Advice on care of racemotor
01-19-2007, 04:59 PM
#1
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Advice on care of racemotor
I'm back to try a new season after being off since 2004.
That was the first year I had run a full out race motor... and needless to say I had more than a little reliability trouble.
Oiling issues upon hard corners took out the motor twice... rod bearings. Finally a dry sump fixed this. A valve spring broke and took out nearly all of the components except the block... a couple of rods and one titanium intake valve... oh well. The last race I did in 2004 was on a freshened motor and it lasted until the last lap of the race... then a rod began to knock.
The motor has now been freshened and I'm ready to begin again. However, I wonder if it's not just me?
Any advice on how to get restarted, and keep it running? (ie what's a safe rpm limit for a 406 sbc? Is it easier on the motor to feather it off to keep from exceeding the top RPM? or, is it better to keep your foot planted for a few seconds slightly exceeding the rpm limit? Can you run a sbc full out for 30 mins?, or are you better to back off near the end of your session?
410ci, brodix -10 RISP, 2.10/1.6 (tit intakes only), Howards mechanical roller cam 272/264 @ 0.50, JE flattops/Lunati pro-mod rod and crank.
thanks for constructive critisizm and advise. cj
That was the first year I had run a full out race motor... and needless to say I had more than a little reliability trouble.
Oiling issues upon hard corners took out the motor twice... rod bearings. Finally a dry sump fixed this. A valve spring broke and took out nearly all of the components except the block... a couple of rods and one titanium intake valve... oh well. The last race I did in 2004 was on a freshened motor and it lasted until the last lap of the race... then a rod began to knock.
The motor has now been freshened and I'm ready to begin again. However, I wonder if it's not just me?
Any advice on how to get restarted, and keep it running? (ie what's a safe rpm limit for a 406 sbc? Is it easier on the motor to feather it off to keep from exceeding the top RPM? or, is it better to keep your foot planted for a few seconds slightly exceeding the rpm limit? Can you run a sbc full out for 30 mins?, or are you better to back off near the end of your session?
410ci, brodix -10 RISP, 2.10/1.6 (tit intakes only), Howards mechanical roller cam 272/264 @ 0.50, JE flattops/Lunati pro-mod rod and crank.
thanks for constructive critisizm and advise. cj
01-19-2007, 05:50 PM
#3
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Sounds like my friend's GT1 engine.
He spins the drive belt going to the drysump with a drill to prelube it before he fires it up. He's also got an electric heater on the dry sump tank.
On a 406 the rod/stroke ration is going to be real hard on a road racing engine.
He spins the drive belt going to the drysump with a drill to prelube it before he fires it up. He's also got an electric heater on the dry sump tank.
On a 406 the rod/stroke ration is going to be real hard on a road racing engine.
01-19-2007, 06:22 PM
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Yes, I've taken the advice of my engine builder... he's a reputable circle track motor builder. He's offered a 7400 rpm limit, given instructions on valve adjustment specs... and that's about it. Still, I wonder if there's a difference in keeping a motor together on a circle track vs. a roadcourse. One observation that I have made is that the 1 mile front straight at PIR keeps me one the gas alot longer than a circle track driver is on the gas. I hit 7400 and then feather it off for about 1 second before I'm hitting the brakes... sometimes I've kept my foot planted, but have never greatly exceeded the rev limit.
A reputable roadracing engine tuner (Loynings) did the initial timing and jetting.
I'm just wondering if there's a driving "technique" inherent in a successful v-8 roadracer... I'm pretty green at this high powered racing gig. I've got more torque than most an am able to jump right ahead of faster cars at the start, and then spend the rest of the race white knuckled and scared stiff while driving the rear view mirrors. I could share some race videos for you all to laugh with me about... but "pearls of wisdom" from a successful v-8 roadracer would be most helpful.
But, it really sucks to give up so many races to mechanicals... and it's quite expensive.
I've finally got the car back to "race ready"... and need to "learn" how to keep it running and fun.
How fast would you-all spin a 410 in a 30 min road race? Is a mechanical roller cam just too hard on the valvetrain components to be reliable? I've never kept track of my oil temp since I installed the drysump... is an oil heater a necessary part of the system, or just a performance tweak? cj
A reputable roadracing engine tuner (Loynings) did the initial timing and jetting.
I'm just wondering if there's a driving "technique" inherent in a successful v-8 roadracer... I'm pretty green at this high powered racing gig. I've got more torque than most an am able to jump right ahead of faster cars at the start, and then spend the rest of the race white knuckled and scared stiff while driving the rear view mirrors. I could share some race videos for you all to laugh with me about... but "pearls of wisdom" from a successful v-8 roadracer would be most helpful.
