Hydraulic roller lifters with titanium valves
#2836601
10/23/20 04:29 PM
10/23/20 04:29 PM
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Joined: Jun 2016
Posts: 903
Washington
hemienvy
OP
super stock
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OP
super stock
Joined: Jun 2016
Posts: 903
Washington
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Thought occurred to me this would be a good idea. (Can't remember if I wrote about this previously)
With any given combo of cam-lifters-springs, if you made only one change, that is,
changing out steel valves for titanium valves, your safe RPM limit would go up (safe for the valvetrain that is).
This includes hydraulic roller deals, which have definite valvespring pressure limits. So with the same valvespring
you could rev the valvetrain to a higher RPM limit with Ti valves. As a generality, this is true.
I'm interested in building a hydraulic roller engine that can reliably run at 7000 RPM with .700" valve lift.
I'm guessing you would still be limited to what, 400 lbs open spring pressure ?
Ignoring horsepower or cubic inch arguments, or cost arguments, would this valvetrain be stable ?
Now I understand that many would say to use as much valve spring pressure as you can to safeguard the valvetrain,
but my philosophy would be to use the least amount of valvespring pressure that would safely work.
***********
Also, is there such a thing as titanium pushrods ?
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Re: Hydraulic roller lifters with titanium valves
[Re: hemienvy]
#2836603
10/23/20 04:42 PM
10/23/20 04:42 PM
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Joined: Jan 2005
Posts: 2,540
Milwaukee WI
TRENDZ
master
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master
Joined: Jan 2005
Posts: 2,540
Milwaukee WI
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If you come up with a way to achieve those goals, please post them. I wouldn’t think that plan is realistic, but if you succeed, more power to you! Literately.
"use it 'till it breaks, replace as needed"
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Re: Hydraulic roller lifters with titanium valves
[Re: hemienvy]
#2836612
10/23/20 04:58 PM
10/23/20 04:58 PM
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Joined: Oct 2007
Posts: 4,205
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,205
New York
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The valve weight difference is an improvement, but if it were a big deal it would have been used everywhere 20 years ago. In some engines, the best shape cannot be made in titanium (small stem to head radius, 7mm stem).
Titanium makes a good spring, to be as stiff as steel it would be much larger.
Boffin Emeritus
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Re: Hydraulic roller lifters with titanium valves
[Re: TRENDZ]
#2836644
10/23/20 05:43 PM
10/23/20 05:43 PM
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Joined: Aug 2011
Posts: 2,853
Pattison Texas
CSK
master
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master
Joined: Aug 2011
Posts: 2,853
Pattison Texas
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George Bryce from Star Racing does it with Harley Davidson engines, he applied his knowledge from winning Championship Pro stock Motorcycle , to the street, he uses special seats & a coating on the Titanium valves for street duty, BUT the Hydro Roller lifters they use are VERY good, not like the Mopar ones we can get from the aftermarket.
1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5
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Re: Hydraulic roller lifters with titanium valves
[Re: hemienvy]
#2836782
10/23/20 11:13 PM
10/23/20 11:13 PM
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Joined: May 2019
Posts: 710
Lake Villa Il
INTMD8
super stock
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super stock
Joined: May 2019
Posts: 710
Lake Villa Il
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Thought occurred to me this would be a good idea. (Can't remember if I wrote about this previously)
With any given combo of cam-lifters-springs, if you made only one change, that is,
changing out steel valves for titanium valves, your safe RPM limit would go up (safe for the valvetrain that is).
This includes hydraulic roller deals, which have definite valvespring pressure limits. So with the same valvespring
you could rev the valvetrain to a higher RPM limit with Ti valves. As a generality, this is true.
I'm interested in building a hydraulic roller engine that can reliably run at 7000 RPM with .700" valve lift.
I'm guessing you would still be limited to what, 400 lbs open spring pressure ?
Ignoring horsepower or cubic inch arguments, or cost arguments, would this valvetrain be stable ?
Now I understand that many would say to use as much valve spring pressure as you can to safeguard the valvetrain,
but my philosophy would be to use the least amount of valvespring pressure that would safely work.
***********
Also, is there such a thing as titanium pushrods ?
What would you say the pressure limit is for a hydraulic roller and why? I've ran them to 8k on steel valve LS7 engines with 200 on the seat. Multiply that by the 1.8 rocker ratio how much was the lifter seeing? (200 seat is 360 to the lifter, or the same as 240 on the seat with a 1.5 rocker) Lightweight anything on the lifter side of the valvetrain basically means nothing. Rigidity is priority.
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
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Re: Hydraulic roller lifters with titanium valves
[Re: hemienvy]
#2836793
10/23/20 11:51 PM
10/23/20 11:51 PM
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Joined: May 2019
Posts: 710
Lake Villa Il
INTMD8
super stock
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super stock
Joined: May 2019
Posts: 710
Lake Villa Il
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IMO the only downside to a hydraulic is you would see less net valve lift than mechanical due to potential aeration of the oil. For that you would have some degree of compressibility, otherwise liquids are mostly incompressible. I think this would to some degree be compensated for by no lash.
The cam was single pattern 3705 lobes. (236/236 @.050). Twin turbo. Open was 450. thick wall 3/8 pushrod. So, not much lift, only .612. 1,340 rwhp
Last edited by INTMD8; 10/23/20 11:53 PM.
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
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Re: Hydraulic roller lifters with titanium valves
[Re: hemienvy]
#2836890
10/24/20 12:21 PM
10/24/20 12:21 PM
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Joined: Aug 2003
Posts: 1,313
Charlotte, NC
LSP
pro stock
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pro stock
Joined: Aug 2003
Posts: 1,313
Charlotte, NC
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LSP,
Great info, thanks. Do you recall the valvespring setup specs ? 240 lbs. seat, 540 lbs. open
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