Starting to think Morels like a little more preload than suggested

Mike T

Well-Known Member
Joined
May 3, 2013
1400 miles ago I put a set of standard travel morel rollers in my new build and was obsessed with not going over the max .025 recommended for fear of hanging a valve open at higher RPM. Well after initial break in of the motor they rattled a little. I put readjustment off because of tall valve covers and poly mounts in conjunction with flat body mounts making the passengers side a nightmare.

Finally took the bull by the horns and striped it down to do the job and before just randomly adjusting things I double checked that tolerances hadn't changed or that I hadn't adjusted them wrong in the first place. All were very even and took right at 1/2 turn (.025 in my case) to remove preload. Ended up going to a little over 5/8 of a turn past zero on readjustment and the valve train sounds MUCH better. Under just the right conditions I get just a hint of a VERY small tick so I'm thinking of going to 3/4 or possibly a full turn. In all fairness they recommend 5-30 oil and I'm running 20-50 so that could be part of the issue.
 
Do you like to adjust preload with the lifters pumped up or soft? I installed mine soft and have always performed the job with the lifters pumped up.
 
I let it set over night to help with bleed down. Was really surprised that they were still full and it took roughly 10 revolutions by hand to clear them of oil. They suggest adjusting them empty when new. Just an observation here but proper adjustment would totally depend on the spring loaded plunger returning back to the top of the lifter body.
 
Also another thought about preload..... It really seems odd that all lifters in an engine would take exactly the same amount of preload given that oil pressure, lifter bore and internal differences could vary a bit.
 
I've had the preload on my Morels at .040" for a few years and they are still quiet with no loss in performance. After talking with Steve at Full Throttle when I was ordering pushrods, he assured me that .040 to .050 preload is just fine on the Morels...even saying that many don't run enough preload.

I also used to be hung up on the whole .025" preload rule. I realize every engine is different but for someone who has issues with noisy lifters (given there is nothing actually wrong with the lifters, because there have been quality issues with these lifters), I truly believe it wouldn't hurt to try a little more preload to quiet them down.
 
I've had the preload on my Morels at .040" for a few years and they are still quiet with no loss in performance. After talking with Steve at Full Throttle when I was ordering pushrods, he assured me that .040 to .050 preload is just fine on the Morels...even saying that many don't run enough preload.

I also used to be hung up on the whole .025" preload rule. I realize every engine is different but for someone who has issues with noisy lifters (given there is nothing actually wrong with the lifters, because there have been quality issues with these lifters), I truly believe it wouldn't hurt to try a little more preload to quiet them down.


How high are you revving them? Mine are at the edge of the recommended operating limits with #400 pounds of open presser but it will still pull right up to the 6250 rev limiter and doesn't seem to fall off. Will need to re verify this with the addition preload.
 
How high are you revving them? Mine are at the edge of the recommended operating limits with #400 pounds of open presser but it will still pull right up to the 6250 rev limiter and doesn't seem to fall off. Will need to re verify this with the addition preload.

I've revved them to around 6000 several times with ease but most of the time I keep it under that....I usually shift around 5500 anyway. Also I'm still running stock rocker arms but with heavy duty shafts.
 
When I assembled my engine about 3 years ago I read many articles about hydraulic lifter preload and cylinder head / block material expansion. There was a good article about the expansion of all cast iron, aluminum head/iron block and all aluminum engines. I wish I had a link to post, but if I recall the basics it was 1/4 turn all cast, 1/2 aluminum/cast and 3/4 all aluminum.

I decided to go with the all aluminum 3/4 turn on my engine. It is aluminum head and cast, I didn't want to take a chance on to little as I don't believe I can get my valve covers back off without pulling the engine! Lol
They are running quiet compared to others I have heard and I have gone 6000-6200 RPM but normally shift at 5600-5800.
My spring pressure is a little light only around 340 open so I expect I would see valve float if I consistently ran 6000+ RPM.
 
Is there a way to adjust the preload on the stock-style shaft mount rockers other than longer pushrods?
 
Not that I am aware of? I used an adjustable push rod and 12 in calipers to find the proper length the add the pre load to it.
 
I contacted Brian at Weber and he said they DO like a full turn. I went from 1/2 to full and all noise went away, except a slight tick the first few seconds in the AM I rev mine to 6500 every time with a hydraulic roller and run 6.30 in the 1/8th. I had put way too much thought into it until I spoke with him.
 
Not that I am aware of? I used an adjustable push rod and 12 in calipers to find the proper length the add the pre load to it.

That's what I thought.

Mine are noisy as all get out, and I measured and put custom pushrods in it. I think I'm going to have to pop the valve covers and turn the engine over a few times. Any pushrod that's loose gets replaced with one that .010" longer.
 
I contacted Brian at Weber and he said they DO like a full turn. I went from 1/2 to full and all noise went away, except a slight tick the first few seconds in the AM I rev mine to 6500 every time with a hydraulic roller and run 6.30 in the 1/8th. I had put way too much thought into it until I spoke with him.

What spring pressure do run?
 
all these liters (not just Morel) like more than .025, we just don't run enough rpm to pump them up. I have run them at .070 as a test to 6300 RPM no problems. .040 is where i start and .050 is great, They really don't like or need thick oil/ either 20 -50 will make them noisy and not work well according to Morel and our testing. regardless of what some other people say i believe that. 10-40 is a really good oil for us. .
 
Not quite the topic, but anybody worried about the reliability of the Morels. I will be doing a rebuild and have to decide to reuse my Morels (with cir-clips) with only a 2000 miles or replace. Thoughts?
 
Not quite the topic, but anybody worried about the reliability of the Morels. I will be doing a rebuild and have to decide to reuse my Morels (with cir-clips) with only a 2000 miles or replace. Thoughts?
Not really for the reason your asking, but I recycled my lifters and now I have 1 that's noisy. Kinda wish I had just replaced them.

Sent from my SM-N950U using Tapatalk
 
Well there have been a few failures. I see how the c-clip could be a "potential" weak spot but If you consider the hundreds or even thousands that are out there operating and to only have a few failures I'd say the odds are in our favor.

There's probably 5 cars in our local Buick club running them without a problem other than the typical clatter now and then which could be an adjustment issue.

Now in all fairness mileage could play a major role in failure...……..IMHO driving a car a couple of thousand miles a years wouldn't be sufficient to determine if they pass the test or not.
 
Last edited:
A little update....My Morel lifters now have over 5000 miles of every day use.
I have been chasing a tick that certainly sounded like a lifter but turned out to be the cam sensor.

In the process of chasing down the noise discovered that even at .035 preload the lifters are on the edge of being a little noisy. .050 seems to be the number.
 
Top