But, it really sucks to give up so many races to mechanicals... and it's quite expensive.
I've finally got the car back to "race ready"... and need to "learn" how to keep it running and fun.
How fast would you-all spin a 410 in a 30 min road race? Is a mechanical roller cam just too hard on the valvetrain components to be reliable? I've never kept track of my oil temp since I installed the drysump... is an oil heater a necessary part of the system, or just a performance tweak? cj
01-19-2007, 06:51 PM
#5
Le Mans Master
What kind of oil are you using?
The top alcohol crowd(drag racing) suffered lots of engine damage a while back. They discovered the oil companies stopped adding a couple of ingredients to the oil. Zinc and something else.
Many began to add lucas oil treatment to the oil. Damage stopped.
The top alcohol crowd(drag racing) suffered lots of engine damage a while back. They discovered the oil companies stopped adding a couple of ingredients to the oil. Zinc and something else.
Many began to add lucas oil treatment to the oil. Damage stopped.
01-19-2007, 07:41 PM
#6
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You want to get the oil up to temp before you fire it up, otherwise your pumping mud. What kind of temps are you seeing on the track?
Road racing is harder on an engine than circle track. You tend to use it from braking as well as acceleration, your also keeping it at peak rpm a lot longer. Do you heel&toe downshift to match rpms?
BTW There's a few drivers in the road racing section, that have engines like yours. I'm sure they'd help you out. If anything else get a you a proper engine builder to talk to.
Road racing is harder on an engine than circle track. You tend to use it from braking as well as acceleration, your also keeping it at peak rpm a lot longer. Do you heel&toe downshift to match rpms?
BTW There's a few drivers in the road racing section, that have engines like yours. I'm sure they'd help you out. If anything else get a you a proper engine builder to talk to.
01-19-2007, 08:12 PM
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I have a Jerico 4-sp... so I don't clutch it to shift. The gears are closely spaced, so the rpms stay from 5500 to 7400. On one track configuration I run out of gear at the end of the front straight, so on a good run I'll hit 7500 for a few seconds.
Most of my troubles have been with rod bearing failures. Am I naive to think that a well built, forged 400 can hold up to this?
Most of my troubles have been with rod bearing failures. Am I naive to think that a well built, forged 400 can hold up to this?
01-19-2007, 10:19 PM
#9
Le Mans Master
Sounds like a nice package.
My vote is that you ignore the engine builder's 7,400 RPM
limit and step your redline back to 6,400 (or less.) Change
to numerically lower gears so that the car reaches this
lower limit just before braking on the longest straight.
The key factor in my recommendation is piston speed. Now
you first describe the engine as a 406, later you call it
a 410 and then it is a 400. No matter, a 400, 406 and 409
all typically use a 3.75" stroke (4.125, 4.155 and 4.165"
bores)
With a 3.75" stroke at 7,400 rpm, piston speed is 4,625 feet
per minute. This is very fast - loads increase by the square
of the increase in RPM and my vote is that even great rotating
components will be highly stressed in a SBC at 4,625. I do not
doubt that with an appropriate budget for maintenance and parts
replacement that someone could operate at these pistons speeds
- I believe that you are saying you'd rather live more modestly.
I once looked at a cross-section of performance engines to evaluate
what the piston speeds were in relation to the OEM redline. My
examples included small and large displacement North American,
Euro and Japanese auto engines, Euro and Japanese bike engines,
as well as Austrian and Japanese two-stroke snowmobile engines.
As I recall, the values fell between 3,600 and 4,000 FPM.
What kind of cam does this engine have? A 406 with 264/274º
(@ 0.050") and 0.588" lift can make 580 CHP at 6300.
If the builder has more cam than this, then consider going to a
smaller cam to make power where it is most useful. If the cam is
smaller than this example, spinning the engine above 6,300 is a matter
of diminishing returns.
In either event, you seem to indicate that you have a bit more juice
than you are presently comfortable with so pulling back can only help
car control, durability and the amount of seat time you get in a season.
.
My vote is that you ignore the engine builder's 7,400 RPM
limit and step your redline back to 6,400 (or less.) Change
to numerically lower gears so that the car reaches this
lower limit just before braking on the longest straight.
