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I still think there is something to moving the mix fast, swirled, and finally tumbled as compressed. Not worried about going sonic as the LS6 intake will limit that.
We're getting off the subject though; what should 02WSsicks look for in a valve job ? Ron, tell us about your valve job.
My guy builds stock car engines. SB chev, but the principals are the same.
He uses a cutter that does all the angles at once. Then touches up the portion that contacts the valve with a stone.
5 angle on the intake and 3 on the exh. The throat cut on the exh is actually a radius.
When he gives me the heads back, he shows me how to carefully blend his cuts into the throat.
I'm lucky to have a good mentor like he is. He helped me with my port job as well.
Talented machinist.
Although he thinks I'm nuts for turbocharging a stock 5.3.....
I've got mine ready to go on my Trans Am. I don't even mess with the guide.
This is one of the main areas I'm concerned with, is a good blend in pocket. What percentage are you opening up to , and are you guys finding any core shift from cylinder to cylinder .
"This is one of the main areas I'm concerned with, is a good blend in pocket. What percentage are you opening up to , and are you guys finding any core shift from cylinder to cylinder."
I just smoothed the seat into the bowl area, and combustion chambers, and took very little Aluminum out, opening the throat very little. If you like theory; I shot for approx 85% E/I ratio based off stock flow numbers as a base. I don't have a flow bench, nor do I really like them unless it's wet.
This is one of the main areas I'm concerned with, is a good blend in pocket. What percentage are you opening up to , and are you guys finding any core shift from cylinder to cylinder .
I opened it up to 1.805" and polished it out maybe another .010", so that's just barely over 90% for a 2" valve. I wouldn't go much over 91-92%, but I'll be going much lower in my next set of heads.
I posted I was looking for some 806's cause it looked like a cheap head to start on.
I have been building and selling serdi machines for 25 years now and I always have 2-3 in the shop to use plus my old faithful perfection machine a 1970's Vintage Serdi 50 which was the 3rd machine ever imported in to the US.
Once I look at the port and get a model done of it I will design a couple cutters and then I will post a couple pics of how the heads look after each cut. I can cut all the angles at once and that is cool but not really the way to go with what we know about accuracy and concentricity. I usually do my intakes with 4 or 5 cutters to ensure the absolute accuracy and position of the valve seat in relation to the throat of the port.
I like to scallop the top cut into the chamber first to de-shroud the valve, then I like to mate the de-shroud to the top intake angle which might be 15-15*.
Knowing the valve seat will be in the 45-55*, I leave that to the last as I want it to be as high as possible. To me that means as close to the piston as possible...
Almost like setting the booster in the proper place in the Carb Venturi. When you get that exactly right it is hard for even the best E.F.I to match it. It took Hendrick, Penske and McLaren 3 years to surpass the 50 year old Holley design and that was a couple hundred of the best and highest paid folks in the biz.
Ok so after the second cut on the top, then I drop down into the bottom bowl area which is probably in the 70-80* range and I start to scallop out the deep bowl by the guide as much as possible while still leaving enough meat there to build my venturi to the valve seat.
My next cut is just above that area in the 60-70* range and that allows me to clean almost all the way up to the bottom of the steel seat ring.
At this point I look to make a 3rd cut below the seat to roll the bowl area into the bottom angle of the valve seat cut and that is usually in the 50-60* range depending on what seat angle we decide to put on the heads and valve.
Once you finish off all but the last seat cut you can tootsie roll and blend the bottom in to the bottom cut and the chamber into the top cut and you will be ready to final cut the valve seat angle.
At this point if I said anything about the best valve seat I would be Bull$hizzing you cause I have not gone thru my process on these LS heads that I have on 23*, 21*, 18* 15* 12* and SB2.s.
With the angle of the port and the direction of the fuel from the intake it looks like the 47-52* seat angle would be the ticket. With good seats, good valve and a proper valve job you should have no problems making it 50,000 miles. If we get in the 55-60* range we might pick up 20-30Hp on the top end while sacrificing 20,000 miles of durability.
