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In line with some recent threads discussing smaller cams and "milder" combinations... http://www1.ls1tech.com/forums/showt...=625715&page=1 I thought it would be appropriate to share with you guys information pertaining to a recent 403 LS2 build I was involved in with just that philosophy.... It started back in last August....just another phone call with a potential customer discussing AFR heads and his wanting to build an engine that really placed on emphasis on usable power, but something that would also make enough grunt to propel his 4000 lb GTO to a respectable time slip when he and his wife occasionally take it to the track. Fast foward five months....Roy decides to allow me to build his GTO dream engine with the goals being set forth mandating a combination that had "stock like" perfect driving manners (his wife drives it more than him) and a powercurve that has tons of usable torque and really focus's on area under the curve. Roy was looking for huge grunt in the lower and middle part of his powercurve....the area which accounts for most of your driving conditions....not just WOT. Peak HP would actually be secondary (no dyno queen with this combination), but I had a hunch with the right selection of parts and completely optimizing every component and clearance in the build, making good power would still be possible. I told Roy going in that with a very optimized build and the 402/403 CID we had already agreed on building that I was hoping for an engine that would ultimately produce close to 550 ft/lbs, generate at least 500 of that at an early RPM where it could be appreciated every day, and hopefully knock down close to 575 HP at the same time. Also, like some of you, Roy had overcammed a few of his other projects and he was adament on not doing the same here which obviously makes producing a big HP number a lot more challenging. A "smoother" idle was also the order of the day. Here's a quick rundown of the parts (and a few extra machining op's) which helped us achieve the numbers we did... LS2 Block honed .005 oversize with TQ plate and ARP head studs (hence the 403 CID displacment....not a 402) Premium rotating assembly which consisted of a Dragon Slayer Callies Crank, Callies Comp Star rods, and Diamond pistons (which were also hard-coated as well). ATI Harmonic Balancer Painstaking time spent on shortblock clearances including bearings, piston to wall, ring end gaps, cylinder wall finish, etc., etc. I bring this up because it will have an outcome on the total power produced. Static CR was kept at only 11.25 to 1 with a quench distance of .031 (pistons .010 out of the hole.....041 thick Felpro Head gaskets). Ported GM Hi Perf Oil pump Comp Custom ground cam 232 / 232 on a 114 LSA +1 (113 ICL) GM Cadillac Racing lifters set to .100 pre-load. AFR 205 Heads with reworked chambers to take advantage of the larger bore and light porting on intake and exhaust (minimal increase in cross section). Killer "area under the curve" gains with the mods performed allowing alot more average air to enter the cylinder on each gulp....especially useful at higher RPM's when the engine has only a tiny fraction of a second to fill the cylinders....none of the airspeed was reduced, in fact increased due to all the additional airflow passing thru essentially the same size hole....a very lethal combination. I have included the actual flow number down below the dyno charts. FAST 90 ported as well as a ported NW billet TB Yella Terra "Ultra-lite" shaft rockers 1.7 ratio QTP 1.75 headers which made the same power and ten more ft/lbs of TQ over a conventional dyno header at 3000 RPM's. That covers some of the quick basics....I'm sure a few more facts and figures may find its way to you over the course of the thread. We dyno'ed this engine a little over a week ago at the same facility (Westech) I have tested all of my personal engine builds you guys are familiar with (the 346 and more recently my solid roller 383). Needless to say we were all very pleased with the results.... The engine idled almost stock like at 850 RPM where it was producing about 14.5" of engine vacuum. What I thought would be a light lope was barely audible....(in hindsight I might have bumped the cam a couple of degrees....the engine was even smoother than I expected). The curve was about as pretty as I could have hoped and looked like this.... http://www.lifeinwidescreen.com/siih... Graph (2).jpg Here is all the data in chart form where it is easier to see at a glance the TQ and power this engine produced... http://www.lifeinwidescreen.com/siihp/Raw%20Data.jpg And here is the flow information from the reworked 205's....again noting that most of the serious work was performed in the chambers and the rest of it assuring that the ports perfectly copied the prototype there were copied from. http://www.lifeinwidescreen.com/siih...ow Figures.JPG Last but not least a quick video of some of the last few pulls we made with this engine....the original video was a little clearer but due to keeping the vid a reasonable file size its a bit compressed. If your computer has a small subwoofer you may note the engine idling smooth in the background between the two pulls you see featured.... Enjoy! http://www.youtube.com/watch?v=OHXJx5MXlIk Look foward to seeing the actual results in Roy's GTO.....unfortunately its an A4 car so we wont see any hero numbers on the chassis dyno but you can rest assure this car should run pretty well at the track....while I know Roy would have been thrilled to run low 12's on moter (about what his former combination ran on spray), I have a sneaking suspicion his car may crack into the 11's assuming decent traction at a reasonable D/A.... Catch you guys later.... Tony Mamo |
