Stock LT1 heads flowed (chart)
Thread Starter
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Stock LT1 heads flowed (chart)
Brian Cunninghams heads freshly soda blasted and flowed...
Very similar to the #s pulled off the web, never hurts to double check it.
Heads and intake will be ported and the flowed (again) seaprately and together. Just for reference. Odd intake port shape.....
Ive seen #s printed out here but no charts yet, just curious.
Very similar to the #s pulled off the web, never hurts to double check it.
Heads and intake will be ported and the flowed (again) seaprately and together. Just for reference. Odd intake port shape.....
Ive seen #s printed out here but no charts yet, just curious.
Last edited by cv67; Dec 5, 2007 at 03:16 PM.
Team Owner
Joined: Mar 2001
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From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Thanks for getting that done, man they cleaned up nice 
This will both end of lot of debates, and start many more.
peaked at .400 lift!
Makes you wonder about putting big rockers on stock heads.
This will both end of lot of debates, and start many more.
peaked at .400 lift!
Makes you wonder about putting big rockers on stock heads.
Advanced
Joined: Jul 2004
Posts: 83
Likes: 0
From: Orlando Fl
Great info... Could you post the Casting # ...
The later heads flow about 5-10% more according to Lloyd Elliott.
However, the earlier castings have more meat for an all out port job, hence the requirement for an earlier casting with either Advanced Induction or LE.
The later heads flow about 5-10% more according to Lloyd Elliott.
However, the earlier castings have more meat for an all out port job, hence the requirement for an earlier casting with either Advanced Induction or LE.
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Had one intake and one exhaust flowed just to see where things were headed. Keep in mind each port is still in need of more work, chambers are untouched with an 80k mile vavle job on them.
Still plenty of room for improvement. Gotta say the exaust ports suck on these head out of the gate.
Intake
Exhaust (on left)
Tony Mamo at AFR was kind enough to spend some time on our lo-budget drone build and put them on the bench. Due to time constraints I didnt have timr to get these "done", but does give an idea of where wer'e at and what needs more attention.
The same port that was flowed before unported was flowed only this time it was done with a fixture in the intake to mimic a perfect entry (such as a ported intake
), and flowing the exhaust with a pipe. interesting to see the difference..
Below is the first shops results without those two items and the top line of the intake/exhaust on the AFR sheet also shows the same ports flowed with these differences. This is why having heads flowed at two different places can have 2 different results..Weve all seen these threads that result in flame wars, heres why.
+1 cfm @.200
Here is Tony in action
Wanted to thank Tony again for his time with our stuff.
-The Sheepster
Still plenty of room for improvement. Gotta say the exaust ports suck on these head out of the gate.
Intake
Exhaust (on left)
Tony Mamo at AFR was kind enough to spend some time on our lo-budget drone build and put them on the bench. Due to time constraints I didnt have timr to get these "done", but does give an idea of where wer'e at and what needs more attention.
The same port that was flowed before unported was flowed only this time it was done with a fixture in the intake to mimic a perfect entry (such as a ported intake
), and flowing the exhaust with a pipe. interesting to see the difference..Below is the first shops results without those two items and the top line of the intake/exhaust on the AFR sheet also shows the same ports flowed with these differences. This is why having heads flowed at two different places can have 2 different results..Weve all seen these threads that result in flame wars, heres why.
+1 cfm @.200
Here is Tony in action
Wanted to thank Tony again for his time with our stuff.
-The Sheepster
Last edited by cv67; Dec 21, 2007 at 08:32 PM.
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Safety Car
Joined: Apr 2003
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From: VA
These do peak sooner than the other stock flow numbers I've seen, but why would it make you wonder about big lift? This flow sheet shows what we already know from real world results - that stock unported LT1 heads will support a lot more lift than the stock cam+rockers provide.
Drifting
Joined: Feb 2003
Posts: 1,978
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From: San Antonio Texas
and, that while the stock port flows 215 @.400, it flows 211 from around .380 on up to at least .550. So, with whatever cam duration you have, the port will be flowing nearly at its max, for more of that avaliable time.
Thread Starter
Team Owner
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From: altered state
St. Jude Donor '05
More pics to come next week, betting the intake is now on its way to 270 and exhaust surpassing the 190 mark, still on stock valve size. We will see. Goal is to keep the intake runner as small as possible while acheiving this, not easy. Time, time, and more time. 
Le Mans Master
Joined: Oct 2004
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From: CLT, North Carolina
Look at the valve seats. The throat cut and how it is blended might respond to a change and show an increase. The port is peaking too soon, it should be capable of more flow than that. The drop after the peak at .400 was because the port is developing turbulance in the area of the valve seat. Rocker ratio increases lift under the curve and rate of acceleration of the valve off the seat. Comparing lifts at the valve with a degree wheel on the c/shaft will show increases everywhere not just peak lift.
Melting Slicks
Joined: Jul 2004
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From: Chicago Illinois
Port velocity is important to keep that low end grunt.
Thread Starter
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
I may wind up giving some up to get the bigger #s. Honestly I feel that whats there already is good enough for a mild 350 on the street.
Havent had tiem to mess with them lately, went to plan B. More to come...
Racer
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From: San Antonio Texas
Team Owner
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From: eville in
Race Director
Joined: Jan 2008
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From: oregon
same numbers almost to the T as the 113 casting. After some cartrage rolls, better valves {still stock size} i was able to get a set of 113s up to 231@.500 and 190@.500, mid lift gained similar percentages of +15-20% Probably had 8-10 hours in the set. The neat thing about 1.94/1.50 valves is they rev a few hundred rpm higher than 2.02 1.60s with the same spring. Those heads cleaned up great, did you ever consider tinkering out in your shop to pick up the flow? basic porting isn't as hard to learn as some people will have you think.
Burning Brakes
Joined: Oct 2001
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So i guess skipping the 1.6 rockers and getting a cam with more duration would be a wiser choice? less valvetrain movement = better/cheaper high rpm ability?
Drifting
Joined: Feb 2003
Posts: 1,978
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From: San Antonio Texas
383s and bigger strokers can rev plenty high. 8-8500 if you've got the parts, and a good balance, to support it. If you're talking about 15-18000 then you might want a 2" or smaller stroke crank.
