IS-F Documentation Available on TIS
11-21-07, 09:56 AM
#1
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iTrader: (2)
IS-F Documentation Available on TIS
Only the EWD is up now, but I suspect the NCF and RM will be available soon. Can't wait for the NCF to see all the details of what is really new.
11-29-07, 07:53 AM
#8
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LoBuxRacer,
The October C&D article says that the IS F has solid lifters. I have ask the dealer and others if this means that valve adjustments will be required as part of the periodic maitenance like that required on the Acura NSX, and so far no one seems to know the answer. When the RM is up on the TIS would you lets us know if periodic valve adjustments will be required?
Thanks,
Bruce
The October C&D article says that the IS F has solid lifters. I have ask the dealer and others if this means that valve adjustments will be required as part of the periodic maitenance like that required on the Acura NSX, and so far no one seems to know the answer. When the RM is up on the TIS would you lets us know if periodic valve adjustments will be required?
Thanks,
Bruce
11-29-07, 09:04 PM
#9
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Nothing yet. As soon as I see any info on it, I'll be posting here.
11-30-07, 08:11 AM
#10
Lexus Connoisseur
Advanced Valvetrain
I. Advanced Valvetrain
- -A. Camshaft design
- - -1. Hollow camshaft with forged lobes pressed on
- - -2. Lighter-weight high-strength hollow tube utilized
- - -3. Net-shame sintering of cam lobes improves the cam profile and improves power and fuel economy.
- - - - a. Net-shame sintering is a shaping method that stamps products with dies for a very precise form and eliminates the needfor grind finishing.
- - -4. Phased-tuned camshaft
- - -5. Mirror polishing of camshaft reduces friction, thus reducing power loss.
- -B. Roller-rocker arm design reduces cam drive friction and allows more "radical" cam grind:
- - -1. Solid Lifters
- -C. Titanium intake valves:
- - -1. Lower intertia weight (about 1/2 the weight of other UR engines) and reduced friction loss at high rpm.
- - -2. Maximum lift increased 10%
Source: P.17 Lexus Technical
I. Advanced Valvetrain
- -A. Camshaft design
- - -1. Hollow camshaft with forged lobes pressed on
- - -2. Lighter-weight high-strength hollow tube utilized
- - -3. Net-shame sintering of cam lobes improves the cam profile and improves power and fuel economy.
- - - - a. Net-shame sintering is a shaping method that stamps products with dies for a very precise form and eliminates the needfor grind finishing.
- - -4. Phased-tuned camshaft
- - -5. Mirror polishing of camshaft reduces friction, thus reducing power loss.
- -B. Roller-rocker arm design reduces cam drive friction and allows more "radical" cam grind:
- - -1. Solid Lifters
- -C. Titanium intake valves:
- - -1. Lower intertia weight (about 1/2 the weight of other UR engines) and reduced friction loss at high rpm.
- - -2. Maximum lift increased 10%
Source: P.17 Lexus Technical
11-30-07, 05:02 PM
#12
Lexus Connoisseur
12-03-07, 11:14 AM
#13
Lexus Connoisseur
Here is the answer I got from my direct sources:
The special high-performance Yamaha cylinder heads of the IS F 5.0L V8, type 2UR-GSE (not 2GR-FSE: *that's a Lexus V6), use solid lifters. *Valve lash is adjusted with shims under the bucket-shaped valve lifters.
We have not had any other model with valve adjusting shims for a few years, and when we did, checking of the clearance was recommended at 30,000 mile intervals. *The Maintenance Guide will detail the service interval. *
The Maintenance Guide should be posted on TIS soon - prior to vehicle on-sale date - along with the Repair Manual, which will detail how to do it.
As an aside, many of the Lexus engines that used to require the valve clearance to be checked ended up being in spec when techs would open them up, and not needing any adjustment. *With the expanded adoption of high-tech steel alloy valves & seats, and titanium intake valves, this engine is unlikely to need adjustment either - maybe just a check to ensure clearance is within spec.
We have not had any other model with valve adjusting shims for a few years, and when we did, checking of the clearance was recommended at 30,000 mile intervals. *The Maintenance Guide will detail the service interval. *
The Maintenance Guide should be posted on TIS soon - prior to vehicle on-sale date - along with the Repair Manual, which will detail how to do it.
