mrgwrnch

I'm in the middle of rebuilding an LS1 and would like to know how much power gain would I see installing TSP Stage 1 heads over my stock 799's with equal size combustion chambers and a mild 224ish cam?

A.R. Shale Targa

iTrader: (2)

Texas Speed could give you the most accurate answer to that question. I'd
be purely guessing, perhaps others can verify, but I'd say 30 rwhp on the low
and 40 more if milled for higher compression.

BattleSausage

iTrader: (3)

To be honest with you, you'd most definitely see the most bang for your buck by having a good valve job done on your 799's versus spending 1g on having them cnc'd. Not taking away from TSP mind you, but their stage one uses the stock valves anyhow so having someone who knows what they are doing provide you a good valve job and a bit of cleanup in the chambers and throats will net you nearly the same results for far less since you already have the heads. From my experience, ~25hp is pretty accurate for that work.

2000PewterT/A

+1 On the valve job, If it was my car that is what I would do. If you want to get ported heads then I would just spend a little more and get stage 2 heads or better.

BOBS99SS

iTrader: (2)

Agree with the last 2 post,if ya already have heads just get those worked,or sell them and step up to at least a stage 2 or better,

BattleSausage

iTrader: (3)

I know prices have gradually moved up in the past few years, but I'm wanting to say that it cost me ~300 to have a valve job done and blend bowls/throat/chamber work done. If memory serves me correctly, on that setup it netted low 20ish rwhp on the setup I was running. Don't let anyone talk you into some fancy 5 angle valve job either...I would just walk away imho. A good machinist/builder will not try to sell you on that bullshit for a street build. Just a good 3 angle with a back cut to help low/mid lift will make awesome power on the cheap with your heads. Just my .02, hope it helps.

badazz81z28

iTrader: (6)

I disagree

First off TSP heads are brand new with new stock size valves. For 1k you will get that valve job plus the Cnc work.

Depending on the wear of your heads you may have to invest more into your 799s than you think

You could sell your stock heads for 350

I feel the tsp stg 1 would be a smarter way to go. Do it right the first time.

98ws6blk

I'm taking a similar approach. I bought some used 799s. Plan to get a valve job, milled for compression, and am doing some very mild porting myself..blending the seats and smoothing down the rocker bump. Hopefully I won't mess anything up : )

mrgwrnch

Thanks for all your input, I like seeing a good cross section of views. I bought the heads from this site. They are as new, I disassembled them and the heads look like they have never been run. I think cleaning them up would be worth the time, but labor in San Jose, Ca. is pretty pricey, so I might be at the price of a set of TSP heads. Does anyone have information on how to clean up the 799's?

Thanks in advance

A.R. Shale Targa

iTrader: (2)

Search DIY threads as plenty of people have home ported and there are
lots of pics for you.

BattleSausage

iTrader: (3)

Since they're essentially new, I doubt he'll have to spend much in that area. Spending an additional $600 or so for 15-20 cfm on a stock cube rebuild is not money well spent imho. Proper bowl work and a valve job will net in the 290/230 range and will enhance low/mid lift flow just the same as a ported head. Unless he's running high rpm and high lift, probably above .625 or so, I highly doubt the gains would be seen on the street or dyno, if at all. Proper valve/seat shape as well as the throat/bowl transition areas are the main reason for making power, and he would keep the velocity up which is essential for low lift/low rpm flow to enhance cylinder filling. The vast majority who cnc realize the increase in power numbers primarily in that area, not in the port program itself. Look at some of Gregg Good's posts on YB to see how much power just addressing those areas and not opening up the ports will net.

dr_whigham

iTrader: (49)

Why not send your 799's you already have, to AI for the 226 program?

427LS7HCI

AI's uses stock valves and majority of everyone giving him advice is saying go with larger valves because of the marginal increase of flow but also increase in shrouding.

TSP 799 Stage 1 and 2 is the same port job with the only difference being the valve sizes.

JakeFusion

iTrader: (7)

Send them to AI.

Sales2@Texas-speed

iTrader: (5)

We can port your castings to save you some cash, or after you buy a new set from us, yuo can sell your stock casting for $400-500 pretty easily to offset some cost too!

Let us know if we can help!

Trevor @ Texas Speed & Perf.

iTrader: (3)

Do you have a comparison of the PRC port vs. the AI port that leads you to this conclusion?

68BBChevelle

iTrader: (12)

Id be interested in seeing one.

dr_whigham

iTrader: (49)

After having a lengthy talk with Phil in the past, it's not about the valve size. PM him or call him and let him explain it to you. Knowledge is power.

speedtigger

iTrader: (16)

Why not go with the PRC CNC 5.3 heads? They have the same great flow numbers but a smaller combustion chamber for a compression bump. As great as the price is on the CNC PRCs, there is no way I would spend money on used heads.

I have the CNC 799s and I am very pleased with the performance and quality.

badazz81z28

iTrader: (6)

I wouldnt expect him to tell you his own heads "could be better" with larger valves. Re-grinding stock valves saves him money....


I would like to see a comparison of TSP vs AI as well...I'm about sick to death of "AI lovers" and TSP "Haters"....lets get the real data out there!