Balancing (please step inside)
Thread Starter
Drifting
Joined: Jun 2001
Posts: 1,625
Likes: 1
From: Zagreb, Croatia
Actually, I'm building two engines. First one will be very soon,
and it'll be stock crank but with forged SCAT rods and forged .020"
over SRP pistons. It'll be more less engine in my sig, but with new rods
and pistons, and probably a little bit "more" cam.
Second engine will be much more complex. It'll be all forged 383
that'll have to rev to 7500, and this engine MUST be machined to
perfection.
I plan to visit this locl shop, and talk a little bit more with owner.
First impression was really good, but as you suggested, I'll try
to make sure that he knows exactly what he's doing.
Thank you very much for your input and suggestions, they're
much appriciated!
and it'll be stock crank but with forged SCAT rods and forged .020"
over SRP pistons. It'll be more less engine in my sig, but with new rods
and pistons, and probably a little bit "more" cam.
Second engine will be much more complex. It'll be all forged 383
that'll have to rev to 7500, and this engine MUST be machined to
perfection.
I plan to visit this locl shop, and talk a little bit more with owner.
First impression was really good, but as you suggested, I'll try
to make sure that he knows exactly what he's doing.
Thank you very much for your input and suggestions, they're
much appriciated!
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
At 7,500 RPM, piston speeds for two variations
of 383 ci displacements are as follows:
4.30 x 3.75: 4,688 feet per minute
4.00 x 3.80: 4,750 Ft/min
Consider where these Ft/min numbers place you in4.00 x 3.80: 4,750 Ft/min
relation to the following company (hint: between
#8-9 and #7-8, respectively):
... the LS1 & LS6 rotating assemblies are similar, but not the same.
New, higher strength connecting rod bolts were introduced on the LS6 and
these contributed to the LS6's 500 RPM increase in redline (6,500 for the
LS6 versus 6,000 for the LS1.) These rod bolts are available as p/n #12568069
to retrofit LS1 rods (an LSx buildup intended for sustained piston speeds
at and above those at the OEM redline would perhaps benefit from rod
bolts (& rods) from the aftermarket.)
The LS1, LS6, LS2 and LS3 all share a stroke of 92.0 mm (3.62").
The first iteration LS1 has a redline of 6,000. This results in piston speeds
of 3622 FPM which are in line with the speeds of the previous gen
1996 LT4 - it has a stroke of 3.48" and a redline of 6,300 - good for
3,654 FPM.
Like the LS6, the LS2 and LS3 also have a redline of 6,500. This results in
piston speeds of 3924 FPM, high for a production engine by traditional standards
but increasingly mundane in modern terms.
By comparison, the LS7 has a stroke of 101.6mm (4.00") and a redline of 7,000.
This results in piston speeds of 4,666 FPM - exceptional for a production
7.0 L (427 ci) engine covered by a 5yr/100k powertrain warranty.
Here is where the LS7 slots in amongst engines with some of the highest piston
speeds. When the displacement, configuration and production levels of the other
engines is considered, this makes the redline of the LS7 all the more remarkable
to me.
New, higher strength connecting rod bolts were introduced on the LS6 and
these contributed to the LS6's 500 RPM increase in redline (6,500 for the
LS6 versus 6,000 for the LS1.) These rod bolts are available as p/n #12568069
to retrofit LS1 rods (an LSx buildup intended for sustained piston speeds
at and above those at the OEM redline would perhaps benefit from rod
bolts (& rods) from the aftermarket.)
The LS1, LS6, LS2 and LS3 all share a stroke of 92.0 mm (3.62").
The first iteration LS1 has a redline of 6,000. This results in piston speeds
of 3622 FPM which are in line with the speeds of the previous gen
1996 LT4 - it has a stroke of 3.48" and a redline of 6,300 - good for
3,654 FPM.
Like the LS6, the LS2 and LS3 also have a redline of 6,500. This results in
piston speeds of 3924 FPM, high for a production engine by traditional standards
but increasingly mundane in modern terms.
