Moparts

Preload on Hydraulic Lifters

Posted By: The Shocker

Preload on Hydraulic Lifters - 05/30/10 02:12 PM

I was planning to upgrade to a solid cam ,but i just cant bring myself to tear into this thing andd just upgrade the cam.i have decided to wait until it needs to be freshend up and just pull the motor and upgrade the cam then.Until then i have decided to just try and get what i can from the current setup.Its running 7.20's in the 1/8 and 11.40's in the 1/4 but has a problem .The cam is a hydraulic .488/.510 with 234 duration @ 50.Its designed to work from 1500-6500.The problem is when i get to about 5900-6000 its fading.The guy i got the car from told me that he set the valves at "Zero" lash .Im begining to suspect that its lifter pump up thats causing the problem and not the springs.These springs were matched to the cam and it doesnt have much lift with the cam anyway.Yesterday i relashed the valves.I wanted to do it with it running ,but that proved to be impossible with the shaft rockers .Its got Harland Sharp 1.5 rockers with Econo W2 heads and this is on a 10 to 1 408 stroker.I am a former Chevy and Ford guy and im not sure if i did it right adjusting them with the engine not running and was hoping someone could tell me either way befroe i race it agian .I warmed the motor up about 10 minutes ,then backed the lock nuts off on one head.I then bumped the starter over until the rocker was on the back of the cam lobe .I backed the adjuster off until the pushrod was loose and went back slowly till i felt a tiny bit of drag with my fingers.I then preloaded them by 3/8 of a turn more and locked the jam nut down.Went down the head doing this one rocker at a time.I then cranked the motor to get it warmed up again and the lifters pumped up ,shut it off and repeated the process to the other head .The motor sems to run as it did before down low ,but i havent havent raced it yet either.I dont want to take a chance of hanging a valve open or colapsing a lifter ,but it seems fine .Is 3/8 turn preload too much for this Mopar or not enough ???
Posted By: smokinwoody

Re: Preload on Hydraulic Lifters - 05/30/10 02:27 PM

I sent you a PM...nice Dart...I had a 64 Dart GT back in 69...was a fun car
Posted By: Crizila

Re: Preload on Hydraulic Lifters - 05/30/10 02:56 PM

Mancini sells a nice little sticker that you can put in the engine bay that gives you the proper adjusting sequence ( 2 rockers at a time ) so you only have to rotate the engine 720 degrees to get them all done. Any amount of preload will work. 3/8 is fine. I do mine at 1/4 turn. The key is to make sure the lifter cup is not riding on the cup retainer. With a minimum amount of preload, you stand less of a chance of crashing the valves in to the pistons if you are experiencing valve float and the lifters pump up. If the springs are right for the application and in good shape, you are probably not experience valve float at those rpm'S. When you have valve float, it's almost like turning the key off - motor just dies.
Posted By: The Shocker

Re: Preload on Hydraulic Lifters - 05/30/10 03:19 PM

Thanks guys ,i feel better about it ...
Posted By: emarine01

Re: Preload on Hydraulic Lifters - 05/30/10 03:40 PM

We ran a hyd roller in a w2 headed small block a while back with o lash, no pre load, you need lifters with spap rings not the light clips, It gained us around 300 rpms up top from 1/4 turn pre load, we ran that way for a season with no problems race only
Posted By: RemCharger

Re: Preload on Hydraulic Lifters - 05/30/10 06:21 PM

I ran the comp cams Promagnum hyd lifters which call for .002-.004 preload hot. basically a hyd lifter that performs like a solid.
I don't see any point in screwing down a lot of preload .... other than keeping a cheap lifter from blowing the plunger out ,as mentioned.
Posted By: Crizila

Re: Preload on Hydraulic Lifters - 05/30/10 11:43 PM

If you are running any kind of performance cam and lifters, the lifters should come with the good "E" clips. I would still run some preload, just to play it safe - IMHO.
Posted By: Cab_Burge

Re: Preload on Hydraulic Lifters - 05/31/10 03:28 AM

Different brands of hydraulic lifters(and stock versus anti pumpups) want and need different amounts of preload. I'm going to assume you have adjustable rockers with 3/8 adjusters with fine threads, 24 per inch which equals close to .042 per thread of preload. I like to warm the motor up, go drive it for at least twenty minutes to get the oil warmed up and then set the valves, try 1/4 turn(.0105) of preload from zero and see if that helps. the try 1/2 turn(.0210) preload. Most hydraulic lifters can absorb .030 of travel, not much more
Posted By: The Shocker

Re: Preload on Hydraulic Lifters - 06/01/10 12:44 AM

Quote:

Different brands of hydraulic lifters(and stock versus anti pumpups) want and need different amounts of preload. I'm going to assume you have adjustable rockers with 3/8 adjusters with fine threads, 24 per inch which equals close to .042 per thread of preload. I like to warm the motor up, go drive it for at least twenty minutes to get the oil warmed up and then set the valves, try 1/4 turn(.0105) of preload from zero and see if that helps. the try 1/2 turn(.0210) preload. Most hydraulic lifters can absorb .030 of travel, not much more

Yes i do have adjustable Harland Sharp roller rockers on it .Thanks for the help on this guys .Im gunna try and haul it to the track next Friday for sum TNT and see if i gained any rpm with the preload on the lifters .Will report back with the results .If this doesnt help im gunna pull the bumpstick in favor of a Solid ,with more valve springs .No more nostalgia races till September anyhow ,so i have plentyo time to change it out...
Posted By: Cab_Burge

