My sexy refurbished P8R head.

72Spitfire

Member
Found this P8R head for $320 completely refurbished....a good deal in my opinion as these head are hard to find. The biggest difference from the P75 head is the combustion chambers diameter (84mm) and the intake valve is 33 mm versus 31 mm on all other b series nonvtec heads. I may leave it stock, i may send it off for a port and polish, crower cams and extra goodies depending on cash flow. Either way, it's gonna be sitting in the box for a while as my B20 is still very healthy and this head will go on a new B20 swap that i am hoarding pieces for. Have a look and give me suggestions!!8)





 

mirrorimg

Well-Known Member
Brothers!

Nice pickup. When you say "completely refurbished" do you mean 3 angle valve job, new valve guides, and new valve stem seals? I paid for $150 for my P8R before I dropped it off at the machine shop. I see some pop up ever now and again on a local forum of mine and I am always tempted to snatch them up, just in case you know...

They are not very common, but they are also not highly sought out. When the pop up for sale, they usually stay there for a while.
 


72Spitfire

Member
Yes, it has a 3 angle valve job, new valve guides, new springs, and new valve stem seals. A slight skim also.
Mirrorimg...is your port polished and flowed? If so, how much did that cost you?
 
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mirrorimg

Well-Known Member
Yes, it has a 3 angle valve job, new valve guides, new springs, and new valve stem seals. A slight skim also.
Mirrorimg...is your port polished and flowed? If so, how much did that cost you?
I took a little material out with a Dremel on the intake side. Nothing major, just smoothing the ports. In stock form, it flows on par with a B16 head. I have some flow diagrams I saved from some websites when I did a lot of searching on the head. They are on my home PC, so I can throw them up here if you like when I get to it.

A port and polish though, would probably run you $300 to $350.
 

DaddyBuiltRacing

Resident Asshole
Mirroing do you have any flow bench sheets to back up those claims? Not saying your lying, just having a hard time believing your home made port and polish has your LS head flowing at the same CFM as one of the best flowing Honda heads. The biggest issue with LS heads is their lack of flowing. Its been said over the years that even a port and polished head will still not flow as good as a stock b16 head. Thats one of the reasons people go LS/Vtec is to have the better flowing head (aside from vtec)

I would call local machine shops and ask them if they port and polish, be sure to ask if they use a flow bench. If they say no, then look elsewhere. Without a flowbench all your doing is gasket matching which isn't going to do a whole lot. Some people will do it "by eye" which is a big no no. You can actually take too much material away and hurt the flow of the head, plus you gotta watch how much you remove so you don't get into water jackets and stuff. Also ask them if they are going to blend the bowls at all or just do the intake and exhaust ports.

A port and polish is usually a 5-600 dollar investment. There are some really good well known companies out there, but you gotta pay to play. PortFlow, Endyn, Headgamez (I think thats how they spell their name) are all good companies that do headwork.

My GSR head was done by Pure Tuning here in Ohio and looks good. I wish I had flow bench results but the kid I bought it off of couldn't find them. The biggest advantage of a port and polished head in my situation is it will help spool the turbo a few hundred rpms sooner. On an NA car its a nice improvement power wise as head works is where all the power is gonna come from anyways, the bottom end just has to hold on for the ride.
 
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mirrorimg

Well-Known Member
Mirroing do you have any flow bench sheets to back up those claims? Not saying your lying, just having a hard time believing your home made port and polish has your LS head flowing at the same CFM as one of the best flowing Honda heads. The biggest issue with LS heads is their lack of flowing. Its been said over the years that even a port and polished head will still not flow as good as a stock b16 head. Thats one of the reasons people go LS/Vtec is to have the better flowing head (aside from vtec)
Please re-read my post. Never once did I say my "port and polish" flowed "X" amount. I said I took a dremel to clean up the intake ports. That is all.

As for an actual head that HAS been tested, here is where the data came from. It actually looks as though he had the head ported, then compared the flow before and after a valve job.
http://www.honda-tech.com/showthread.php?t=2709206

Remember that this is NOT a typical LS head. This is the best non-vtec head. It is not the same as a PR4 or P75 head. 33mm Intake valves (just like the VTEC head) allow it to breath that well.

And the pictures. This is the P8R, I assume before and after a valve job, but the head must have already been ported. edit:yep.
The first numbers are not stock head but ported no valve job.


And a B16 head.
 
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DaddyBuiltRacing

Resident Asshole
I am well aware of what a P8R head is, as I had on in my turbo b20 powered crx. Re-read your post, still comes off as your saying your head flows x ammount but whatever, no since in arguing about it.
 

mirrorimg

Well-Known Member
I am well aware of what a P8R head is, as I had on in my turbo b20 powered crx. Re-read your post, still comes off as your saying your head flows x ammount but whatever, no since in arguing about it.
Eh, I sort of see it now, but thats not what I really meant. My bad.
 
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