The key factor in my recommendation is piston speed. Now
you first describe the engine as a 406, later you call it
a 410 and then it is a 400. No matter, a 400, 406 and 409
all typically use a 3.75" stroke (4.125, 4.155 and 4.165"
bores)
With a 3.75" stroke at 7,400 rpm, piston speed is 4,625 feet
per minute. This is very fast - loads increase by the square
of the increase in RPM and my vote is that even great rotating
components will be highly stressed in a SBC at 4,625. I do not
doubt that with an appropriate budget for maintenance and parts
replacement that someone could operate at these pistons speeds
- I believe that you are saying you'd rather live more modestly.
I once looked at a cross-section of performance engines to evaluate
what the piston speeds were in relation to the OEM redline. My
examples included small and large displacement North American,
Euro and Japanese auto engines, Euro and Japanese bike engines,
as well as Austrian and Japanese two-stroke snowmobile engines.
As I recall, the values fell between 3,600 and 4,000 FPM.
What kind of cam does this engine have? A 406 with 264/274º
(@ 0.050") and 0.588" lift can make 580 CHP at 6300.
If the builder has more cam than this, then consider going to a
smaller cam to make power where it is most useful. If the cam is
smaller than this example, spinning the engine above 6,300 is a matter
of diminishing returns.
In either event, you seem to indicate that you have a bit more juice
than you are presently comfortable with so pulling back can only help
car control, durability and the amount of seat time you get in a season.
.
01-19-2007, 10:45 PM
#10
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St. Jude Donor '05
Id try alittle less gear in it so you arent buzzing it quite as high. There are calculators to figure this. What are the rest of the guys running as far as gear for different tracks...Might want to ask around and get some input..That kind of RPM is brutal to just about any motor so I woudnt blame it on anything in particular.
01-19-2007, 11:10 PM
#11
Le Mans Master
Sorry, found the answer upon rereading your initial post.
.
Originally Posted by Slalom4me
What kind of cam does this engine have?
01-20-2007, 12:01 AM
#12
Le Mans Master
What are the Int/Exh lift specs for the cam. Is a girdle used or possibly
shaft-mounted rockers? What is the rocker ratio.
two different objectives.
A heater is a tweak if the car is being started in ambiant temps
of 70ºF+ and if it can always be warmed so that the oil is near
operating temp before running it hard.
As BrianCunningham has already mentioned, for a dry sump system,
heating the oil in the remote oil tank prior to start-up helps get the
10 or more quarts stored there above ambiant temp and thus more viscous.
The remote tank (and the typically included oil cooler) means that dry
sump systems take a while to build heat on their own. Event
organization or the usual pit chaos may mean that there is little time to
run the engine to build heat before the flag drops. You want to attain
some minimum oil temp before using significant power - for sake of this
discussion, let's peg the minium oil temp before using partial power at
150ºF.
You also want to monitor oil temps under operating conditions to be
sure the oil is not overheated (or overcooled). For the sake of this
discussion, let's pick an operating range of 210º - 240ºF for mineral
oil, with 260º being the danger point. For synthetics, let's pick
210º-280º with 300ºF+ being the danger point.
People can quibble with the numbers but my points are:
- that there is an optimal oil temperature range,
- synthetic tolerates more heat than mineral,
- a driver should monitor his engine's oil temps and take
appropriate action if they stray outside the desired range.
.
01-20-2007, 03:31 AM
#13
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I'd agree with the above comments. Just because the builder says it can take 7400, it doesn't mean that it will do it many times. Roadracing is about endurance of your powertrain.
A couple more things to check:
You may want to double-check your drive speed of the oil pump. Your engine builder should know what the ideal GPM flow rate of oil for your engine is and be able to match it to the appropriate pulley combo for your particular oil pump.
Also, not sure if the valve spring failure was a freak thing or a symptom of your motor's setup, but you may want to look in to spring oilers. If it's a moderate cam, you shouldn't need them. But if it's a pretty agressive lift, spring oilers go a long way to keeping them cool. Ususally overkill for anything short of extreme setups, though.
We're all *assuming* you have an oil cooler, right? As slalom states, you need to monitor your coolant temp, oil temp, and oil pressure frequently.
Also, if your engine blew before, chances are you have bits of crap throughout your dry sump system (tank, lines, cooler, pump), and possibly need a pump rebuild. Those aluminum casings get chewed up quickly. You probably already checked that stuff, but just in case.
Lastly, since you're posting here, I assume you have a C4, which means that you have a dry sump installed in a C4
I'd be VERY interested in seeing pics of your setup since I'm in the process of trying to engineer one in mine. I've only seen a couple others.
Good luck!
A couple more things to check:
You may want to double-check your drive speed of the oil pump. Your engine builder should know what the ideal GPM flow rate of oil for your engine is and be able to match it to the appropriate pulley combo for your particular oil pump.
