Got my flow numbers from Lloyd
Registered User
Joined: Dec 2001
Posts: 180
From: Texas
Originally posted by Mindgame
No doubt the exhaust #s would increase with a pipe installed but it's not that big a deal.
Where it counts.... from .200-.400 lift, the ratio averages to 72%.
An engine we just put together for a race car using 18* castings (yep, it's internal combustion like your street car) flowed less than 67% at peak intake valve lift and only averaged 68% from .2-.400 lift. Poor in most peoples book but I've seen "worse".
After dyno testing three camshafts we ended up with 779 hp and 556 lbs-ft of torque n/a, 994 hp and 791 lbs-ft of torque on a 200 shot. The best results were found with a cam using 6* more exhaust duration. The difference in the three cams primarily being the amount of the duration split. Lift, LSA and advance was all identical and the three were chosen based on the builder's (Shafiroff) wave simulation data, utilizing pressure-volume diagrams.
The other two cams utilizing 8* and 10* splits were down on average torque some 10 lbs-ft from 4500 rpm on up with the 10* split showing the most average torque loss.
Again, it can be difficult painting with broad brush strokes and I believe the intake/exhaust ratio thing is a little overplayed. Never really works out the way you think it will in the real world. A ratio doesn't tell you how well the port flows for it's size and if you ever get the chance to pick the brain of a top-shelf porter you'll find out that port shape and average velocity is what it's all about.
Nice numbers!
-Mindgame
No doubt the exhaust #s would increase with a pipe installed but it's not that big a deal.
Where it counts.... from .200-.400 lift, the ratio averages to 72%.
An engine we just put together for a race car using 18* castings (yep, it's internal combustion like your street car) flowed less than 67% at peak intake valve lift and only averaged 68% from .2-.400 lift. Poor in most peoples book but I've seen "worse".
After dyno testing three camshafts we ended up with 779 hp and 556 lbs-ft of torque n/a, 994 hp and 791 lbs-ft of torque on a 200 shot. The best results were found with a cam using 6* more exhaust duration. The difference in the three cams primarily being the amount of the duration split. Lift, LSA and advance was all identical and the three were chosen based on the builder's (Shafiroff) wave simulation data, utilizing pressure-volume diagrams.
The other two cams utilizing 8* and 10* splits were down on average torque some 10 lbs-ft from 4500 rpm on up with the 10* split showing the most average torque loss.
Again, it can be difficult painting with broad brush strokes and I believe the intake/exhaust ratio thing is a little overplayed. Never really works out the way you think it will in the real world. A ratio doesn't tell you how well the port flows for it's size and if you ever get the chance to pick the brain of a top-shelf porter you'll find out that port shape and average velocity is what it's all about.
Nice numbers!
-Mindgame
Mindgame, I just noticed your signature car info the other day. That's an awsome setup.
I just had a few questions
1. Is it a daily driver or street car?
2. Are the ports on the heads huge? And if so, what is your low end tourque like at say 2000 rpm - 3700rpm?
Registered User
Joined: Jul 2001
Posts: 162
From: CA, USA
I think of it as doing more with less.
The heads I had done for my car, while they only flowed 260 @ .550 & 265 @ .600, it was all done with a 180cc intake runner!
If someone goes out and hogs out the runners and gets only 10 more cfm from 40 more cc's out of the intake runner, then they might not have done a very good job.
The heads I had done for my car, while they only flowed 260 @ .550 & 265 @ .600, it was all done with a 180cc intake runner!
If someone goes out and hogs out the runners and gets only 10 more cfm from 40 more cc's out of the intake runner, then they might not have done a very good job.
Banned
Joined: Aug 2001
Posts: 3,505
From: looking for a flow bench so Brook and I can race
Re: Re: Got my flow numbers from Lloyd
Originally posted by rskrause
Nice flow on the intake, but the E/I of ~69% isn't too good. You should use a cam with a wide split pattern (in the range of 10+ degrees more exhaust than intake duration) for best results.
Good luck.
Rich Krause
Nice flow on the intake, but the E/I of ~69% isn't too good. You should use a cam with a wide split pattern (in the range of 10+ degrees more exhaust than intake duration) for best results.
Good luck.
Rich Krause
LLoyd-
I am going to try those heads my buddy ported for me with your help.
I think i might be in for a set of your heads though-
my cam will have substanditally more lift though (.585)
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Originally posted by Rpm280
Mindgame, I just noticed your signature car info the other day. That's an awsome setup.
I just had a few questions
1. Is it a daily driver or street car?
Mindgame, I just noticed your signature car info the other day. That's an awsome setup.
I just had a few questions
1. Is it a daily driver or street car?
The whole point in me building this engine in the first place was to drive the car. I could/would have went more radical if this were a weekend only runner.
