THE porting thread....

So the head is back from it's compromised valve job.  Yep, and making it better 

Photo below shows the head sporting its new valve job, and it's compromise.  The compromise is the top cut couldn't be any larger, or smoother do to the head gasket fire ring placement.   One area NOT to be compromised!

The results is a top cut that is only .050" wide, and is "sunken" into the chamber by .062"!

Using a 1/8" "tree" burr as a file, I slowly reshape the ledge

With the ledge now removed, flow should be undisturbed

more to come.... 

Sometimes head cores have not been well taken care of...  as is this one with seriously decayed seats.  Now with new seats, and a fresh 3 angle valve job. 

plus the short radius was cliff like before being dealt with....

So a guy goes and buys a flow bench yesterday...

I'm looking forward to things to come over the next couple months.

In reply to Asphalt_Gundam :

Did it come with a velocity probe?

After seeing David Vizard map airflow velocity in a port, especially seeing areas of reverse flow, I really want to play with one of those!

In reply to Pete. (l33t FS) :

Yes. Probes for both intake and exhaust.

I've done this stuff long enough to not really "need" it but in my current job doing diesel heads it's an uphill battle trying to convince the boss that port efficiency and velocity are way more important than he wants to think. I've started doing velocity checks on everything to prove the point.

Its a great reference in any case because I'll take a faster port any day up to the mid 300s FPS that still meets the airflow requirements.

Exh I almost never check unless there's something funky going on. Case in point will be Monday: we have an exh port that by every means should flow more than the previous version but doesn't. My gut says its too big but velocity checks and adding some clay for testing will confirm that or not.

In reply to Pete. (l33t FS) :

Also be careful with Vizard's info. Good basics but his book and "advanced" info is outdated by a couple decades now. Largely because he focused heavily on factory heads and was stuck with old casting limits.

The stuff Darin Morgan put out in the late 90's/early 2000's is way better for modern and aftermarket head development.

In reply to Asphalt_Gundam :

very nice!  Did it come with a calibration plate?

In reply to oldeskewltoy :

A couple of them and extensive paperwork on the build, wiring, schematics and conversion charts

Asphalt_Gundam said:

In reply to oldeskewltoy :

A couple of them and extensive paperwork on the build, wiring, schematics and conversion charts

The first rule about flow benches... you don't race flow benches....  they are a tool, nothing more, nothing less.

have fun using it!

In reply to oldeskewltoy :

Oh I know... been using them since 2007

Ported this intake for another Oldsmobile guy and decided to do a little video on it. Trying to decide if some educational porting and engine building related videos would be worth my time putting together. This is a test run.

I would love to see more educational videos from you - I love what you do!

another oddball, sorry unusual head.  A Renault 807/841/843 head for this Alpine A110

It has not seen an easy life, one of the previous handlers was a bit abusive....  The red arrows pointing to the deepest scare.  As this engine is carbureted, the intake ports, and bowls were finished in 80 grit. 

The exhaust side wasn't spared......     Apologies for different lighting, these are the same exhaust bowls, the black arrows pointing out the same chamber marks