PART I- N/A 5SFE head Port & Polish

[frenum49]

The Science:
It is commonly known that in most cases the amount of power, or lack there-of, that an engine makes is decided largely upon the design and performance of its head(s). In fact this performance is measured in what is known as volumetric efficiency (VE). VE is described as, "the amount of air being pumped into and out of an engine as compared to its theoretical maximum". With this description in mind one would think that when improving upon a given heads flow larger ports and runners are the way to go, right? Wrong. Most modern heads actually flow quite well right from the factory. Engineers know from years of experience that the air velocity moving through an engine can be increased by applying simple principles that relate to air density and natural air acceleration. Air can be made to accelerate through a port when it is forced through a smaller passage as compared to the diameter of the valve. Ideally this number is 85% of the valve diameter to acheive maximum potential of air velocity. This is not to say that we cannot improve upon our engines VE.

What can be done?
First of all, let me write a bit of a disclaimer. I am by no means an expert when it comes to head work. PnP is a highly specialized endeavor. I am relying a great deal on research, Tech school training and a bit more on actual experience. I am however, a full time technician with all the tools I need at my immediate disposal. I am sure there will be those that may disagree with some of what I will be outlining in this post. I welcome any input that you may have. Just remember that I am sticking to known, factual information and techniques in hopes of filling a void of good information concerning our little explored 5SFE. I have already performed this work on my 5SFE Camry and am doing it again for a local man with the same engine in his Celica. This thread will be a multiple part posting detailing the work as I go. Lastly, it is extremely easy to render a good head useless by taking off material that serves a function. You could end up cutting into a water jacket or damaging some other function of the head. Cut at your own risk. Generally the idea here is LESS IS MORE. We do not want to interrupt proper air acceleration through the head by taking too much material. We are only removing as many sources of turbulence as possible without completely reshaping the ports. This is considered light head work. For this first part of the thread I will be looking at problem areas of the head. No cutting will be performed until part II.


With all that said, the first thing I did was to send the 5SFE head out to a local shop to have it cleaned, crack-checked and decked 16 thousandths. Crack checking the head is inexpensive and absolutely necessary. You do not want to waste your effort on a worthless cracked head unless you are practicing for the real deal. (which isn't a bad idea if you are at all uncomfortable with this process) They also checked that the valve guides are ok and that the valve seats are in good enough condition for a 3-angle valve job after the PnP is complete. It is a good idea to wait for any valve work until all the cutting is complete lest you nick a seat and have to pay for the same service twice. I opted for a 3-angle as opossed to 5 after much consideration as to the cost vs performace gain between the two. The deck was milled 16 thousandths to bring compression up without messing with the bottom end of the engine. The higher compression resulting from this milling will add power but will require that no lower than 92 octane fuel be used. If you use lesser quality fuel after this mod you run a risk of detonation and damage to the engine. Also if you plan on boosting your 5SFE forget this step as the combination of higher compression and boost will eventually cause a break-down. I estimate that with this deck milled and with the use of a metal head gasket, compression will be near 10:1 maybe a bit less.

The intake ports:

A peak into the intake port reveals a few areas of interest that can be improved upon. The red arrows show the divider between the two intake valves will need to be worked down into more of a knife edged surface while being careful to preserve the flatter area to the right to ensure proper air flow to that valve. The yellow arrows indicate that a small amount of the valve guide is protruding into the port. I have chosen to cut these guides down flush to the floor of the port. Some may argue that this will shorten the life of the valve. Considering the amount to be cut and the benefit of removal I will be cutting these. Also a peak just behind the guides reveals a sharp drop the floor of the port that will be smoothed out and blended in. The blue arrows show poor casting quality. These areas will, as well as the whole of the intake port, be smoothed out paying close attention to turns that have sharp edges or bumps that will cause turbulence. On the intake side of the head it is more beneficial to leave the surface slightly rough to assist in proper atomization of the fuel before entering the combustion chamber. A mirror polish here will cause more harm than good. At the bottom of the photo one can see the injector inlet. This area can be smoothed a bit as well helping the transition of air over this port. One more area of concern is the inside radius of the port along the roof as it transitions into a turn to the valve seat. With your finger you can feel a ridge that should be taken down. It is important to consider the direction of air flow when looking for potential turbulence areas.

The exhaust ports:

When looking into the exhaust ports one can see the valve guides in this side of the head (blue arrows) present a major obstruction to airflow leaving the combustion chamber indicated by the blue arrows. I chose to cut these down as well. Again the transition to the floor around the valve guide is quite steep and needs work just like the intake side. Remember air is flowing the opposite direction now so a knife edge on the divider between valves is not necessary. Rather we need to address the areas indicated in red to smooth the airflow. The roof of this port indicated by another red arrow has a particularly nasty ridge that needs to be taken down. And the transition to the exhaust manifold just before leaving the head needs smoothing. Again areas marked in yellow are casting imperfections that need attention. Unlike the intake ports, the exhaust side will be getting a complete mirror polish. This will help to eliminate carbon build-up on this side that will slow air-flow significantly.

