Technical 389 cu. in. Roller SBC Build

It shouldn't be that hard. This is tried and proven ground. Sometimes it feels like I'm trying to re-invent the wheel! But it's starting to come around. Thanks guys for your input.

 

Here is a rehash of the link to the MOREL lifter thread... https://www.jalopyjournal.com/forum...r-recommendation-usa-made-preferable.1069388/

​

Well, I just found out about MOREL lifters the other day. Here's what happened. Last June when I built this motor, I used a mild Comp roller cam, XR264HR-10. I never did a roller before, so I thought I'd give it a try.

When doing some research on the cam and lifters, I found that Comp was having some trouble with their lifters collapsing and being noisy on start up, due to being sticky from cosmoline applied at the factory.

So everyone said they were switching to Howard's lifters. (I think it's because they're only $392 instead of $457 and up.) Anyway, I thought I'd get the jump on it by starting with Howard's Rollers #91164N. https://www.howardscams.com/hydraul...t-lifters-chevy-265-400-howards-cams-91164n-2.

When I first tried to prime the oil system (with the proper tool and a 1/2" drill), it took forever to get oil up to the rockers. When I first fired it up, it rattled excessively, so I re-adjusted the valves while running.

It seemed to settle down some, but there were a few rockers that wouldn't stop clacking. They always made a considerable amount of noise. I figured I'd drive it a while and see what happens.

Sometimes it would go away and sometimes it was worse. I couldn't tell if it was temperature or weight of the oil and sometimes it didn't matter. I tried everything.

Well, after about 6,000 miles it broke a rocker stud. Then a month later it broke another stud. So, I installed all new studs and .100" shorter pushrods (because they were about .050" long), but it seemed to be worse than before.

I started checking some other things and found that two lifters were stuck at the top of the preload. They were also the same ones that the studs broke on. They wouldn't bleed down by adjustment. The plungers were stuck and acted like solids!

I finally decided to get another new set of lifters and my parts guy sold me a set that were made in the USA by MOREL. I did some research and found that MOREL is a subsidiary of Callies Cranks, and they make lifters for a lot of cam companies, including Howard's under private label. MOREL #5372 is Howard's #91164N.

Are they the same inside? I don't know, I'll let you know in few days when I get them installed.

​

Well, I received the new MOREL lifters on Friday. (#5372 on the box - same as on the Howard's box). I believe they're exactly the same, except no name etched on the tie bar. Anyway, I got her running on Saturday.

I discovered that Morel lifters like a LOT of preload! According to the reference made by Russco in post #18, it says .030" - .035" preload is normal for an iron block with aluminum heads. (thanks Russco)

With 3/8-24 studs, each 1/4 turn on the rocker nut gives .0105" preload, and 1 full turn gives .042". I also found there is .120" travel in the plunger, so there is plenty of room before bottoming out. I also installed new rockers at this time.

I lubed the new lifters in 10-40 oil and installed them. I adjusted the rockers to 0 lash +1/4 turn, like I always did with flat tappets, and primed them with a drill. It only took about 30 seconds this time, and I had oil squirting over the fenders. That's what I like to see!

But they made a lot of noise when I first fired her up, so I went 1/2 turn, still not enough and then I went to 3/4 turn. I may go 1 full turn for good measure.

I still don't know for sure why the lifters failed, but It's running good now!

​

Well, I'm not completely satisfied yet. I ended up at 1 1/8 turns preload. That's way more preload than I like to run, but it seems quieter. I might have a couple of valve guides getting loose and that's probably contributing to some extra noise.

When I'm just putting along at about 1500 rpm, I can hear it come and go in a harmonic cycle. One guy told me to try a heavier balancer. I might try that.

It seems to make more noise after it gets up to temperature. When its cold, it's the quietest. Everybody I talk to says to give it a full turn preload. I still think it's too much preload, and way more money spent than I like, for a noisy set of roller lifters.

I'm working on putting a set of stud girdles on it. I read that it will stop the studs from flexing and snapping off. I have 3/8" studs and they say they flex a lot after .500" lift. I'm running .530" lift and beehive springs. I'll get her figured out one of these days.

​

Tickety Boo said,
"When you get the long stud girdle nuts on, before installing the girdle, pull the coil wire and have some one turn the engine over while you watch the 3/8 stud flex. You will be amazed at how much movement there is, the long nut for the girdle makes it more noticeable. I run a girdle on all my engines with a performance cam/springs since seeing this."

Yes! Thanks Tickety Boo for the confirmation.

I've heard it to be about .015"-.020" flex, and if it's continually clacking, it's like an impact wrench pecking on the stud, and finally it breaks away. I will check this to satisfy my mind.