By comparison, the LS7 has a stroke of 101.6mm (4.00") and a redline of 7,000.
This results in piston speeds of 4,666 FPM - exceptional for a production
7.0 L (427 ci) engine covered by a 5yr/100k powertrain warranty.
Here is where the LS7 slots in amongst engines with some of the highest piston
speeds. When the displacement, configuration and production levels of the other
engines is considered, this makes the redline of the LS7 all the more remarkable
to me.
1. Scuderia Torro Rosso Ferrari STR2 F1 (2.4L V8)
Engine Code: Ferrari Type 056
Bore/Stroke: 3.8583" x 1.565" (98 mm x 39.751 mm)
Redline: 19800rpm (Educated guess)
Piston Speed: 5165 Ft/min
2. Chevrolet NASCAR 358 (5.86L V8)
Engine Code: R07
Bore/Stroke: 4.185" X 3.25"
Redline: 9400rpm (Educated guess)
Piston Speed: 5092 Ft/min
3. Honda S2000: (2.0L I4)
Engine Code: F20C1
Bore/Stroke: 3.43" X 3.31"
Redline: 9000rpm
Piston Speed: 4965 Ft/min
4. Lamborghini Gallardo (5.0L V10)
Engine Code: N/A
Bore/Stroke: 3.25" X 3.65"
Redline: 8000rpm
Piston Speed: 4866.67 Ft/min
5. Acura Integra Type R (1.8L I4)
Engine Code: B18C5
Bore/Stroke: 3.19" X 3.43"
Redline: 8400rpm
Piston Speed: 4802 Ft/min
6. BMW M3 (Germany) (3.3L I6)
Engine Code: S54
Bore/Stroke: 3.43" X 3.58"
Redline: 8000rpm
Piston Speed: 4773.33 Ft/min
7. Honda S2000 2004 (2.0L I4)
Engine Code: F22C
Bore/Stroke: 3.43" X 3.57"
Redline: 8000rpm
Piston Speed: 4760 Ft/min
8. Honda Integra Type R (JDM - 2.0L I4)
Engine Code: K20A
Bore/Stroke: 3.39" X 3.39"
Redline: 8400rpm
Piston Speed: 4746 Ft/min
9. Acura Integra GSR 2001 (1.8L I4)
Engine Code: B18C
Bore/Stroke: 3.19" X 3.43"
Redline: 8200rpm
Piston Speed: 4687.67 Ft/min
10. Corvette Z06 (7.0L V8)
Engine Code: LS7
Bore/Stroke: 4.125" X 4.00" (104.8 mm x 101.6 mm)
Redline: 7000rpm
Piston Speed: 4666.67 Ft/min
11. Katech Street Attack LS7 (7.0L V8)
Engine Code: KAT-A4730
Bore/Stroke: 4.125" X 4.00" (104.8 mm x 101.6 mm)
Redline: 7000rpm (*)
Piston Speed: 4666.67 Ft/min
Engine Code: N/A
Bore/Stroke: 4.125" X 4.00"
Redline: 7000rpm
Piston Speed: 4666.67 Ft/min
13. Acura TSX (2.4L I4)
Engine Code: K24A2
Bore/Stroke: 3.43" X 3.90"
Redline: 7100rpm
Piston Speed: 4615 Ft/min
14. Suzuki Hayabusa Sport Prototype (1.3L I4)
Engine Code: W701
Bore/Stroke: 3.19" X 2.48"
Redline: 11000rpm
Piston Speed: 4546.67 Ft/min
15. Honda Civic Type R (1.6L I4)
Engine Code: B16B
Bore/Stroke: 3.19" X 3.03"
Redline: 9000rpm
Piston Speed: 4545 Ft/min
16. Toyota Celica GTS / Matrix XRS 2001 (1.8L I4)
Engine Code: 2ZZ-GE
Bore/Stroke: 3.23" X 3.35"
Redline: 8100rpm
Piston Speed: 4522.5 Ft/min
17. Honda Prelude Type S (JDM - 2.2L I4)
Engine Code: H22A
Bore/Stroke: 3.43" X 3.57"
Redline: 7500rpm