What is this process???
You take the same valve and cut them at 45*, 50* and 55* and then in the same port, you first cut the 55*, 50* and 45* and stick the valve in and flow the head to see what the port likes. Once the port tell me the seat angle it wants I like to test maybe 10 different valves in the same port to see what valve shape the port likes best.
Once this is decided I now have the proper seat profile and then I cut it into the top of the seat at the right width to take the seat all the way out to about .030-.100 of the margin ( outer edge ).
After all this process you take the heads back to the bench and see what she pulls. And you compare this to what you got when you first put the heads on the bench in 100% stock form at the very beginning.
If you are lucky and good you might pick up 25-50% airflow without changing valve size or additional porting.
I have been hand porting heads and intakes for 35 years and about 80% of the real important flow numbers will take place withing 2" of the valve seat either way. If that area is not perfect the rest of the work will not be utilize to its' maximum.
I will post a new thread when I get some additional info and pics, will also shoot them up on my website.
The difference I'm seeing between the two pictures is the area to the outside of the intake valve has been de-shrouded and the bump above the spark plug boss has been removed. On a 243/799/317 head these mods can increase flow at the cost of reduced compression.
I look forward to raceman14 findings as he uses his experience to learn the LSx head's secrets, even though he can not offer his services openly without being a sponsor. As it stands, I hope to get a Serdi valve job from TEA. I hope they can check in this thread to tell us what we get for the $175.00 price they offer on their website.
The difference I'm seeing between the two pictures is the area to the outside of the intake valve has been de-shrouded and the bump above the spark plug boss has been removed. On a 243/799/317 head these mods can increase flow at the cost of reduced compression.
I look forward to raceman14 findings as he uses his experience to learn the LSx head's secrets, even though he can not offer his services openly without being a sponsor. As it stands, I hope to get a Serdi valve job from TEA. I hope they can check in this thread to tell us what we get for the $175.00 price they offer on their website.
I too would like to hear from TEA , as I am considering them for a valve job also.
For those of you who have been following this thread I'd thought I'd post up the results. Remember I'm not a pro porter, but wanted to do a budget build. All the head work was done by myself with a lot of emphasis on velocity, swirl, and cylinder tumble. After much research, I put together a combination that I thought would do well. Theses are un-milled 799's. Check sig for the details
Not bad for a baby reverse split cam, and some hand bench work
Last edited by 02WSsicks; 12-30-2014 at 02:35 PM.
Reason: better pic
A friend of mine has a 99 FRC with the same cam and I am fairly certain the same basic mods as yours but stock heads. Depending on the dyno it has put down between 370-399rwhp but I don't recall the tq numbers.
Thanks for the follow up, def better than putting them on stock.
Thanks Guys! I figure most cam only (with this cam) cars made around 380ish. The heads seem to have added quite a bit. Feels good to have this come together. For those wanting to port their own heads, it can be done with decent results. Use these forums for help, and take your time. Picked up the heads used for $350. I had all the tools so, the cutters, and sand rolls cost me about $150. So I'm sitting on a $500 dollar pair of heads, that can still be pro ported in the future when the budget, and motor needs it. I figure it's a win win.
Is it me or did everyone else expect to see nothing but a giant ball of orange flame in the camera lens when the explosion happened? You know, sort of like in your action movie explosions. Maybe I have been watching too many action movies, lol??
Thanks Guys! I figure most cam only (with this cam) cars made around 380ish.
I agree, back when I was researching that cam I only found a couple TR230 cars that had made over that HP +/- 10hp. Mine ended up getting ground wrong but made 355-368rwhp depending on dyno through my unlocked auto.
Thunder Racing marketed it like it was "a TR224 with a little more mid to upper RPM pull", so it's not a big cam at all. Your numbers look solid, hope to see some track results too...MPH versus weight and DA will tell more than the dyno.
12-19-2014, 09:35 PM
