[Unknown User]

Hi.

Got question for all of you my friends.
I am planning to remove my P-90A head, and replace it with modified P-90 head.

Here is the question: What should be done, and how much it should cost?

I was thinking about getting it all 3 angle ported, polished, fitting larger stainless steel valves ( What size?), competition springs, and matching to the 60mm TB. What am I missing, or wrong? Anything else? I was given price of around 1K for the work, does that sounds fair?

Thanks.

 

[Ian]

> Hi.

> Got question for all of you my friends.
> I am planning to remove my P-90A head, and
> replace it with modified P-90 head.

> Here is the question: What should be done,
> and how much it should cost?

> I was thinking about getting it all 3 angle
> ported, polished, fitting larger stainless
> steel valves ( What size?), competition
> springs, and matching to the 60mm TB. What
> am I missing, or wrong? Anything else? I was
> given price of around 1K for the work, does
> that sounds fair?

> Thanks.

Make sure that the person or shop you are planning to take the head to has experience with Datsun cylinder heads. Also make sure that he has a flow bench. This is a device that is used to match the flow of all of the ports when doing a port/polish job. Now, about what should be done. This depends on your driving style and how much money you want to spend. A three angle valve job is standard on all Datsun cylinder heads, so be sure that the shop does not charge you extra for this. I would recomend a 5 angle valve job. This will help improve the flow of the head, however it is not as reliable as a 3 angle. Also don't try to get too crazy opening up the ports. The P90 is an excellent head and you shouldn't need to do a whole lot to improve performance. Concentrate on blending the valve seats into the ports and combustion chambers. Also, you may want to smooth the bowl areas. Manley makes some very nice valve, however, make sure that you get the correct ones. The P90 has a raised combustion chamber roof and the valve stems are shorter than the 240, 260 and early 280 heads. Cams, is this a turbo motor? A cam will make a big improvement on the top end. Consult the shop that does the work about what cam to go with. The useage of the car, your driving style, and other factors play a big role in choosing a cam. Have fun and good luck!!!!!