This motor has been a big learning curve for me, but I'm too close to give up now!

​

I put the girdle on today, after I measured the flex on the 3/8" studs. It was right at .013". I could actually see the studs flex as I cranked it over!

I will probably always run a stud girdle from now on. It took the rocker noise out and now it sounds like a well oiled sewing machine.

​

Today I went on a 40 mile breakfast run with the guys in the club. I couldn't believe how much smoother the motor ran after installing the stud girdle! It even has a couple more inches of vacuum and noticeably, a little more power. WOW!

Also, there was always this certain vibration at about 48-53 mph that I'd have to drive through. Now, it's almost undetectable. I always thought it was the front end or tire run-out/balance or something, but I could never find it.

Today I found it. Rocker arm stud flex! Who would of thought?

​

I've been re-thinking this roller cam thing. (There I go, thinking again! ) My motors in this car always had a vibration or shudder at about 3500 rpm under full throttle, even with the flat tappet cam. It was an XE262H-10 with springs and 1.6 rockers, which gave it right at .500 lift. I liked that cam a lot!

It did break a rocker arm stud one other time on a set of re-worked iron heads with screw in ARP studs. I fixed it and never gave it another thought.

At about 1500 rpm when puttin' along, the front end had this shake like a tire was out of balance or something. I checked everything, including the drive shaft for balance. I even had the wheels straightened and trued to no avail. I even thought it might be the cam loping at that speed.

I did find a front rotor that the studs were not concentric with the bearing surface. They were Chevy rotors with a Ford bolt pattern and the studs were .030" TIR out. That's another long story for another time.

When I built this 389" motor and did the roller cam, all of these vibrations became very apparent. This motor balanced out perfectly, so I never considered that. I never gave it a thought that it could be rocker arm stud flex.

Could it be that the lobe profile of the roller cam, being much more aggressive off the base circle, and the beehive springs being a little more pressure over the nose, make the rocker studs flex enough without a girdle, to make the whole care shudder at these different rpms?

I don't know, but it's a different motor today!

 

Here is an interesting video about changing rocker arm ratio geometry with pushrod length. It's not what everybody thinks...

It's about shorter pushrods giving more lift per degree of cam rotation!
GOOD STUFF!

 

Thank you ,it was very good

 

What this video actually accomplishes is changing the contact point on the end of the valve stem where a slight advantage can be gained for lift. In racing short distances where every last hp is being sought, thats a nice trick.
For a street driven vehicle I would be concerned that the side pressure it would induce on the valve tip would result in increased valve guide wear. If I was going to want more rocker ratio I think I would simply go with a rocker that had an increased ratio and some high perf pushrods of the correct length. In racing, I think many times racers may be limited to a certain ratio like 1.6 and they are just looking for ways to obtain more lift while working within the confines of the rules.
When you start changing the angle of the rocker arm you also have to insure that it doesn't cause interference between the spring retainer and the bottom of the rocker arm. I'm looking for a solution to installing some roller rocker arms on 500 Cadillac heads. Right now the only bolt on option is rediculously priced, so I'm looking into what I may be able to morph from some other engine. Think I'll just start a thread and ask for some ideas.

 

Just got wind of this, very interesting and significant. I wonder how many racers confined to cam and rocker arm limits knew about this trick? Here is a snippet of the results from the video.

 

Just a guess, as I'm not an expert on harmonics. When you change components in an engine, the harmonics it produces change too. The stroker may balance perfectly, but the harmonics produced will occur at a different point.
If you are using a stock balancer it is tuned for the range where your original stock 350 produced harmonics. Some times its not a problem, sometimes it can be. I think I would look into getting a Rattler or a Fluidampener that covers all rpm ranges.
Hazarding another guess, it could be that the harmonics of your cam and the harmonics of the crank now play off each other where the different harmonics of the flat tappet didn't. Whatever the reason, dampening the crank with a more efficient dampener shouldn't hurt anything. Will it help, I don't know.

 

I was steered to 7/16" studs by my engine builder, what are you running?

 

I hear what you're saying. I admit that I don't understand harmonics either. All I know is that when I put a stud girdle on, it was noticeably smoother all around.

I think the valve timing was greatly affected by the stud flex and consequent random preload variation, which made the motor run ragged. It also stressed the studs past their limit.

Anyway, I'm fairly happy with how it runs now, but I did have my doubts for a while.

 

3/8" - It was a weird thing. I never did a roller cam before. If I had to do it all over again I would have started with 7/16" studs, but it broke a rocker stud first. I changed it and then a month later it broke another. Finally I put a whole new set in.

I had no idea the 3/8" studs flexed that much at only .530" lift. I couldn't get the rockers to quit clacking.

