273 questions...a few of them
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BillGrissom
Well-Known Member
Just catching back on this thread. You guys nailed almost everything. I was also thrown by the hydraulic-looking solid lifter. I noticed that in your photo of the engine ~pg 4 that you appear to have standard pistons, not the factory higher compression "HiPo" pistons. The later have a bulging ridge, and aren't flat on top (I have a HiPo engine). There was no special HiPo block, as I understand. I don't recall if standard pistons have valve relief cuts, but I have an aftermarket set (Norco) that is standard compression w/ valve reliefs. Not to say there aren't aftermarket HiPo pistons with a flat top, but I recall Badger ones having the bulging ridge. Not sure about Egge.
In my 273, I switched to a hydraulic cam (0.422/0.444), setup 4 deg advancem, w/ Rhoads lifters. My goal was smooth running and good mileage, not high rpm racing.
If I read correctly, it sounds like the main binding problem you had came from not using a matching set of slots on the cam and sprocket, since unclear which slot had the "o" mark. I spent some time staring at my 3 slot timing set since my marks weren't obvious either. A 9-slot set is too much risk of screwing up, since I have proven really good at installing things incorrectly.
In my 273, I switched to a hydraulic cam (0.422/0.444), setup 4 deg advancem, w/ Rhoads lifters. My goal was smooth running and good mileage, not high rpm racing.
If I read correctly, it sounds like the main binding problem you had came from not using a matching set of slots on the cam and sprocket, since unclear which slot had the "o" mark. I spent some time staring at my 3 slot timing set since my marks weren't obvious either. A 9-slot set is too much risk of screwing up, since I have proven really good at installing things incorrectly.
Bulldozer
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after reviewing this thread, and as you guys have pointed out, it would seem to me, the valves springs and retainers should be at equal height across the head, as the same springs and retainers should be identical ?. the retainers in my 360 heads are level , maybe im wrong here ....just another observation.....
Ok dropped by dads, had the vistation today and Easter at grammas, so it was a quick visit with dad. Here are some pics for reference, but this is what I noticed,
1. Old and new lifters are definitely solids, tried pushing down with a push rod...no go!!
2. Old and new lifters have same recess depth, put a push rod in each and they are the same. I didnt put verniers on them, just by eyeball, but bang on from what I can tell.
3. All the valves that are sitting higher are the exhaust valves.
4. Both the intake and exhaust valves have different #'s of grooves for the keeper.
5. New keepers from Comp were all the same, we could only use 1/2 the keepers from Comp.
6. Exhaust valves were the only ones to get the new keepers.
7. Pics of keepers, black one is new one from Comp, the one beside it has same amt of grooves, but you can see is smaller diameter.
8. Pic of rocker arm looks like it is real close to the valve spring???
9. Looked for cam card and there isnt one, just the specs on the outside of the box....I thought all new cams had a card??
So could there be issues with the keepers?? Maybe put the old ones back in?? We thought to put the new ones in as they match to the new springs and the black ring(whachamacallit) from Comp. I will post pics in a bit of the old and new keepers in the old spring topper.
1. Old and new lifters are definitely solids, tried pushing down with a push rod...no go!!
2. Old and new lifters have same recess depth, put a push rod in each and they are the same. I didnt put verniers on them, just by eyeball, but bang on from what I can tell.
3. All the valves that are sitting higher are the exhaust valves.
4. Both the intake and exhaust valves have different #'s of grooves for the keeper.
5. New keepers from Comp were all the same, we could only use 1/2 the keepers from Comp.
6. Exhaust valves were the only ones to get the new keepers.
7. Pics of keepers, black one is new one from Comp, the one beside it has same amt of grooves, but you can see is smaller diameter.
8. Pic of rocker arm looks like it is real close to the valve spring???
9. Looked for cam card and there isnt one, just the specs on the outside of the box....I thought all new cams had a card??
So could there be issues with the keepers?? Maybe put the old ones back in?? We thought to put the new ones in as they match to the new springs and the black ring(whachamacallit) from Comp. I will post pics in a bit of the old and new keepers in the old spring topper.
67Dart273
Well-Known Member
Steve do you have a compressor that allows you to remove the no1 springs with the head on the car?
If so, I'd suggest you read what I posted earlier, put light springs on the no1 cylinder, leave all other pushrods out, and try to walk the thing through a cycle (2 crank turns)
Light springs will allow you to push down with your finger as you go, and check for piston clearance. If you don't have a dial indicator or even a caliper with a depth stem, you can "try fit" feeler gauges stacked up as the piston comes "up and over" to check for valve/ piston hit
Look especially for the rockers hitting the valve retainers, IE in the "inside heal" of the rocker.
Again, I do NOT think that a few degrees advance/ retard can cause this problem.
So, what DO we know?
We know the lifters are same "pushrod height" as the old ones?
Same pushrods, or same height?
Same rockers, or same stock type?
Have you checked valve installed height against factory specs? Is either valve stem height "as per factory?"
Don't check for spring bind "by looking" you need to get a feeler or a nail or something in there. Don't forget that EITHER inner or outers can be binding.
I don't know if you posted, but crank degrees where it stops would be helpful.
ALSO if you think this can be a valve to piston problem, it would help to try with ONLY first one pushrod in, then the other. And ONLY install the pushrods for no1, leave all others out.
