LT1-383/LLoyd Elliot Heads/XFI280/Bryan Herter Dyno Results
Thread Starter
Registered User
Joined: Dec 2004
Posts: 827
From: Philly, Pa
Awesome guys... thank you very much, i contacted the engine builder and he pretty much doesnt want to do the job unless i remove the heads and give it to them. :/ i know they just dont want to deal with it. So i will get that tool. i installed these springs with the spring compression grip tool mentioned above, and it made me never want to look at valve springs again. hah.
Does anyone know of the airhose fitting khojo mentioned?
lloyd recomended these springs....
as a "drop in" with my current retainers/locks & locators
Howards, Max Effort Mech. Roller Valve Springs, Dual
O.D.: 1.437
I.D.: .800
Description: Dual
Seat Pressure: 175 @ 1.750
Open Pressure: 400 @ 1.150
Rate: 375
Coil Bind: 1.050
Max. Lift: .625
Does anyone know of the airhose fitting khojo mentioned?
lloyd recomended these springs....
as a "drop in" with my current retainers/locks & locators
Howards, Max Effort Mech. Roller Valve Springs, Dual
O.D.: 1.437
I.D.: .800
Description: Dual
Seat Pressure: 175 @ 1.750
Open Pressure: 400 @ 1.150
Rate: 375
Coil Bind: 1.050
Max. Lift: .625
Last edited by CreatiVe2; Mar 25, 2009 at 07:15 PM. Reason: spelling
Registered User
Joined: Aug 2005
Posts: 4,405
From: Kantuckee Yo'
Awesome guys... thank you very much, i contacted the engine builder and he pretty much doesnt want to do the job unless i remove the heads and give it to them. :/ i know they just dont want to deal with it. So i will get that tool. i installed these springs with the spring compression grip tool mentioned above, and it made me never want to look at valve springs again. hah.
Does anyone know of the airhose fitting khojo mentioned?
lloyd recomended these springs....
as a "drop in" with my current retainers/locks & locators
Howards, Max Effort Mech. Roller Valve Springs, Dual
O.D.: 1.437
I.D.: .800
Description: Dual
Seat Pressure: 175 @ 1.750
Open Pressure: 400 @ 1.150
Rate: 375
Coil Bind: 1.050
Max. Lift: .625
Does anyone know of the airhose fitting khojo mentioned?
lloyd recomended these springs....
as a "drop in" with my current retainers/locks & locators
Howards, Max Effort Mech. Roller Valve Springs, Dual
O.D.: 1.437
I.D.: .800
Description: Dual
Seat Pressure: 175 @ 1.750
Open Pressure: 400 @ 1.150
Rate: 375
Coil Bind: 1.050
Max. Lift: .625
You do NOT need the air tool and you do NOT need to pressurize the cylinders. If the piston is at TDC or very close to it, the piston will NOT fall down unless you have holes in your pistons.
Registered User
Joined: Aug 2005
Posts: 4,405
From: Kantuckee Yo'
why does he need to bring the piston to TDC for the one he's working on? woudnt a line from an air compressor in the place of the spark plug work just as well??? it holds the valves up in place so you cant drop them...i dunno maybe im missing something, so please correct me if im wrong before i make this mistake if i change out my springs on the car as well...
Registered User
Joined: Nov 2005
Posts: 459
From: Stratford, NJ
lol ok, just making sure i wasn't crazy and that was a way to do it...something just doesnt sit right with me to crank the engine a little to get each piston at TDC, but that may be the easiest way to do it...anyway, if i do change my springs, im pulling the heads and having my intake runners opened up anyway, so ill do the work on my bench at home
thanks for the confirmation tho
thanks for the confirmation tho
Registered User
Joined: Dec 2003
Posts: 2,724
From: Oklahoma where trees are made of wood.
Sometimes the valve seals arent tight enough to hold the valve up, much less if you touch it, But I use the tool mentioned and it saves massive amounts of time easy under the cowl, and lets you do 2 at once.
Registered User
Joined: Nov 2005
Posts: 459
From: Stratford, NJ
both intakes were port matched to the heads, so on my setup, the intake is match to my 180cc intake runners, whereas on Creative2's setup, his intake is port matched to his 200cc intake runners...
looks like its time for a set of AFR 227's for me :-P haha
looks like its time for a set of AFR 227's for me :-P haha
Registered User
Joined: Aug 2005
Posts: 4,405
From: Kantuckee Yo'
lol ok, just making sure i wasn't crazy and that was a way to do it...something just doesnt sit right with me to crank the engine a little to get each piston at TDC, but that may be the easiest way to do it...anyway, if i do change my springs, im pulling the heads and having my intake runners opened up anyway, so ill do the work on my bench at home
thanks for the confirmation tho
thanks for the confirmation tho
The valve would have to drop several inches down and completely clear the guide to actually become dislodged and fall into the cylinder. Just not likely to happen unless you are super careless or drunk and stupid.
Negative on the "eating" horsepower. When one spring is being forced closed, another is being forced open so they are canceling each other out. With a roller cam, even the increased friction from heavier springs are nill. The only negative thing from super heavy springs might be accelerated cam wear assuming its a cast cam and not a billet or the lifter not remaining fully pumped up under high RPM AKA bleed-off.
