7 replies to this topic

[Apdiliars250]

Hi I have a cylinder head what has had work done years ago by minisport what they class as stage 3
37mm inlets/29mm exhaust valves
Double valve springs
Steel guides
Unleaded seats

Would this cylinder head be OK for being modified for your turbo spec? or would it be better off start with a unmodified head?

Or my other option is to keep my cylinder head as it is and find another cylinder head to be modified for turbo spec.

Are all 1275 cylinder heads good enough to use or is there a certain one to look out for?

Who would you recommend for getting my cylinder head modified for turbo spec

Thanks

[DeadSquare]

A cylinder head is a cylinder head. 

 

You are going to pump more "gas" into an existing "space", and the easiest way to obtain the ideal "gas" /  "space"  ratio is to fit a suitable decompression plate.

[mini13]

Normally on turbo heads the exhaust valve gets enlarged first, so normally your looking at 35.6 x 31mm valve sizes, also they stear clear of overly large valves to limit the posibility of cracking between the valves, the 37mm intake might be betting a bit close.

 

I always recommend getting the chambers taken out to suit the pistons, and also having the pistons flushed with the top of the block ( or close to, say 5 thou down), as iim not a fan of decomp plates as they screw up the quench/squish.

 

My recomendation for head would would be TurboPhil ( link https://www.turbo-mi...cylinder-heads/ ) but with any one good he does get busy,

 

[Apdiliars250]

Normally on turbo heads the exhaust valve gets enlarged first, so normally your looking at 35.6 x 31mm valve sizes, also they stear clear of overly large valves to limit the posibility of cracking between the valves, the 37mm intake might be betting a bit close.

I always recommend getting the chambers taken out to suit the pistons, and also having the pistons flushed with the top of the block ( or close to, say 5 thou down), as iim not a fan of decomp plates as they screw up the quench/squish.

My recomendation for head would would be TurboPhil ( link https://www.turbo-mi...cylinder-heads/ ) but with any one good he does get busy,

I noticed the difference in valve size with turbo spec heads. So probably best to start with a different head.
I have emailed turbo mini. Com but no reply so must be busy

[hazpalmer14]

He doesn't do cylinder heads full time, he does it alongside his day job. He is also very busy so be patient.

[DeadSquare]

 

Normally on turbo heads the exhaust valve gets enlarged first, so normally your looking at 35.6 x 31mm valve sizes, also they stear clear of overly large valves to limit the posibility of cracking between the valves, the 37mm intake might be betting a bit close.

I always recommend getting the chambers taken out to suit the pistons, and also having the pistons flushed with the top of the block ( or close to, say 5 thou down), as iim not a fan of decomp plates as they screw up the quench/squish.

My recomendation for head would would be TurboPhil ( link https://www.turbo-mi...cylinder-heads/ ) but with any one good he does get busy,

I noticed the difference in valve size with turbo spec heads. So probably best to start with a different head.
I have emailed turbo mini. Com but no reply so must be busy

 

 

You don't mention what are you aiming for ?

 

Fuel consumption, top speed, acceleration or just for the hell of it.

[Apdiliars250]

Just for more power it's not a daily car

[DeadSquare]

Just for more power it's not a daily car

 

 

I have blown various A series for 60 odd year with a Shorrock supercharger, but I did have a Turbo Metro, whose engine found its way into a Mini.

 

A supercharged MG Midget 1098 (bored +.060) felt like driving a 1600 but the same in a Mini could be a bit of a handful. 

 

By comparison, I found that a turbo in a Mini could be nasty when powering out of a wet corner as the understeer was too often a front wheel drift and all arms and legs to get the back end round.