FastZinTennessee

I recently got my port and pray, errrr home port job done I took them over to the machine shop to get flow tested today. The owner told me that his flow bench is "quite stingy" as far as numbers go. He explained to me that he flowed some heads on his bench, and the same set of heads flowed 20 CFM higher on another bench. He gave me a rundown of flow numbers from a *stock* LT1 head that was tested on his bench, and I would like to compare them to stock LT1 heads flowed on other benches. The test was done on a Superflow SF600 bench.

For now I will compare the stock LT1 head numbers on said SF600 bench to my ported numbers flowed on the same bench-

Stocker Int- 61(.100) 120(.200) 169(.300) 204(.400) 223(.500) 223(.600)
Ported Int-- 63(.100) 126(.200) 179(.300) 219(.400) 243(.500) 243(.600)

Stocker Exh- 52(.100) 106(.200) 135(.300) 151(.400) 157(.500) 158(.600)
Ported Exh--- 51(.100) 98(.200) 126(.300) 152(.400) 166(.500) 175(.600)

Not sure what the heck is going on with the exhaust side, but since the heads are done and at the machine shop I guess that's neither here nor there

If anyone has some stock LT1 head flow sheets I'd like to see them to compare to this bench that my heads were flowed on. Here's the bench-

http://img.photobucket.com/albums/v6.../headSF600.jpg

Finished intake port (crappy pic, I know)-

http://img.photobucket.com/albums/v6...inishedInt.jpg

got8?

Not bad lookin, i definatly couldnt do that.

MachinistOne

Link to flow numbers on LTx stuff. Here

FastZinTennessee

Thanks, that link is great! Just for fun I calculated the horsepower potential using my airflow specs from that calculator they show on the top of the page- said I can make 497 hp! I'm sure it's better for entertainment purposes than for making any kind of accurate estimate, but still fun to work out nonetheless!

So for the experienced head porters/cam grinders, how much do you think I can make with this? Anyone care to throw some numbers out? I'm going to be using the 1.6 ratio roller rockers from the HOTcam, so I'll be limited to .575 lift(don't think I'd want that much or more anyway). I would love to hit 400 rwhp with some homeported heads, but I think I might need some more flow....... Well I'll quit thinking and leave the question up to the experts!

Oh, and Bret (SStrokerAce) if you read this email me! I'm having trouble getting in touch with you via email, I think I might have your address saved wrong. Reach me at John.P.Gardner@gmail.com

SStrokerAce

Z,

That's about what a stock LT1 head flows so those numbers seem to be inline.

The valve job on the exhaust looks like it's a bit odd since the low lift flow numbers are down now... He did a VJ on these things right?

Bret

FastZinTennessee

The valve job has about 10k miles on it(I'm assuming you're asking about VJ refers to valve job). Basically what happened was I did a home port job, put heads on the car, block cracked after about 10k miles of use, then I took the heads off, did some more porting and took them to the machine shop.

I did a lot of removal on the exhaust side, so maybe it just killed off my low lift numbers? I'm not too familiar with the exhaust side, I did more research about the intake side.......

Edit: I also should add that the intake/exhaust valves used in the flow test were not necesarily the same valves that were in that cylinder before disassembly. I simply disassembled the head before porting, and put the valves in a box. We just grabbed one random intake and exhaust valve for the test...... not sure if that makes a difference.

SStrokerAce

You could have hurt the short turn in the exhaust and caused that dip in flow.

Bret

Jameslt1TA

^it may make a difference since your seats are matched seat-to-valve. I did my own port job and valve job also. I just opened up and polished the intake and exhaust ports. I should have done something with the bowls but i did the valve job first(not sure why) and didnt want to risk hitting the seats. What all did you do for porting on yours?

FastZinTennessee

I port matched the intake ports, flattened the roof of the runner, opened up just a little at the bend around the pushrod. I did not touch the short side radius other than to go over it with some 80 grit sanding rolls. I took a lot of material out of the valve guide, and opened up the bowls slightly, but paid more attention to blending the bowl area to the flattened roof.

On the exhaust side I didn't change the shape of the runner much, but I essentially ground down the guide and flattened the roof of it. Perhaps I should have opened up the exhaust port more after doing this?

On the chambers, I tried to unshroud the intake valve some, but didn't remove too much material.

shawn39

Good to see that you picked up some flow.I hope mine do as good as yours.I'm going to get the head i have done flowed and if it turns out ok i will match the other head to it.Here are some pics.

http://pg.photos.yahoo.com/ph/flinch...bum?.dir=/1c6c

FastZinTennessee

Your port job looks good! I'm sure they'll pick up just fine, I just hope you don't lose low lift exhaust flow numbers like I did!

Jameslt1TA

Ya i opened up my exhaust ports quite abit. Ill be getting the car on the dyno here in a few so that may tell me something. Sooner or later ill be taking the heads off the car to port them some more now that i have gained more knowlage...ill make sure to get them flowed too.

shawn39

Hey FastZinTennessee where did you get your heads flowed?I was going to get TEA to flow mine but they moved to ohio.I guess i will get ForceFed High Performance to flow them.They are located just outside of Louisville, Ky.That is the nearest place that i know of that can flow my lt1 heads.What cam are you going to run?

FastZinTennessee

TEA had a very good reputation, I hated to see them up and leave! I had the heads flowed at a place called Revolutionary Performance and Machine(RPM) in Mt. Juliet, Tennessee. They were recommended to me by a bunch of guys around here, so I went to check them out. I walked in and there were LT1's all over the place. A few 383 LT1's, and a 396 LT1 were there, along with some standard rebuilds, mild rebuilds, etc.

Not sure what cam cam specs I'll have. I'm going to get a custom one made, so whatever it ends up being. I'll post specs up when I know something.

SiCk PuPpY

I know you were asking about stock flow numbers, but I just finished having my heads ported by a friend. I also installed Manley 2.00 intake and 1.57 exhaust valves.

Intake CFM (max lift is .525)

.100- 65.9
.200- 128.2
.300- 185.7
.400- 228.9
.500- 251.3 (max flow is at .525 lift)
.600- 239.2

Exhaust CFM
.100- 55
.200- 108.9
.300- 155
.400- 180
.500- 186
.600- 190.4

The numbers were at 28" and no pipe was used. I'm going to polish the exhaust ports to a shine and attempt to pull better numbers out of the exhaust side.