Cylinderhead difference

[bjerre]

do someone know if the cylinder head on f4r 736 Clio 182 is the same as in the f4r engines in laguna and megane. I need another head but it difficult to find a 182 head i denmark. I have a spare head from a 172 but the exhaust port are bigger than the 182 head. and they are too big I think.

 

[Nick r26r]

surely it should be the other way around , 182 have bigger ports ? if the ports are bigger would it not mean more air flow so more power , unless someone has done with a dremmel tool there self , i have a 172 head in my shed that i could post to denmark for you ??? but as you have a 172 head it would be no good to you ...

 

[Fred@BTM]

the heads with the larger exhaust ports are generally the "faster" engines (such as the phs1 172)

but it doesn't make much of a difference, use any 172 or 182 head

 

[sideways danny]

Meg ports aren't cnc ported

 

[GodSpeed]

As Fred says go with the Ph1 172 head it is the best choice with the bigger ex-valves. Smaller valves on the later 172 +182 is only because of emissions if I remember correctly.

 

[sideways danny]

surely it should be the other way around , 182 have bigger ports ? if the ports are bigger would it not mean more air flow so more power , unless someone has done with a dremmel tool there self , i have a 172 head in my shed that i could post to denmark for you ??? but as you have a 172 head it would be no good to you ...

ph1 exhaust ports are about 30% bigger.

 

[sideways danny]

As Fred says go with the Ph1 172 head it is the best choice with the bigger ex-valves. Smaller valves on the later 172 +182 is only because of emissions if I remember correctly.

the valves are exactly the same

 

[bjerre]

I have tried and testet both the 172 large port and the 182 small port and the small port head give the best torque curves the big port is good for topend power. but I have designet another exhaust manifold which among other changes is made to fit the small exhaust port precisly and this realy worked. this gave us the same top end power but 17 hp and 20 nm more at 5500 rpm. so I have to use the small port top.
www.bjerre-rally.dk

 

[Fred@BTM]

man you like doing stuff the hard way!

 

[GodSpeed]

I have designet another exhaust manifold which among other changes is made to fit the small exhaust port precisly and this realy worked. this gave us the same top end power but 17 hp and 20 nm more at 5500 rpm. so I have to use the small port top.
www.bjerre-rally.dk

Interesting, any chance you could post an image of that? I guess it is a 4-2-1 construction like on the 182 but with a lot longer sections à la Super 1600?

 

[bjerre]

I will see if i can take a picture. yes it is made á la the super 1600 and the R3 maxi manifold. but with different pipe lenght