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Raptor 700 Information => 700 Motor Mods => Topic started by: Buck on November 16, 2008, 01:12:20 AM

Title: Head Porting Dilemma!
Post by: Buck on November 16, 2008, 01:12:20 AM
Alright guys Im takin this to the streets! I have been tossing it around for the last few weeks and I don't know what to do. Bo has a deal going on right now on his port work that is really hard to pass up! But I really really want a CNC head. My only thoughts are that I ride about 70% trails 30% dunes...and 90% of the time I'm riding every time (sorry the statistics took me on an Anchorman tangent  :lol:). Would the CNC head really be worth the coin I would have to drop on it? I want big power but I also want rideability on the trails. I'm trying to tell myself that I want to do it right the first time, but at the same time I'm afraid if I get too deep into the HP then I will lose a lot of rideability in the trails. I currently have 60 HP with 7 mods, the only thing I have left that I really want is the P&P...And if I could get in the upper 60s I would be happy...If I had hair I would be ripping it out right now! Any help would be greatly appreciated. Bo your input is welcome too, I would like to hear your take on it as well.  :thumbs:
Title: Re: Head Porting Dilemma!
Post by: socalrappy700 on November 16, 2008, 06:21:33 AM
Bo does great work no doubt but those cnc heads are putting up big numbers.  Myself I would recommend going with a cnc head from RE, Barker, or Kenny.
Title: Re: Head Porting Dilemma!
Post by: jwraptor on November 16, 2008, 07:35:32 AM
I believe there was a gain of 5-6 hp over the hand port.  You have to ask your self is it worth it for the extra coin.  If your not an all out racer I don't think it's worth it for the money.  just my .02. 
Title: Re: Head Porting Dilemma!
Post by: digitalhearing on November 16, 2008, 10:12:02 AM
my opinion is: go big now or you will regret it down the road.  If you get a CNC head port you won't have to redo it later.  It is one of the most reliable ways to get bigger power and the price isn't too much more.  After all, that's why you are spending all the time to remove your head and having it redone right?  This is with all due respect to Bo,  He does a great Job and is one of the most helpful and honest guys that we have looking out for us !

Grant
Title: Re: Head Porting Dilemma!
Post by: preddy08 on November 16, 2008, 11:00:01 AM
Unless you are running a big cam and big compression you wont really see all the benifits of the big CNC porting. The big porting also come with a small lose down low to gain bigger results on the top end. Unless you want EVERY little bit of power with no expenses spaired, then I would do a CNC.

If you were a drag racer then with out a doubt I would do a CNC, but being a all around rider I would save the money and put it eles where. Bo's work is really hard to beat. Dont forget even Kenz, Kenny, and KBR all say that Bo does really good work.
Title: Re: Head Porting Dilemma!
Post by: Buck on November 16, 2008, 11:54:07 AM
I really appreciate the input guys. Im not going to up the compression. Im happy with the 11:1 and being able to use pump gas. If anything I would only upgrade to one of Kenny's true comp pistons, but that wouldnt be until later. I'm still at the point that I want to do it right the first time, not that Bo doesn't do it right, I just don't want to pay to have him do it then realize I want more later. And for getting the "full" potential out of the CNC head Im not worried about. Im not too worried about that as long as I can get my HP up into the high 60s which I'm confident a CNC head can do where as Im not sure how much HP bos port will get me with stock valves. Keep in mind here guys I am debating on keeping the Stage 2 cam in there for now . I was talking to Barker and he told me he thought I could still get into the upper 60s HP wise with my piston and Cam with one of his CNC heads. And still have room for improvement in the future by adding a bigger cam IF I want. I just don't want to lose rideability thats my biggest concern as I do quite a bit of trails and hill climbs etc.  But I also love to be able to put the smack down at Sand Mt. I just dont want to have to be revving it all the time to get it to do what I want you know.
Title: Re: Head Porting Dilemma!
Post by: digitalhearing on November 16, 2008, 12:13:22 PM

Sounds like you will make the right choice.  It's always good to get other peoples perspecitve  ;)

Grant
Title: Re: Head Porting Dilemma!
Post by: VelociRaptor on November 16, 2008, 06:46:38 PM
It varies on the build, the more ragged edge the build the more difference the Track port would be compared to a CNC big valve port.
Title: Re: Head Porting Dilemma!
Post by: Tim Barker on November 16, 2008, 06:50:41 PM
Quote from: preddy08 on November 16, 2008, 11:00:01 AM
Unless you are running a big cam and big compression you wont really see all the benifits of the big CNC porting. The big porting also come with a small lose down low to gain bigger results on the top end. Unless you want EVERY little bit of power with no expenses spaired, then I would do a CNC.