Also, not sure if the valve spring failure was a freak thing or a symptom of your motor's setup, but you may want to look in to spring oilers. If it's a moderate cam, you shouldn't need them. But if it's a pretty agressive lift, spring oilers go a long way to keeping them cool. Ususally overkill for anything short of extreme setups, though.
We're all *assuming* you have an oil cooler, right? As slalom states, you need to monitor your coolant temp, oil temp, and oil pressure frequently.
Also, if your engine blew before, chances are you have bits of crap throughout your dry sump system (tank, lines, cooler, pump), and possibly need a pump rebuild. Those aluminum casings get chewed up quickly. You probably already checked that stuff, but just in case.
Lastly, since you're posting here, I assume you have a C4, which means that you have a dry sump installed in a C4
I'd be VERY interested in seeing pics of your setup since I'm in the process of trying to engineer one in mine. I've only seen a couple others.Good luck!
01-20-2007, 08:29 AM
#14
Le Mans Master
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Did the builder ever dyno this motor? My motor is a 308 CID and is limited to 8600. I suspect that your piston speed at 7400 is higher than mine at 8600. I preheat the oil for an hour and use a drill to spin the pump every day before I run it. I use Royal Pruple Synthetic #21 (like a 0-30) and at teardowns all the bearings looked great. Oil that is too thick actually can damage it, I need it to flow the 4-5 feet from the tank to the dry sump.
01-20-2007, 10:46 AM
#15
Le Mans Master
I remembered the original Honda S2000 being a benchmark for piston
speed when it came out, so I went back to check it.
The 2002-03 engine has an 84mm (3.3071") stroke and a 9,000 RPM
redline - this gives a piston speed of 4,961 FPM. Perhaps warranty
claims as much as calls for more torque resulted in the 2004 move
to a 91mm (3.571") stroke and an 8,000 RPM redline - which produces
piston speeds of 'only' 4,761 FPM.
My review was done a couple of decades ago. Someone else has compiled
a more current ranking of engines with the fastest piston speeds. I'm
puzzled to see the Saleen at #8 (4,666 FPM) but I have my thoughts on this.
I do not know who compiled the original list but here is the source for the following
FWIW, I still think 4,000 FPM is a pretty respectable ceiling for an
endurance SBC.
speed when it came out, so I went back to check it.
The 2002-03 engine has an 84mm (3.3071") stroke and a 9,000 RPM
redline - this gives a piston speed of 4,961 FPM. Perhaps warranty
claims as much as calls for more torque resulted in the 2004 move
to a 91mm (3.571") stroke and an 8,000 RPM redline - which produces
piston speeds of 'only' 4,761 FPM.
My review was done a couple of decades ago. Someone else has compiled
a more current ranking of engines with the fastest piston speeds. I'm
puzzled to see the Saleen at #8 (4,666 FPM) but I have my thoughts on this.
I do not know who compiled the original list but here is the source for the following
FWIW, I still think 4,000 FPM is a pretty respectable ceiling for an
endurance SBC.
Honda has 6 of the top 10
1. Honda S2000:
Engine Code: F20C1
Bore/Stroke: 3.43" X 3.31"
Redline: 9000rpm
