I know I'll have about another 4 or 5 hours worth of "blending" which back in 2011 when I worked my 241s resulted in 246.5 cfm IN and 220 EX w/pipe on the GM valve job and no chamber work. So you're right; it could be argued that if these only flow 30 or 40 more on the intake side, well was that worth it then for 500 bucks......
I'm happy so far that the work done looks good and the runners seem small promoting great velocity....

 

Why wouldn't you want to mess with the chambers?

 

I suppose I could widen them on the sides of the valves to un-shroud but then would be trading compression for flow. The 241/853 already have a crappy shape on the spark plug side of the intake valve.......the area where A.I. welds them up to reshape after CNC work.....essentially making the chamber shape more similar to the 243/799 stuff
My whole purpose here was to purchase consistency and save time...I do enjoy minor massaging but an all out start to finish job usually takes about 12-15 hours.....IMO the ten hours of my life were worth the 500 bucks; as well as trying a slightly different way to "skin this cat"......

 

I think the port work looks good.

Other comments.
Regarding 250 cc intake runners, the GMPP LS6 heads by LPE were 250 cc. Katech had to use these in some of the GM sponsored Corvette racing back in the day because LpE wanted to sponsor. It's actually a good intake port for racing, or so I was told by a former Katech person.

My understanding is Katech's LS1 heads were very good back in the LS1 heyday.

Here are some flow numbers for a Katech ported LS1 806 head. Looks pretty good

https://ls1tech.com/forums/generatio...head-info.html

The flow numbers as given by the seller are:

int.
.200 /137.6 exhaust@ .200/107.3
.300 /202.8 exhaust@ .300 /142.3
.400 /244.2 exhaust@ .400 /175.4
.500 /272.3 exhaust@ .500 /194.3
.600/ 285.6 exhaust@ .600/205.4

 

I sent assembled heads to Texas Speed for Stage 1, they dissambled, cleaned, ported and reassembled them for $750. At 227cc intake ports they work great on a stock ls1 block. They looked a bit smoother than the Katech ones. Either one is a bargain.

 

Before



After



Before



After

 

Gonna have these back cut a bit



Decent lapping line

 

Before



After



Before



After

 

Got one cylinder head done today. Took my time and invested about three hours total with lapping valves and solvent tank cleaning, rinsing, blowing dry etc.
try to finish second head tomorrow then Monday they get welded

 

Side by side before and after



Slightly different angle

 

Nice just take your time. I ported my own efi Super Vic I was very happy with the work and saved a little coin. Just cut on a nice radio station and relax.

 

Thanks man and yeah the music chills the patience with a bit alcohol too
Don't wanna hack the original GM valve job but still need to blend that inner angle.......similarly to your heads at half cost my goal here is to keep a decent factory casting under a grand when all is said and done. Surfaced, valve springs, etc. just always seems that by the time you end up with $1400-1700 bucks into some factory castings well then Mamo 223s, TFS220s, and PRC225s begin to look like the better way to go.
Bang for buck or shear frugality is still relevant in today's age with all the other **** needed to put a car/truck together.
Think my flow predictions might be high as I just checked AI's website and they're getting 285@.600" but what the heck. Enjoying the process over here and trying to provide lotsa pics. People love photos. lol
My work is no sweet treat but it will be adequate IMO

 

Thanks for posting. I have a set of 853's coming off my heap this winter and I am back and forth what to do with them. I am between getting them a valve job, decking, then porting myself vs Thompson Motorsports heads. For $1199 out the door they offer a ported 243 head, no core charge (that I can see), assembled with PAC 1218 springs.

Good luck with your project.

 

I usually come up with a idea 1st and come up with a Cheap purchase for a set of heads. But called in pricing for porting and modification from a well Known porter. I buy the parts and it’s a win win it’s all on my budget and time. Most exspensive thing is porting but that’s general but even better when you get a good porter. I figure another set of Ls7 heads may cost max 2000 bare with new guides and port work. But the start up cost is only 600 bucks. Budget and time is always key. I need to learn how to show Pic’s got Plenty. Keep up the good work and providing info.

 

Waiting on Frankenstein to get back at me as I have a spare head that hit a water jacket in the bowls. Darin”s 1st CNC program didn’t make it. Figure we could Test a few ports to see which one she can take. Thinking FRH smaller Ls7 Brodix program. Flows 400 and done simple.

 

Plenty of great options on this site but this here is an option of "do it yourself" for really cheap. Just need to continue pressing on to get the final results numbers to prove the effort/worth

 

I am digging it.

 

Thanks man. Tomorrow lunch with my buddy the welder. Once those ugly notches are filled it's off to the shop for a flow job and cut.
Think my original guesstimates were perhaps overly optimistic. Was thinking 280/230 w/ pipe but seeing AI only gets 285 and 230 w/o pipe I'm Kinda worried. I mean they look nice but hell anything less than 270/220 will be a disappointment IMO. based on my prior 241 casting garbage. Good thing being no real build plan or set parameters but just a monetary investment to return sorta thing I don't mind looking like an idiot, like Geico; it's what I do !!!

 

Before



After

 

I figure if you optimize the potential of the heads by matching supporting components you'll be ahead of the game. Plus, if you are having fun - what's the harm?

Your attention to detail is showing.