noob valve spring question

[Keystone]

Hi everyone, my first time doing valve springs. The engine is the rebuilt (by the previous owner) 318 that I was told is from an 80's Ramcharger. He used a Summit K6900 cam but left the stock springs. I thought that the bad cutting out when it hit about 4000 rpm was a fuel problem, since it still had a 2bbl on it, but after changing to a 4bbl I've now concluded it's valve float since I can duplicate it with the trans in Park by slowing increasing the throttle.

I ordered a set of TrickFlow TFS-16901-16 springs and the matching TFS-514000423 retainers from Summit. I've gotten as far as taking one spring off and noticed there's a shim under it. My first question is, do I reuse that shim with the new springs? I'm guessing no, but thought I should check.

Second question, which is the real problem... When I put the springs in my "cart", I also added the retainers that Summit said were required.

I just found out when struggling to get the keepers to fit that they are for use with 0.342" valve stems:

I measured the valve stem and it's 3/8". Does anyone know if the Comp Cams 740-16 retainers will work with the TrickFlow springs? The application tab says they cover a wider range of valve stem diameters:

COMP Cams Steel Valve Spring Retainers 740-16

I just tried calling Summit but they don't have weekend tech support, so hopefully some here can set me straight.

 

[toolmanmike]

No don't reuse the shim with a new spring. The shim is to correct the installed height of that particular spring.

 

[Keystone]

No don't reuse the shim with a new spring. The shim is to correct the installed height of that particular spring.

Thanks for the confirmation.

 

[PRH]

The OP’s pic shows the heads have rotators on the exhaust, which usually result in substantially shorter installed heights.

The installed height really should be measured, and corrected it necessary, before installing the new springs.

The 740-16 retainer is for 10* locks.
You would need the correct locks to go along with those retainers
If you go that route you should pull an ex rotator off to see how many grooves are in the valves, so you can be sure to order the correct locks.

The 7* 3/8 retainer to fit that spring is a 744-16, which would use the stock locks.

Aftermarket retainers usually alter the installed height, so don’t assume shims won't be necessary.
They easily could be.

 

[Wyrmrider]

best to measure your seat to retainer height and see if it matches your new springs
were these seats cut before
are the valve seats sunk from a previous valve job
check and find out
you are replacing the stem seals- right?
and what prh said about the rotators make sure your new retainers work with those stems and keepers

 

[Keystone]

Oh man, this is more complicated than I first thought.

I don't have the current contact info from the previous owner. What I have saved from my early correspondence with his is only: "4 angle valve job on the heads". Here's a couple pictures he sent me:

I've got some homework to do now.

 

[Keystone]

Hey guys. Thanks again for the info. My new job doesn’t allow the free time I used to have, so it’s taken me a while to get back to this. I went ahead and removed the exhaust valve spring from cylinder 2 and found it used the same 2-groove locks as the intake.

I noticed the springs on the exhaust are visibly shorter than the intake springs, which makes sense since they had that large, heavy rotator retainer on top of them.

I ordered the Comp Cams 744-16 retainers and this Sunday I swapped all the springs and retainers for the new parts. When I got to the driver’s side head I found those exhaust valves have 4 grooves.

Not sure why they used one style exhaust valve on one head and another on the other head, but I got all the springs changed out.

The problem I’m having is when I bolted the rocker shaft back on, all of the rockers feel tight. Aren’t some of them supposed to be loose, based on where the cam lobes are oriented? I tried turning the crank with a ratchet and it only goes maybe 10 degrees before stopping. I didn’t try to force it because something is apparently not right.

How does changing valve springs make everything too tight? I didn’t touch the pushrods or rockers; I’m at a loss here. This was a running engine. It wouldn’t go over 4 grand, but it ran fine up to that point. I guess I can take the rocker shaft off of one side to see if that frees things up because the even number head does look like it's tighter than the other side.

 

[Phreakish]

Did you measure installed height? It's pretty critical. Some of those springs look like they're at or near coil-bind which is bad. Springs can only be compressed 'so far' before they stop compressing and start failing.

You really need to measure installed height and have an idea of how much lift the cam has so that you know the springs aren't binding.

 

[PRH]

Which springs did you buy?

Make sure the pushrods are properly seated in the lifter, and in the rocker arm.

The fact that you have 2 springs from the same cylinder compressed this far...... at the same time...... raises a red flag.

 

[Keystone]

Did you measure installed height? It's pretty critical.

Yeah, I tried but I was having a hard time getting a consistent number. I've since learned that a caliper isn't the right too for that. I found the micrometers made for the job aren't that expensive, so I'll order one. I'll go back and take everything apart and check and check them properly so I know what the actual numbers are.

