The exact response I got was "Sorry we do not do any head work anymore" so I'm guessing it was purely a financial decision, not necessarily because it isn't worth doing. At least, that's how I interpret it.

 

Bowl blend and valve job are important.

But look this is like going from a street tire to a slick and choosing to pre warm the slick with a tire blanket or not. It's still MASSIVELY better than the replacement when used as is.

 

Ahh, gotcha! Thanks!

 

So I got curious and couldn't find the info I was looking for. I called TSP and asked, their heads do come with a multi angle cut on the intake valves, radiused exhaust valves, and bowl blended. That is a definite plus.

Can't get ahold of trick flow at this time because they just closed.

 

Right tsp hand finishes every set of their ported stock castings on chamber

 

Good to know! This plus very reasonable pricing for their CNC porting makes it a good deal.
A question- I notice their Stage 1 ports increase very little in volume considering how much better they flow. Is it basically a multi-angle valve job and bowl blend along with minimal actual port work? If so, I am impressed!

 

Seems to me, it ends up on the potential buyer (or the shop involved) to carefully research what's needed for a given application. With "budget hardware" any otherwise good cylinder head can end up with issues in certain applications.

1. Quality with durability and attention to detail
2. Outstanding performance
3. Budget price

Pick two of the three.

 

TSP stage 1 and stage 2.5 are the same size ports from what I understand. The difference is the valve size.

 

Not just the valve "size" but also the seats are cut larger. They use an aftermarket backcut stainless valve also that helps with flow and heat dissipation etc.

 

Right. If you've noticed, flow #'s are very close between the 2 stages. That's why, on a smaller displacement (4.8, 5.3) build, I would use Stage I to avoid shrouding by the cylinder.

 

You cant use stage 1 on a 706/862 head. Since they have the smaller valves to begin with tsp automatically uses their 2.5 program to make them a 2.02/1.57. There are no real issues there and i havent seen any losses.

 

Oopps! That's right, and I had forgotten that.
On a stock 5.3 LM7, would a good bowl blend and multiangle valve job show worthwhile gains with the stock small valves? Or are the larger valves still the best all the way around? I would not want to lose the crisp low end response it now has.

 

I would assume the added flow is a combo of reshaping/smoothing to port a bit, bowl blend, valve job. If cc doesn't change it must be a minor amount of material they are removing from the port, which was your point and so yeah, a good part of it is likely the bowl and valve.

I think some may under estimate the power you can find in the bowl and valve job. But it's also a matter of how bad the area is before you work on it. I would (and maybe foolishy) assume that a high end aftermarket head would have less overhang of the valve seat into the pocket than a stock head. So the gains on a stock head would be higher from a pocket/bowl blend than a nicely done after market head if that were true. Unfortunately when I had the TFS in my hands a few years back I didn't pull a valve and look at that. I was on limited time and just threw them on.

Back many years ago I bent some valves on a little 8k rpm honda motor (integra GSR) it didn't like going to about 10k on a mis shift lol. Took the head to a machine shop and had the bent ones replaced. This was far before I knew anything of multi angle cuts and they asked me if I wanted a 5 angle (or 7? it was 18 years ago) done. I was like uh sure? And man oooh weee that mother ran after I got it back together. It was surprising. Then later the owner of the car bent the valves on it and I helped them get it fixed and they didn't have much money so we just had the valves replaced and lapped in. It was noticeably down on power compared to before with the multi angle cut.

 

With this statement, you have permanently invalidated anything you could ever hope to say or offer as far as tech advice. This statement is laughably ignorant, 100 psi wouldnt budge a valve, much less the pressures seen in the real world. Unless somehow you believe 20-30# of intake side pressure is causing the valve to tulip into a 200# combustion chamber. It's a heat issue, the regular alloy doesn't like the heat and bends (slowly) over time. Thicker, different alloyed valves don't. Period.

At least base your arguments in reality. They're **** valves, yes. They aren't bending because of "boost pressure". Lol...

 

The cut is on the seat, not the valve. Wat. (yes, sometimes an extra angle is cut on valves in rare cases, but a "valve job" is on the valve seat)

 

On the seat, not the valve but sometimes on the valve. Got it.

Being that it was more than a 3 angle I believe they were doing work on the valve. I wasn't experienced enough or wise enough to ask enough questions back then. I let them do their thing. I did mine. And there was a noticeable difference. I believe the mentioned something about the valve but was so long ago I can't remember 100% exactly what it was and I was only 21 so I just didn't know enough to ask enough.

 

Typically valves are just backcut. The valve job is on the valve seat. any time you hear (x angle valve job) its on the valve seat, not the valve.

 

Point out where I said it was on the valve.

 

I have HEARD (possibly erroneously) that a 5-angle valve job was 3 angles on the seat, and 2 on the valve, where besides the "normal" one, one more is a back cut. I would think this would gain some stealthy power, as it's not that obvious a mod.

 

Seems like someone needs a nap.

Anyway, ive seen some home ported or shop ported heads do ok, but recently a few people contacted me with flow numbers on some pnp heads they had done by local guys that were nearly stock. So it can be a waste of time and money, when you can go with a true setup.
Tsp has quite a few videos on their fb page of their newen machines cutting the seats on some heads so you can kind of get an idea on the contour and seat overlap.
There are too many schools of thought and process on cyl head options and flow etc for any one of them to be right. As long as they perform its a good thing. Also most newer stock 2.000 ls valves have 2 face cuts so they come stock with multi angle job on the valve. Maybe something someone didnt know. It did help immensely with low and midift flow even if on a stock head with 0 extra work. That was done on the valve not the seat also