If you were a drag racer then with out a doubt I would do a CNC, but being a all around rider I would save the money and put it eles where. Bo's work is really hard to beat. Dont forget even Kenz, Kenny, and KBR all say that Bo does really good work.

Preddy i have to disagree with you. If the porting is done right you will gain power and torque everywhere not just on the top end.
Title: Re: Head Porting Dilemma!
Post by: Buck on November 16, 2008, 09:23:22 PM
Quote from: VelociRaptor on November 16, 2008, 06:46:38 PM
It varies on the build, the more ragged edge the build the more difference the Track port would be compared to a CNC big valve port.
What do you mean by ragged edge?
Title: Re: Head Porting Dilemma!
Post by: preddy08 on November 16, 2008, 10:40:45 PM
Quote from: tbarker on November 16, 2008, 06:50:41 PM
Quote from: preddy08 on November 16, 2008, 11:00:01 AM
Unless you are running a big cam and big compression you wont really see all the benifits of the big CNC porting. The big porting also come with a small lose down low to gain bigger results on the top end. Unless you want EVERY little bit of power with no expenses spaired, then I would do a CNC.

If you were a drag racer then with out a doubt I would do a CNC, but being a all around rider I would save the money and put it eles where. Bo's work is really hard to beat. Dont forget even Kenz, Kenny, and KBR all say that Bo does really good work.

Preddy i have to disagree with you. If the porting is done right you will gain power and torque everywhere not just on the top end.

Tim, care to explain a bit more? I was always under the assumption that if you go with BIG porting with out supporting mods you will loose bottom end?
Title: Re: Head Porting Dilemma!
Post by: Krandall on November 17, 2008, 09:10:08 AM
An old wise one was talking to me about porting a while back. "Hogging out everything (valves, intake, exhaust ect..) isn't always a good thing"

And although I'm sure there are benefits of CNC'd porting for a smaller build, I think where it'd shine more is the bigger builds. Although gains would still be there for the smaller builds it's not up to its full potential.

I think flow tests are cool on heads, but just because so and so's flows 10CFM more.. Doesn't mean its going to run better or make more horse power. In my personal opinion. Not at all discrediting those who have done their time on the motors. But I don't think there's enough out there to say this head is better for this application. Especially for those of us who hang out in the woods.

Title: Re: Head Porting Dilemma!
Post by: Buck on November 17, 2008, 01:56:55 PM
Its looking like I may be able to work a deal with a member that will kind of be a happy medium for me...we'll see.
Title: Re: Head Porting Dilemma!
Post by: Tim Barker on November 18, 2008, 11:57:25 AM
Quote from: preddy08 on November 16, 2008, 10:40:45 PM
Quote from: tbarker on November 16, 2008, 06:50:41 PM
Quote from: preddy08 on November 16, 2008, 11:00:01 AM
Unless you are running a big cam and big compression you wont really see all the benifits of the big CNC porting. The big porting also come with a small lose down low to gain bigger results on the top end. Unless you want EVERY little bit of power with no expenses spaired, then I would do a CNC.

If you were a drag racer then with out a doubt I would do a CNC, but being a all around rider I would save the money and put it eles where. Bo's work is really hard to beat. Dont forget even Kenz, Kenny, and KBR all say that Bo does really good work.

Preddy i have to disagree with you. If the porting is done right you will gain power and torque everywhere not just on the top end.

Tim, care to explain a bit more? I was always under the assumption that if you go with BIG porting with out supporting mods you will loose bottom end?

If you have the velocity correct for the amount of airflow going thru the head you will not lose any bottom end you should gain some everywhere instead. You do have to take into consideration the cam you use though the more duration that it has will affect the power curve but there are ways to compensate for that also.  can't just assume that if you go Big you will lose somewhere.
Title: Re: Head Porting Dilemma!
Post by: theshee on November 18, 2008, 12:19:41 PM
racers edge port work all the way...

amazing customer service, and amazing work...