For what it's worth, I did write down the measurements I came up with, but after looking at them after the fact I’m sure there are at least a few erroneous readings. I put them into a spreadsheet and calculated the change from the installed height with the stock retainers to the Comp Cams retainers. Looking at that, the numbers for cylinder 1 and 8 intakes definitely look wrong.

So I'll be redoing that. When I order the mic I'll get a pack of 0.030 and 0.015 shims so I have them on hand should I need them.

 

[Keystone]

Which springs did you buy?

Make sure the pushrods are properly seated in the lifter, and in the rocker arm.

The fact that you have 2 springs from the same cylinder compressed this far...... at the same time...... raises a red flag.

View attachment 1715561897

Trick Flow... I don't have the part number in front of me but they're supposed to be identical to the Comp Cams 901-16 set.

Hmm, I double checked the pushrods are in the proper spot in the rockers arms, but I didn't realize they can be not properly in the lifters. Sorry, still learning here. I will verify that when I do take it all apart again to get good readings on the installed height, but I think this might be what's going on.

 

[PRH]

What’s the valve lift?

Edit- I see in the first post you said it’s the K6900 cam.

With the installed heights you’ve got listed, that spring shouldn’t be near coil bind at all.

Look for the pushrods not seated in the lifters properly before going any further.
Should be able to tell if they’re right or wrong with a flashlight.

 

[PRH]

This is the #3 intake valve, which you have listed as having an installed height of 1.703.
With .425” lift...... it wouldn’t be even close to coil bind.

 

[Keystone]

I finally got time to get this wrapped up. Using a mic I ordered, I went back and checked through all the installed heights. Some of my original measurements were close, but others weren't. So lesson learned there, use the right measuring tool.
The other thing I learned is (I think this is what happened) when I removed the rocker arm shaft, most of the pushrods stuck to the rockers and lifted up a few inches before falling back down. When I was done, I just bolted the shaft back on and didn't realize I was supposed to make sure they weren't hanging up on the edges of the lifters. The second time around I was careful to make sure they were seated properly and everything went smoothly.

So it's back to running but I still have the same issue where it hits a wall right around 4K rpm. Before I did the springs I went through the ignition as best I could. I adjusted the pickup/reluctor gap, cleaned the ground at the voltage regulator, tried with the tach disconnected. I even pulled the distributor, ignition box, ballast resistor and coil, connected them to a spare engine harness I have, applied 12V to the harness, put a set of old plugs in a fixture I made, then spun the distributor with a drill that's rated for 2500 rpm, which should be equivalent to 5000 engine rpm. All the plugs made spark up to full speed.

I took a video of the above setup working if anyone is interested. Guess I have to upload it somewhere else then provide a link.

So I'm not sure what's next. I guess I'll post up on another sub forum. But thanks again to everyone for the tips with the valve springs. I'll get this car back fully operational one of these days, it's just taking way longer than I was hoping.

 

[PRH]

I didn’t read through it again to see if this was discussed.......
Have you done a compression test?
Does it seem higher than you’d expect?

I know of three builds that all had the “it won’t rev over 4000” type of symptom....... where it ended up being the cam was installed wrong.
All three had the cam installed with the bottom keyway straight up, and the upper gear dot straight down.
That arrangement will have the cam advanced 2 1/2 teeth..... which is about 35*....... and the motor will run into a wall from 4000-4500.
In all three of these cases the car drove around fine until you tried to get it to rev..... and one of them had been being run like that for a couple of years.

 

[gzig5]

If the mechanicals are straightened out, the first thing I would do is change out the ECU. The silver box with the heat sink. Make sure all of the grounds are good and the motor is grounded to the frame. I always add a braided strap.

 

[RustyRatRod]

The tightness of the rockers when reinstalling is simple. When you removed them, the lifters relaxed and the plungers moved all the way up and allowed oil to flow into them. When you replaced the rocker assemblies, a lot of the lifters had more oil than when they were removed so that tightness is the oil being compressed. That's actually a good sign that the lifters are in really good condition.

 

[Keystone]

I didn’t read through it again to see if this was discussed.......
Have you done a compression test?
Does it seem higher than you’d expect?

No, at least not that I recall. I'll see if I can find the time this afternoon, but we're leaving for vacation tomorrow, so if I can't get to it, it may be a little while.

I know of three builds that all had the “it won’t rev over 4000” type of symptom....... where it ended up being the cam was installed wrong.
All three had the cam installed with the bottom keyway straight up, and the upper gear dot straight down.
That arrangement will have the cam advanced 2 1/2 teeth..... which is about 35*....... and the motor will run into a wall from 4000-4500.
In all three of these cases the car drove around fine until you tried to get it to rev..... and one of them had been being run like that for a couple of years.

Now that's interesting. I guess the only way to confirm that is to pull the timing cover?