Piston Speed: 4462.5 Ft/min
18. Acura RSX Type S (2.0L I4)
Engine Code: K20A2
Bore/Stroke: 3.38" X 3.38"
Redline: 7900rpm
Piston Speed: 4450.33 Ft/min
19. Ferrari 360 Modena (incl. Challenge, Stradale, etc) (5.4L V12)
Engine Code: N/A
Bore/Stroke: 3.35" X 3.11"
Redline: 8500rpm
Piston Speed: 4405.83 Ft/min
20. Katech Sneak Attack LS7 (5.7L V8)
Engine Code: KAT-A4725
Bore/Stroke: 4.125" X 3.268" (104.8 mm x 83.01 mm)
Redline: 8000rpm (Advertised)
Piston Speed: 4357.33 Ft/min
21. Lamborghini Murcielago (6.2L V12)
Engine Code: N/A
Bore/Stroke: 3.43" X 3.42"
Redline: 7600rpm
Piston Speed: 4332 Ft/min
22. McLaren F1 (6.1L V12)
Engine Code: BMW S70/2
Bore/Stroke: 3.386" X 3.425"
Redline: 7500rpm
Piston Speed: 4287.5 Ft/min
23. Renault Clio 2.0 RS 2003 (2.0L I4)
Engine Code: F4R
Bore/Stroke: 3.26" X 3.66"
Redline: 7000rpm
Piston Speed: 4270 Ft/min
24. Porsche 911 GT3 RS 2004 (3.6L H6)
Engine Code: N/A
Bore/Stroke: 3.94" X 3.01"
Redline: 8500rpm
Piston Speed: 4264.17 Ft/min
.Engine Code: Ferrari Type 056
Bore/Stroke: 3.8583" x 1.565" (98 mm x 39.751 mm)
Redline: 19800rpm (Educated guess)
Piston Speed: 5165 Ft/min
2. Chevrolet NASCAR 358 (5.86L V8)
Engine Code: R07
Bore/Stroke: 4.185" X 3.25"
Redline: 9400rpm (Educated guess)
Piston Speed: 5092 Ft/min
3. Honda S2000: (2.0L I4)
Engine Code: F20C1
Bore/Stroke: 3.43" X 3.31"
Redline: 9000rpm
Piston Speed: 4965 Ft/min
4. Lamborghini Gallardo (5.0L V10)
Engine Code: N/A
Bore/Stroke: 3.25" X 3.65"
Redline: 8000rpm
Piston Speed: 4866.67 Ft/min
5. Acura Integra Type R (1.8L I4)
Engine Code: B18C5
Bore/Stroke: 3.19" X 3.43"
Redline: 8400rpm
Piston Speed: 4802 Ft/min
6. BMW M3 (Germany) (3.3L I6)
Engine Code: S54
Bore/Stroke: 3.43" X 3.58"
Redline: 8000rpm
Piston Speed: 4773.33 Ft/min
7. Honda S2000 2004 (2.0L I4)
Engine Code: F22C
Bore/Stroke: 3.43" X 3.57"
Redline: 8000rpm
Piston Speed: 4760 Ft/min
8. Honda Integra Type R (JDM - 2.0L I4)
Engine Code: K20A
Bore/Stroke: 3.39" X 3.39"
Redline: 8400rpm
Piston Speed: 4746 Ft/min
9. Acura Integra GSR 2001 (1.8L I4)
Engine Code: B18C
Bore/Stroke: 3.19" X 3.43"
Redline: 8200rpm
Piston Speed: 4687.67 Ft/min
10. Corvette Z06 (7.0L V8)
Engine Code: LS7
Bore/Stroke: 4.125" X 4.00" (104.8 mm x 101.6 mm)
Redline: 7000rpm
Piston Speed: 4666.67 Ft/min
11. Katech Street Attack LS7 (7.0L V8)
Engine Code: KAT-A4730
Bore/Stroke: 4.125" X 4.00" (104.8 mm x 101.6 mm)
Redline: 7000rpm (*)
Piston Speed: 4666.67 Ft/min
(*) Katech does not advertise a max RPM for the Street Attack
LS7 on their site. My figure of 7,000 is based on the max engine
speed recorded in a dyno test of an engine with what may have
been the "Torquer LS7" camshaft, conducted 12 mo ago.
