.5, like the 1.0 piston mate

 

[Skinner_87]

i think a 2mm skim is about 11.5, like the 1.0 piston mate

Cheers Frank il have to break my calculator out & work this new engine build properly!

1348 high comp FTW eh

 

[SuperUno]

Sounds good to me, so a 2mm skim seems like a good starting for a high comp build, using a stock CGA13 bottom end with standard pistons is this viabale ?

 

[frank]

Sounds good to me, so a 2mm skim seems like a good starting for a high comp build, using a stock CGA13 bottom end with standard pistons is this viabale ?

i ran a 2mm skim for a while matt, the only issue is the slack lower chain

 

[SuperUno]

Ok thanks, is there anyway to take up this slack? Does it cause any real issues bearing in mind this will be an engine recieiving a lot of abuse and high revs?

 

[frank]

Ok thanks, is there anyway to take up this slack? Does it cause any real issues bearing in mind this will be an engine recieiving a lot of abuse and high revs?

i slotted 1 of the chain guides to take up a little bit of the slack, its low revs that have an issue really mate (spark and cam jitter @ idle)
flat-top pistons are better option tbh (£££ for CGA3,s unless you use corsa pistons, deck the block, and take 2 links out the chain )

 

[SuperUno]

Ok i may start at 1 or maybe 1.5mm to start with.

 

[SuperUno]

Just for info what is the corse piston mod?

 

[l_jonez]

This

Basicly fitting corsa pistons and a rebore

 

[jk9194]

There is engine reconditioning/engineering LTD in my area so i am just wondering what are they?
I took a pic so it said 'engine machining specialists and component stockists'

• exchange engines and gearboxes
• exchange service on crankshafts, camshafts, cylinder heads, flywheels and con-rods.

is it good to me? cos its close to my place.
cheers
jk

 

[frank]

Ok i may start at 1 or maybe 1.5mm to start with.

there,s no easy solution with the CGA,s matt, because of the huge dish in their piston, there is some info on the corsa mod half way down here http://www.micra.com.au/community/message.php?messageid=69926.
but you would get just as much power from 1.0 pistons in a 1.3, rather than a 1348 with a 1mm skim tbh

 

[SuperUno]

Thanks - I am looking for torque more than outright power, so hopefully those extra CC's will help with that.

 

[reflexuk]

Power IS torque Matt, with a little maths applied. We want a good spread of power as opposed to a high peak power for rally sport. If I'm not mistaken camshaft design will have a bigger influence on that than simply raising the compression of what is already essentially a low compression engine.