434 CID Engine Dyno results w/ AFR 245's
06-24-2011, 02:18 PM
#1
434 CID Engine Dyno results w/ AFR 245's Guys,
Been busy or I would have posted and shared this with all of you alot sooner.
I recently built a 434 for a customer/friend of mine who recently grenaded (in grand fashion!) an OEM short 346 he ran for years with an AFR heads/cam package I helped him with a loooong time ago (AFR 205's, G5X3 cam, Mamo ported 90 mm FAST/LS2 TB, LG Pro longtubes, etc). His 346 ran awesome (485 RWHP/440RWTQ) but when it finally expired John was in the market for something bigger and badder.
We first discussed building a 416 LS3 block combination which I have had a lot of good success with lately but one thing leads to the next and we decided to go a little bigger when I mentioned I had a Darton wet-sleeve LS6 block under my workbench just begging for a new home!
Wanting to keep the pistons better supported at the bottom of the bore for the extended WOT this combination will see in Johns road-race C5 (he also does high speed closed highway events like the Nevada Silver State), we decided to run a 4" stroke and a 4.155 bore netting us the 434 cube powerplant that we ultimately settled on.
I kept the build only moderately aggressive knowing our main focus was to build low and midrange torque and John didn't want to spin the engine over 7K....I tried to spec the cam and valve events hoping for a power peak to occur around 64-6500 and I was hoping the large heads would help carry the power well past peak with a slow roll off. I hate when big motors just run into a wall upstairs...you need alot of airflow to keep them hanging on....especially with a moderate sized cam. Ultimately the actual results presented us with a power curve only down 19 HP off its peak even at 7000 RPM so we were pleased.
Truthfully....if I were drag racing this combo and the curve on the chassis dyno looks the same or similar, I would probably shift it closer to 7200 to take advantage of the most average power thru all four gears (best utilizing the crest of the power curve). However, one of the big perks about a combination like this is it wont really matter where you shift it....LOL It has explosive torque and HP at almost any RPM and should really be a handful compared to what John was accustomed to with his 346. Even at 3500 RPM's this engine produces 50+ more ft/lbs of torque than his stout 346 produced at its peak....his car is going to be traction challenged for sure!
The engine is only 11.6 to 1, and has a 247/251 cam which I also installed advanced to bring the power curve in sooner. Had this been mainly a street car that saw some occasional drag racing I would have installed the cam a little bit later swapping some low speed torque for high RPM power.
And low speed torque is where this package really shined IMO....we rolled into the throttle at 3500 RPM and it was already producing 535 ft/lbs of torque or so exploding higher from there as it climbed towards its peak of 600 at about 5400 but it carried 590+ from 4700 to 5800 (within 10 ft/lbs of its highest output).
At the end of the day, peak power hit 678 HP with a fairly broad curve and the engine sounded great with dare I say a reasonably tame idle considering the fury this thing was capable of producing at WOT. I kept the LSA of the cam on the wide side to improve idle quality and drivability as this car will also see a fair amount of street time as well....its not a dedicated race car.
Here is a graph of the power curve and the word that comes to mind is FAT....gotta love a big motor with a really good set of heads.....the combination of the two is killer!
Also, here is a video from the day we tested it at Westech....
Don't mind the guy screaming during the pull (what an idiot!). It was a fun day and I was a little excited we just finally hit the 600 ft/lb mark which had been eluding us for hours (a tease of sorts in the mid/high 590's all day once the tune got close). This was our last pull and I had a sneaking suspicion the engine would respond to being a little leaner (the A/F ratio was slightly conservative in the mid/high 12's most of the day) so we took a little fuel out and gave it a whirl). This was the best and last run of the day.....don't mind John the stone face owner.....if you look closely he is grinning ear to ear inside and his wife knows it!!
(Just click on this screenshot....and you can view this video full screen btw....it's HD and quite clear)
Note this engine is just about ready to fire in John's C5 and I expect in the next three weeks or so we might have an opportunity to get it on the chassis dyno and see how she does. I will update this thread with those results when I get them.....perhaps an idle clip as well if we get the chance.
My personal engine is finally on deck (a 454 CID combo)....I plan on pushing things a little further with that power plant trying to exploit the AFR 245's a little more, yet still focusing on maintaining a very streetable reasonably docile combination (I have to enjoy driving it around town).....also still employing a hydraulic roller which is nice (no maintenance). Should have that engine on Westech's dyno in a month or so.....I will keep you guys posted.
Cheers,
Tony
Been busy or I would have posted and shared this with all of you alot sooner.
I recently built a 434 for a customer/friend of mine who recently grenaded (in grand fashion!) an OEM short 346 he ran for years with an AFR heads/cam package I helped him with a loooong time ago (AFR 205's, G5X3 cam, Mamo ported 90 mm FAST/LS2 TB, LG Pro longtubes, etc). His 346 ran awesome (485 RWHP/440RWTQ) but when it finally expired John was in the market for something bigger and badder.
