340 issue after camshaft change

-
Hellrats said:
For Sure
Click to expand...

Yeah and with them charts, you have to be very careful, because they are far from accurate for everything. Really fast ramps and really BIG camshafts cannot be adjusted using them charts, because it will not be right worth snot. Doing them one at a time right down the line has always been the dead easiest way for me. I've made PRECIOUS FEW errors using that method.
 
RustyRatRod said:
I never have used the MP valve adjustment chart. Never have used the EOIC or ABC, XYZ, PDQ or LQBTQA+ method or whatever the hell else there is. I get ONE camshaft lifter at a time on the base circle of the lobe and adjust that valve and move on to the next. Always done it that way and it's always worked well "FOR ME". That means turning the engine to close the valve you're fixing to adjust and turn it "a little" more to assure that lifter is on the base circle of that lobe. Anything else is just too complicated for my simple mind. You have the valve covers off. You can shine a light into the intake valley through the heads and SEE the camshaft lobes and lifters and make SURE they're on the base circle. Simplest way ever to do it, IMO.
Click to expand...
I believe the 180 degree MP chart was made to be an accurate method that was useful at the track vs doing one at a time. And the other 90 degree chart is for bigger duration cams iirc. Whatever works for anyone as long as you do it right right?:thumbsup:
I will tell you this, and I know you know, not every cam lobes base circle is accurate, many can be out of round (due to old machinery etc) as you rotate from the close side to the open side of the lobe. You move the cam one way or the other on what is still considered the base and you may find eye opening variances.
 
According to the op both valves are open at tdc on all cylinders. Using the chart correctly and all other methods mentioned would not have that result. Even if the base circle was off a little.
 
What kind of lifters are you using. were they pumped up before adjusting ?
 
He needs to give more info. My bet is his push rods are too long. He said he has adjustable rocker arms so between the camshaft and the rocker arms something will be off. It may be good he walked away for a bit. When he goes back at it he may just see what is wrong. Mom always said come back with fresh eyes. Sometimes it works. Sometimes you can't see the forest for the trees.
 
Hope the valves didn't introduce them self to the pistons at this point
 
Hellrats said:
He needs to give more info. My bet is his push rods are too long. He said he has adjustable rocker arms so between the camshaft and the rocker arms something will be off. It may be good he walked away for a bit. When he goes back at it he may just see what is wrong. Mom always said come back with fresh eyes. Sometimes it works. Sometimes you can't see the forest for the trees.
Click to expand...
You would have thought that he would have noticed the push rods were to long when adjusting the hydraulic lifters ie with spring pressure on the push rods thus hanging the valves open you would not be able to spin the push rods with your fingers.
 
512Stroker said:
You would have thought that he would have noticed the push rods were to long when adjusting the hydraulic lifters ie with spring pressure on the push rods thus hanging the valves open you would not be able to spin the push rods with your fingers.
Click to expand...
Yes I know. U mentioned spinning the p/r which doesn’t work with a hydro cam. Kim
 
92b said:
According to the op both valves are open at tdc on all cylinders. Using the chart correctly and all other methods mentioned would not have that result. Even if the base circle was off a little.
Click to expand...

There's no way in the world hes right about that.
 
oldkimmer said:
Yes I know. U mentioned spinning the p/r which doesn’t work with a hydro cam. Kim
Click to expand...
Exactly, you can only spin the push rods at zero preload which he would never have if the valves are hung up from too long of push rods.
I think we are all in agreement.
 
RustyRatRod said:
I never have used the MP valve adjustment chart. Never have used the EOIC or ABC, XYZ, PDQ or LQBTQA+ method or whatever the hell else there is. I get ONE camshaft lifter at a time on the base circle of the lobe and adjust that valve and move on to the next. Always done it that way and it's always worked well "FOR ME". That means turning the engine to close the valve you're fixing to adjust and turn it "a little" more to assure that lifter is on the base circle of that lobe. Anything else is just too complicated for my simple mind. You have the valve covers off. You can shine a light into the intake valley through the heads and SEE the camshaft lobes and lifters and make SURE they're on the base circle. Simplest way ever to do it, IMO.
Click to expand...
This sounds quite easy and makes the most sense. I did use the EO/ IC method and that’s where I think things may have gone south. Pushrods are not too long nor did the valves touch the pistons. It’s not that hot of a cam. Hydraulic lifters we’re not pumped up or filled per Comp Cams instructions. Valves have been adjusted per RustyRatRod method and appear to be fine now. I’ve built a number of engines over my time and this has been a new one for me. Still not sure why the adjustment allowed for the valves to be open just enough to not build compression before. Engine is producing compression and will plan to fire it in the next couple of weeks when I can get back to it. Thanks to those who provided good information.
 
Sabremech said:
This sounds quite easy and makes the most sense. I did use the EO/ IC method and that’s where I think things may have gone south. Pushrods are not too long nor did the valves touch the pistons. It’s not that hot of a cam. Hydraulic lifters we’re not pumped up or filled per Comp Cams instructions. Valves have been adjusted per RustyRatRod method and appear to be fine now. I’ve built a number of engines over my time and this has been a new one for me. Still not sure why the adjustment allowed for the valves to be open just enough to not build compression before. Engine is producing compression and will plan to fire it in the next couple of weeks when I can get back to it. Thanks to those who provided good information.
Click to expand...
Cool, we need pic's.
A picture speaks a thousand words, video's are even better
 
Sabremech said:
This sounds quite easy and makes the most sense. I did use the EO/ IC method and that’s where I think things may have gone south. Pushrods are not too long nor did the valves touch the pistons. It’s not that hot of a cam. Hydraulic lifters we’re not pumped up or filled per Comp Cams instructions. Valves have been adjusted per RustyRatRod method and appear to be fine now. I’ve built a number of engines over my time and this has been a new one for me. Still not sure why the adjustment allowed for the valves to be open just enough to not build compression before. Engine is producing compression and will plan to fire it in the next couple of weeks when I can get back to it. Thanks to those who provided good information.
Click to expand...
What was the length of the pushrods you used? Are you using 273 type adjustable rockers?
 
Last edited:
How can valves be properly adjusted if the lifter isn't pumped up.
Rhoads lifters are required to be pumped up before installation.
makes me wonder if not pumping Comp lifters up as per Comps instructions is reason for so many Comp lifter failures.
 
fishmens67 said:
How can valves be properly adjusted if the lifter isn't pumped up.
Rhoads lifters are required to be pumped up before installation.
makes me wonder if not pumping Comp lifters up as per Comps instructions is reason for so many Comp lifter failures.
Click to expand...
Exactly, He said he didn’t pump them up even though the instructions said to. Kim
 
I like to adjust them with the intake off and see a good .040-.060 depression of the unpumped lifter cup.

There is an idea of .060 from the lifter cup bottoming out some do.. but that's a different set of springs
 
As noted in the Mopar Performance Book. The 4 position/180* method is suitable for adjusting lash for cams up to 290@050 duration. Longer than 290 requires the 8 position/90* method.
 
You must log in or register to reply here.
-

Back
Top