951 Engine build porn - Sunday fun
08-23-2015, 07:35 PM
#1
Drifting
Thread Starter
951 Engine build **** - Sunday fun
Went over to Sean's to assist/see his 2.5 build progress. My assistance consisted "today" of opening a few beers.
The TIAL engine/turbo mount in the pictures is the first prototype developed by Sean/TIAL for the Garrett Turbo setup for our cars. The new compressor is a TIAL housing with a GTX 3076. The pistons are Mahle with Swain coatings, and the block is one over/NiCom - Nikasil bores. Mahle started making these turbo pistons again recently, with rings for the NiCom - Nikasil bores.
Head was ported, and valves will be stock 951 exhaust with 48mm intake. The crank is bull nosed and balanced.
Jealous he powder coated his sump! Makes clean up much easier, but who's looking under skirts here anyway.
G
The TIAL engine/turbo mount in the pictures is the first prototype developed by Sean/TIAL for the Garrett Turbo setup for our cars. The new compressor is a TIAL housing with a GTX 3076. The pistons are Mahle with Swain coatings, and the block is one over/NiCom - Nikasil bores. Mahle started making these turbo pistons again recently, with rings for the NiCom - Nikasil bores.
Head was ported, and valves will be stock 951 exhaust with 48mm intake. The crank is bull nosed and balanced.
Jealous he powder coated his sump! Makes clean up much easier, but who's looking under skirts here anyway.
G
08-24-2015, 12:24 AM
#3
Drifting
Thread Starter
Unfortunately enough to force a Cometic, otherwise be close to 9.2 CR, which I'm OK with, but this car is running piggy back software tied into OE Motronic. The thickness of the gasket will keep the CR close to stock.
His car is well sorted. Hoot to drive.
His car is well sorted. Hoot to drive.
08-24-2015, 04:19 AM
#5
Drifting
Thread Starter
Hey Pauly, OT: Killer work shared in PM. Neat talent...
Nope, we get killer power from OE cams. Especially the NA versions with intake to exhaust valve sizing as close to 85% as possible. Exhaust valves are stock. Cam is N/A/hydraulic.
I'm running a N/A 968 hydraulic cam, knowing I have options.
Nope, we get killer power from OE cams. Especially the NA versions with intake to exhaust valve sizing as close to 85% as possible. Exhaust valves are stock. Cam is N/A/hydraulic.
I'm running a N/A 968 hydraulic cam, knowing I have options.
08-24-2015, 04:55 AM
#6
Drifting
Thread Starter
Prior to hitting the sack, got a call from the guy "friend" that purchased my old 89 951. He chose, against my sincere "NO" to run an aggressive cam with solid lifters in his 3.0. Couldn't wrap his head around how I pull him. Must be my turbo, efficient intercooler, etc. Yeah, maybe, but his TQ delivery is not the same as mine, I get on boost sooner, and his 8000 rpm solid lifter capability with matching cam, in a motor that has to shift by fuel cut/7000 rpm.
Without the ability to run to 8K, using solid lifters and cams designed to max output beyond the motor's range is - counter productive.
Good Copy/Paste Read:
Curtis Boggs of Race Flow Development says, "We build a [supercharged engine] head as efficiently as we can based on a normally aspirated engine. Usually bigger valves don't help, but sometimes a bigger exhaust port can help a little bit." He adds, "Flow bench numbers can't duplicate what happens in the real world." Instead, Boggs looks at port efficiency and shape, the size of the port, and its ability to evacuate the cylinder. "I'm listening to the port, to make sure it's not turbulent, measuring with a nanometer. The E/I ratio is only good for the cam guy." As for specific race classes, the guys who run 10.5-inch slick or drag radial cars with turbos or blowers don't need to worry. "It's a case of mechanical force (the piston) forcing mixture out of the port. My turbo cylinder heads are exactly like my NA heads. On a turbo engine, you build the most efficient engine you can, then add the turbos."
Interestingly, turbo engine builder Ken Duttweiler sometimes specs a smaller (than standard for the engine) exhaust valve on maximum-effort engines. The exhaust valve is opening into a pressure zone, so in this case it's mainly a matter of durability.
There may be one instance where a larger exhaust port could be of benefit: the huge Roots blower in professional racing on alcohol-fueled engines making more than 2,500 hp. Running on alcohol with a 16-71 supercharger in Pro Mod or Top Alcohol, "requires a lot of exhaust port," Boggs says. "But again, there's not a hard-and-fast rule. We look at valve size versus cross-sectional area, port area, throat area, and area under the valve job. Airspeed and port efficiency make horsepower, not just cfm."
Read more: http://www.hotrod.com/how-to/additio...#ixzz3jiT3pxJe
Follow us: @HotRodMagazine on Twitter | HotRodMag on Facebook
Without the ability to run to 8K, using solid lifters and cams designed to max output beyond the motor's range is - counter productive.
Good Copy/Paste Read:
Curtis Boggs of Race Flow Development says, "We build a [supercharged engine] head as efficiently as we can based on a normally aspirated engine. Usually bigger valves don't help, but sometimes a bigger exhaust port can help a little bit." He adds, "Flow bench numbers can't duplicate what happens in the real world." Instead, Boggs looks at port efficiency and shape, the size of the port, and its ability to evacuate the cylinder. "I'm listening to the port, to make sure it's not turbulent, measuring with a nanometer. The E/I ratio is only good for the cam guy." As for specific race classes, the guys who run 10.5-inch slick or drag radial cars with turbos or blowers don't need to worry. "It's a case of mechanical force (the piston) forcing mixture out of the port. My turbo cylinder heads are exactly like my NA heads. On a turbo engine, you build the most efficient engine you can, then add the turbos."
Interestingly, turbo engine builder Ken Duttweiler sometimes specs a smaller (than standard for the engine) exhaust valve on maximum-effort engines. The exhaust valve is opening into a pressure zone, so in this case it's mainly a matter of durability.
There may be one instance where a larger exhaust port could be of benefit: the huge Roots blower in professional racing on alcohol-fueled engines making more than 2,500 hp. Running on alcohol with a 16-71 supercharger in Pro Mod or Top Alcohol, "requires a lot of exhaust port," Boggs says. "But again, there's not a hard-and-fast rule. We look at valve size versus cross-sectional area, port area, throat area, and area under the valve job. Airspeed and port efficiency make horsepower, not just cfm."
Read more: http://www.hotrod.com/how-to/additio...#ixzz3jiT3pxJe
Follow us: @HotRodMagazine on Twitter | HotRodMag on Facebook