We first discussed building a 416 LS3 block combination which I have had a lot of good success with lately but one thing leads to the next and we decided to go a little bigger when I mentioned I had a Darton wet-sleeve LS6 block under my workbench just begging for a new home!
Wanting to keep the pistons better supported at the bottom of the bore for the extended WOT this combination will see in Johns road-race C5 (he also does high speed closed highway events like the Nevada Silver State), we decided to run a 4" stroke and a 4.155 bore netting us the 434 cube powerplant that we ultimately settled on.
I kept the build only moderately aggressive knowing our main focus was to build low and midrange torque and John didn't want to spin the engine over 7K....I tried to spec the cam and valve events hoping for a power peak to occur around 64-6500 and I was hoping the large heads would help carry the power well past peak with a slow roll off. I hate when big motors just run into a wall upstairs...you need alot of airflow to keep them hanging on....especially with a moderate sized cam. Ultimately the actual results presented us with a power curve only down 19 HP off its peak even at 7000 RPM so we were pleased.
Truthfully....if I were drag racing this combo and the curve on the chassis dyno looks the same or similar, I would probably shift it closer to 7200 to take advantage of the most average power thru all four gears (best utilizing the crest of the power curve). However, one of the big perks about a combination like this is it wont really matter where you shift it....LOL It has explosive torque and HP at almost any RPM and should really be a handful compared to what John was accustomed to with his 346. Even at 3500 RPM's this engine produces 50+ more ft/lbs of torque than his stout 346 produced at its peak....his car is going to be traction challenged for sure!
The engine is only 11.6 to 1, and has a 247/251 cam which I also installed advanced to bring the power curve in sooner. Had this been mainly a street car that saw some occasional drag racing I would have installed the cam a little bit later swapping some low speed torque for high RPM power.
And low speed torque is where this package really shined IMO....we rolled into the throttle at 3500 RPM and it was already producing 535 ft/lbs of torque or so exploding higher from there as it climbed towards its peak of 600 at about 5400 but it carried 590+ from 4700 to 5800 (within 10 ft/lbs of its highest output).
At the end of the day, peak power hit 678 HP with a fairly broad curve and the engine sounded great with dare I say a reasonably tame idle considering the fury this thing was capable of producing at WOT. I kept the LSA of the cam on the wide side to improve idle quality and drivability as this car will also see a fair amount of street time as well....its not a dedicated race car.
Here is a graph of the power curve and the word that comes to mind is FAT....gotta love a big motor with a really good set of heads.....the combination of the two is killer!
Also, here is a video from the day we tested it at Westech....
Don't mind the guy screaming during the pull (what an idiot!). It was a fun day and I was a little excited we just finally hit the 600 ft/lb mark which had been eluding us for hours (a tease of sorts in the mid/high 590's all day once the tune got close). This was our last pull and I had a sneaking suspicion the engine would respond to being a little leaner (the A/F ratio was slightly conservative in the mid/high 12's most of the day) so we took a little fuel out and gave it a whirl). This was the best and last run of the day.....don't mind John the stone face owner.....if you look closely he is grinning ear to ear inside and his wife knows it!!
(Just click on this screenshot....and you can view this video full screen btw....it's HD and quite clear)
Note this engine is just about ready to fire in John's C5 and I expect in the next three weeks or so we might have an opportunity to get it on the chassis dyno and see how she does. I will update this thread with those results when I get them.....perhaps an idle clip as well if we get the chance.
My personal engine is finally on deck (a 454 CID combo)....I plan on pushing things a little further with that power plant trying to exploit the AFR 245's a little more, yet still focusing on maintaining a very streetable reasonably docile combination (I have to enjoy driving it around town).....also still employing a hydraulic roller which is nice (no maintenance). Should have that engine on Westech's dyno in a month or so.....I will keep you guys posted.
Cheers,
Tony
Last edited by Tony Mamo @ AFR; 06-24-2011 at 06:29 PM.
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06-27-2011, 01:12 PM
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Hey Tony,
I have a 500CId in the works, actually sitting in a crate in my living room haha.
Looking for some heads, I'm not going all out. this still has to be a daily driver when needed. What potential do your 245s have on this type of CI's, obviously with one of your ported 102's. Car will be an auto.
Thanks,
I have a 500CId in the works, actually sitting in a crate in my living room haha.
Looking for some heads, I'm not going all out. this still has to be a daily driver when needed. What potential do your 245s have on this type of CI's, obviously with one of your ported 102's. Car will be an auto.
Thanks,
06-29-2011, 12:29 AM
#14
Hey Tony,
I have a 500CId in the works, actually sitting in a crate in my living room haha.
Looking for some heads, I'm not going all out. this still has to be a daily driver when needed. What potential do your 245s have on this type of CI's, obviously with one of your ported 102's. Car will be an auto.
Thanks,
I have a 500CId in the works, actually sitting in a crate in my living room haha.
