Head Porting - Worth it?

[Funky Phil]

Yeah Eric (notstock) ran a 5857 billet BB with a T4 .58 and that sucker saw 18psi at like 3200rpm hahaha. But that turbine wheel is only capable of so much and definitely choked out in the mid 5000rpm range. Supposidly the new CEA turbine can flow alot more air.

[psu_Crash]

I had my head ported and OS undercut SS valves put in at the same time. One or a combination of the two made a very noticeable difference in throttle response and mid range seat of the pants pull. Spool time on the holset wasn't really effected but it did seem to come on stronger when it spooled up. My local shop did what I think is a nice job on the porting job for $400. With the amount of cash I have given him over the years maybe he just cut me a deal

[kev]

Cool! Thanks guys, you just gave me more to research, haha. I have seen the PTE turbos before but I never realized on how versatile they were...most of them are available in any flange type, configuration, etc.

 

Just looked up that 5858 turbo. The price didn't shock me as much as I thought it would. I'm assuming 'T4 tangential' means a standard T4 flange?

 

http://www.precisionturbo.net/Street-and-Race/ss/600-800HP/details/Street-and-Race-Turbocharger---PT5858-CEA®/232

 

There are just so many darn choices. For instance, I was just looking at the 5558 turbo as well. I'm going to call up PTE and talk with them too.

 

 

 

I believe the consensus of this thread is going the direction that I have been leaning towards the past few weeks; do a mild porting consisting of primarily match porting to my manifolds and save the cash for a better turbocharger.

 

 

kev

[superscan811]

For even a mildly worked engine, the work I do to the head is:

1. Port matching

2. Smoothing out the port casting marks

3. Larger valves

4. Increase the ID of the valve seats

5. Reduce the big chunk of aluminium around the valve guides.

6. Deshroud the valves

7.Smoothing the port radii before the bottom of the valve.

8. Remove all sharp edges in the combustion chamber.

 

REASONS..

1. {AIR TURBULANCE}

You are driving down a road that has subsided by 6".

a. If you are going from the high side to the low side (Large head port, small manifold port), it's not a major problem.

b. If you are going the other way (Large manifold port to small head port) you have an issue.

It's less of an issue if you have bigger wheels (More Boost) but it is still an issue.

 

2. {AIR TURBULANCE}

You are driving down a road, how fast would you be willing to go if:

a. it’s well sealed and smooth.

b. it has a lot of dips and poorly repaired pot holes.

The poor road won’t stop you going fast but it will unsettle the car.

 

3 , 4, 5 and 6. {AIR RESTRICTION}

These are the points of the high restriction, a bit like when you have 4 lanes of highway traffic trying to go across a 2 lane bridge.

 

7. {CHANGING DIRECTION}

If you were traveling at 60 and had to make a 90º turn, how quickly can you do it if there is a long sweaping corner as opposed to a "T" intersection?

 

8. {DETONATION}

No analogy for this one, just that the sharp edges are more likely to get hot and cause detonation.

 

 

 

What this all boils down to is that you can overcome issues 1-7 either by fixing the issues or adding more boost.

 

If you could make the same amount of HP/Torque with 5lbs LESS boost, is it worth it to you, to spending the extra $?

 

If the work is done properly, you should also see an increase in economy as well.

 

 

Food for thought..

 

 

Cheers.

[Caliber308]

Trying to start up a debate here...a technical one. Head porting...is it worth it?

 

Kinda hard to put facts on the table because most of us who port the head are also adding many other goodies to the engine at the same time.

 

kev

 

You answered your own question Porting and polishing a Cylinder Head is money wasted without installing supporting modifications to utilize the increase in air flow.

 

Bill

Edited April 10, 2013 by Caliber308

[Funky Phil]

Cool! Thanks guys, you just gave me more to research, haha. I have seen the PTE turbos before but I never realized on how versatile they were...most of them are available in any flange type, configuration, etc.

 

Just looked up that 5858 turbo. The price didn't shock me as much as I thought it would. I'm assuming 'T4 tangential' means a standard T4 flange?

 

http://www.precision...58-CEA®/232

 

There are just so many darn choices. For instance, I was just looking at the 5558 turbo as well. I'm going to call up PTE and talk with them too.

 

 

 

I believe the consensus of this thread is going the direction that I have been leaning towards the past few weeks; do a mild porting consisting of primarily match porting to my manifolds and save the cash for a better turbocharger.

 

 

kev

 

5558 is too small. You want the undivided 5858 unit. Tangential means the turbine housing has a gangster lean like stock rather than On-center which hardly anyone makes anymore.

