Ported 317 LS Heads for the beginner

[groberts101]

Yeah Charlie. Similar to that but I'm a "vane fanatic" and tend to leave as much material behind the guide as possible by not touching it till the very end on the final blends. Gives a good trailing edge.

I took some pictures of those heads while studying them on my bench but damned if I can find them on this computer. Guessing they may have been lost on some raided hard drives I lost several years ago. Sucks too because I had most of my previous semi-pro engine builds and head porting pic's stored on there. No more raid 0's for me these days. Lol

[maxracesoftware]

by MTENGINES » Sun Apr 29, 2018 6:30 pm
Nice post Larry, those numbers are in line with what mine do also.
With a 4.125 bore mine go 325. And not a Max ported deal either.
I usually tell the customer to get a square port. I like less work hahah

have you Ported or Bowl Ported a pair of these newer style GDI Heads yet

they have a lot of potential
especially if Chevy would have installed much larger OD seat inserts

GM_Chevy_35L_355HP_GDI_12620214
https://www.speed-talk.com/forum/viewtopic.php?f=1&t=53134

[mag2555]

Here's some tips to break 300 cfm with a 2.05" valve, and note that you only need valve bowl ( Throat size ) and some short turn work and valve guide trimming to get there!

[RevTheory]

It's funny you mentioned customers wanting "pretty": we had a set of LS3 heads CNC'd at Lingenfelter for a twin-turbo build and the customer came over to check them out and he was all kinds of twisted up because the cutter didn't touch certain parts of the port. I did my best to explain why that was but he just couldn't wrap his head around it and thought he was getting screwed.

Thanks for the write-up, btw.

[cv67]

Keep the info and pics coming, good stuff.

Mag those are the guys who pay too much for a fluff and shine job they just dont know any better.

[BILL-C]

Do you guys use the 2.055 dia intake valve on the stock factory seat? Any durability issues with the now much thinner seat insert?

[n2xlr8n]

I know this is waaay off topic, but if any of you cylinder head guys know Rick Kempf (spelling?) from California, pm me. He had a shop in Carson and worked at TRD.

[Frankshaft]

So far we have a basically stock port that hasn't really been picked up our stage 3, but she does look pretty.

Now stage 5 is tricky, this isn't noticeable since it looks like stage 4. But we work the width of the short turn and the bowl. Then pull the bowl back to the radius of the pushrod pinch.

IMAG0156_1524932572891_2.JPGIMAG0155_1524932573217_4.JPGIMAG0154_1524932573040_3.JPG

Time about 10 minutes.

Could be an optical allusion, but, that short turn needs more work.

[racin69z]

I know this thread is going on a year old, but I was reading it and found it useful. Being a non head porter I hear the term "work the short turn" a lot, but but what does that mean?

Too small a radius and the flow wont follow?

Could be an optical allusion, but, that short turn needs more work.

What would a person do to make it better. And for that matter, what did the OP do to compared to the factory casting. Its hard for me to see a difference in the pics.

I do like the idea to make a "form" that can be removed and looked at outside the port, like what mag2555 did with the wire. It really makes it easier for me to see the shape of the short turn.

All the porting reading that I have been doing is confusing me. Several years ago I remember reading that mid to low lift flow was very important. Now it seems that high lift flow is what people are shooting for. Is the high lift flow trend just for race engines, or is it universal? I have spent about 8 hours reading up on it, and while there is some good info out there, many porting threads turn into ego fest pretty quick and the useful info gets thin.

I happen to have a set of 862 heads with 1.89 for my 2002 6.0 on the bench now. So far I have just narrowed the guide, reduced the rocker bolt bump, and blended the seat to the bowl. The bottom cut is really large already. 90% of the intake valve size from the factory.

Lynn

[midnightbluS10]

Anybody know why MTENGINES account was deleted? Was he another who asked for his to be deleted?

[GARY C]

Anybody know why MTENGINES account was deleted? Was he another who asked for his to be deleted?

He got banned on the last go round, not sure why. I heard Frankshaft thought he was banned but his name is still active.

[CGT]

Anybody know why MTENGINES account was deleted? Was he another who asked for his to be deleted?

We used to chat privately. I believe it was possibly a disagreement privately with Don about some blatant advertising on the site and how it was being handled.....I think...if I remember correctly.

Both of those guys (Frank and MT) were an asset. They were and had been actually racing and actually building racing engines for a long time. So they offered some valuable information from the trenches. That's been the trend, replacing the "have done's" with the "have never done's". Maybe they will come back or at least contact me privately.

I happen to have a set of 862 heads with 1.89 for my 2002 6.0 on the bench now.

90% of the intake valve size from the factory.

Are you sure they aren't greater than 90%? 862 and 706 casting (pre-2007) 5.3 heads both are horrible in that area. It looks to me like GM took the same seat insert used in the 2.00" valved LS heads and put them in those castings, slapped the 1.89 intake valves on them, cut a 45 to seal them and let them fly....looks like bean counters were involved in that process.

They literally have a 45 and straight down from there. That would be the first thing to address if it were me, and its going to take using a 2" valve to "fix that" and get a decent valve job on those.

[rdwedge]

[quoteDo you guys use the 2.055 dia intake valve on the stock factory seat?][/quote]


Same question

[CGT]

[quoteDo you guys use the 2.055 dia intake valve on the stock factory seat?]

Same question
[/quote]

Unless the 317 head is special, any of the 2 inch valved LS heads that I measured the seat rings on.....2.04 would be the most. But I haven't measured them all for sure.

[midnightbluS10]

Anybody know why MTENGINES account was deleted? Was he another who asked for his to be deleted?

We used to chat privately. I believe it was possibly a disagreement privately with Don about some blatant advertising on the site and how it was being handled.....I think...if I remember correctly.

Both of those guys (Frank and MT) were an asset. They were and had been actually racing and actually building racing engines for a long time. So they offered some valuable information from the trenches. That's been the trend, replacing the "have done's" with the "have never done's". Maybe they will come back or at least contact me privately.

I happen to have a set of 862 heads with 1.89 for my 2002 6.0 on the bench now.

90% of the intake valve size from the factory.

Are you sure they aren't greater than 90%? 862 and 706 casting (pre-2007) 5.3 heads both are horrible in that area. It looks to me like GM took the same seat insert used in the 2.00" valved LS heads and put them in those castings, slapped the 1.89 intake valves on them, cut a 45 to seal them and let them fly....looks like bean counters were involved in that process.

They literally have a 45 and straight down from there. That would be the first thing to address if it were me, and its going to take using a 2" valve to "fix that" and get a decent valve job on those.

Thanks for sharing that. You're exactly right. Even for people like me, it sucks. I don't have near the experience of a lot of you guys, so I'd much rather learn stuff from guys who've been there and done that rather than other people like me, who are still trying to learn, themselves. Thanks again.