Honestly nothing that the previous owner did to this car would surprise me anymore. This past winter I thought I'd tackle the badly leaking exhaust headers. Thought I could unbolt them and slide them back just enough to swap gaskets, without having to get into more involved tear down due to the clearance issues. What I found was a gasket that obviously wasn't what I expected to come with a cheap set of headers. It's a layered aluminum gasket. So he had tried to correct it and wasn't successful. Then I saw the problem. He didn't know that he had to plug up the air injection ports. You could see the carbon all over the bottom of the gasket.

It was just blowing exhaust right out of the heads

Of course getting a tap and handle in there required a lot more room, so it became a much bigger project. Good times. But yeah, installing the cam wrong would be par for the course. I'll checking into that.

 

[Keystone]

If the mechanicals are straightened out, the first thing I would do is change out the ECU. The silver box with the heat sink. Make sure all of the grounds are good and the motor is grounded to the frame. I always add a braided strap.

That was one of the first things I tried. I swapped it with the one from my slant 6 car. Made no difference in either vehicle. I don't know where the 225 shifts at since there's no tach in that car, but I'm guessing it probably gets up around 4K at full throttle in first and second.

 

[Keystone]

The tightness of the rockers when reinstalling is simple. When you removed them, the lifters relaxed and the plungers moved all the way up and allowed oil to flow into them. When you replaced the rocker assemblies, a lot of the lifters had more oil than when they were removed so that tightness is the oil being compressed. That's actually a good sign that the lifters are in really good condition.

Ah, now that makes sense. Thanks for explaining.

 

[PRH]

If the cam timing is as I described, it’s off far enough where you should be able to determine if it’s the problem or not without pulling the cover.

“Most” cams will end up being installed somewhere near 110*atdc.
Measure the circumference of the damper, divide by 360, multiply by 110....... make a mark on the damper there.....110atdc.
Remove the drivers side v/c, and with an indicator on the #1 intake valve, turn the motor over and eyeball the peak lift.
It will kind of dwell there for several degrees, so work the crank forward and backward to try and zero in on the mid-point.
When you have it where you think that is....... look at where that mark on the damper is relative to the 0 on the timing tab.
If it’s pretty close(you should be within 10deg or so) that’s not your problem.
If the mark is like 2” away...... the cam is in 2.5 teeth off.

You could also mark the damper at 75* atdc, and see if that mark is pretty close to the 0 on the pointer, as another confirmation the cam is installed way advanced.

On some timing sets, particularly the 3-way adjustable ones, there is a dot or zero on the tooth...... and another above the center position keyway.
Apparently some people get a little confused by this, and end up lining up the dot over the keyway with the dot on the upper gear....... and this is what you end up with....... cam advanced 35*

If it’s something with a big cam....... you often never get to the point where it won’t go over 4000....... you end up with a bunch of bent intake valves instead.
Although, one of the 3 examples I’m aware of was a low cr 440 with a 509 cam.
In that one the compression test wasn’t immediately obviously conclusive, since it was a fairly normal-ish looking reading.
But with the long duration cam and the rather low CR the cranking numbers should have been pretty low...... instead of “normal”.

 

[AJ/FormS]

Another, less labor intensive way, to check the cam timing is check were split overlap is.
To do that You put #1 cylinder to TDC compression, then go to #6 cylinder.Split overlap should occur within a few degrees of TDC.
The usual way to measure this, is to lay a straightedge across the two lifters for this cylinder, and rock the crank back and forth until the straightedge touches all 4 edges of the two lifters, then taking up the chain slack in the normal direction, then reading the crank degrees, on a proven damper.
Of course in your case, the intake is in the way. So you will need to improvise. This is not rocket-science when you are looking for 35 degrees. You just have to eyeball the valves as one is going up and the other one, down. Then they reverse direction lock-step with the crank-reversal. . After a few rocks of the crank, you will get a feel for it and just guess as to a common amount of opening; then read the damper. It should be within a few degrees of TDC perhaps up to 5* advanced. But NOT double digits.
Happy hunting

 

[AJ/FormS]

Another thing that kills revs is a plugged exhaust. This also makes the engine rev sluggish, the closer it gets to the limit.

 

[AJ/FormS]

And a seriously overfilled crankcase will do it too.

 

[yellow rose]

The simple way to see if the cam is even close is pull the drivers side valve cover and roll the engine over until you are on OVERLAP of number 1. That is 180 degrees from TDC on the compression stroke.

To make it less murky, roll the engine over until you are a TDC on the compression stroke, and then turn it one more full turn until the mark on the damper is lined up with the zero on the timing cover.

Then look at the intake and exhaust valves. If the intake and exhaust are open the same amount, the cam is in straight up.

If the intake is open more, it’s advanced.
If the exhaust is open more, it’s retarded.

The greater the amount of difference the greater the advance or retard.

My thinking is the cam was never degreed and it’s seriously advanced as PRH said many posts back.