Re: Preload on Hydraulic Lifters - 06/01/10 02:48 AM

I forgot to mention that the motor that is in my Duster now has a Comp Cams XE295 HL (hydraulic lifters) hydraulic cam and lifters, I have shifted it at 6000 and at 6900 RPM with almost no change in the time slip this past Saturday I did set the preload at 1/4 turn from zero play with harland Sharp 1.5 rockers I do set my valve spring tension up a little hgher than most, 150 to 160 lbs. on the seat and 360 to 375 lbs opened
Posted By: The Shocker

Re: Preload on Hydraulic Lifters - 06/01/10 10:39 AM

Quote:

I forgot to mention that the motor that is in my Duster now has a Comp Cams XE295 HL (hydraulic lifters) hydraulic cam and lifters, I have shifted it at 6000 and at 6900 RPM with almost no change in the time slip this past Saturday I did set the preload at 1/4 turn from zero play with harland Sharp 1.5 rockers I do set my valve spring tension up a little hgher than most, 150 to 160 lbs. on the seat and 360 to 375 lbs opened

I agree that there is no sense in spinning a motor higher than the output of the cam .On the other hand having it cutting up 40 or 50 ft from the end of the 1/8 at 5900 rpm couldnt be doing my ET much good .Im not trying to get it to rev higher persay ,im just trying to have enough rpm to get to the end of the track pulling the whole way.I think 6300 rpm would sure help if not cure the problem.I could change my gears ,but then it would proly take away from my 60 foot and the car is hooking great and consistant as is ,so i would like to leave that alone.I have never been much of an RPM junkie ,just trying to get what i can from what i have and get things tweaked as much as they can be ...
Posted By: RemCharger

Re: Preload on Hydraulic Lifters - 06/01/10 04:14 PM

Quote:

Quote:

I forgot to mention that the motor that is in my Duster now has a Comp Cams XE295 HL (hydraulic lifters) hydraulic cam and lifters, I have shifted it at 6000 and at 6900 RPM with almost no change in the time slip this past Saturday I did set the preload at 1/4 turn from zero play with harland Sharp 1.5 rockers I do set my valve spring tension up a little hgher than most, 150 to 160 lbs. on the seat and 360 to 375 lbs opened

I agree that there is no sense in spinning a motor higher than the output of the cam .On the other hand having it cutting up 40 or 50 ft from the end of the 1/8 at 5900 rpm couldnt be doing my ET much good .Im not trying to get it to rev higher persay ,im just trying to have enough rpm to get to the end of the track pulling the whole way.I think 6300 rpm would sure help if not cure the problem.I could change my gears ,but then it would proly take away from my 60 foot and the car is hooking great and consistant as is ,so i would like to leave that alone.I have never been much of an RPM junkie ,just trying to get what i can from what i have and get things tweaked as much as they can be ...

I have the exact same problem at the end of the 1/4.... about 150? from the stripe. Since this is a nice little street 440, I'm going taller tires instead of digging into the motor, until my race engine is back together.
Posted By: Cab_Burge

Re: Preload on Hydraulic Lifters - 06/01/10 05:01 PM

I forgotto mention that I was running on a 1/8 mile Saturday,not a 1/4 I use to race a NHRA stocker(must use hydraulic lifters)1970 Hemi cuda, that motor was sensitive to the prelaod, 1/4 turn was better than a 1/2 or a full turn. the preload made the difference in the upper RPM, above 6000 Test yours
Posted By: The Shocker

Re: Preload on Hydraulic Lifters - 06/01/10 09:17 PM

Quote:

I forgotto mention that I was running on a 1/8 mile Saturday,not a 1/4 I use to race a NHRA stocker(must use hydraulic lifters)1970 Hemi cuda, that motor was sensitive to the prelaod, 1/4 turn was better than a 1/2 or a full turn. the preload made the difference in the upper RPM, above 6000 Test yours

Cant wait to try it out.May go Friday night and see what she will do with sum lifter preload .I added a 1 inch carb spacer as well as jetted her up a bit more since i ran it last ,so it may not be a fair comparison ,but we shall see if it will turn any higher . Thanks again man.You are alot like MRPBody as far as helpfull advise goes IMO,without sarcasim to us that are trying to learn ...
Posted By: 3ddart

Re: Preload on Hydraulic Lifters - 06/02/10 12:13 PM

cab's a good guy!!! lots of experience and willing to share it. mike's a good guy also.
Posted By: Mac's Hemi 64

Re: Preload on Hydraulic Lifters - 06/02/10 01:43 PM

He made me have traction problems!
Posted By: The Shocker

Re: Preload on Hydraulic Lifters - 06/12/10 06:12 PM

BINGO!!!I ran the car last night and it will go all the way to 6200 (maybe more ,but didnt try)without nosing over with the lifters preloaded 3/8 of a turn.With the lifter set at true Zero lash as it was it would fall off at 5800-5900 and start breaking up.I will post a vid later and you can hear how clean it is in the lights at 6100-6200.Thanks guys for the help widit .If anyone tells you that preload on hydraulic lifters makes no difference on float at high rpm,they are sadly mistaken ...
Posted By: 65 DODGE POST

Re: Preload on Hydraulic Lifters - 10/18/12 08:03 PM

I know this is old....but I just threw some W2 heads with 1.7 Harlands on my 318...I set mine at 1/4 turn...running a MP Purple 227/231 @ .050
I was wondering if you knew the spring pressure with your setup....Mine is 110 seat....330 Open.....I want to go to the track this weekend....I just do not want any valve float...or loss of power...
Posted By: Thumperdart

Re: Preload on Hydraulic Lifters - 10/18/12 08:19 PM

Quote:

We ran a hyd roller in a w2 headed small block a while back with o lash, no pre load, you need lifters with spap rings not the light clips, It gained us around 300 rpms up top from 1/4 turn pre load, we ran that way for a season with no problems race only

That`s how we set up the stockers at Pettis and the dyno numbers confirmed it made the most power compared to being pre-loaded..........
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