Look up IQ52. He has done Dyno tests on changing lifters. I have changed each way depending on if I wanted more or less duration. The ramps are different so there is about a 20* difference. Hyd : more duration with a solid cam. Solids on a hydro cam : less duration. Has less lift now as u have lash. I believe u can get away with as little as .006 lash
Variable hydraulic lifters for 440 engine
- Thread starter WietseR/T
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WietseR/T
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Not sure if that is going to take enough duration and lift out of this cam..
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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With solids, you have to have an adjustable valve train. By varying your lash between minimum and maximum, you actually change your Ica, and it is possible as oldkimmer suggests,to increase the lash quite a bit, and so change the Ica quite a bit.
You can achieve similar results by running anti-pump-up hydraulic lifters with some lash. This is what I'm doing with my 276/286/110 Hughes cam. I started out with .020 preload, when the cam was new. Over time, the preload has changed to lash. The idle improved so I decided to leave it. They have been ticking for well over a decade lol.
My butt-dyno has not noticed any powerloss because the old, hard, BFGs spin to past the speed-limit anywhere in Canada, so if there is a powerloss, I say so what, lol.
You can achieve similar results by running anti-pump-up hydraulic lifters with some lash. This is what I'm doing with my 276/286/110 Hughes cam. I started out with .020 preload, when the cam was new. Over time, the preload has changed to lash. The idle improved so I decided to leave it. They have been ticking for well over a decade lol.
My butt-dyno has not noticed any powerloss because the old, hard, BFGs spin to past the speed-limit anywhere in Canada, so if there is a powerloss, I say so what, lol.
WietseR/T
Active Member
I have adjustable roller rockers so i can make the adjustments.
Although, I am leaning more towards the variable lifters to be honest.
They really provide the reduced duration where the engine needs it, and restore to full lift right after the TC flash rpm, as AJ mentioned to me.
That should really throw in everything she's got at the right time and in the meanwhile can rumble along at low rpm.
In the email from Rhoads they did not mention to me the height of the lifter.
Maybe one of you guys who used them know?
How much difference could i get away with? My adjuster screws are on the high side with the smallest safe amount of adjustment and as long as possible push rods so i can go down if these lifters are shorter.
But if they are higher that would be a problem.
Guess they need to be adjusted down though, as in the instructions it say's you need to screw the lifter piston all the way down first.
Although, I am leaning more towards the variable lifters to be honest.
They really provide the reduced duration where the engine needs it, and restore to full lift right after the TC flash rpm, as AJ mentioned to me.
That should really throw in everything she's got at the right time and in the meanwhile can rumble along at low rpm.
In the email from Rhoads they did not mention to me the height of the lifter.
Maybe one of you guys who used them know?
How much difference could i get away with? My adjuster screws are on the high side with the smallest safe amount of adjustment and as long as possible push rods so i can go down if these lifters are shorter.
But if they are higher that would be a problem.
Guess they need to be adjusted down though, as in the instructions it say's you need to screw the lifter piston all the way down first.
WietseR/T
Active Member
Also makes me think about the current lifters i have installed.
I don't know what type i have at the moment and don't know what effect my engines relative high oil pressure has on the lifters.
Do in a normal situation hydraulic lifters stay at the same position at idle and "lowest" oil pressure?
Or are they also working a bit variable depending on oil pressure?
I don't know what type i have at the moment and don't know what effect my engines relative high oil pressure has on the lifters.
Do in a normal situation hydraulic lifters stay at the same position at idle and "lowest" oil pressure?
Or are they also working a bit variable depending on oil pressure?
WietseR/T
Active Member
I got a reply from Rhoads regarding lifter height, they are significantly higher than the current installed lifters which means in will need new push rods as well.
So going with new lifters will push probably for another $500 with shipping and import charges.
I will keep playing around for now to see to get the most out of it as is and probably plan to do this next winter.
So going with new lifters will push probably for another $500 with shipping and import charges.
I will keep playing around for now to see to get the most out of it as is and probably plan to do this next winter.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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I have never thought I might need a variable duration lifter. Not even with the 292/292/108 installed in my 367. Not even with a 4-speed and 3.55 gears.
Your Ica is 68* to my 66*;
My current cam could easily be reset to match your Ica.
Your compression degrees plus power is 216 to my 219
Your effective overlap is 68* to my 60, but roller lifters are notorious for long clearance ramps, so this number is IMO somewhat misleading.In other words, as to advertised numbers,where it counts; our cams are practically identical.
As to .050s yours is 238/244 to my 230/238; of which only the intakes make a difference. In other words Your 440 and my 367 should idle as good as the same.