Sweet, Tony you outdo yourself everytime. Another proof bigger isn't always better. |
Damn that badass!! On a baby 232 cam too, awesome. That is one awesome torque curve. :drool: |
keep up the good work tony!! |
Originally Posted by Tony Mamo @ AFR http://www1.ls1tech.com/forums/showt...=625715&page=1 I thought it would be appropriate to share with you guys information pertaining to a recent 403 LS2 build I was involved in with just that philosophy.... It started back in last August....just another phone call with a potential customer discussing AFR heads and his wanting to build an engine that really placed on emphasis on usable power, but something that would also make enough grunt to propel his 4000 lb GTO to a respectable time slip when he and his wife occasionally take it to the track. Fast foward five months....Roy decides to allow me to build his GTO dream engine with the goals being set forth mandating a combination that had "stock like" perfect driving manners (his wife drives it more than him) and a powercurve that has tons of usable torque and really focus's on area under the curve. Roy was looking for huge grunt in the lower and middle part of his powercurve....the area which accounts for most of your driving conditions....not just WOT. Peak HP would actually be secondary (no dyno queen with this combination), but I had a hunch with the right selection of parts and completely optimizing every component and clearance in the build, making good power would still be possible. I told Roy going in that with a very optimized build and the 402/403 CID we had already agreed on building that I was hoping for an engine that would ultimately produce close to 550 ft/lbs, generate at least 500 of that at an early RPM where it could be appreciated every day, and hopefully knock down close to 575 HP at the same time. Also, like some of you, Roy had overcammed a few of his other projects and he was adament on not doing the same here which obviously makes producing a big HP number a lot more challenging. A "smoother" idle was also the order of the day. Here's a quick rundown of the parts (and a few extra machining op's) which helped us achieve the numbers we did... LS2 Block honed .005 oversize with TQ plate and ARP head studs (hence the 403 CID displacment....not a 402) Premium rotating assembly which consisted of a Dragon Slayer Callies Crank, Callies Comp Star rods, and Diamond pistons (which were also hard-coated as well). Painstaking time spent on shortblock clearances including bearings, piston to wall, ring end gaps, cylinder wall finish, etc., etc. I bring this up because it will have an outcome on the total power produced. Static CR was kept at only 11.25 to 1 with a quench distance of .031 (pistons .010 out of the hole.....041 thick Felpro Head gaskets). Ported GM Hi Perf Oil pump Comp Custom ground cam 232 / 232 on a 114 LSA +1 (113 ICL) GM Cadillac Racing lifters set to .100 pre-load. AFR 205 Heads with reworked chambers to take advantage of the larger bore and light porting on intake and exhaust (minimal increase in cross section). Killer "area under the curve" gains with the mods performed allowing alot more average air to enter the cylinder on each gulp....especially useful at higher RPM's when the engine has only a tiny fraction of a second to fill the cylinders....none of the airspeed was reduced, in fact increased due to all the additional airflow passing thru essentially the same size hole....a very lethal combination. I have included the actual flow number down below the dyno charts. FAST 90 ported as well as a ported NW billet TB Yella Terra "Ultra-lite" shaft rockers 1.7 ratio QTP 1.75 headers which made the same power and ten more ft/lbs of TQ over a conventional dyno header at 3000 RPM's. That covers some of the quick basics....I'm sure a few more facts and figures may find its way to you over the course of the thread. We dyno'ed this engine a little over a week ago at the same facility (Westech) I have tested all of my personal engine builds you guys are familiar with (the 346 and more recently my solid roller 383). Needless to say we were all very pleased with the results.... The engine idled almost stock like at 850 RPM where it was producing about 14.5" of engine vacuum. What I thought would be a light lope was barely audible....(in hindsight I might have bumped the cam a couple of degrees....the engine was even smoother than I expected). The curve was about as pretty as I could have hoped and looked like this.... http://www.lifeinwidescreen.com/siih... Graph (2).jpg Here is all the data in chart form where it is easier to see at a glance the TQ and power this engine produced... http://www.lifeinwidescreen.com/siihp/Raw%20Data.jpg And here is the flow information from the reworked 205's....again noting that most of the serious work was performed in the chambers and the rest of it assuring that the ports perfectly copied the prototype there were copied from. http://www.lifeinwidescreen.com/siih...ow Figures.JPG Last but not least a quick video of some of the last few pulls we made with this engine....the original video was a little clearer but due to keeping the vid a reasonable file size its a bit compressed. If your computer has a small subwoofer you may note the engine idling smooth in the background between the two pulls you see featured.... Enjoy! http://www.youtube.com/watch?v=OHXJx5MXlIk Look foward to seeing the actual results in Roy's GTO.....unfortunately its an A4 car so we wont see any hero numbers on the chassis dyno but you can rest assure this car should run pretty well at the track....while I know Roy would have been thrilled to run low 12's on moter (about what his former combination ran on spray), I have a sneaking suspicion his car may crack into the 11's assuming decent traction at a reasonable D/A.... Catch you guys later.... Tony Mamo |
