RW dyno numbers: 370 CI LT4, AFR 210s, dry sump
07-02-2008, 11:29 AM
#1
Melting Slicks
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RW dyno numbers: 370 CI LT4, AFR 210s, dry sump
Finally!
As some of you know I've been working on gradually building up a new engine over the past year or so. It's finally done and just got the computer tuned yesterday. Here are the details:
Engine specs:
Shortblock
LT1 / 4 small block
bore: 4.03"
Stroke 3.625"
6.0" rods
Static compression 10.96:1
Hydraulic roller cam, specs at .05" lift:
Intake duration 230, .622 valve lift
Exhaust duration 236, .624 valve lift
Lobe separation: 112.0
Installed 108.0 intake center line
Caddy racing lifters
Oil system:
Johnson's 4 stage dry sump pump (3 sunction stages all in the pan)
Hamburgers 3 stage dry sump pan with extra scavenge fitting/tube added
custom oil tank
Canton oil thermostat and earls cooler
Intake:
Ported LT4
42lb injectors
58mm throttlebody
Heads:
AFR 210cc LT4 competition ported
Other:
Trans: ZF6
Clutch: Carolina stage 3
Exotic Muscle headers
Corsa exhaust with Carsound 3" Cats
Delteq ignition
Meziere Electric water pump
180* Thermostat
The motor was built for a combination of street and road racing (HPDEs). Shortblock built and cam selection by Midwest engine tech in Mokena, IL. top-end, dry sump, etc was done by me.
My HP goals were ~500HP at the crank (~425 RWHP). Overall I'm very pleased with the result, particularly given the 'unknowns' of the AFR Eliminator heads and the practicality of fitting a dry sump system into a street C4 while retaining all accessories (AC, cruise, traction control, etc). That being said, getting it all in there was a massive pain in the butt. Among many other things I had to fab up new solid motor mounts which move the motor 1/4" back to clear the drive mandrel and also clear the oil fittings on the passenger side. No frame or structural mods were made, though.
Here are the results:
RWHP Dyno graph:
Engine during assembly showing location of dry sump pump and drive mandrel (you can also see the tank pre-installation in the lower left:
Oil tank installed in factory battery location (battery is in the rear storage compartment):
Engine from driver's side:
Engine from passenger side:
Dry sump tank breather can and oil pump (it's down there somewhere):
Link to earlier thread with AFR head pics and flow numbers: http://forums.corvetteforum.com/show....php?t=1775117
Link to earlier thread with Engine dyno numbers: http://forums.corvetteforum.com/show....php?t=1990466
As some of you know I've been working on gradually building up a new engine over the past year or so. It's finally done and just got the computer tuned yesterday. Here are the details:
Engine specs:
Shortblock
LT1 / 4 small block
bore: 4.03"
Stroke 3.625"
6.0" rods
Static compression 10.96:1
Hydraulic roller cam, specs at .05" lift:
Intake duration 230, .622 valve lift
Exhaust duration 236, .624 valve lift
Lobe separation: 112.0
Installed 108.0 intake center line
Caddy racing lifters
Oil system:
Johnson's 4 stage dry sump pump (3 sunction stages all in the pan)
Hamburgers 3 stage dry sump pan with extra scavenge fitting/tube added
custom oil tank
Canton oil thermostat and earls cooler
Intake:
Ported LT4
42lb injectors
58mm throttlebody
Heads:
AFR 210cc LT4 competition ported
Other:
Trans: ZF6
Clutch: Carolina stage 3
Exotic Muscle headers
Corsa exhaust with Carsound 3" Cats
Delteq ignition
Meziere Electric water pump
180* Thermostat
The motor was built for a combination of street and road racing (HPDEs). Shortblock built and cam selection by Midwest engine tech in Mokena, IL. top-end, dry sump, etc was done by me.
My HP goals were ~500HP at the crank (~425 RWHP). Overall I'm very pleased with the result, particularly given the 'unknowns' of the AFR Eliminator heads and the practicality of fitting a dry sump system into a street C4 while retaining all accessories (AC, cruise, traction control, etc). That being said, getting it all in there was a massive pain in the butt. Among many other things I had to fab up new solid motor mounts which move the motor 1/4" back to clear the drive mandrel and also clear the oil fittings on the passenger side. No frame or structural mods were made, though.