Last edited by wrd1972; Mar 26, 2009 at 02:14 PM.
Registered User
Joined: Feb 2004
Posts: 948
From: Stroudsburg, PA
I didnt read all the replies on here but my car was running an XFI 242* intake lobe with PAC1518s flawlessly. it held power all the way to 7000 rpm. they were installed at 130 lbs too. possibly another valve spring option for you to look in to.
Registered User
Joined: Aug 2004
Posts: 334
Well, i've been waiting for a while to get the new 383 motor tuned, and let me just say. It was well worth the wait. Some interesting combination results came from this 1 on 1 tune with bryan.
My cousin had the EXACT same bottom end built (forged bottom end-eagle/eagle 383/pistons/rods/XFI280 cam/ etc...) He had the machine shop that assembled the engine, port his heads. They did a good job, and got them to flow 280cfm intake 195 cfm exhaust.
I however had a different set Ported by LLoyd Elliot, these were an older port job, before he had "le1, le2, and le3" packages. My intake flows 265 and exhaust 192, and heres the kicker...
My results
427hp/421tq
http://img22.imageshack.us/img22/972...3dynochart.jpg
My cousin made 401hp/411tq with a peak @ 5,800rpm
He pulled first and then i pulled second.
Bryan Herter also though he should have had more HP, but he squeezed every last bit of power out of his car (he was on the dyno longer than i was)
The Reasoning: Bryan asked where my cousin had his heads ported, and he had told them as a local machine shop, who normally builds drag SBC/BBC motors, and not Many LT1's.
He then said that Lloyds head cuts put a spiral flow on the air which increases the velocity in the (rather small) runner size. "and in the end it always comes down to the head"
So, moral of the story....
Lloyd Elliot
Edit: -Dyno chart posted below to compare engine #'s
-Doing rough math there is a 7-8% increase on my #'s across the board.
My cousin had the EXACT same bottom end built (forged bottom end-eagle/eagle 383/pistons/rods/XFI280 cam/ etc...) He had the machine shop that assembled the engine, port his heads. They did a good job, and got them to flow 280cfm intake 195 cfm exhaust.
I however had a different set Ported by LLoyd Elliot, these were an older port job, before he had "le1, le2, and le3" packages. My intake flows 265 and exhaust 192, and heres the kicker...
My results
427hp/421tq
http://img22.imageshack.us/img22/972...3dynochart.jpg
My cousin made 401hp/411tq with a peak @ 5,800rpm
He pulled first and then i pulled second.
Bryan Herter also though he should have had more HP, but he squeezed every last bit of power out of his car (he was on the dyno longer than i was)
The Reasoning: Bryan asked where my cousin had his heads ported, and he had told them as a local machine shop, who normally builds drag SBC/BBC motors, and not Many LT1's.
He then said that Lloyds head cuts put a spiral flow on the air which increases the velocity in the (rather small) runner size. "and in the end it always comes down to the head"
So, moral of the story....
Lloyd ElliotEdit: -Dyno chart posted below to compare engine #'s
-Doing rough math there is a 7-8% increase on my #'s across the board.
i have the xfi 292 with pretty much the same everything else you have. what size rods did you go with? oh and i'm also running a blower, so i,m interested in what im making. i need to get to bryans shop soon for a dyno tune, do you remember whats he charging right now? ohh i dont know what rockers you are running, but i have promags and i'm running patriots no problem.
Registered User
Joined: Feb 2003
Posts: 2,639
From: Mooresville, NC
Negative on the "eating" horsepower. When one spring is being forced closed, another is being forced open so they are canceling each other out. With a roller cam, even the increased friction from heavier springs are nill. The only negative thing from super heavy springs might be accelerated cam wear assuming its a cast cam and not a billet or the lifter not remaining fully pumped up under high RPM AKA bleed-off.
Registered User
Joined: Aug 2005
Posts: 4,405
From: Kantuckee Yo'
Fair enough. I will backup my statement with evidence.
I dynoed (same day too) on a local dyno with PSI LS1 beehives that had a tad less seat pressure than the 1218's but a bit more pressure over the nose. Still had float. Installed Manley beehives that were 25# mores seat and ~50# more over the nose. Clearly a much stronger spring.
The setup with the manley beehives eliminated the float completely and the rest of the torque/power numbers ALL the way up the scale were exactly the same within 1%.
So that comparision was with a spring lighter than a 1218 and one much heavier than 1218 and there was no "eating of horsepower" that I could verify. Just gotta disagree with ya.
I dynoed (same day too) on a local dyno with PSI LS1 beehives that had a tad less seat pressure than the 1218's but a bit more pressure over the nose. Still had float. Installed Manley beehives that were 25# mores seat and ~50# more over the nose. Clearly a much stronger spring.
The setup with the manley beehives eliminated the float completely and the rest of the torque/power numbers ALL the way up the scale were exactly the same within 1%.
So that comparision was with a spring lighter than a 1218 and one much heavier than 1218 and there was no "eating of horsepower" that I could verify. Just gotta disagree with ya.