2. Are the ports on the heads huge? And if so, what is your low end tourque like at say 2000 rpm - 3700rpm?
Torque from 2-3500 rpm is probably just about as good as most of the 400-425 rwhp cars on this board. So they'd hang with me...... for a couple seconds.
My torque peak is at ~4900 rpm so the "sweet spot" when rolling along at 2500 revs or so, is only a downshift away. From a launch I'd never see less than 3k (on Nitto drag radials) so anything under that really doesn't matter much to me.
-Mindgame
Thread Starter
Registered User
Joined: Feb 2002
Posts: 1,534
From: Lousiana
Anyone care to comment on what my compression ratio will be with these heads. I am getting a 0.010 mill and I believe Llyod told me my chambers would be 1 or 2 cc smaller than stock. This is what I have come up with so far. Don't know how correct the valve relief is. I am guessing 7cc. I used this calc page to get these numbers. http://www.gafba.com/calculators/cmpratio.asp?mode=ntr
Bore Size: 4"
Piston Size: 3.999"
Stroke: 3.48"
Deck Height: 0.02"
Piston Ring Land: 0.3"
Piston Dome/Dish: 7 cc
Head Gasket Bore: 4.125"
Head Gasket Height: 0.039"
Cylinder Head Volume: 52 cc
Cylinder Volume: 716.602 cc
Gasket Volume: 8.541 cc
Deck Volume: 4.118 cc
Total Volume: 788.292 cc
Engine Displacement: 349.84 cid
Compression Ratio: 11:1
Does that look to be correct?? That's with the felpro 1074 gasket btw.
Thanks for the input guys
Jeff D.
Bore Size: 4"
Piston Size: 3.999"
Stroke: 3.48"
Deck Height: 0.02"
Piston Ring Land: 0.3"
Piston Dome/Dish: 7 cc
Head Gasket Bore: 4.125"
Head Gasket Height: 0.039"
Cylinder Head Volume: 52 cc
Cylinder Volume: 716.602 cc
Gasket Volume: 8.541 cc
Deck Volume: 4.118 cc
Total Volume: 788.292 cc
Engine Displacement: 349.84 cid
Compression Ratio: 11:1
Does that look to be correct?? That's with the felpro 1074 gasket btw.
Thanks for the input guys
Jeff D.
Last edited by PoorMan; Jun 6, 2003 at 10:23 PM.
Registered User
Joined: Dec 2001
Posts: 180
From: Texas
Originally posted by EvlViln
MINDGAME!!!!!!
15 Degree Aluminum Heads
What is this all about? What exactly does this do for you?
MINDGAME!!!!!!
15 Degree Aluminum Heads
What is this all about? What exactly does this do for you?
Hopefully he will chime in, but as far as what 15* heads will do, ask someone with an ls1.
If you need further indication , look at Mindgame's rwhp and tourque.
Ls1's have awsome 15 degree heads, and Mindgames heads seem to be better than those. His heads are probably in the range of C5R heads, which are I think basically LS1 Racing heads.
That's one of the good things about lt1's , they are basically just Small block chevy, and you can use or adapt many of the "delicious" parts to them. On my next rebuild, I possibly may look into getting some smaller port 18 or 15* degree heads converted . It would be nice to have 450 +rwhp with a little bitty 22x cam. LOL. I think their was talk on one of these fbody boards of a guy that put SB 2.2 's on his lt1.
If he doesn't chime back in , maybe Phil, Mr. hp, or some of the other guys can let you know why. I don't know as much as those guys , but could tell you quite a bit regarding the benefits if they don't chime in. But to get a hint of what it will do for you, again, just look at his numbers .
I have not even seen a 434 Ls1 stroker put down that much a the wheels yet On ALL MOTOR. (Not saying there are none, but I just have not seen that much power yet at the wheels from a Naturally aspirated Ls1. And they are making some good numbers.
Last edited by Rpm280; Jun 7, 2003 at 11:04 PM.
Registered User
Joined: Jul 2001
Posts: 1,887
From: Kingsport, TN
Originally posted by Rpm280
That's one of the good things about lt1's , they are basically just Small block chevy, and you can use or adapt many of the "delicious" parts such as heads and intakes to them.
That's one of the good things about lt1's , they are basically just Small block chevy, and you can use or adapt many of the "delicious" parts such as heads and intakes to them.
Last edited by Loadre; Jun 7, 2003 at 11:32 PM.
Registered User
Joined: Oct 2000
Posts: 786
From: Charlotte, NC
Originally posted by Loadre
This statement is completely invalid.
This statement is completely invalid.
Can you convert stuff? Sure.. that's what the guy said.. you can adapt them. If everyone could afford setups like Herr 'Game however, you'd see more of them methinks... people whine about spending under $2k on a set of heads - you probably don't want to know what something a little wilder costs by the time you make the rest of the setup work with it :). Provided you're dealing with someone decent, you get what you pay for. Hopefully people will eventually realize that :)