As an aside, many of the Lexus engines that used to require the valve clearance to be checked ended up being in spec when techs would open them up, and not needing any adjustment. *With the expanded adoption of high-tech steel alloy valves & seats, and titanium intake valves, this engine is unlikely to need adjustment either - maybe just a check to ensure clearance is within spec.
12-03-07, 12:12 PM
#14
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FlipSide909,
Thank you for getting the answer for us. My concern regarding required valve inspections and possible valve adjustments are as follows:
1. The valve inspections can be costly even if it turns out that no valve adustments are required, because to inspect the valve clearance you have to remove the cylinder head covers and measure each of the valves for proper clearance.
2. I do not trust the modern-day mechanics at Lexus work on my car. When they changed the oil on my IS350 at 5,000 miles they failed to tighten the oil pan plug, which I found when I did the next oil change my self. When a valve inspection is done a lot of parts are removed to gain access for the inspection, which provides a lot of opportunities to make mistakes.
3. Some of the more unreputable Lexus dealers charge you for the valve inspection/adjustment even if they don't acturally measure the valve clearances. On my NSX I had one dealer tell me that they conducted the valve inspection by listening to the engine, and then they charge me $600, and that was 10 years ago.
I would be very interested to hear more about the valve inspections/adjustments that will be required on the on the IFS when you learn more about them.
Thanks again,
Bruce
Thank you for getting the answer for us. My concern regarding required valve inspections and possible valve adjustments are as follows:
1. The valve inspections can be costly even if it turns out that no valve adustments are required, because to inspect the valve clearance you have to remove the cylinder head covers and measure each of the valves for proper clearance.
2. I do not trust the modern-day mechanics at Lexus work on my car. When they changed the oil on my IS350 at 5,000 miles they failed to tighten the oil pan plug, which I found when I did the next oil change my self. When a valve inspection is done a lot of parts are removed to gain access for the inspection, which provides a lot of opportunities to make mistakes.
3. Some of the more unreputable Lexus dealers charge you for the valve inspection/adjustment even if they don't acturally measure the valve clearances. On my NSX I had one dealer tell me that they conducted the valve inspection by listening to the engine, and then they charge me $600, and that was 10 years ago.
I would be very interested to hear more about the valve inspections/adjustments that will be required on the on the IFS when you learn more about them.
Thanks again,
Bruce
12-03-07, 01:45 PM
#15
Lexus Connoisseur
FlipSide909,
Thank you for getting the answer for us. My concern regarding required valve inspections and possible valve adjustments are as follows:
1. The valve inspections can be costly even if it turns out that no valve adustments are required, because to inspect the valve clearance you have to remove the cylinder head covers and measure each of the valves for proper clearance.
2. I do not trust the modern-day mechanics at Lexus work on my car. When they changed the oil on my IS350 at 5,000 miles they failed to tighten the oil pan plug, which I found when I did the next oil change my self. When a valve inspection is done a lot of parts are removed to gain access for the inspection, which provides a lot of opportunities to make mistakes.
3. Some of the more unreputable Lexus dealers charge you for the valve inspection/adjustment even if they don't acturally measure the valve clearances. On my NSX I had one dealer tell me that they conducted the valve inspection by listening to the engine, and then they charge me $600, and that was 10 years ago.
I would be very interested to hear more about the valve inspections/adjustments that will be required on the on the IFS when you learn more about them.
Thanks again,
Bruce
Thank you for getting the answer for us. My concern regarding required valve inspections and possible valve adjustments are as follows:
1. The valve inspections can be costly even if it turns out that no valve adustments are required, because to inspect the valve clearance you have to remove the cylinder head covers and measure each of the valves for proper clearance.
2. I do not trust the modern-day mechanics at Lexus work on my car. When they changed the oil on my IS350 at 5,000 miles they failed to tighten the oil pan plug, which I found when I did the next oil change my self. When a valve inspection is done a lot of parts are removed to gain access for the inspection, which provides a lot of opportunities to make mistakes.
3. Some of the more unreputable Lexus dealers charge you for the valve inspection/adjustment even if they don't acturally measure the valve clearances. On my NSX I had one dealer tell me that they conducted the valve inspection by listening to the engine, and then they charge me $600, and that was 10 years ago.
I would be very interested to hear more about the valve inspections/adjustments that will be required on the on the IFS when you learn more about them.
Thanks again,
Bruce
-Ryan