Originally Posted by Tony Mamo @ AFR Comp Custom ground cam 232 / 232 on a 114 LSA +1 (113 ICL) Hammer |
Curious Tony,why you only do 300RPM\SEC pulls? Why are the A and B fuel numbers so different,is it due to how you are using the flow meters? |
Did I hear in the video that you guys were using 91 octane?! |
Originally Posted by Xtnct00WS6 Did I hear in the video that you guys were using 91 octane?! |
In no specific order.... The engine was designed to run on 91 octane, but 92 or 93 would be preferable assuming you knew you were going to the track or planned on racing it (Roy has 93 octane available to him in his area but I told him he would be wasting his money if 91 was available at the same pumps for less....again though, heading to the track or a cruise night you might be tempted to "play" the extra couple of points of octane certainly wouldn't hurt). 300 RPM per second pulls are what Westech and most dyno shops I have attended use to sweep their engines at....more data points per second to see the results/benfits of smaller changes and better repeatability. The fuel was different most likely due to the fact we used the factory "dead head" style fuel rails when we tested the engine. While on the subject, this engine was equipped with the "green top" 42 lb. Ford SVO injectors which I also run on my 383 engine. Cam lobes were from the XER lobe family which have personally had great luck with time and time again. The BSFC numbers this engine produced were spectacular IMO for a pump gas 11 to 1 type engine....they were .36-.40 for most of the sweep and only went into the .45 range when the A/F ratio went towards the fatter side. If this were my own engine I would have spent even more time fine tuning (such as leaning the A/F ratio at 6K plus) and probably would have left with a 600 number purely for bench racing and bragging rights but that wasn't what this dyno session was about....We went in hoping for 575/550 and cleared both handily....the owner can spend the extra time on the chassis dyno when the engine is actually installed in his vehicle. Time spent optimizing then would pay much greater dividends. Regarding "flow concerns", the curve from Roy's reworked 205 cc port was exceptional and the results back up that data....I could get into a lengthy discussion on our pholosophy on cylinder head design but this isnt the time or the place. Three things I will quickly mention....the heads "stalled" at .600 lift but did not back up.....the lift of the cam I chose and application mandated a head that was optimized from the crack of the valve to .600 lift (and benefited from the smaller runner design as well)....and put a manifold in front of a port that may back up at higher lifts and see what happens (delays or eliminates the port from backing up). I think that covers most of the questions asked....I will post a little more info later when I have more time. Cheers, Tony |
Tony, since the heads picked up a good amount from the hand porting, did you guys copy these heads and modify the CNC program for the 205s? |
Tony, Do you know what the DCR is on the motor? I'm building my motor for 91 octane as well and want to get a recomendation on the DCR. Also, what temp thermostat do you plan on running? |
Originally Posted by Quick Double Nickel Tony, Do you know what the DCR is on the motor? I'm building my motor for 91 octane as well and want to get a recomendation on the DCR. Also, what temp thermostat do you plan on running? Both those numbers fall in line for 91 octane use. Hammer |
I always enjoy reading your threads Tony...when the time comes for a new engine, I'll be looking to you for your expertise since I'll be wanting an engine that performs on the street, where my car has spent 100% of its life for the last 2.5 years (that was the last time I was at the track). On the note of street performance, how many miles would a setup like this be expected to last (assuming regular maintenance, checking valve springs, etc)? |
To achieve the same goals with a 427, would it be time to move to the 225s? And maybe step up the duration specs by 4 degrees? |
Excellent numbers from such a conservative setup. Did the emphasis on torque and street driven power play a role in selecting a symetric (no split duration) cam? |
Very impressive. Making that kind of power and torque with such a mild setup is a real accomplishment. Josh |
why do you show everything in STD correction when everyone else shows SAE? |
Originally Posted by Mr Drunken McWasted Tony, since the heads picked up a good amount from the hand porting, did you guys copy these heads and modify the CNC program for the 205s? AFR, what's the final port size of your massaged 205's. I thought you always said there was nothing to be gained by porting your ports?? How much is your complete top end package as it sit's on that engine? Ported AFR 205's and a Mamo ported Fast 90..... which valves are in the head? 592 STD hp on a engine dyno with zero intake or exhaust restrictions vs. longblock price... = not impressed. |
Originally Posted by Flow Wizard AFR, what's the final port size of your massaged 205's. I thought you always said there was nothing to be gained by porting your ports?? How much is your complete top end package as it sit's on that engine? Ported AFR 205's and a Mamo ported Fast 90..... which valves are in the head? 592 STD hp on a engine dyno with zero intake or exhaust restrictions vs. longblock price... = not impressed. |
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