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P90 head porting???? Is it worth it???


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I am considering having my head ported while replacing the headgasket and all that.

 

I talked to Rebello, they recommend a full port on the exhaust side, intake match and bowl work, which will include the valve work.

 

Anyone done this? Were the results good, ie was it worth it?

 

Anyone use someone else and get good results? If so, please put the price. Before and after dyno numbers would really be nice.

 

Rebello wants about 550.00

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I'd also like to know if this is worth it. I would be willing to port match the intake myself, but bowl work? What are they actually doing? I have upped the compression on my 3 liter to 8.5-1 with custom pistons and was contemplating doing some bowl work to unshroud the valves. $550 is a little steep for me right now so I may try this myself. Anyone do this themselves and take some pictures of what the bowl looked like when you finished? How about some pictures of a Rebello or Sunbelt bowl on a P90?

Joe

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Guest Zcarsmakemyheadhurt

Match porting is a good thing smothing out the bowl is nice but it isn't going to make a world of difference. On a forced induction car the most important thing is a smoth clean flowing port from the T-body to the valve, dont go crazy porting around the valve seat area or you may ruin the head. Mr. Gasket sells a head proters kit for $40.00 and ofcourse like always I have it in stock now. Have fun with it.

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I can't believe how few replies there are to this thread. I'll just say this because I don't have a turbo, but I've always been interested in it: It seems like porting the manifold to the turbo would do more for your turbo then just an exhaust side port job on the head. I think it was Cody ZXT who had before and after pics, they were posted on a thread that was discussing Extrude Honing a few months ago. He had taken LOTS of metal out of the manifold.

 

Rebello will clean up the ports nicely, I'm sure. And I'm sure it is worth the money. I think you would get more from doing what Cody did. Probably a lot more, from the looks of it.

 

Just my uninformed opinion, but maybe it will get the thread rolling...

 

Jon

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Well my thoughts coincide with Jon's on this. I'm not sure what you are running for a manifold Lockjaw, but I would think that if its stock then you'd see far more gains porting it...

 

I guess you have to ask yourself what else you could do to make more power with $550. If you are at the point where there isn't much else to do to squeeze power out of the engine with that much money, then go for it.

 

Sorry this is not a terribly informative reply, just throwing in my 2 cents.

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The intake ports are already match ported, I did that when I put the engine together 6 years ago. The intake is a turbo one, with the EGR cut off and a plate welded to it, and all the idle control stuff, except the cold start idle air bypass removed.

 

The inlet is ported to match the 60 mm throttle body.

 

I ported the exhaust manifold myself as well.

 

Extrude hone wants 700 bucks to do my head, and personally I think that is a good way to go, but then I could get the full port job from Rebello for another 100 on top of that, and that would still include the valve work.

 

As for bang for the buck, the dry NOS controller from JWT would give me 65 hp, all controlled by a board in the ECU, comes on at 2200, cuts off when I want it to. With a race and pump program. If the clutch could hold it, that would be the way to make some serious hp.

 

Surely someone has done a port job and can say what it is worth. As for blending in the bowls, yes I can do that, and have considered it, but personally, I think unless you have a flow bench, you don't have any business porting or messing around in there.

 

Probably going to leave it stock for now. Just do a valve job, and slap it back on there.

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Guest Zcarsmakemyheadhurt

If you have a upgraded turbo, fuel injection upgrades and the car goes 12.50's with a stock head I would port it. You have most bases covered, that would be the way to go. If your not afraid to boost the car and take advantage of the available area you have created with porting do so. I rarely put together a stock turbo car so almost all my builds have match porting to a very ported intake and I think that is where your gonna get big gains from the combination. I also like large exhaust valves to free up exhaust flow, it makes a difference. Good luck my .02 cents.

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Guest bastaad525

For me this quote from the FAQ on this forum sums it up quite nicely:

 

Porting and Polishing

For the less than 400hp crowd you don't really need to port and polish, though a general "cleanup" doesn't hurt. In the past it has been summed up to me like this. "Take the cash you'd spend on porting and polishing and spend it on a better intercooler, better turbo, better engine management, etc" You'll end up with more for your buck this way. The P90 head already flows well.

 

I have also read people saying things like "a good turbo will be able to push out more air than the head will ever be able to use anyways"

 

Makes sense to me... I just dont think this kind of work is essential unless you're going for a balls out max hp engine, otherwise, spend your money elsewhere and get more back for your investment.

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I'd say go for it. I am planning on doing it myself. I have touched almost everything but the bottom head. I have a tubular manifold, k26 turbo, will have an upgraded cam soon, megasquirt, larger injectors, and a lot of other crap, but basically even with some bolt ons it is worth it. You can always use more air flow, but be careful, poor porting can lead to bad performance. http://www.sa-motorsports.com/diyport.htm

 

Ryan

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