Can't keep lash + preload

[sputnik 440]

I just rebuilt the valve train (did not remove valves). The cam is new, but is the same one from Comp Cam that I took out. All the components are Comp Cam. Bottom line is that I cannot get the power I had before the change, even when I had 5 broken lifters and nearly all pushrods worn at different lengths and the springs rubbing on the roller rockers, as were the cups on the pushrods. That's history. Here is my problem.

I have adjusted the valves at 0 lash and added 1/2 turn on three occasions. I keep hearing the chatter on one or possible two sets of pushrods ONLY when I accelerate hard. I almost sounds like cheap gas pinging, but I filled up with 91 and some octane booster, no alcohol. Same thing. So, I brought the 440 (+.040) in and checked the lash. About 6 out of 8 sets were loose. Not real loose, but at 0 lash or slightly looser. This I did 3 times. My torque should be fine. The locking nuts all seem to work as they should and require reasonable torque to loosen. I have set the 0 lash cold and hot. No apparent difference. There are three ways that I know how to establish the point at which the lash is set. The method I used was to start with #1 and sequence adjustments according to firing order. I chose to determine the set point when the intake valve just closed.

I know I have work to do on a small vacuum leak where a bolt on the intake stripped and will not torque all the way. (I am fixing it with a heli coil) The timing needs to be set a little better. It is advanced a little too much (can't tell you how much til I get a new tape on the balancer). The 4150 850 Holley seems to be adjusted ok. I have great idle and does not miss going through the gears unless I get on it. Then chatter and low power. I should mention it has a MSD electronic system with 8546 distributor. I also set the Champions J14Ys at .040.

Any suggestions or cures??

 

[hangn0ut]

Hate to say this but it sounds like your cam has gone flat. You keep setting lash cause the lobes are getting smaller. Check it out and maybe I'am wrong. I hope so.

 

[sputnik 440]

It sounds that way, but I don't see how? Your talking about driving it no more than 20 miles between each reset, 3 resets. New everything, springs (I wonder about them), push rods, roller rocker, cam, timing gear. Used Comp Cam break in grease on everything, racing oil (20W50) with quart of additive for zinc etc. Makes not sense, but this was my first 440 valve train. Runs great if I do not mash the pedal. Soon as I do, I don't have the power I had and I hear a "chatter" until it gets to speed and I cruise, then everything is perfect. I sure was hoping to get a little more advise on this. Thanks for yours "hangnOut"

 

[hangn0ut]

Did you buy pushrods 'over the counter'. If so your pushrods might be to long. You need to pull a lifter and see if the cam is wiped.

 

[khryslerkid]

I'm thinking you are useing hydraulic lifters? You stated "0 lash, then a half a turn."
A half a turn on a hydraulic lifter isn't enough. More like a 1-1/2 turn. Most adjustable rockers are 1 to 1- 1/2 turns for a .060 preload, which is required. My crane ductal rockers are 1-1/2 turn = .064
Not having enough preload will result in not opening the valve far enough and the valve components will beat the crapp out of one another...

 

[sputnik 440]

Did you buy pushrods 'over the counter'. If so your pushrods might be to long. You need to pull a lifter and see if the cam is wiped.

Push rods were bought with the rest of the "kit" from comp cam after several discussions with their tech people. The pushrods were sized with a adjustable rod from them as well. 6 measurements were taken and all within a very acceptable range. I just opened up the valley and could not see anything that stood out. However, the intact manifold was not tight. On bolt probably had 5 - 10 pounds of torque. Sucking air might make the valves "ping", would it not. I sprayed some starter fluid around the intake, but never got a reaction out of the motor. Maybe it wasn't leaking.

Another problem. Excessive engine compartment heat. I mean HOT. Temp of engine on two guages was only 195 and the idiot gauge low to mid range. But, the engine components were extremely hot. There is not much room in that compartment and little air coming in from the grill.