Based on the RPM at which max HP/TQ occured, there was no
need to run to, let alone exceed 7,000 during the dyno run.
12. Saleen S7 (7.0L V8) LS7 on their site. My figure of 7,000 is based on the max engine
speed recorded in a dyno test of an engine with what may have
been the "Torquer LS7" camshaft, conducted 12 mo ago.
Based on the RPM at which max HP/TQ occured, there was no
need to run to, let alone exceed 7,000 during the dyno run.
Engine Code: N/A
Bore/Stroke: 4.125" X 4.00"
Redline: 7000rpm
Piston Speed: 4666.67 Ft/min
13. Acura TSX (2.4L I4)
Engine Code: K24A2
Bore/Stroke: 3.43" X 3.90"
Redline: 7100rpm
Piston Speed: 4615 Ft/min
14. Suzuki Hayabusa Sport Prototype (1.3L I4)
Engine Code: W701
Bore/Stroke: 3.19" X 2.48"
Redline: 11000rpm
Piston Speed: 4546.67 Ft/min
15. Honda Civic Type R (1.6L I4)
Engine Code: B16B
Bore/Stroke: 3.19" X 3.03"
Redline: 9000rpm
Piston Speed: 4545 Ft/min
16. Toyota Celica GTS / Matrix XRS 2001 (1.8L I4)
Engine Code: 2ZZ-GE
Bore/Stroke: 3.23" X 3.35"
Redline: 8100rpm
Piston Speed: 4522.5 Ft/min
17. Honda Prelude Type S (JDM - 2.2L I4)
Engine Code: H22A
Bore/Stroke: 3.43" X 3.57"
Redline: 7500rpm
Piston Speed: 4462.5 Ft/min
18. Acura RSX Type S (2.0L I4)
Engine Code: K20A2
Bore/Stroke: 3.38" X 3.38"
Redline: 7900rpm
Piston Speed: 4450.33 Ft/min
19. Ferrari 360 Modena (incl. Challenge, Stradale, etc) (5.4L V12)
Engine Code: N/A
Bore/Stroke: 3.35" X 3.11"
Redline: 8500rpm
Piston Speed: 4405.83 Ft/min
20. Katech Sneak Attack LS7 (5.7L V8)
Engine Code: KAT-A4725
Bore/Stroke: 4.125" X 3.268" (104.8 mm x 83.01 mm)
Redline: 8000rpm (Advertised)
Piston Speed: 4357.33 Ft/min
21. Lamborghini Murcielago (6.2L V12)
Engine Code: N/A
Bore/Stroke: 3.43" X 3.42"
Redline: 7600rpm
Piston Speed: 4332 Ft/min
22. McLaren F1 (6.1L V12)
Engine Code: BMW S70/2
Bore/Stroke: 3.386" X 3.425"
Redline: 7500rpm
Piston Speed: 4287.5 Ft/min
23. Renault Clio 2.0 RS 2003 (2.0L I4)
Engine Code: F4R
Bore/Stroke: 3.26" X 3.66"
Redline: 7000rpm
Piston Speed: 4270 Ft/min
24. Porsche 911 GT3 RS 2004 (3.6L H6)
Engine Code: N/A
Bore/Stroke: 3.94" X 3.01"
Redline: 8500rpm
Piston Speed: 4264.17 Ft/min
Thread Starter
Drifting
Joined: Jun 2001
Posts: 1,625
Likes: 1
From: Zagreb, Croatia
I see where you're aiming and I gave a lot of thought to it.