Edited April 10, 2013 by Funky Phil

[jszucs]

Cool! Thanks guys, you just gave me more to research, haha. I have seen the PTE turbos before but I never realized on how versatile they were...most of them are available in any flange type, configuration, etc.

 

Just looked up that 5858 turbo. The price didn't shock me as much as I thought it would. I'm assuming 'T4 tangential' means a standard T4 flange?

 

http://www.precision...58-CEA®/232

 

There are just so many darn choices. For instance, I was just looking at the 5558 turbo as well. I'm going to call up PTE and talk with them too.

 

 

 

I believe the consensus of this thread is going the direction that I have been leaning towards the past few weeks; do a mild porting consisting of primarily match porting to my manifolds and save the cash for a better turbocharger.

 

 

kev

 

Did you factor in all there "up sells" ? Like +600 for BB, I'm sure if you choose the upgraded wheel (if not standard) there is another $ upsell..... They are really good though about putting together allot of combos and choices.

 

As for the smaller charger choaking out in the 5000 RPM range. If the quick spool is not making it and you find your needing to hang in that RPM range you could always opt to get the wheel clipped to allow more flow past it.

 

I say yes the mild clean up would be well worth it, just to cut down on hotspots where it was ruff in casting. Might as well while it's off / new.

[Funky Phil]

Clipping has been shown time and time again to do more harm than good.

 

The Billet 5858 journal bearing is $8XX. Just buy it, youll love it.

[Caliber308]

The porting of a Cylinder Head has turned into a Turbo post???

 

Clipping of the Exhaust side of a Turbo.....Slows it down. Good for a high spooling short range Turbo. 16g and above Turbos that come in at 16 psi and above....... Clipping the Exhaust side of a turbo that comes in that late.........You decide. What you guys seem to miss is this.....FUEL!!!!! A Cylinder Head can be ported and polished but, if the fuel flow is not increased to accomidate the Cylinder Head modification..... You are wasting your time. AIR/ FUEL,AIR/ FUEL, AIR/ FUEL. That should be your main concern when Porting a Cylinder Head....Not the Turbocharger choice. The Camshaft,Cylinder Head, Fuel Delivery system and Engine Block modifications will determine the Turbo choice.

 

Don't put the cart before the horse

 

Bill

Edited April 10, 2013 by Caliber308

[kev]

The Billet 5858 journal bearing is $8XX. Just buy it, youll love it.

 

That's most likely what I'll be doing! Thanks so much for the advice/recommendations. This thread has helped me tremendously.

 

It's been fun getting back into this engine...it sat covered up in the corner of the garage for way too long.

 

 

 

Kevin

[Caliber308]

That's most likely what I'll be doing! Thanks so much for the advice/recommendations. This thread has helped me tremendously.

 

It's been fun getting back into this engine...it sat cover

 

d up in the corner of the garage for way too long.

 

 

 

Kevin

 

 

 

Good luck. Seeing how you didn't respond to sound advice I don't know why I waste my time posting??

Maybe I should quit.

 

Bill

Edited April 10, 2013 by Caliber308

[Funky Phil]

Cal, did you miss where he said, "going MPI"

 

The post was, is porting WORTH the money.

 

In this case, NO its not. He can get a better flowing turbo for that or less money and make great power.

 

And what "sound" advice did he miss out on?

 

Your the one that missed MPI and started rambling about 16g's.

 

Maybe YOU missed something.

 

[creakyjoints]

Might want to look into the EFR turbos also.

[StarquestRescue]

That's most likely what I'll be doing! Thanks so much for the advice/recommendations. This thread has helped me tremendously.

 

It's been fun getting back into this engine...it sat covered up in the corner of the garage for way too long.

 

 

 

Kevin

Ok, now that you did not drink the mega buck turbo koolaid.

 

Take the $800 you saved and buy a ems with user friendly tuning and data logging soft ware.

 

I one heard sds described as a reliable system that was almost impossible to tune. Granted you probably have experience with it.

[jszucs]

The porting of a Cylinder Head has turned into a Turbo post???

 

Clipping of the Exhaust side of a Turbo.....Slows it down. Good for a high spooling short range Turbo. 16g and above Turbos that come in at 16 psi and above....... Clipping the Exhaust side of a turbo that comes in that late.........You decide. What you guys seem to miss is this.....FUEL!!!!! A Cylinder Head can be ported and polished but, if the fuel flow is not increased to accomidate the Cylinder Head modification..... You are wasting your time. AIR/ FUEL,AIR/ FUEL, AIR/ FUEL. That should be your main concern when Porting a Cylinder Head....Not the Turbocharger choice. The Camshaft,Cylinder Head, Fuel Delivery system and Engine Block modifications will determine the Turbo choice.