I think I will stop here for now. In the next part I will illustrate proper port matching of the intake and exhaust manifolds to the head using stencil ink by Dykem. I will also cover tools needed to perform the upcoming work. There is plenty more to come.

[Red_T_SwiftCam]

Hey, pnp my head please!!!! LOL I'm not that far from ya.

I've been looking for a shop for months, but no dice.

[ghettosled]

any "before" dyno results so we can measure the actual results after everything is done?

[frenum49]

I have pre-work flow-bench numbers and can find stock dyno on the net somewhere. There is no dyno in my area. But I will put up the new flow bench numbers upon completion. Perhaps a dyno run on my own car after all my planned mods have been put in place. I wouldnt mind taking the crown for N/A whp 5SFE eventually.

[Red_T_SwiftCam]

Originally Posted by frenum49

I have pre-work flow-bench numbers and can find stock dyno on the net somewhere. There is no dyno in my area. But I will put up the new flow bench numbers upon completion. Perhaps a dyno run on my own car after all my planned mods have been put in place. I wouldnt mind taking the crown for N/A whp 5SFE eventually.

Good luck with taken the crown frenum.
Can you please talk more about the bad combination of turbo+Porting the 5sfe head?

[frenum49]

Originally Posted by Red_T_SwiftCam

Good luck with taken the crown frenum.
Can you please talk more about the bad combination of turbo+Porting the 5sfe head?

Generally speaking, higher compression engines are not boost friendly because of the limitations of pump gas. This is not to say that you cannot boost a high compression engine if you run high octane fuel. High boost with high compression = high cylinder temps and a huge potential for melt-down and detonation if the engine cannot disperse the heat efficiently. There is a bit of a trade-off here. Run high compression and low boost, or run low compression and high boost. There are race engines that run crazy compression and equally insane amounts of boost but these machines are fully built and in most cases completely custom applications running race fuel. Realistically, we are talking about the 5SFE here. There are other limiting factors as well concerning head design and cam durations to do with valve timing overlap. I did not mean to say that you should not PnP your head if you plan on running boost. Rather, that you limit the static compression ratio based upon the amount of boost you choose to run. Boost away. Just don't tinker with the compression ratio too much on these engines.

[frenum49]

Originally Posted by Red_T_SwiftCam

Hey, pnp my head please!!!! LOL I'm not
that far from ya.

I've been looking for a shop for months, but no dice.

Money talks my friend

[Red_T_SwiftCam]

Originally Posted by frenum49

Money talks my friend

HAHA i know it does.... how long does it take? I should be coming your way soon i could drop it off? Im shooting for boost 9,0,1 comp pistons fully built bottom end and hopefully some good head work let me know when you got time and price?? thanks Frenum

[frenum49]

Originally Posted by Red_T_SwiftCam

HAHA i know it does.... how long does it take? I should be coming your way soon i could drop it off? Im shooting for boost 9,0,1 comp pistons fully built bottom end and hopefully some good head work let me know when you got time and price?? thanks Frenum

Well, I will start cutting on this head Friday night and should have it done by next weekend. Then I have to wait for his intake cam to come back from Web Cam Inc. While I am waiting I need to port match and polish a 5FSE intake for kontra. So it is hard to say when I will be done with any accuracy. As far as cost is concerned....shoot me a PM.

[CTG]

Nice little summary!
On the exhaust side, in order to prevent any kind of turbulence on that ridge, would it not be a good idea to at least taper it in a little more? I'd think if its a pretty blunt curve you get some turbulence, disrupting exhaust flow. Any validity to this?


What? You don't want to run 10.25:1 with 6-8 PSI boost? lol... Look up the 62 Oldsmobile Jetfire turbo 215. Crazy Olds engineers... "In order to remedy the boost lag issue, we decided to increase the compression ratio to bring up lower end torque." wow.

[N/A Camry Sleeper]

Am reviving this thread to see if you ended up porting the head or not - any pics?

[RichieRichJP]

He hasn't logged on since January. Probably not.

[LynchburgCSI]

Dang. This still may deserve a sticky. I need to read it more throughly though. I also found a good guide for port/polishing the 3VZ heads yesterday too.

[OldElPaseo]

Im am practising a pnp on my wifes 5sfe camry before i do it on my 5sfe celica convertible. i just wanted to know a couple of things. first , are there any cooller or oil passages near these parts (like between the divider between the 2 intake valves, or anywhere i should be careful).
also, any updates on your pnp job ? i see that this post is old.
Thanks
ps: sorry for the mistakes i had a couple of tequilas in front of my computer... lol

[N/A Camry Sleeper]

I've heard that near the valves there is lots of metal to play with - don't have any specific figures but maybe I could find a blown head and cut it in half on a bandsaw to see what there is to work with...

Any volunteers?