Has anyone opened up the plugged vents on the GTX hoods? The '67 ones. It would look like the air could channel and find one or two of the inch diameter holes that might push enough air to help cool the beast and feed the holley a bit.

 

[sputnik 440]

I'm thinking you are useing hydraulic lifters? You stated "0 lash, then a half a turn."
A half a turn on a hydraulic lifter isn't enough. More like a 1-1/2 turn. Most adjustable rockers are 1 to 1- 1/2 turns for a .060 preload, which is required. My crane ductal rockers are 1-1/2 turn = .064
Not having enough preload will result in not opening the valve far enough and the valve components will beat the crapp out of one another...

Yes, hydraulics! I had this discussion with comp cam and with members of the forum. The consensus was to turn 1/2 or 3/4 turn, especially on a new valve train. To be honest, I have no idea, only from what I read. I have everything from 1/4 to 1 1/2 turns. To be honest, my "feel" told me 1/2 was a little light, either that or my "0" lash was something less than zero to begin with. No vertical movement of the rods, only a stiff turn and I called it "0". Maybe I didn't start off tight enough. I'll know more tomorrow when I adjust them again

 

[miller]

The method I used was to start with #1 and sequence adjustments according to firing order. I chose to determine the set point when the intake valve just closed.

That's correct, except...after intake closes, don't stop until piston is at TDC. Many cams have slow 'ramps' on 'em, that eases the close. Getting the piston on top makes sure your on the cam lobe's base circle.

Hydraulic tappets MUST have positive contact...means no lash. Tappet 'piston', or cup where the pushrod sets, should be pushed in a little, the .060 bit, that gives positive contact all the way through the cycle. But, also allows the tappets to pump up correctly.
Setting 'em on 0 is just asking for noise.

 

[moper]

First - What part number are the lifters? The preload setting is not an internet average... It's figured by the type of hydraulic lifter you're running. Most times with street profiles Comp has two possibilities.
Second - Did you change the valve springs without removing the valves? Or you left the springs alone on the valves?
Almost every issue with valvetrain parts failure (aside from not getting the right "first start" process successfully completed) are from bad harmonics. Broken parts, loosening parts, that's from the parts experiencing a vibration they were not designed for. So spring selection is critical. Especially with a more modern cam profile. So what camshaft, and what springs are on it?
Last on the heat - you're in AR. If you are truly concerned get a infra-red temp "gun" and check it around the compartment. My guess is that it's hot to you, but not "hot" in terms of engineering and performance.

 

[sputnik 440]

First - What part number are the lifters? The preload setting is not an internet average... It's figured by the type of hydraulic lifter you're running. Most times with street profiles Comp has two possibilities.
Second - Did you change the valve springs without removing the valves? Or you left the springs alone on the valves?
Almost every issue with valvetrain parts failure (aside from not getting the right "first start" process successfully completed) are from bad harmonics. Broken parts, loosening parts, that's from the parts experiencing a vibration they were not designed for. So spring selection is critical. Especially with a more modern cam profile. So what camshaft, and what springs are on it?
Last on the heat - you're in AR. If you are truly concerned get a infra-red temp "gun" and check it around the compartment. My guess is that it's hot to you, but not "hot" in terms of engineering and performance.

Thanks for your help. On the engine compartment temp....what temp do you think is normal for my set up (hp, headers, 440 = .040, dominator/holley (thin valley cover))insulated hood (can only get a 2" Mopar performance air cleaner under hood). I have no idea. I know I cannot touch the altinator or power steering pump with out it burning me. hoses are very hot to touch, but, it does not run hot (195). The hot air under the hood can't be good for the intake or the carb, can it?

I have opened up the valley and will remove the pushrods and examine the lifters. How do I check for wear on the lobes with cam not being pulled? Any visual? I could set up a depth gauge and measure the lobe and the flat on each...I think. Just a peek at the cam, it looks good. No scars, burning, uniform wear on all.