Here are the results:
RWHP Dyno graph:
Engine during assembly showing location of dry sump pump and drive mandrel (you can also see the tank pre-installation in the lower left:
Oil tank installed in factory battery location (battery is in the rear storage compartment):
Engine from driver's side:
Engine from passenger side:
Dry sump tank breather can and oil pump (it's down there somewhere):
Link to earlier thread with AFR head pics and flow numbers: http://forums.corvetteforum.com/show....php?t=1775117
Link to earlier thread with Engine dyno numbers: http://forums.corvetteforum.com/show....php?t=1990466
07-02-2008, 12:11 PM
#2
Le Mans Master
Very nice! So about a 13% drivetrain loss, interesting. More loss than I expected but great #s.
Why not more compression since it's an LTx?
How does it drive around town on the street?
Why not more compression since it's an LTx?
How does it drive around town on the street?
07-02-2008, 12:11 PM
#3
Wow! Those are great numbers. Your car should really fly. Looks like the power may have been still climbing when the dyno was shut down. Your shift point should be around 7000rpm for the most power under the curve.
What pushrods did you use? I'm build a very similiar L98 motor with a 4.562 crank and 4.060" bore. Also using the AFR 195cc Competition heads.
What pushrods did you use? I'm build a very similiar L98 motor with a 4.562 crank and 4.060" bore. Also using the AFR 195cc Competition heads.
07-02-2008, 12:25 PM
#5
Team Owner
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Nicely done! 
You even got it down with the pump down low.
Most drysumps I've seen in C4's mount it up high.
EDIT
How far back did you move the engine?
Do you have drawings for the mounts? and/or re you willing to sell them?
How did moving the c-beam back effect the rest of the drivetrain.
You even got it down with the pump down low.
Most drysumps I've seen in C4's mount it up high.
EDIT
How far back did you move the engine?
Do you have drawings for the mounts? and/or re you willing to sell them?
How did moving the c-beam back effect the rest of the drivetrain.
Last edited by BrianCunningham; 07-02-2008 at 12:33 PM.
07-02-2008, 01:04 PM
#6
Melting Slicks
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Thanks guys! some quick responses to the questions:
So about a 13% drivetrain loss?: Unfortunately the engine dyno numbers were with open headers and a carb manifold, so hard to tell exactly what the true drivetrain loss was.
Why not more compression since it's an LTx? We went a little conservitave since it was built more for street and endurance (and in case of a tank of crap gas!)
How does it drive around town on the street? Pretty well -- the clutch took a little getting used to, but otherwise it's fine even with the AC on.
What pushrods did you use? Trickflow. After checking valvetrain geometry I ended up with 7.1" pushrods (as opposed to stock 7.2"
Did you consider using the Z06 GM version (oil tank) adn modifying it? I looked at it, but would have been a lot more work and cost. I actually started with an e-bay used coleman tank for the top, and fabbed a new bottom out of 1/8" aluminum to fit with the contour of the frame. Fortunately a friend of mine is an awesome TIG welder so that saved me a ton of $ By the way, it holds slightly over 2 gallons, but you need to leave the top ~1/2 gal empty. With all the lines, filter, etc total system oil capacity is at about 2.5 gal.
How far back did you move the engine? 1/4"
Do you have drawings for the mounts? and/or re you willing to sell them? I can easily make up drawings -- they're very simple. My brother was contemplating selling some (he welded the mounts for me), but we also don't want the potential legal baggage that goes along with that (getting sued over a broken mount, etc.) -- maybe a good business venture with Gary...
How did moving the c-beam back effect the rest of the drivetrain. basically shifted everything back 1/4 inch. Since the poly bushings on the diff have a small bit of flex to them, it was enough to absorb the difference. Couldn't go any more than that though without causing problems. The only pain that it added was more because of the solid mounts themselves: tilting the motor back to install the trans was hard since you can't tilt it as much.
So about a 13% drivetrain loss?: Unfortunately the engine dyno numbers were with open headers and a carb manifold, so hard to tell exactly what the true drivetrain loss was.
Why not more compression since it's an LTx? We went a little conservitave since it was built more for street and endurance (and in case of a tank of crap gas!)
How does it drive around town on the street? Pretty well -- the clutch took a little getting used to, but otherwise it's fine even with the AC on.