Looking for some heads, I'm not going all out. this still has to be a daily driver when needed. What potential do your 245s have on this type of CI's, obviously with one of your ported 102's. Car will be an auto.
Thanks,
Low speed part throttle torque would probably bring giggles from the manliest of men.....LOL
Seriously....it would feel retarded down low like the car was 1000 lbs lighter and pull extremely strong all thru the middle of the curve with a reasonably strong top end charge as well peaking earlier than a typical LS combo (around 6K or so)....shiftpoints around 6500. It would feel like a boosted motor with ALOT more response on the bottom where boosted motors are always really soggy off boost.
Camshaft would be key in dialing in this combo properly....it would take more duration than you might think and not hurt the bottom with the high speed ports and long runner FAST intake. I would spec a custom cam for you if you took the plunge on the heads. In fact you should PM me....I have a set I did for a project that flow almost 370 CFM (I did extra handwork, lightweight intake valves, special valvejob, etc.). The customer's financial situation changed and he pulled the plug. We can discuss it more in a PM if your interested.
Cheers,
Tony
Last edited by Tony Mamo @ AFR; 06-29-2011 at 01:01 AM.
06-29-2011, 10:58 PM
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They would work excellent....especially for a daily driver. The engine would feel 50 CID larger with a high flowing cathedral head and a properly ported FAST 102.
Low speed part throttle torque would probably bring giggles from the manliest of men.....LOL
Seriously....it would feel retarded down low like the car was 1000 lbs lighter and pull extremely strong all thru the middle of the curve with a reasonably strong top end charge as well peaking earlier than a typical LS combo (around 6K or so)....shiftpoints around 6500. It would feel like a boosted motor with ALOT more response on the bottom where boosted motors are always really soggy off boost.
Camshaft would be key in dialing in this combo properly....it would take more duration than you might think and not hurt the bottom with the high speed ports and long runner FAST intake. I would spec a custom cam for you if you took the plunge on the heads. In fact you should PM me....I have a set I did for a project that flow almost 370 CFM (I did extra handwork, lightweight intake valves, special valvejob, etc.). The customer's financial situation changed and he pulled the plug. We can discuss it more in a PM if your interested.
Cheers,
Tony
Low speed part throttle torque would probably bring giggles from the manliest of men.....LOL
Seriously....it would feel retarded down low like the car was 1000 lbs lighter and pull extremely strong all thru the middle of the curve with a reasonably strong top end charge as well peaking earlier than a typical LS combo (around 6K or so)....shiftpoints around 6500. It would feel like a boosted motor with ALOT more response on the bottom where boosted motors are always really soggy off boost.
Camshaft would be key in dialing in this combo properly....it would take more duration than you might think and not hurt the bottom with the high speed ports and long runner FAST intake. I would spec a custom cam for you if you took the plunge on the heads. In fact you should PM me....I have a set I did for a project that flow almost 370 CFM (I did extra handwork, lightweight intake valves, special valvejob, etc.). The customer's financial situation changed and he pulled the plug. We can discuss it more in a PM if your interested.
Cheers,
Tony
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07-01-2011, 10:27 PM
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Nice results Tony! With your combos it's hard to argue in favor of going FI for street motors, especially when traction will be hard to come by on a handling oriented suspension. That torque curve is very close to a typical ported Eaton 03 Cobra. 
I didn't see anything, but did you hand finish the heads and intake (assuming a 102)?
Jason
I didn't see anything, but did you hand finish the heads and intake (assuming a 102)?
Jason
07-08-2011, 05:20 PM
#20
Nice results Tony! With your combos it's hard to argue in favor of going FI for street motors, especially when traction will be hard to come by on a handling oriented suspension. That torque curve is very close to a typical ported Eaton 03 Cobra.
I didn't see anything, but did you hand finish the heads and intake (assuming a 102)?
Jason
I didn't see anything, but did you hand finish the heads and intake (assuming a 102)?
Jason
Regarding the heads I did slightly modify them with the addition of lighter hollow stem intake valves (90 grams versus 120 grams....a huge weight savings in valvetrain terms) and a slightly different valvejob to optimize the custom valves I installed. I did see a slight bump in flow from the additional work (about 5-7 CFM), but IMO the larger benefit of the change was the much lighter valve enabling the smooth perfect power curve to 7000 RPM (looks more like a solid roller curve than a typical hydraulic). Perfect valve control is worth more power than a few CFM of additional head flow but clearly both helped this combo put up a solid number.
Also, the lighter valves also helps to extend valve spring life....bonus in applications that see extended high RPM running which this combination will.
Obviously extremely well.....365 CFM of high speed air coupled with an extremely efficient exhaust port is a recipe for success. I bet you could see close to four digits at the wheel at less than 12 PSI. Think about it....this engine is making close to 700 normally aspirated....with a reasonably efficient turbo set-up it would be a cinch to add 50% to the power output of this engine at moderate boost levels.
Cheers,
Tony