I will put helicoils in the block to tighten down the intake to the 50 lb torque spec, reset the lash and give it another 1/4 turn (3/4 total) of preload. Reset timing, probably about 36-38 advance at 2500 - 3000 (12-14 at idle), and see what I get.

thanks again for all the advise.

For Moper..........:

All Comp Cam. I did LEAVE the valves alone when I replaced springs.

824-16 ST 134.0200 134.02
HYDRAULIC LIFTERS, CRB 58-67
824-16 High Energy™ Hydraulic Lifters • Chrysler Big Block & Hemi

23-224-4
CAMSHAFT, CRB3 XE274H-10
7703-1

PUSHROD LENGTH CHECKER, #3

7918-16 ST 175.7500 175.75
PUSHRODS, HI-TECH 3/8 9.000

K23-223-4 KT 470.9200 470.92
CAMSHAFT KIT, CRB3 XE268H-10 This was for cam 23-223 which was swapped for 23-224. Same kit (springs, timing gear, steel retainers, lash caps, valve locks, oil seals)

Ultra pro magnumRocker Arms, Shaft Mount, 1.5 Ratio, Steel, Rockers, Shafts, Spacers, Mopar, Big Block B/RB, Set of 16
(Mfr. #: 1621-16)

 

[moper]

The lifters are for the '67 and earlier 440s with the smaller tip pushrods. The pushrods are for the '68-up big blocks using the larger radius cups... That may not be "the" problem, but it certainly is A problem. Or 16 problems. Replace the lifters with the std 822-16s and then go back through the camshaft break in process. The 822-16s are the std lifter. Preload should be between .030-.050". Using most rocker arms, that is approximately 1 full turn past zero preload. But - I will ALWAYS measure preload at the lifter's pushrod seat retaining clip before I put the intake back on.
Lastly on the intake - it's 35 foot pounds. Not 50...

 

[Mike67]

Trying to follow along here...you stated that the springs are new, but said " I wonder"... Why, are the valves floating??? Are/were they matched to the cam? Can you provide the specs/ mod# on the cam and the springs? I might be heading the wrong direction with the question, just trying to figure out if everything was truly matched...

 

[moper]

On the heat thing - if it's running at 195 internally, the underhood temps of some parts will be 200+. That will burn you - especially the upper hose, heater hoses, and cylinder heads. If you have aluminum covers they will wick that heat up and get hot too. However, none of that is not to be expected. Yes - hot air is not the best for a normal carburetor but it's not that big a deal on a street car. If you want pull the rear hood seal off the hood or cowl. That goes a goo ways to get cooler air across those surfaces.

 

[coloradodave]

Reading your #1 post, I am wondering about your method for adjusting your valves. I'll give you an easy way to adjust them for a mild cam. Take an old distributor cap and cut enough of the top off so that you can see the rotor. Mark each remaining tower with its cylinder #. 1-8-4-3-6-5-7-2, in a CCW rotation. Using a remote starter button or a socket on the crank bolt, rotate the motor CW until the rotor points at the #1 distributor cap tower. Adjust both the intake and exhaust valve for #1 cylinder at zero lash (pushrod has no up and down clearance when lightly moved) and then another full turn tighter. Rotate the motor again until the rotor aligns with the #8 tower and adjust both valves for #8 cylinder. Continue like this through the firing order. As I said, this method works very well for a stock or mild cam and takes all the guessing out of the equation. Other issues, such as expressed by moper, should be looked at also. As far as under hood temperatures are concerned, timing that is too far retarded will add a tremendous amount of heat to headers, which will elevate the temperature under the hood. Good luck to you...