What pushrods did you use? Trickflow. After checking valvetrain geometry I ended up with 7.1" pushrods (as opposed to stock 7.2"
Did you consider using the Z06 GM version (oil tank) adn modifying it? I looked at it, but would have been a lot more work and cost. I actually started with an e-bay used coleman tank for the top, and fabbed a new bottom out of 1/8" aluminum to fit with the contour of the frame. Fortunately a friend of mine is an awesome TIG welder so that saved me a ton of $ By the way, it holds slightly over 2 gallons, but you need to leave the top ~1/2 gal empty. With all the lines, filter, etc total system oil capacity is at about 2.5 gal.
How far back did you move the engine? 1/4"
Do you have drawings for the mounts? and/or re you willing to sell them? I can easily make up drawings -- they're very simple. My brother was contemplating selling some (he welded the mounts for me), but we also don't want the potential legal baggage that goes along with that (getting sued over a broken mount, etc.) -- maybe a good business venture with Gary...
How did moving the c-beam back effect the rest of the drivetrain. basically shifted everything back 1/4 inch. Since the poly bushings on the diff have a small bit of flex to them, it was enough to absorb the difference. Couldn't go any more than that though without causing problems. The only pain that it added was more because of the solid mounts themselves: tilting the motor back to install the trans was hard since you can't tilt it as much.
Last edited by MarkBychowski; 07-02-2008 at 01:06 PM.
07-03-2008, 01:42 AM
#10
Melting Slicks
Wow, very nice. Tons of power, and the dry sump is especially impressive.
Are these the AFR ported heads, or did you send them somewhere else to get ported? Do you have any actual flow number from this set? This is one of the first setups I've seen dynoed with the new Eliminator stuff.
Are these the AFR ported heads, or did you send them somewhere else to get ported? Do you have any actual flow number from this set? This is one of the first setups I've seen dynoed with the new Eliminator stuff.
07-03-2008, 08:34 AM
#11
Drifting
Man ... got scary close on that SIm model, didn't we? 
Thanks for posting your final results, nice to see and compare them
http://forums.corvetteforum.com/show....php?t=1792878
Thanks for posting your final results, nice to see and compare them
http://forums.corvetteforum.com/show....php?t=1792878
07-03-2008, 09:42 AM
#12
Melting Slicks
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Thanks guys!
Mojave: They were ported by AFR. It's their "Competition porting" option -- basically a little better CNC program then the "race ported" option. The only thing I did to them was a tiny bit of gasket matching at the top of the intake ports to match my intake. I did have them flowed (on page 2 or 3 of this post: http://forums.corvetteforum.com/show....php?t=1775117 ).
The interesting thing was that both the engine builder (who selected the cam to match these heads) as well as the tuning shop were both very surprised at how much power it made. The dry sump is likely contributing some HP due to windage reduction and crankcase vacuum, but I'd guess the heads are the biggest piece.
I must admit I'm particularly proud of the dry sump since there aren't many C4's with them. The only other C4's I've seen with them are dedicated race cars. It was one of those things that I honestly didn't need, but seemed like a cool project.
SuperL98: Yea that is pretty amazing! Thanks for superimposing the two graphs -- that really helps! You've been a great help along the way, thanks very much for your time and expertise!
Mojave: They were ported by AFR. It's their "Competition porting" option -- basically a little better CNC program then the "race ported" option. The only thing I did to them was a tiny bit of gasket matching at the top of the intake ports to match my intake. I did have them flowed (on page 2 or 3 of this post: http://forums.corvetteforum.com/show....php?t=1775117 ).
The interesting thing was that both the engine builder (who selected the cam to match these heads) as well as the tuning shop were both very surprised at how much power it made. The dry sump is likely contributing some HP due to windage reduction and crankcase vacuum, but I'd guess the heads are the biggest piece.
I must admit I'm particularly proud of the dry sump since there aren't many C4's with them. The only other C4's I've seen with them are dedicated race cars. It was one of those things that I honestly didn't need, but seemed like a cool project.
SuperL98: Yea that is pretty amazing! Thanks for superimposing the two graphs -- that really helps! You've been a great help along the way, thanks very much for your time and expertise!
Last edited by MarkBychowski; 07-03-2008 at 11:09 AM.