 

Don't put the cart before the horse

 

Bill

 

When your starting from the beginning, I would think that would be the other way around. Figure out what kind of #'s you want, what kind of spool time you want, and other charterristics of the turbo you want, and build the motor around that. If you did end up with a super 16G your going to want that thing to be in the 20PSI + range to really perform. So you would not want to build a low reving motor around that. Where as you might put some huge turbo on it (like a desial application) and that turbo flows a huge number at a low PSI level. In that case you could build a low reving motor.

 

Turbo tec has come along way, it's not the inefficient turbos of the past anymore.

[Tim_C.]

The gain will be good with the low profile back of SST valves. The 1mm oversize won't hurt, but it isn't much. I prefer stock sized valves on stock thickness seats. Grinding into the seats from new can lesson the life of the head too. Not so bad with 1mm, so it is fine. Just more expense to grind on a perfectly good seat compared to a touch angle grind to just clean it up to seal the valve.

I like to just unshroud the seat into the port. My roundy track machinist uses a 38 degree "Bull Hog". That is a cheap and fast way to increase flow for considerable gain. He hates it when he has a lot of time into a port job, only to win and have his engine claimed by someone else. So he comes up with these innovations of his to get bang for less.

5 angle valve job is better too but I usually don't go for it on a new head. More so on a head that needs a good cleaning up. New seats still need ground to get a superior seal, but it don't take much. I have an old-timer, old school muscle car mechanic who was amazed how much better a new head sealed to new valves AFTER he ground the seats on a new marnal I had.

The heads flow more than other restrictions. Even a Magna MPI can't outflow the head.

I hope your header is bullet proof. Be prepared to run it for a while to see where it starts to leak, then pull it and have a pro seal it up again. After that it should be good for a long while if it is strong enough. If the header has any grinding on the inside, beware the grinding could be far into the weld and thinner than the tube steel. That is where it will start to leak and need repaired later.

[kev]

Tim,

 

I was wondering when you'd hop onto this thread. Almost sent you a PM yesterday. Thanks for the input.

 

As far as my header goes..I haven't looked at it since the day I bought it. It is one of Chad's headers that I bought second hand (un-used) from another member here.

 

The outcome of this thread has made me not want to spend a lot of cash on port/polishing with flow testing. My next step is to start talking with machine shops to get their point of view and prices. I'm still willing to pay some money to do some minor work based on the machinist's expertise and experience (without flow testing).

 

I'm trying to make an educated decision here and not break the bank or add many more months to my rebuild. It's funny how the opinions and advice change over the years though. For instance when I bought my SDS system, it was the recommended engine management system by members here. Now I barely see anyone using it. Oh well, it isn't time to second guess decisions that I made in the past.

 

 

Kevin

[Caliber308]

Here is some information:

 

Flow #s for Intake @28" and .400 lift:

 

Stock JV head about 151 cfm.

NJV head about 165 cfm.

Mild Ported Marnal 188 cfm.

Heavy Ported Marnal 211 cfm.

Stock 2nd Gen Magna 187 cfm.

Ported 2nd Gen Magna 208 cfm.

Stock 3rd Gen Magna 179 cfm.

2nd Gen Magna w/50mm valves 285 cfm.

 

More flow= more power(with the correct modifications)

 

After looking at the cfm numbers.....You decide if Porting and Polishing a Cylinder Head makes sense

 

Compression Ratio Changes for Aftermarket Heads:

 

Stock CR is 7:1.

Clearwater: Lowers .27 CR 6.73:1.

Marnal: Raises .11 CR 7.21:1.

 

In response to Jszucs post:

 

I have built lots of Engine/Cylinder Head combinations and have always started out with the Engine Block rebuild first. Then moved to the Cylinder Head (or heads). After those two things have been accomplished...That is the time to choose your Air/Fuel and Spark modifications.The proper way to build a complete motor is from the bottom up, not the top down. You always want the bottom end of your Engine as "bullet proof" as is possible

 

Bill

Edited April 13, 2013 by Caliber308

[jszucs]

Here is some information:

 

Flow #s for Intake @28" and .400 lift:

 

Stock JV head about 151 cfm.

NJV head about 165 cfm.

Mild Ported Marnal 188 cfm.

Heavy Ported Marnal 211 cfm.

Stock 2nd Gen Magna 187 cfm.

Ported 2nd Gen Magna 208 cfm.

Stock 3rd Gen Magna 179 cfm.

2nd Gen Magna w/50mm valves 285 cfm.

 

More flow= more power(with the correct modifications)

 

After looking at the cfm numbers.....You decide if Porting and Polishing a Cylinder Head makes sense

 

Compression Ratio Changes for Aftermarket Heads:

 

Stock CR is 7:1.