Piston Speed: 4965 Ft/min
2. Lamborghini Gallardo
Engine Code: N/A
Bore/Stroke: 3.25" X 3.65"
Redline: 8000rpm
Piston Speed: 4866.67 Ft/min
3. Acura Integra Type R
Engine Code: B18C5
Bore/Stroke: 3.19" X 3.43"
Redline: 8400rpm
Piston Speed: 4802 Ft/min
4. BMW M3 (Germany)
Engine Code: S54
Bore/Stroke: 3.43" X 3.58"
Redline: 8000rpm
Piston Speed: 4773.33 Ft/min
5. Honda S2000 2004
Engine Code: F22C
Bore/Stroke: 3.43" X 3.57"
Redline: 8000rpm
Piston Speed: 4760 Ft/min
6. Honda Integra Type R (JDM)
Engine Code: K20A
Bore/Stroke: 3.39" X 3.39"
Redline: 8400rpm
Piston Speed: 4746 Ft/min
7. Acura Integra GSR 2001
Engine Code: B18C
Bore/Stroke: 3.19" X 3.43"
Redline: 8200rpm
Piston Speed: 4687.67 Ft/min
8. Saleen S7
Engine Code: N/A
Bore/Stroke: 4.13" X 4.00"
Redline: 7000rpm
Piston Speed: 4666.67 Ft/min
9. Acura TSX
Engine Code: K24A2
Bore/Stroke: 3.43" X 3.90"
Redline: 7100rpm
Piston Speed: 4615 Ft/min
10. Suzuki Hayabusa Sport Prototype
Engine Code: W701
Bore/Stroke: 3.19" X 2.48"
Redline: 11000rpm
Piston Speed: 4546.67 Ft/min
11. Honda Civic Type R
Engine Code: B16B
Bore/Stroke: 3.19" X 3.03"
Redline: 9000rpm
Piston Speed: 4545 Ft/min
12. Toyota Celica GTS / Matrix XRS 2001
Engine Code: 2ZZ-GE
Bore/Stroke: 3.23" X 3.35"
Redline: 8100rpm
Piston Speed: 4522.5 Ft/min
13. Honda Prelude Type S (JDM)
Engine Code: H22A
Bore/Stroke: 3.43" X 3.57"
Redline: 7500rpm
Piston Speed: 4462.5 Ft/min
14. Acura RSX Type S
Engine Code: K20A2
Bore/Stroke: 3.38" X 3.38"
Redline: 7900rpm
Piston Speed: 4450.33 Ft/min
15. Ferrari 360 Modena (incl. Challenge, Stradale, etc)
Engine Code: N/A
Bore/Stroke: 3.35" X 3.11"
Redline: 8500rpm
Piston Speed: 4405.83 Ft/min
16. Lamborghini Murcielago
Engine Code: N/A
Bore/Stroke: 3.43" X 3.42"
Redline: 7600rpm
Piston Speed: 4332 Ft/min
17. McLaren F1
Engine Code: N/A (BMW V12)
Bore/Stroke: 3.39" X 3.43"
Redline: 7500rpm
Piston Speed: 4287.5 Ft/min
18. Renault Clio 2.0 RS 2003
Engine Code: F4R
Bore/Stroke: 3.26" X 3.66"
Redline: 7000rpm
Piston Speed: 4270 Ft/min
19. Porsche 911 GT3 RS 2004
Engine Code: N/A
Bore/Stroke: 3.94" X 3.01"
Redline: 8500rpm
Piston Speed: 4264.17 Ft/min
20. Pagani Zonda C12S
Engine Code: M120 7.3 AMG
Bore/Stroke: 3.6" X 3.64"
Redline: 7000rpm
Piston Speed: 4246.67 Ft/min
21. Peugeot 206RC 2004
Engine Code: EW10 J4 S
Bore/Stroke: 3.35" X 3.46"
Redline: 7300rpm
Piston Speed: 4209.67 Ft/min
22. Porsche Carrera GT
Engine Code: N/A
Bore/Stroke: 3.86" X 2.99"
Redline: 8400rpm
Piston Speed: 4186 Ft/min
23. Acura NSX-T
Engine Code: C32B
Bore/Stroke: 3.66" X 3.07"
Redline: 8000rpm
Piston Speed: 4093.33 Ft/min
24. BMW M5 2002
Engine Code: S62
Bore/Stroke: 3.70" X 3.50"
Redline: 7000rpm
Piston Speed: 4083.33 Ft/min
25. BMW M5 E60
Engine Code: S65 (?)
Bore/Stroke: 3.62" X 2.96"
Redline: 8250rpm
Piston Speed: 4070 Ft/min
26. Nissan Primera W20V
Engine Code: N/A
Bore/Stroke: 3.39" X 3.39"
Redline: 7200rpm
Piston Speed: 4068 Ft/min
27. Ferrari Enzo
Engine Code: F140
Bore/Stroke: 3.62" X 2.96"
Redline: 8000rpm
Piston Speed: 3946.67 Ft/min
28. Ferrari 575 Maranello
Engine Code: 650 V21
Bore/Stroke: 3.50" X 3.03"
Redline: 7750rpm
Piston Speed: 3913.75 Ft/min
1. Honda S2000:
Engine Code: F20C1
Bore/Stroke: 3.43" X 3.31"
Redline: 9000rpm
Piston Speed: 4965 Ft/min
2. Lamborghini Gallardo
