To show my point...
Here is your typical construction DOHC v6. It has an open breather to pre-throttlebody intake, and a PCV valve from the opposite bank directly to intake manifold.

It is not the oil that has built up, burned, and is causing a problem. It is the presence of carbon from the EGR system that is causing the problem...


https://www.fuelly.com/attachments/fo...5228578d77.jpg
https://www.fuelly.com/attachments/fo...08ef717cdc.jpg
This particular engine was only 4 years old at the time, of normal mileage. It shows a normal amount of carbon build-up for an EGR equipped vehicle.

Well, just remember it cakes the entire intake, and is caused by EGR. Not breathered oil.




I will also state for the record... 9-12 months you should clean the ports or they'll look like that. You'll also loose 5-10bhp depending on the engine because of the velocity drop caused by the carbon build-up.


The fastest way to remove it is with a die grinder, or dremel with a flexable extension. Use a #502 80 or # 503 120 grit flap-wheel sanding disk. You can also do minor smoothing & porting with it. In the case of a dremel, they cost around $9 for either. And have enough of a lifespan when not used for porting to do a long runner 32 valve v8. Both the intake ports in the head, and any upper manifold runners, and pluemn chambers in the process.

https://66.77.255.87/Images/DREMELACC..._PD/503_pd.jpghttps://66.77.255.87/Images/DREMELACC..._PD/502_pd.jpg







https://www.fuelly.com/attachments/fo...45b9587dae.jpg
VS
https://www.fuelly.com/attachments/fo...7d265dd73d.jpg
https://www.fuelly.com/attachments/fo...ed7987abd5.jpg


https://www.fuelly.com/attachments/fo...41fe2df517.jpg
VS
https://www.fuelly.com/attachments/fo...d46e466404.jpg

[QUOTE=Toysrme]But as a mechanic, racer, engine builder, and tuner.

https://www.fuelly.com/attachments/fo...41fe2df517.jpg

https://www.fuelly.com/attachments/fo...d46e466404.jpg

As a mechanic, racer, engine builder, and tuner it looks like to me that you have failed at head work 101.
Matching and/or englargening ports went out of style 30 years ago.

Do you realy think that auto makers that designs and builds hi-tech 4 valve per cylinder engines are so stupid as to allow a mistake like a missmatch between the intake and head ports for no reason ?

in the early 90s toyota realized it's about being able to change the intake runner length, and if i'm not mistaken, implemented it in the 3vz-fe. not that porting, polishing. balancing, etc... won't help a modern engine, but they probably won't help a modern engine significantly. variable length intake manis already optimizes intake velocity. otoh, it's kinda like the idea of weight reduction. every little bit helps, but you're not gonna shave anything significant off your qm times by taking out an air freshener.

Ok , ime going to put mine back in then - thanks :D

https://www.protecdirect.co.uk/Images...s/SXNSMTNC.jpg

Hmmm... makes me wonder why you need it. :D ;)
https://z.about.com/d/animatedtv/1/0/..._stinky_72.jpg

[QUOTE=onegammyleg]Ahem! Is this what you really said? If we regard an engine as an air pump, with production tolerances being (as loose) what they are, then we can ignore all the turbulence-causing steps, ID /OD mismatches, jammed up port cross-sections, rough walls, flashings, poor design curvatures (bean counter me$$), and the like? NIMBY...! I like smooth,non-twisting paths for my airflow. Requires less power, too! After all, 14.7 psi ain't gonna push in but so much "air"... even under ideal (ported, polished) conditions. I'll admit, low RPM work isn't bothered by this, but if you try to make serious power...you'll need good airflow. :D

Matching and/or englargening ports went out of style 30 years ago.
Hi Ted :-)

¨Ahem! Is this what you really said?¨ - YES , i said exactly that.

¨If we regard an engine as an air pump¨ - we cant assume that under all circumstances.

¨with production tolerances being (as loose) what they are,¨ - Are they ?? - I dont think so.
A production tolerance means that a specification may vary within an allowable percentage.
When talking dimensions of a crankshaft journal for example , a tolerance could be between 1.5 and 2.5 thousands of an inch, which as you would agree is small in relation to the journal size.
This possible variation in size is tolerance.
Having a manifold mismatch of 5mm is NOT production tolerance.

¨rough walls, flashings¨ - in an inlet manifold for example these have little influence on total flow.

¨poor design curvatures¨ - Under most conditions even a 90 degree bend in an inlet or exhaust manifold wont seriously affect flow as long as the area remains the same.

¨I like smooth,non-twisting paths for my airflow. Requires less power, too!¨ - as most of the air flows in the centre of the manifold , umm hole , surface texture has minimal effect on flow. Twisting paths as i said earlier have minimal effect if the area is unchanged.

This manifold has a few twisty bits., but ime sure it flows well.

https://www.romanvirdi.com/tuscany/001_582.jpg

¨but if you try to make serious power...you'll need good airflow. :D¨ - well . I was making 100+ horsepower per litre engines about 25 years ago now , with no EFI , turbos , twin cams ,4 valves per cylinder or variable cam timing.
With turbos I have made 200 hp per litre.(but still no twin cam or 4v) , and I must add that these were normal road cars , with good road manners not some undrivable track racer.

Ime not blowing my own horn here , but I think that shows that I know a little about how to make power.,,

The fact is , that most power gains with porting are done with work within an inch of the valves head., Cutting and grinding excessivley further up the intake port rarely makes more power , but effectively screws bottom end drive ability.

As flow benches have become more common the idea of huge ported and polished ports are dead and buried , this has been proven time and again.

Your rite.

In fact many of the old v8's had quite screwy shapes in the ports.

Likely this was because of them trying to improve flow in a bad port.
Pre efi V8's often had very low ports so as to meet up with the valley intake manifold and have a low hood hight.

https://www.airflowresearch.com/pages...-int-tweak.jpg

In old v8 heads often the charge had to navigate around casting for the pushrods.(and/or head bolts) , then they have to alter the direction again to try and generate some sort of swirl.

It rarely was done well and so head workers had good work modifying them to flow well.

Now days with port efi , better intake system designs and OHC engines manufacturers can get a fairly straight shot down the port now.

https://www.timgilles.com/photogaller...chaindrive.jpg

This is where a lot of power has been made in new generation v8's.


--Man , has this gone off thread or what ?! .. Sorry , me bad.:o

olg thanks for the education! you saved me a lot of typing:)