I thought it was one thing, and then another, and I changed the questionable parts one set at a time. Pretty soon I had everything new again; 3/8" studs, lifters, pushrods, rockers. Then I learned about stud girdles. Thankfully that fixed it.

 

Oh, I thought the stud girdles had "mostly" solved the problem but that you were still noticing a minor issue.
My Bad.....

 

.530 is not that much of a lift either. I'm at a .504 lift with a 268/276 flat tappet cam. I have to get a valve cover off to add another breather, will look everything over at that time.

 

Well, I was chasing a number of things at one time. I didn't realize that the roller lifters needed a full turn of preload. I always used 1/4 turn on the flat tappet cams with success, and I thought these would be the same. Not so!

I think the valving is different in the roller lifters, so they recover faster with the added weight and extra spring pressure. That would make them clack with 1/2 to 3/4 turn preload. I wasn't used to that much preload. I was a little confused.

When I finally turned them in one full turn and measured the stud flex, I was shocked when I saw .013" flex at the poly lock. Everything seemed to straightened out when I installed the stud girdle.

 

I'm using a XR264HR-10 with 1.6 rockers and Beehive springs.

 

I think the preload thing threw you. I'm not familiar with roller cams myself, but will use one on an upcoming BBC project.

 

Yes, you are right!

I went from an XE262H-10 flat tappet to the XR264HR-10 roller, because it had similar advertised duration, but less @ .050". I was a little too cautious on going overboard with my first roller, and I lost that sweet sound the flat tappet cam gave me with a little more duration @ .050". Oh well, it's only money. Next time...

 

I had no idea Col. Sanders worked for G.M. and Crane Cams. I am Butch/56sedandelivery.

 

I went a little conservative on my FT cam, I could have gone to the next one up in the Lunati Voodoo series. I was expecting a little more lope out of it. BUT it goes like a scalded dog and has great street manners. I'm looking at a few Howards kits for the BBC.

 

On a BBC it is even easier to go too small, because of the large cu. in. and large ports. BBC's are more forgiving on over caming than SBC's.

If it's a certain sound you like, find one that is running already and lean towards that duration @ .050" and LSA around 110. Higher LSA will take the sound away too.

Also, remember that a roller will take away some of the sweet exh. sound (duration for duration), because of more lift "under the curve" per degree of rotation. On a BBC it's a $400+ mistake instead of $200.

I think my 389" motor fooled me too, because of the larger cu. in. That same cam in a 283 would sound BAD!, but never make the power of the 389". Oh well.

Look on U-Toob and find some sound bites of the cam you think you want and go from there. Also on Comp's site, they have dyno sheets and you can pick the highest torque nearest the RPM you like to run at. That's what makes it street friendly and get good mileage.

A few simple cam rules:
(generally speaking)
More lift makes more torque,
More duration makes more RPM,
More torque and or more RPM, makes more HP.
Wider LSA extends the power curve past the peak.
More overlap (and or lower LSA) makes sweet sounds.
There's always somebody that has a better idea and will knit-pick these rules!
If you error on the side of conservative, you will be much happier than the alternative.
Bigger is not always better!

Our job is to pick the right combination for our application.

 

Yeh, a simple rule of thumb for street engines when looking at specs in the camshaft book........................stay away from the bottom of the page!

 

LOL

 

My LSA is 110, the next one up was 108, but I'm happy with the performance. With the stock cars I had Chet Herbert grind up a cheater cam for that, idled TOO well for me, but it had a great pull down the straights.

I did listen to a bunch of sound bites before I bought the cam, they are pretty helpful.

 

Well, it happened today, it broke the nose cone right off the starter. Ouch!

 

Ouch!

 

I put the brace on it this time!

 

Wow ! Good thread.

 

Sure seems like you’re having plenty of trouble, more than your fair share. Trouble with the obscure as well as the basics.

 

I know... Just when you think you got it figured out, somebody changes the rules! (Mostly me.)

 

Might just be camera angle , but Wow ! That header/ starter placement look close ! Maybe think about a mini starter , Mind's been good for 20 years & 50k miles on a 10.2:1 389 sbc

 

Tom let me know the engine application and I’ll get you a GM PMGR (permanent magnet gear reduction) starter. You won’t get the heat soak problem that the copper fields will give you on the original 10mt starter. It’s quite a bit shorter also.
Charlie has made the most of self isolating and has got a ton done on his 29 RPU. I guess since the gang has not been there to distract him it’s made a big difference
Hope all is well stay healthy.


Sent from my iPhone using The H.A.M.B. mobile app
www.speedoservice.com
Should I rush your rush job or the rush job I was rushing when you rushed in?