When I say 7500 rpm redline, I don't think that this revs are
sometning that this engine will see all of the time.
There are a lot of things to be considered here:
1. This is by no means my daily driver. Average milage is 3.5k/year.
2. This will be 50% street/ 50% strip (road race) driven car.
3. 7500 rpm redline will only be seen in 1st gear (I plan shifting
on 7200-7300 on other gears. With auto tranny, most of the time on
the track is in 2nd and 3rd gear.).
4. Peak power should be at ~6900rpm.
5. All internal parts will be best quality forged parts (I allready have
Callies Dragonslayer crank and Carrillo rods).
6. All valvetrain parts will also be best quality and lightest as
possible.
BTW., those are some good infos. Thanks.
When I say 7500 rpm redline, I don't think that this revs are
sometning that this engine will see all of the time.
There are a lot of things to be considered here:
1. This is by no means my daily driver. Average milage is 3.5k/year.
2. This will be 50% street/ 50% strip (road race) driven car.
3. 7500 rpm redline will only be seen in 1st gear (I plan shifting
on 7200-7300 on other gears. With auto tranny, most of the time on
the track is in 2nd and 3rd gear.).
4. Peak power should be at ~6900rpm.
5. All internal parts will be best quality forged parts (I allready have
Callies Dragonslayer crank and Carrillo rods).
6. All valvetrain parts will also be best quality and lightest as
possible.
BTW., those are some good infos. Thanks.
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Peak power at 6,900? Is this the point of peak torque or peak HP?
Piston speeds at 6,900 RPM
shift points for optimal acceleration? Peak engine HP? Peak engine
TQ? Peak transmission output TQ? Maximising area under the HP
curve?
Is the package being developed for use at a single circuit or for
several tracks with different gearing requirements?
On a separate, but related matter. A discussion in the following
thread may offer some insight into the preventative maintenance
cycle recommended for engines that will be operated at the upper
limits of component durability. See comments by "DLM 18" near
the end.
Piston speeds at 6,900 RPM
4.30 x 3.75: 4,310 feet per minute
4.00 x 3.80: 4,370 Ft/min
Which school of thought do you follow with regard to choosing4.00 x 3.80: 4,370 Ft/min
shift points for optimal acceleration? Peak engine HP? Peak engine
TQ? Peak transmission output TQ? Maximising area under the HP
curve?
Is the package being developed for use at a single circuit or for
several tracks with different gearing requirements?
On a separate, but related matter. A discussion in the following
thread may offer some insight into the preventative maintenance
cycle recommended for engines that will be operated at the upper
limits of component durability. See comments by "DLM 18" near
the end.
Thread Starter
Drifting
Joined: Jun 2001
Posts: 1,625
Likes: 1
From: Zagreb, Croatia
By peak power I meant peak HP.
With shift points, I'll try to use max of power (HP) curve,
with right gearing.
Of course, this is still just a combination of theory,
other peoples engine combos and playing with dyno software.
My main goal with this 383 (4.030" x 3.75") was 550 plus crank HP.
A lot of people suggested that this goal could be achieved with
lower rpm's. That's O.K., but I believe that with high quality
parts I can build engine that will still be reliable with 7500 redline,
and every HP that will be above 550 (at least I hope it will be),
wil be very welcome!
With shift points, I'll try to use max of power (HP) curve,
with right gearing.
Of course, this is still just a combination of theory,
other peoples engine combos and playing with dyno software.
My main goal with this 383 (4.030" x 3.75") was 550 plus crank HP.
A lot of people suggested that this goal could be achieved with
lower rpm's. That's O.K., but I believe that with high quality
parts I can build engine that will still be reliable with 7500 redline,
and every HP that will be above 550 (at least I hope it will be),
wil be very welcome!