Title: Re: Head Porting Dilemma!
Post by: Troy on November 18, 2008, 05:32:35 PM
what he said :thumbs:  I had my head ported and it did good, then I went to a Racer's Edge head and it's a whole new animal, it performs better everywhere and the top end is very nice.
Title: Re: Head Porting Dilemma!
Post by: Buck on November 19, 2008, 12:03:43 PM
thanks for the input guys. I will definitely keep it all in mind when it comes down to biting the bullet.  :clap:
Title: Re: Head Porting Dilemma!
Post by: Troy on November 19, 2008, 07:51:17 PM
I'd say you really can't lose by going with Bo's head now, it's a great performer for cheap.  If you decide down the road you want more then you can go cnc and bigger valves.  I don't really regret getting a cheap port job first, it did great at the time and I was happy.  And I was just as happy when I upgraded to a cnc.  Yeah you are spending money twice but I've been doing that on everything so far, as soon as I'd buy what was the best, something better comes along and eventually I upgraded, that's the game we are all playing.
Title: Re: Head Porting Dilemma!
Post by: Peelz on November 19, 2008, 09:19:26 PM
Quote from: troywcc on November 19, 2008, 07:51:17 PM
I'd say you really can't lose by going with Bo's head now, it's a great performer for cheap.  If you decide down the road you want more then you can go cnc and bigger valves.  I don't really regret getting a cheap port job first, it did great at the time and I was happy.  And I was just as happy when I upgraded to a cnc.  Yeah you are spending money twice but I've been doing that on everything so far, as soon as I'd buy what was the best, something better comes along and eventually I upgraded, that's the game we are all playing.

Well Said! :lol:
Title: Re: Head Porting Dilemma!
Post by: Buck on November 20, 2008, 12:13:14 AM
Quote from: troywcc on November 19, 2008, 07:51:17 PM
I'd say you really can't lose by going with Bo's head now, it's a great performer for cheap.  If you decide down the road you want more then you can go cnc and bigger valves.  I don't really regret getting a cheap port job first, it did great at the time and I was happy.  And I was just as happy when I upgraded to a cnc.  Yeah you are spending money twice but I've been doing that on everything so far, as soon as I'd buy what was the best, something better comes along and eventually I upgraded, that's the game we are all playing.
Bos porting it will be soon, but if I decide to go with a CNC it will probably wait until tax return time.
Title: Re: Head Porting Dilemma!
Post by: perhamite on November 20, 2008, 07:46:56 PM
What are the costs for the different port jobs? Also does anyone have the dyno charts to show the differences?
Title: Re: Head Porting Dilemma!
Post by: Buck on November 20, 2008, 10:15:05 PM
Quote from: perhamite on November 20, 2008, 07:46:56 PM
What are the costs for the different port jobs? Also does anyone have the dyno charts to show the differences?

Bo is running a special right now on his porting for $250 until the end of the year (great deal) and a new CNC head is gonna cost around $500 plus cost of valves, and springs if u get better springs, that will up the price real quick to around $800. But Bo's porting uses stock valves so you pay $250 then throw it back on the bike. But the CNC heads are putting some serious power to the wheels.
Title: Re: Head Porting Dilemma!
Post by: Kenny on November 21, 2008, 11:31:08 AM
Quote from: perhamite on November 20, 2008, 07:46:56 PM
What are the costs for the different port jobs? Also does anyone have the dyno charts to show the differences?
Bo has a good head that will run $250. A CNC head with valves, which are required, will run $640 without springs. There is a big disparity in price and the performance between them. This isn't really an apples-to-apples comparison. The thing that really throws this out of whack is that all CNC heads are not created equal, so I can only speak for the heads that I sell.

As far as I know, I am the only one to have a dyno test published that is a head change only. This head was tested on the same dyno, same day without being unstrapped from the dyno. Even though this is a big engine, the cam and intake were a big restriction for the bigger head. The ported head that was on it was already a very good performing head.

(http://i233.photobucket.com/albums/ee157/kennybasham/beforeandafterKDSport.jpg)

As you can see, on an 869 there is a 5.75 hp gain at peak power. With a larger intake, there was a 15hp gain at 8200 RPM. With a larger cam and TB, or if the hand ported head had been stock valved, the differences would have been even greater. We will have a head only test next week on a stock bore stroke engine that is equipped with a Hotcam 3, +3 TB, 11:1 piston, and duals. Then another with drag pipes, KDS "RJ" cam, 12.5:1, +3 TB, ignition, and FCI intake. Both will be compared against the stock head.:thumbs:
Title: Re: Head Porting Dilemma!
Post by: Peelz on November 21, 2008, 12:02:43 PM
 :jaw:

wow. I worried about the difference between 42 and 45 hp when considering my lil' mods.  :lol: :help:

Hats off to ya' bro!
Title: Re: Head Porting Dilemma!
Post by: Buck on November 21, 2008, 09:07:46 PM
there may be another contender in the CNC head game soon as well. I may be looing into that as well  :batman: