hamrad

Some of you may have read my 350 to 454 swap thread. If not as you can guess I swapped in a 454 in my 1973 L48 coupe. I am having an issue and need some help. The engine seems to have a slight miss at idle and it increases with RPM. It feels like a slight vibration but I am pretty sure its a miss. I am thinking it could be a bad lifter or maybe a couple bad lifters. Help me decide.

Motor is a 454 mark IV with speed pro hyper pistons. Compression ratio approx 8.5
119cc oval aluminum heads
Has the 454HO roller cam.
Camshaft Lift (in.): .510 intake / .540 exhaust
Camshaft Duration (@.050 in.): 211° intake / 230° exhaust
Weiand street warrior intake
Rugges reworked quadrajet
Everything is new, distributor, wires, plugs, etc.
The roller lifters were used but I was told they only had about 1,000 miles on them. They are Crane retro roller.

The motor sounds good when cold. After it warms up it has a ticking noise that I consider fairly loud. I can hear it inside the car driving down the road. I have lashed the valves several times and it stays the same. The last time I lashed the valves I noticed I could push on some of the pushrods and bottom them out in the lifters. This happened just after it was running. It seems like they bleed down quickly. Not all of them but probably 3 or 4 of them. Oil pressure is good, 65 lbs cruising and 35 at 700rpm idle when warm. Tried 10w-30 then 10w-40 oil. No change.

I have tried all the usual fixes. New plugs, different carb, timing adjustment etc. I am thinking the hot tapping noise and miss must be related. But the miss is always present hot or cold.
What would you guys do to track this down?
Thanks!

Bullshark

Check your cam Sounds just like my old 454 when it started to wipe a lobe.

HeadsU.P.

I think your best bet is to pull the intake for a visual inspection of the lifters. Somethings not right. With any luck, its the lifters collapsing. Not a cheap fix but easier than the second possibility. And that would be a restriction in the oil galley. Any blockage in the galley would keep the lifters from ever pumping up. That issue would involve removal and cleaning of the oil galley plugs. And they are behind the block, labor intensive being that the plugs are inside the bellhousing. Hope its not that.

You should never be able to push the pushrod down with your hand. A normal oil pressure reading on the gauge does not insure that the lifters / galleys are getting full oil pressure. Pull the intake and have a look-see.

HeadsU.P.

Roller lifters.

hamrad

All the rockers are getting oil so hopefully there isn't a restriction.
Guess I'll have to pull the intake and see if I can find anything. I'm at a loss at this point.....

ronarndt

Before you start taking things apart, see if the rocker arms are moving up and down like they should. Take your spark plugs out to make it easier to turn the engine. Put a socket wrench on the bolt on the harmonic balancer and turn (clockwise) the engine over by hand. With the valve covers removed make sure the intake and exhaust rockers are going up and down in the firing order sequence 1 8 4 3 6 5 7 2. If you spot one that is not going down all the way it means that cam lobe is worn down or the valve lifter is bad. You can also crank the engine with the starter, but everything moves faster, so you may need a helper to help you look.

OldCarBum

How about using a stethoscope and listen through the valve covers at idle and bringing up the rpm's a little at a time.
It may help pinpoint the ticking to a specific location before you start to tear things apart.

73racevette

I would take a listen with either a stethoscope or just a long screwdriver or socket extension held to your ear with your fist. You should be able to isolate the location of the noise. If it is a single lifter, you should be able to find the general location of which lifter. Also you will notice it is turning at 1/2 the speed of the motor.

Unfortunately, if the sound is throughout the entire block, it could be the wrong bearings or bearings with too much clearance have been installed in the motor allowing the crank or rods to move in the bearings. Don't ask how I know this.... This sounds scary, but can be an easy, although messy, fix if you have not wiped the crank or something. If you wipe the crank or one of the rods, then it is machine time, so keep the run time to a minimum until you figure this out.

hamrad

I tried to listen with a piece of vacuum hose and even tried with a socket extension but can't pin point the noise. It sounds almost like it is right at the lifter. I have read they can make more of a ticking noise than flat tappets and would probably write it off as such if it did not have the slight miss.
I thoroughly checked all the bearing and thrust tolerances when I assembled the motor and they were all fine. This is the first retro roller I have tried.

I wasn't sure if I should be able to bottom out the push rod in the lifter body just by pressing on the rocker. I had run the motor about an hour driving around and pulled the passenger side valve cover to adjust the lash and noticed I could push on a couple of the rockers and bottom out the lifter. Just should have bought new lifters but figured if these had less than 1000 miles they should be fine.
Thanks for the suggestions so far............

73racevette

Sounds like possible incorrect lifter for the bore or a bad lifter. Doubt you would have more than one bad lifter, so if you have multiple, maybe they are incorrect for the engine? Just a guess. They should not be able to leak down enough after running to push down with your hand.

OldCarBum

Did you soak and pre-load the lifters before assembly?
Measure and inspect each push rod?
You said you purchased used lifters.
Maybe there was an issue with them and the person you purchased them from "failed" to mention it to you or post it in their add.
Seems suspect they would sell a set of lifters with 1000 miles on them.

hamrad

Yea I am starting to think they probably "failed" to mention the issue.
Seemed like a GREAT deal at the time. This was an $800 set of lifters for 1/4 the cost. Oh well, live and learn.........

derekderek

Those three or four lifters are bad. And of course it's not going to be both of them on one pair either is it? Or can you take the tie bar off of the two and separate them? Cuz buying four rollers is a lot less expensive than buying 16 of them. But if you can compressor right after shutting the engine off they're no good. Or at least they need to be taken apart and cleaned out. That might be worth trying. Vacuum hoses too small for stethoscope. Piece of heater hose will work. Running engine with the valve covers off. Oily mess but you can just about put your hand on the Rockers and feel them clacking as it's doing it.

HeadsU.P.

There is no sense in trying to salvage a lifter or two. Lets face it. You bought junk and now you are paying the price. Pull them all and be done with it.
When you install your new, better quality roller lifters, check the pushrod length geometry with a special tool just for that purpose. I would suspect that the pushrods are of the wrong length, but maybe not. I sure would double check.

TimAT

Take a look at these lifters. About what you paid for the"used" lifters.
http://straubtech-morellifters.com/c...-lifters-4603/

FWIW: I'm running Morel solid rollers in my BBC- and they're rebuildable.

OldCarBum

terrys6t8roadster

My engines have Morel and Crower solid rollers, but I'm a small block freak. T

derekderek

There are YouTube videos on disassembling and cleaning out hyd lifters. You paid for these. If the rollers aren't coming apart, they may clean up. DON'T BUY AN EBAY SET NEW FOR 200 BUCKS!!! Those will come apart and wreck your engine.

chevymans 77

Pull the lifters that are of concern and pull the internal piston out, closely inspect the check valve spring and ball along with the sealing surface of the hole in the piston. Its not common but does happen for there to be build up on these parts and cause sealing issues which will allow them to bleed down also check the internal bore for build up
.
It is rather common for the newer LS engines to have lifters that will stick down in the bore a little and cause a lifter noise at cold start up but will usually stop after warm up, usually caused by poor maintenance, low quality oil. I've taken them apart just to see the check valve ***** coated with a varnish and it leaves a rough finish that will prevent sealing. It doesn't take much buildup on the internal wall to prevent the piston from reaching the top of its travel which will cause a taping noise at start up or may not stop depending on how far down the bore its stuck.

Neal

derekderek

But, these aren't original lifters. Build up takes time to build up. More than likely these are fairly new and the guy had a couple that bled down, so he dumped them. there are also partial sets of used lifters out there. Once the guy wrecks two of them, he has 14. Reduces their value quite a bit.if you can find a partial set of the identical lifters you have pistons and ***** and check valves and all that you can sit down and make yourself a good set. As long as you are sure that all the rollers on the bottom of the lifters feel good. That's the part that will destroy an engine.
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