Hydraulic/Solid lifter question

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halfafish

halfafish

Damn those rabbits, and their holes!
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As some of you know, I have been known to ponder things of questionable utility. Today as I sit here killing time and swilling coffee we have a cam and lifter question. I'm aware that if using a HFT cam you can use solid adjustable rockers for the preload on the hydraulic lifters. Is there any reason you couldn't use solid lifters too? In other words, a HFT cam with solid lifters and adjustable rockers. Obviously figuring out the lash would be part of the business. What say ye, experienced people?
 
I've heard no and I've heard yes with a tight lash set. I was pondering doing this but instead ordered a solid cam and lifters. Just not worth finding out the hard way which I'm prone to do.
 
I heard storys from back in the day some put solids on the 340 cam with 273 rockers and claimed it got them 500 more rpm .And i also heard no more than 0.460 lift or you could have problems . Idon't know if this is possible but i heard it before . I do know they are ground different so there must be a difference between the two . .
 
I've always been "taught" that solids on a hydraulic profile will eat things up as the hyd sometimes has more rapid ramps

This does not seem to be the case with rollers

Bear in mind LOTS of people have had failures with flat tappet cams because??? poor quality lifters? cams? or not the proper additives? in oil
 
Stock Eliminator cars routine do this with tight lash settings.
(0.004/.006).

Before you scream at me, understand that these engines only
run for EXTREMELY short duration and very cold water temps.
 

Yes, no problem. As others have said, you need to keep the lash tight, 0.006" at operating temp [ hot]. Comp has some FT lobes than can be runs as hyd or solid.
 
Solid lifter cams have more aggressive ramp rates than hydraulic cams. I suspect you could run solid lifters on a hydraulic cam, but you may as well enjoy the benefits of the more aggressive ramp rates of solid lifter Cam if you’re gonna run solid lifters. I can tell you from personal experience that you can’t run hydraulic lifters on a solid lifter cam.Many years ago when I didn’t know better, I let a friend talk me into trying this thinking he knew what he was talking about. I never could get the lifters adjusted and it never ran anything close to good. That engine lasted about two weeks before it came out of the car!
 
My question is, WHY? If I buy a cam, I am going to use the lifters recommended by the manufacturer. If you want to use solid lifters, why not buy a solid lifter cam. Why use solid lifters on a hydraulic cam? This is a serious question. Why do it?
 
Some people should stay in their lane. lol
He said, they said, but they never tried.
But then again those are same people bashing comp cams. lol
 
harrisonm said:
My question is, WHY? If I buy a cam, I am going to use the lifters recommended by the manufacturer. If you want to use solid lifters, why not buy a solid lifter cam. Why use solid lifters on a hydraulic cam? This is a serious question. Why do it?
Click to expand...
This is purely an academic exercise. I just wondered if it would be OK or not.
 
i fitted hydraulic lifters to a solid cam in a rover v8 (buick 215 rebranded here in the uk). a previous owner had not used adjustable rockers and couldn't get it to run after the cam swap. it had no compression on any cylinders as the valves couldn't close. it ran fine with the hydraulics while i owned it, i sold the car (59 ford consul) to a mate who ran it for 4 years with no issues 'til he sold it too. so hydraulics work on a solid cam, at least from my experience.
neil.
 
mygasser said:
i fitted hydraulic lifters to a solid cam in a rover v8 (buick 215 rebranded here in the uk). a previous owner had not used adjustable rockers and couldn't get it to run after the cam swap. it had no compression on any cylinders as the valves couldn't close. it ran fine with the hydraulics while i owned it, i sold the car (59 ford consul) to a mate who ran it for 4 years with no issues 'til he sold it too. so hydraulics work on a solid cam, at least from my experience.
neil.
Click to expand...
Thanks for offering your experience, I never tried hydraulic on a solid shaft.
 
It is incorrect to claim that FT cams have more aggressive ramp rates than hyd cams. Roller cams are different.
With FT cams, the maximum rate of lift is governed by tappet diam. Rate too high, lifter edge digs into the lobe.
With the cam sitting on the bench, it rotates 360* for a full revolution.
The sol lifter cam requires longer lash ramps because it does not have the hyd 'cushion' of the hyd lifter cam. So more of the 360* is used up for lash, leaving less of the remaining 360* for the ' heavy' lifting.

Here are two Ultradyne high rate cams. Top one is hyd, bottom one sol. Using the same 050 numbers.

050/.200 lift/lobe lobe lift. Lift at centrelines 104,106,108,110

239/151/0.3383.... .100, .093, .086, .080

239/150/0.340....... .097, 0.091, 0.084, .077
 
harrisonm said:
My question is, WHY? If I buy a cam, I am going to use the lifters recommended by the manufacturer. If you want to use solid lifters, why not buy a solid lifter cam. Why use solid lifters on a hydraulic cam? This is a serious question. Why do it?
Click to expand...
Why do it?
Assuming you already have a hydraulic cam in your motor, solid lifters can get you more rpm, more horsepower, depending in the quality of the hydraulic lifters and stability of the valve train (geometry, and spring rate).
Personally, I don't think I would try on a hydraulic flat cam, chances of improvement are fairly slim, along with possible destruction. I think I would try, on a hydraulic roller motor, cause the hydraulic rollers are quite a bit heavier than a solid roller. And just swapping lifters is cheaper than a full hydraulic to solid cam swap. And lighter lifters will help with stability without having to increase spring pressure.
Why not do it?
If you don't have an adjustable drivetrain already, you would need rockers or adjustable pushrods. Additional expense.
 
This was common practice in the old days 50's-60's as HP cams "race cams" were few and far between and engine model selection was very scarce, and also very expensive.
When i built my first hot rod motor a 51 Cadillac bottom end and American Cyl head 56 caddy heads I used a 58 caddy cam with chevy solid lifters, "thanks Mr Duntoff for the Duntoff 30-30 cam and lifters so solids were readily available" used the stock caddy pushrods and rockers from a Studebaker V8 as they were adjustable. Had to use two rocker cover gaskets and dimple the rockers to clear the adjuster screws, set the clearance .004" hot I could tirn the engine a little past 6000 RPM with this setup.
You had to be inventive back then as a dollar issue was prevalent then especially as I was just a teenager in high school then.
 
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