So the op has been on lurking but won’t answer any more questions. Maybe he got an actual mechanic to work on it for him. Now is too embarrassed to join back in this thread.
Lifter preload...more or less?
- Thread starter Mojoe9955
- Start date
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If you are shimming the shaft with .125” worth of shims you are moving the rocker up roughly that far, so, the pushrod side grows roughly that much as does the valve side. I did stock magnum rockers on a sft cam with regular pushrods and used arbor shims to set valve lash under the pedestal, a .010” shim gave me way more than .010” at the valve, was happy to get them within .010” to .015” of each other, took a lot of screwing around.
In the long run I ran Hughes adjustable pushrods on the rest of my motors, they are kind of a stinker to set also.
anotheridiot
Active Member
I highly doubt this makes sense to most thinking, but I am struggling with a 5.7 hemi. What I ended up doing was using the pushrod length checker, starting with the zero lash measurement, then kept going until the valve opened. I was shocked to find the lifter opened the valve with only .139 difference. So if you can find out what that is for your brand lifter, you can find a safe point and not end up rounding off your cam lobe. Suggestion is usually .035 to .060. My case .060 wascloseto half, but I still get noise at temp.
I never thought to check the lifter plungers complete travel. Kim
Mikethegreat
Member
When I was racing in the mid 70's I used a cut up and hole punched tunafish can [thick] a beer can [thin] and spark plug washers to shim the shaft. It was a couple hundredths quicker with less preload.
anotheridiot
Active Member
When I am at my wits end, I go where I should not go. This is the problem, Starts fine, runs fine. 1500 to wherever I want to go raped ape. get home to park it and tick tick tick tick. I am about to get a plastic bag and 6 cans of spray foam to make sure I am not just hearing the noisy fuel injectors.
So I am screw this MDS. I turned off MDS and it runs about the same, went to check a solenoid and it breaks. Get a "new" set from Amazon and they leaked. Screw it, I will just get the plugs for 14.00 see what happens. Misfires at 1467. MDS cylinders. Why is MDS doing anything at idle. Well, its not doing nothing, the solenoids are not energizing to depress a pin in the lifter to make it collapse, the solenoids are always on until MDS turns them off, stopping flow to the hydraulic lifters which makes more sense. So back to getting new solenoids. Leave MDS on because, why not, I have new solenoids, lets see how this is supposed to work, codes for solenoids at idle.
So as if I did not go far enough, now I am like, well, the non MDS lifters are solids, why is the lash the same on solids and hydraulics? Should not be. Aluminum heads are expanding decreasing lash when the engine is hot.
Long story short, commit to MDS delete. Pay once cry once when I already put 2 grand more than I expected into this car by doing the eagle head swap. Now I am back to maybe trying to find a lash cap for the MDS cylinders to get more preload on the hydraulics. Some people just cannot be helped.
No lash is true but how much preload?
anotheridiot
Active Member
I bought a howards retrofit hydraulic roller for my SBC, that card also said zero lash and tick tick tick tick.
Hydraulic solids are set at zero, at temp you get .006 squish.
Hellcat lifters are all solids.
Just by definition, they cannot be the same.
I just got another 2011 from Auction, supposed to be nothing wrong with it, but right. Anyway, that has the added problem of VVT, so its keeping one or getting back into a chevy.
Rapid Robert
Well-Known Member
I'm probably missing something but I'd call it good! I do shoot for minimal preload & check the contact pattern
In an earlier post I though my question was answered and that "less is more" was the way to go. I ordered some new shorter 7.40 pushrods, installed them and although no longer have my notes I think I'm at about .035 preload. Anyhow my valve train is much quieter so I'm satisfied. I wasn't lurking but, was watching the post and read what others had posted. I also had to wait for shipping, had Covid, family obligations, and honestly as far as needing a "real mechanic" I have a broad background and am usually perfectly capable of solving and fixing most problems by myself as it's really not rocket science. Also in that time I rebuilt the front and rear suspension on my 2013 Challenger, and replaced the sensor and shift solenoid in the transmission on my 2000 Dodge van, which was used that I swapped from a 2001 van that I scrapped last year. I saved the 5.2 Magnum motor and am gathering parts to rebuild and swap into a slant 6 Demon project that I hope to get onto soon. Against others advice, I aso put 1 inch lowering blocks on the cars rear springs, so I've been a little busy.
When I rebuilt this motor I was considering an adjustable valve train but it's a little expensive so I went with the used stock parts and honestly I still have a little noise which was concerning and I think I tracked it down to some worn rocker arms and ordered a complete set of new ones from Mancini. I hope, no, I'm confident that will clear it up. If not maybe a "real mechanic" can speak up and let me know what I'm doing wrong.
Thanks everyone for your help.
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I’m glad u got it under control. Also happy u reported back with an update. Thanks. Kim
I just set it just below the lifter retainer. I've never had trouble with valve float setting it that way, my engine's 6500 rpm never a problem
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