what are the benefits...besides cams..

 

A healthy drop in compression. If you really want to do the swap, consider a thinner headgasket as well in order to offset the reduced compression. Otherwise, keep the C1 head and swap in the ITR components - less labor involved. Also keep in mind that the stock C1 intake manifold won't bolt up to the C5 head.


[Modified by Spec.R 00-0123, 6:49 PM 6/14/2002]

 

the c5 head drops compression? why is that? i would like to know.... isnt the c5 just a port and polished c1 head with a more agressive valvetrain?

 

the C5 or ITR head is a ported version of the CTR head.

 

keep the GSR C1 head and get a nice port and polish with portflow inernals and a set of CTR cams...u will b more than happy!!

 

The combustion chambers are larger.. It is polished, not ported, mainly on the exhaust side. I wouldn't really call the valvetrain more aggressive, they do have dual valve springs to rev higher but that's about it.

 

Intake valves on the C5 flow slightly better than those on the C1 head as well. The C5 (or B16 for that matter) head is completely different than the C1, rather than simply a re-worked or modified piece.

 

To answer the compression question, there is .2 points difference between the two. The ITR head/B16A head uses a circular combustion chamber while the GSR head utilizes a more squared off chamber. Some shops offer welding of the chambers to make it like a GSR head, i prefer running a thinner head gasket or using pistons to up the compression instead.

A GSR head with headwork and ITR internals mated with a Skunk2 or modified ITR intake manifold will yield better performance based off the slightly higher compression, as well as better flow characteristics.