Clearwater: Lowers .27 CR 6.73:1.

Marnal: Raises .11 CR 7.21:1.

 

In response to Jszucs post:

 

I have built lots of Engine/Cylinder Head combinations and have always started out with the Engine Block rebuild first. Then moved to the Cylinder Head (or heads). After those two things have been accomplished...That is the time to choose your Air/Fuel and Spark modifications.The proper way to build a complete motor is from the bottom up, not the top down. You always want the bottom end of your Engine as "bullet proof" as is possible

 

Bill

 

I have always gown all out on rebuilds. Your opening her up, you might as well do it right.

 

My point being, if you were going to put a dinky little turbo (or no turbo at all) your going to want to build around that. If your going to put a huge 800+ CFM turbo on a motor built for a small turbo is going to have to be opened up and your going to have to redo stuff, to acomidate. Bullet proffing a bottom end for a stock or 100 HP gain is light years away from someone shooting for 3 or 4 times the stock HP.

[Funky Phil]

_{When you see someone use the word "about" they are guessing. Also why no exhaust numbers? .....exactly}

 

_{Heres some real data}

 

_{I can help you guys out on this topic, last night I flowed one of my extra stock Mitsu 2.6 heads to get you guys some good baseline numbers, this head has stock dia. Valves with slightly modified stock valves, the valves are polished with a radius backcut which is worth a few extra cfm. Head was flowed with a clay radius inlet and data was recorded at 28â of depression on a 1020 probench by superflow. I didnât get a chance last night to cc the runner volume, but I will get all that info, Iâll also within the next few weeks, play around with this head and do different variations of porting from mild to really extensive along with a really tricked out port by adding material in the port floor to make somewhat of an acceptable short turn which these heads donât have and post all the progress as I go along, cfm and runner volumes for you guys.}

_{Baseline flow numbers:}

 

_{Lift intake exhaust}

_{0.050 48.1 36.2}

_{0.100 84.6 66.7}

_{0.150 116.0 89.0}

_{0.200 147.1 110.9}

_{0.250 168.9 123.1}

_{0.300 179.1 133.4}

_{0.350 185.7 142.5}

_{0.400 186.9 145.9}

_{0.450 191.1 148.9}

_{0.500 193.8 149.0}

_{0.550 194.7 149.1}

 

 

_Tony

[Shelby]

just to help me get a better handle on your numbers , is this a vacuum draw flow, pressure push flow or exactly how is the flow being measure'd , and whats the diff is flow under say 20 lbs boost ,the exh is always under pressure by the movement of the pistons up the cyl walls

[Funky Phil]

vacuum intake, blow-thru exhaust

[Caliber308]

Bullet proffing a bottom end for a stock or 100 HP gain is light years away from someone shooting for 3 or 4 times the stock HP.

 

Bullet proofing a Engine bottom end for a Lawnmower, 1000 horsepower set up, or anything in between should be done the same......NO SHORT CUTS!!!! with the best parts available. It's like this: Installing Hyper-Us or using the Stock pistons on a 400 HP G54B Engine rebuild .....See what i'm getting at??? You get the end result from what you install and the machine work that has been done Go cheap, you get cheap results Thus my phrase: "Bulletproofing" the bottom end of a engine

 

Trying to "bulletproof" a engines bottom end doesn't mean that it may not fail...But, with what I have done to my engine (Forged pistons, turned crankshaft, rebuilt rods, new rod and main bearings and balancing of the entire rotating assembly) It has held together at 7000 rpms more than once

 

Bill

Edited April 17, 2013 by Caliber308

[Caliber308]

_{When you see someone use the word "about" they are guessing. Also why no exhaust numbers? .....exactly}

 

_{Heres some real data}

 

 

 

Where was "about" mentioned in my post?? I gave approx. Intake flow numbers based upon the posters question concerning: "Is it worth porting a Cylinder Head".

 

The next time a member asks a question about it being worth porting a Cylinder Head, you can answer it with your own CFM Intake numbers. Until then, you should STFU.

 

P.S. The phrase "ABOUT" can be used in ANY Cylinder Head Porting modification. Have you ever seen two Cylinder Heads ported exactly the same, or "ABOUT" the same??? I haven't seen them be EXACT in my 38 years of doing Cylinder Head modifications. You can get them close to each other.....But EXACTLY the same???? Hell no."About the same"....Yes.Give me a break

 

 

Bill

Edited April 17, 2013 by Caliber308

[Caliber308]

just to help me get a better handle on your numbers ,

 

Shelby......Those are not HIS numbers, their Krazed Zs from 2005, just something he read and believed to be accurate

 

Bill

Edited April 17, 2013 by Caliber308