Engine Code: N/A
Bore/Stroke: 3.25" X 3.65"
Redline: 8000rpm
Piston Speed: 4866.67 Ft/min
3. Acura Integra Type R
Engine Code: B18C5
Bore/Stroke: 3.19" X 3.43"
Redline: 8400rpm
Piston Speed: 4802 Ft/min
4. BMW M3 (Germany)
Engine Code: S54
Bore/Stroke: 3.43" X 3.58"
Redline: 8000rpm
Piston Speed: 4773.33 Ft/min
5. Honda S2000 2004
Engine Code: F22C
Bore/Stroke: 3.43" X 3.57"
Redline: 8000rpm
Piston Speed: 4760 Ft/min
6. Honda Integra Type R (JDM)
Engine Code: K20A
Bore/Stroke: 3.39" X 3.39"
Redline: 8400rpm
Piston Speed: 4746 Ft/min
7. Acura Integra GSR 2001
Engine Code: B18C
Bore/Stroke: 3.19" X 3.43"
Redline: 8200rpm
Piston Speed: 4687.67 Ft/min
8. Saleen S7
Engine Code: N/A
Bore/Stroke: 4.13" X 4.00"
Redline: 7000rpm
Piston Speed: 4666.67 Ft/min
9. Acura TSX
Engine Code: K24A2
Bore/Stroke: 3.43" X 3.90"
Redline: 7100rpm
Piston Speed: 4615 Ft/min
10. Suzuki Hayabusa Sport Prototype
Engine Code: W701
Bore/Stroke: 3.19" X 2.48"
Redline: 11000rpm
Piston Speed: 4546.67 Ft/min
11. Honda Civic Type R
Engine Code: B16B
Bore/Stroke: 3.19" X 3.03"
Redline: 9000rpm
Piston Speed: 4545 Ft/min
12. Toyota Celica GTS / Matrix XRS 2001
Engine Code: 2ZZ-GE
Bore/Stroke: 3.23" X 3.35"
Redline: 8100rpm
Piston Speed: 4522.5 Ft/min
13. Honda Prelude Type S (JDM)
Engine Code: H22A
Bore/Stroke: 3.43" X 3.57"
Redline: 7500rpm
Piston Speed: 4462.5 Ft/min
14. Acura RSX Type S
Engine Code: K20A2
Bore/Stroke: 3.38" X 3.38"
Redline: 7900rpm
Piston Speed: 4450.33 Ft/min
15. Ferrari 360 Modena (incl. Challenge, Stradale, etc)
Engine Code: N/A
Bore/Stroke: 3.35" X 3.11"
Redline: 8500rpm
Piston Speed: 4405.83 Ft/min
16. Lamborghini Murcielago
Engine Code: N/A
Bore/Stroke: 3.43" X 3.42"
Redline: 7600rpm
Piston Speed: 4332 Ft/min
17. McLaren F1
Engine Code: N/A (BMW V12)
Bore/Stroke: 3.39" X 3.43"
Redline: 7500rpm
Piston Speed: 4287.5 Ft/min
18. Renault Clio 2.0 RS 2003
Engine Code: F4R
Bore/Stroke: 3.26" X 3.66"
Redline: 7000rpm
Piston Speed: 4270 Ft/min
19. Porsche 911 GT3 RS 2004
Engine Code: N/A
Bore/Stroke: 3.94" X 3.01"
Redline: 8500rpm
Piston Speed: 4264.17 Ft/min
20. Pagani Zonda C12S
Engine Code: M120 7.3 AMG
Bore/Stroke: 3.6" X 3.64"
Redline: 7000rpm
Piston Speed: 4246.67 Ft/min
21. Peugeot 206RC 2004
Engine Code: EW10 J4 S
Bore/Stroke: 3.35" X 3.46"
Redline: 7300rpm
Piston Speed: 4209.67 Ft/min
22. Porsche Carrera GT
Engine Code: N/A
Bore/Stroke: 3.86" X 2.99"
Redline: 8400rpm
Piston Speed: 4186 Ft/min
23. Acura NSX-T
Engine Code: C32B
Bore/Stroke: 3.66" X 3.07"
Redline: 8000rpm
Piston Speed: 4093.33 Ft/min
24. BMW M5 2002
Engine Code: S62
Bore/Stroke: 3.70" X 3.50"
Redline: 7000rpm
Piston Speed: 4083.33 Ft/min
25. BMW M5 E60
Engine Code: S65 (?)
Bore/Stroke: 3.62" X 2.96"
Redline: 8250rpm
Piston Speed: 4070 Ft/min
26. Nissan Primera W20V
Engine Code: N/A
Bore/Stroke: 3.39" X 3.39"
Redline: 7200rpm
Piston Speed: 4068 Ft/min
27. Ferrari Enzo
Engine Code: F140
Bore/Stroke: 3.62" X 2.96"
Redline: 8000rpm
Piston Speed: 3946.67 Ft/min
28. Ferrari 575 Maranello
Engine Code: 650 V21
Bore/Stroke: 3.50" X 3.03"
Redline: 7750rpm
Piston Speed: 3913.75 Ft/min
01-20-2007, 10:55 AM
#16
Le Mans Master
To get back to Corvettes, the new gen LS7 has a stroke of 101.6mm
(4.00") and a redline of 7,000 - this results in piston speeds of 4,666 FPM.