Mine idles down to 550/500 in gear and pulls itself around the parking lot ......... with just 5* of idle timing.
Why doesn't yours?
IDK, but lets find and fix the secondary air leak and see what happens. My secondaries are jammed shut because she's a 750DP carb, the secondary air valves are mechanically flipped open by the primaries. They cannot stick.
Your Ica is 68* to my 66*;
My current cam could easily be reset to match your Ica.
Your compression degrees plus power is 216 to my 219
Your effective overlap is 68* to my 60, but roller lifters are notorious for long clearance ramps, so this number is IMO somewhat misleading.In other words, as to advertised numbers,where it counts; our cams are practically identical.
As to .050s yours is 238/244 to my 230/238; of which only the intakes make a difference. In other words Your 440 and my 367 should idle as good as the same.
Mine idles down to 550/500 in gear and pulls itself around the parking lot ......... with just 5* of idle timing.
Why doesn't yours?
IDK, but lets find and fix the secondary air leak and see what happens. My secondaries are jammed shut because she's a 750DP carb, the secondary air valves are mechanically flipped open by the primaries. They cannot stick.
Bighead440
Well-Known Member
You can run solids with a tight lash setting (.004-.006" etc.), but the ultimate fix for low vacuum, weak low end response is the V-Max lifters by Rhoades. You can use them on hydraulic cams and even solid FT cams to operate without lash! The way to set them is: set the cam position to base circle, run the lifter plunger TO THE BOTTOM and then back off enough to get a .010-.035" feeler gauge in there (more thickness here means more duration reduction/more vacuum increase) and then tighten until it drags-through like setting a solid lifter lash. When you remove the feeler gauge, the internal spring closes the gap so there is never free play. When the engine is started, the V-Max lifter fills with oil and maintains a low pressure inside the lifter (due to bleed-off) and lets the valve remain seated until the plunger bottoms and the valve is forced open, AFTER the lifter shell has moved upwards the amount of the feeler gauge setting. This (time) is how the cam is made "smaller", and it bleeds down less and less as RPM (oil pressure/volume) increases, until at some mid-rpm (some say 3000, others 3500-4000) the lifter cannot bleed off enough to alter the duration (change the TIME) of the actual valve events from the shape of the cam lobe. It basically separates (to a degree) valve action from lifter travel, via the plunger oil bleed-off.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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@Bighead440
I understand that,and I like it, But what are your thoughts as to valve float and PV clearance, using that method?
How fast are those lifters at 6500 rpm, if the valves fly off the nose? or bounce off the seat?
Regular lifters have a plunger travel approaching .125.
So if the Rhoads are the same, then being off the bottom .035, allows .090 additional plunger travel. Does a guy have to re-engineer his PV clearance?
How about installing some height adjuster/ travel limiters, inside the lifter bodies
I understand that,and I like it, But what are your thoughts as to valve float and PV clearance, using that method?
How fast are those lifters at 6500 rpm, if the valves fly off the nose? or bounce off the seat?
Regular lifters have a plunger travel approaching .125.
So if the Rhoads are the same, then being off the bottom .035, allows .090 additional plunger travel. Does a guy have to re-engineer his PV clearance?
How about installing some height adjuster/ travel limiters, inside the lifter bodies
Bighead440
Well-Known Member
Understand that these are V-Max and not regular Rhoads. You still have to set your VP clearance with a solid tappet or the V-Max with zero lash (bottomed). I have truly never seen the rpm limit of them, as I have only revved a 367" cast piston/stock rod J-headed 360 to 7000+rpm with a .508 Purple Plus camshaft and 273 rockers/pushrods. Ran 7.0/96mph in the 1/8mi in a way undergeared 2500lb Daytona RWD conversion. They work! I want to try them in a big-block soon, trying to figure the (over?)cam now, a '65 413 low mileage rering/bearing. Have some MaxWedge rockers or possibly Crane ductiles so I can split the ratios, if dictated by my cam choice.
Big, have u ever ran them with .002 lash like an anti pump up lifter? Or is that a no no? Kim
Bighead440
Well-Known Member
Original Rhoads call for like .030" from TOPPED against the retaining ring, but I have ran those with less, never .000-.002" like Comp and othere recommend with their APUs. The V-Max adjusts off the BOTTOM, so I guess you could TRY them .002" off the bottom, hot, but that would kind of defeat their purpose. Maybe I will try the old original Rhoads that way in a lower RPM application like a BBM or GM 455 Buick or Olds and see. Try at your own risk, Kim
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