 

[sputnik 440]

The lifters are for the '67 and earlier 440s with the smaller tip pushrods. The pushrods are for the '68-up big blocks using the larger radius cups... That may not be "the" problem, but it certainly is A problem. Or 16 problems. Replace the lifters with the std 822-16s and then go back through the camshaft break in process. The 822-16s are the std lifter. Preload should be between .030-.050". Using most rocker arms, that is approximately 1 full turn past zero preload. But - I will ALWAYS measure preload at the lifter's pushrod seat retaining clip before I put the intake back on.
Lastly on the intake - it's 35 foot pounds. Not 50...

 

[sputnik 440]

The engine is a '67 block hp and the pushrods comp cam matched it with are not the cup ones. The reason is that the roller rockers are ultra pro magnum rockers that come with the ball end pushrods. The lifters a, 824-16 are for a 440 '58-67'. The 822s are for 273 - 360 so says Comp Cam. I certainly do not mind challenging Comp Cam or any mfg, but "the kit" (everything in one box, except the roller rockers and shafts) was what the techs said I needed. I will certainly take the advise of those of you that have direct experience with the Mopar engines before some guy that picks up the phone and probably drives a Chevy.

How do you measure the preload at the lifters pushrod seat retaining clip? The 1967 Plymouth Service Manual p. 9-108 covering torque values for intake manifold shows 50 ft lbs. Sure seems like a lot. I would think with modern day valley trays and sealants, 35 is plenty, but.........maybe on the later years of 440s they discovered that 50 lbs was stripping too many threads. Tomorrow I will be installing Heli Coils in three holes in the block for the intake.

I went back through the lash and preload. I went through twice. The second round I could actually feel the lifters "taking" the preload. I had not felt that before. The half turn just seemed to be just that something to increase the firm feeling of twisting the rod when it stiffens. I still only went 1/2 turn. I removed all the lifters and checked them over, as I did on the pushrods. No problems of any kind. I could have used a bit longer pushrods. I am at half way on the adjusters and I thought I would only be 1-2 threads.

More thanks for the education I am getting. I truly appreciate the input.

The lifters are for the '67 and earlier 440s with the smaller tip pushrods. The pushrods are for the '68-up big blocks using the larger radius cups... That may not be "the" problem, but it certainly is A problem. Or 16 problems. Replace the lifters with the std 822-16s and then go back through the camshaft break in process. The 822-16s are the std lifter. Preload should be between .030-.050". Using most rocker arms, that is approximately 1 full turn past zero preload. But - I will ALWAYS measure preload at the lifter's pushrod seat retaining clip before I put the intake back on.
Lastly on the intake - it's 35 foot pounds. Not 50...

 

[sputnik 440]

On the heat thing - if it's running at 195 internally, the underhood temps of some parts will be 200+. That will burn you - especially the upper hose, heater hoses, and cylinder heads. If you have aluminum covers they will wick that heat up and get hot too. However, none of that is not to be expected. Yes - hot air is not the best for a normal carburetor but it's not that big a deal on a street car. If you want pull the rear hood seal off the hood or cowl. That goes a goo ways to get cooler air across those surfaces.

 

[sputnik 440]

I think that the hood seal may have made the difference I felt from before I added it to after. I truly believe it is noticable. I think I will get a gun and see what I get now and then remove it to see what I get then. Thanks for the advise.

 

[sputnik 440]

Trying to follow along here...you stated that the springs are new, but said " I wonder"... Why, are the valves floating??? Are/were they matched to the cam? Can you provide the specs/ mod# on the cam and the springs? I might be heading the wrong direction with the question, just trying to figure out if everything was truly matched...

 

[sputnik 440]

Mike 67...the valve springs are the comp cam 911s that come in the Package with the 23-224 cam. That is the same cam I took out and replaced. high performance street, very strong mid-range with headers, 2200 stall. I don't think the valves were ever "floating", it sounded more like low octane ping on a couple of them. I think I found that noise problem today. The roller rockers have "worn in" and there was some "slop". I put a .030 spacers inbetween 3 of them to tighten them up. I think they were rattling and that is what I was hearing when I accelerated. I hope so. What do you think? Could this have been the "noise"?