The LT4 in the 1996 GS has a stroke of 3.48" and a redline of 6,300
- good for 3,654 FPM.
.
(4.00") and a redline of 7,000 - this results in piston speeds of 4,666 FPM.
The LT4 in the 1996 GS has a stroke of 3.48" and a redline of 6,300
- good for 3,654 FPM.
.
01-24-2007, 06:09 PM
#17
Intermediate
Thread Starter
Member Since: Jan 2007
Posts: 33
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Thank you for your responses:
Mark: I'll surely try an oil tank heater this upcoming season. I'll also try to fab up some guages for my video cam to catch... currently, I'm not able to remember what all the guages are registering in my dash cluster.
as far as the drysump in my C4... I can only describe it as being "very tight quarters". This is going to hamper pre-lubing.
Slalom: The motor is a 3.75 stroke 4.155 bore. I'll try to get those cam specs for you. I believe it's 272/264 @ .050 and a healthy amount of lift on a 108 lobe separation. I'm using rocker shafts with a 1.55 ratio on both the I&E.
Cuisenart: I'm currently using an OEM Dana 44, so the rear gear selections are limited. While the trans that I'm using can only run a 1:1 4th gear, I have heard that you can "overdrive" the 3rd gear spot on the Jerico, then reverse the shifter arm which will give you a correct shifting pattern... with the negative being a loss of strength.
Moreover, my concern is that I had already tried using a smaller camshaft (mid 250's duration @ .050)... thinking that it's be easier to "learn on". Boy was I wrong! It made the motor a "torque monster". It would kick the car off the tires when throttling up off a corner way too easy. (remember I'm on DOT tires, and not slicks)
If too high of RPM is the problem, then I could overdrive the trans (with questionable reliability), while using the same valvetrain (torque killing cam) as I am currently using.
If the engine is just too tweaked to be reliable, then, could I go to a hot street cam... perhaps a street roller?
Any more creative suggestions?
Mark: I'll surely try an oil tank heater this upcoming season. I'll also try to fab up some guages for my video cam to catch... currently, I'm not able to remember what all the guages are registering in my dash cluster.
as far as the drysump in my C4... I can only describe it as being "very tight quarters". This is going to hamper pre-lubing.
Slalom: The motor is a 3.75 stroke 4.155 bore. I'll try to get those cam specs for you. I believe it's 272/264 @ .050 and a healthy amount of lift on a 108 lobe separation. I'm using rocker shafts with a 1.55 ratio on both the I&E.
Cuisenart: I'm currently using an OEM Dana 44, so the rear gear selections are limited. While the trans that I'm using can only run a 1:1 4th gear, I have heard that you can "overdrive" the 3rd gear spot on the Jerico, then reverse the shifter arm which will give you a correct shifting pattern... with the negative being a loss of strength.
Moreover, my concern is that I had already tried using a smaller camshaft (mid 250's duration @ .050)... thinking that it's be easier to "learn on". Boy was I wrong! It made the motor a "torque monster". It would kick the car off the tires when throttling up off a corner way too easy. (remember I'm on DOT tires, and not slicks)
If too high of RPM is the problem, then I could overdrive the trans (with questionable reliability), while using the same valvetrain (torque killing cam) as I am currently using.
If the engine is just too tweaked to be reliable, then, could I go to a hot street cam... perhaps a street roller?
Any more creative suggestions?
Last edited by speedj2; 01-24-2007 at 06:24 PM.
01-25-2007, 02:26 AM
#19
Le Mans Master
For peal & stick oil tank heaters, look at Proheat Products (Chetek, WI).
I have a #512 on an ultimate driving machine because the engineers
forgot to include a provision for a blockheater. Keep in mind that these
have to be plugged in to 120V power.
And separate the starter switch from the ignition switch so that it is
possible to crank the engine without firing until pressure comes up
on the gauge. Once pressure is evident, turn on the ignition to fire
the engine.
.
As an example of modern endurance engine piston speed, I noticed the
305 ci engines (perhaps 3.995" x 3.043"?) in the Aussie V8 Supercar
series have a series-mandated RPM ceiling of 7,500. Watching this
past Tuesday, telemetry for an entrant appeared to show the driver
making most shifts (6 spd sequential Hollinger) within 6,300-6,600 RPM
(3,200-3,350 FPM) with very brief/momentary periods to an observed
max of 7,100 RPM (3,600 FPM).