07-03-2008, 02:38 PM
#15
Safety Car
Mark
I ran your combination on my Engine Analyzer, which is about the best engine dyno sim you can buy.
Using the combo you dynod with the dual plane intake and carb the estimations came within 3hp and 1ftlb tq. The hp curve is biased about 700rpm high but the tq cure is dead on what your motor actually made.
When I use the LT1 intake it is clear that the dual plane intake was hurting you above 5000rpm and killing you above 6000rpm (Your peak HP was down about 40-45hp). Also the power curves match up very close to your actual RWHP dyno.
I believe in your current EFI configuaration you most likely have in the 570-580HP at the crank. Putting your drive train loss at a more realistic 16%-18%.
Will
I ran your combination on my Engine Analyzer, which is about the best engine dyno sim you can buy.
Using the combo you dynod with the dual plane intake and carb the estimations came within 3hp and 1ftlb tq. The hp curve is biased about 700rpm high but the tq cure is dead on what your motor actually made.
When I use the LT1 intake it is clear that the dual plane intake was hurting you above 5000rpm and killing you above 6000rpm (Your peak HP was down about 40-45hp). Also the power curves match up very close to your actual RWHP dyno.
I believe in your current EFI configuaration you most likely have in the 570-580HP at the crank. Putting your drive train loss at a more realistic 16%-18%.
Will
07-03-2008, 03:03 PM
#16
Safety Car
Impressive Numbers !! Was matching the heads with the intake much of a problem? WHen I spoke to Tony I just couldn't get reassurance that matching the heads with my LT4 Intake would work. Just seemed odd that heads listed as LT4 heads wouldnt even mate up to an LT4 manifold. I ended up going with porting the LT4s again. I like the combo tho ! Mine is very similar although theres no dry sump which is pretty trick indeed !
07-03-2008, 03:46 PM
#17
Melting Slicks
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EA is pretty impressive! That definitely explains the low range of the power curve with the carb manifold. I was hoping they'd rev it higher just to see how much it dropped off (or if I hit valve float).
It was actually pretty easy to do the gasket matching on the heads. My LT4 intake was already ported to the 777 LT4 intake gasket. The bottom and sides of the gasket matched up perfectly to the AFR heads. I just had to remove a small 'step' from the heads on the top of the intake ports. I just blended it back about an inch (per guidance from by builder). Both heads only took me maybe 2 hours total. The biggest pain was cleaning them up again to get rid of the metal shavings.
I'm curious to see how yours turns out. I was really on the fence between getting the stock heads ported or going with these. Seems like either way you can't lose.
It was actually pretty easy to do the gasket matching on the heads. My LT4 intake was already ported to the 777 LT4 intake gasket. The bottom and sides of the gasket matched up perfectly to the AFR heads. I just had to remove a small 'step' from the heads on the top of the intake ports. I just blended it back about an inch (per guidance from by builder). Both heads only took me maybe 2 hours total. The biggest pain was cleaning them up again to get rid of the metal shavings.
I'm curious to see how yours turns out. I was really on the fence between getting the stock heads ported or going with these. Seems like either way you can't lose.
07-03-2008, 05:09 PM
#18
Burning Brakes
wow!! thats the highest hp from a streetable 383 LTx i've seen from a hyd.roller cam!
I have made a 11 to 1 ported HSR 383 using 195cc heads and similar cam with similar lift and LSA. I hope to make 420whp or so. I would love to see more tho, your motor kinda gives me hope
I have made a 11 to 1 ported HSR 383 using 195cc heads and similar cam with similar lift and LSA. I hope to make 420whp or so. I would love to see more tho, your motor kinda gives me hope
07-03-2008, 06:02 PM
#19
Safety Car
wow!! thats the highest hp from a streetable 383 LTx i've seen from a hyd.roller cam!
I have made a 11 to 1 ported HSR 383 using 195cc heads and similar cam with similar lift and LSA. I hope to make 420whp or so. I would love to see more tho, your motor kinda gives me hope
I have made a 11 to 1 ported HSR 383 using 195cc heads and similar cam with similar lift and LSA. I hope to make 420whp or so. I would love to see more tho, your motor kinda gives me hope
His isn't even a 383. His crank is only a 3 9/16" stroke, for a 370 inch engine.
I agree the HP is impressive.
Will