Those are vastly lower piston speed numbers than the 4,625 FPM a
406 experiences at 7,400 - keeping in mind that loads change as the
square of the change in speed.
Example of modern race engine piston speed
I'll say again that my vote is for a lower redline to improve longevity.
The engine may run to 7,400, but without a program to monitor and
perform regular maintenance on items like rods and rod bolts, it may not
do so for long.
You mention there is limited rear gear selection for the D44 and that
you are considering modifying/compromising the Jerico transmission,
instead. What is the final drive ratio currently installed in the car?
Yukon Gear appears to offer the following ratios for the
D44-HD as used in the Corvette & Viper applications
3.07, 3.55, 3.73
3.91, 4.10, 4.56
You are running DOT tires - a 275/40 x 17 is about 26" tall. With a
3.07 rear gear, a 26" tire will theoretically give you 186 MPH at 7,400.
Dropping RPM to 6,400 results in a theoretical 161 MPH top speed with
the 3.07 rear. When you factor in losses of say 5-6%, will an actual
top speed of 150 be sufficient?
(If you happened to currently have 3.55 gears, at 7,400 these would
give the same theoretical top speed of 161.)
.
I have a #512 on an ultimate driving machine because the engineers
forgot to include a provision for a blockheater. Keep in mind that these
have to be plugged in to 120V power.
possible to crank the engine without firing until pressure comes up
on the gauge. Once pressure is evident, turn on the ignition to fire
the engine.
.
As an example of modern endurance engine piston speed, I noticed the
305 ci engines (perhaps 3.995" x 3.043"?) in the Aussie V8 Supercar
series have a series-mandated RPM ceiling of 7,500. Watching this
past Tuesday, telemetry for an entrant appeared to show the driver
making most shifts (6 spd sequential Hollinger) within 6,300-6,600 RPM
(3,200-3,350 FPM) with very brief/momentary periods to an observed
max of 7,100 RPM (3,600 FPM).
Those are vastly lower piston speed numbers than the 4,625 FPM a
406 experiences at 7,400 - keeping in mind that loads change as the
square of the change in speed.
Example of modern race engine piston speed
I'll say again that my vote is for a lower redline to improve longevity.
The engine may run to 7,400, but without a program to monitor and
perform regular maintenance on items like rods and rod bolts, it may not
do so for long.
You mention there is limited rear gear selection for the D44 and that
you are considering modifying/compromising the Jerico transmission,
instead. What is the final drive ratio currently installed in the car?
Yukon Gear appears to offer the following ratios for the
D44-HD as used in the Corvette & Viper applications
3.07, 3.55, 3.73
3.91, 4.10, 4.56
You are running DOT tires - a 275/40 x 17 is about 26" tall. With a
3.07 rear gear, a 26" tire will theoretically give you 186 MPH at 7,400.
Dropping RPM to 6,400 results in a theoretical 161 MPH top speed with
the 3.07 rear. When you factor in losses of say 5-6%, will an actual
top speed of 150 be sufficient?
(If you happened to currently have 3.55 gears, at 7,400 these would
give the same theoretical top speed of 161.)
.
01-25-2007, 05:17 PM
#20
Le Mans Master
Another consideration in favour of reducing the RPM limit.
If someone built a 406 with Brodix -10 heads, a
Comp 12-950-9 cam, single plane intake w/ 5" runners,
850 Holley carb, 1-7/8" x 32" open headers and 10.5:1 CR,
Engine Analyzer offers the following estimates of output.
It looks like the party starts winding down after 6,000 RPM.
Changing the duration from Comp's 266/272 (106 LSA) to
speedj2's 274/264 (108 LSA) does not materially change
the shape/placement of the curves.
(Note - Engine Analyzer reports that a CR of 11.5:1 pushes
the Knock Index is above 2.0 and EA warns that detonation
is likely. The graphs here are based on a 10.5:1 compression ratio.)
If someone built a 406 with Brodix -10 heads, a
Comp 12-950-9 cam, single plane intake w/ 5" runners,
850 Holley carb, 1-7/8" x 32" open headers and 10.5:1 CR,
Engine Analyzer offers the following estimates of output.
It looks like the party starts winding down after 6,000 RPM.
Changing the duration from Comp's 266/272 (106 LSA) to
speedj2's 274/264 (108 LSA) does not materially change
the shape/placement of the curves.
(Note - Engine Analyzer reports that a CR of 11.5:1 pushes
the Knock Index is above 2.0 and EA warns that detonation
is likely. The graphs here are based on a 10.5:1 compression ratio.)