If so, I'd suggest you read what I posted earlier, put light springs on the no1 cylinder, leave all other pushrods out, and try to walk the thing through a cycle (2 crank turns)
Light springs will allow you to push down with your finger as you go, and check for piston clearance. If you don't have a dial indicator or even a caliper with a depth stem, you can "try fit" feeler gauges stacked up as the piston comes "up and over" to check for valve/ piston hit
Look especially for the rockers hitting the valve retainers, IE in the "inside heal" of the rocker.
Again, I do NOT think that a few degrees advance/ retard can cause this problem.
So, what DO we know?
We know the lifters are same "pushrod height" as the old ones?
Same pushrods, or same height?
Same rockers, or same stock type?
Have you checked valve installed height against factory specs? Is either valve stem height "as per factory?"
Don't check for spring bind "by looking" you need to get a feeler or a nail or something in there. Don't forget that EITHER inner or outers can be binding.
I don't know if you posted, but crank degrees where it stops would be helpful.
ALSO if you think this can be a valve to piston problem, it would help to try with ONLY first one pushrod in, then the other. And ONLY install the pushrods for no1, leave all others out.
Hey Del, Im gonna try to get a spring off Saturday, so that maybe we can try the old keepers. Here is a thought about the keepers...seeing as how the new keepers went into the exhaust valves only, and they seem to be sitting up higher than the intakes, what if I put pushrods only in the intakes, set the intake valves according to the chart you posted....skipping the exhaust. If we can get all the intakes set then I would say the problem lies within the exhaust.... I will chk on installed height spec, as well as actual height. I dont have a dial indicator, so what do you mean by "try fit" feeler gauge, we are hoping to keep the heads on the block.
Same pushrods, and they are same height in old and new lifters
Stock rockers
Once we get the new pushrods, we will chk out everything you mentioned.
thanks
Steve
Same pushrods, and they are same height in old and new lifters
Stock rockers
Once we get the new pushrods, we will chk out everything you mentioned.
thanks
Steve
67Dart273
Well-Known Member
The feeler gauges are simply a method of measuring piston/ valve clearance if you don't have other measuring instruments. With weak springs installed, you can turn the crank slow, or a little at a time, and push your finger down on the valve and see how much you have before it hits the piston. By stacking increasing amounts of feeler between the valve and the rocker, you can find out what this clearance is. You'll have to "play" because minimum valve/ piston clearance does NOT happen at TDC
Obviously, IF the valve IS hitting the piston, and IS what is stopping the works turning, there will be NO clearance, but you can see/ feel that too, by pushing down the valve and finding that it won't move!!
Try not to overthink this. This is simple mechanical "stuff" and by turning slow, checking as you go, you will eventually find it.
Obviously, IF the valve IS hitting the piston, and IS what is stopping the works turning, there will be NO clearance, but you can see/ feel that too, by pushing down the valve and finding that it won't move!!
Try not to overthink this. This is simple mechanical "stuff" and by turning slow, checking as you go, you will eventually find it.
Bulldozer
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i read everything i could find on the cam spec sheet and it says that it is not necessary to degree this cam. it states that this is basically a bolt in and go with their lifters and springs. make sure your crank sprocket is in the right key way, your adjusters are backed out as far as they can go. we know the lifters are right, the pushrods are right, the springs are right. im almost guessing that with crank and cam in time, there really is no reason for any valve to hit a piston, even at 4* retarded or advanced, that is not enough to cause that kind of interference. with the correct springs rated for this cam, i dont think coil bind would really be an issue here either. you have got make damn sure that the timing is set where it needs to be. im thinking now that it almost has to be in the rocker arm adjustments. everything else seems to be right. what are the reasons for a bent pushrod?
cam out of time with the crank ,valve timing
valve to piston contact
valve spring bind
push rod is too long
wrong lifters
excessive lift
rocker bind/adjustment
what else is there?
cam out of time with the crank ,valve timing
valve to piston contact
valve spring bind
push rod is too long
wrong lifters
excessive lift
rocker bind/adjustment
what else is there?
The silver locks are the originals, and they worked with the valves. The new locks are the black ones, they are 10* and their website says they work with all comp cams retainers... here is the link
http://www.compperformancegroupstor...Store_Code=CC&Screen=PROD&Product_Code=626-16
The valves that all sit up higher have the new 10* lock, we could only use them on the exhaust valves as the intake had different # of grooves in them.
Here is the link to the springs that were in the kit... on the cam spec page it says head machining required but I spoke to "badsport" and he installed the same springs on his 318(i think) with no machining.
http://www.compperformancegroupstor...Store_Code=CC&Screen=PROD&Product_Code=901-16
Oh yeah, why would there be no cam card included with the cam?? Im wondering if this was returned previously due to mis packaging or misgrind??
http://www.compperformancegroupstor...Store_Code=CC&Screen=PROD&Product_Code=901-16
Oh yeah, why would there be no cam card included with the cam?? Im wondering if this was returned previously due to mis packaging or misgrind??
Bulldozer
free ice cream sandwiches
i would think that any machining is only going to bring the compression up and the valves closer to the pistons. the fact that there is no cam card is suspect. i have never bought a cam that didnt have one, sometimes two.
I just measured the outer diameter of the old and new retainers... new is .5600" old is
.5125
.5125
OK the 626-16 locks are 4groove locks and most mopar exhaust valves use 4 groove. Some intake valves only have 2 grooves so you will need the 627-16 locks they are 1/2 two groove and 1/2 four groove. You can't use the stock 7* locks with 10* retainers
Yeah Im wondering about the missing cam card......
Bulldozer
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i found this in a tech archive. this is the isky version of a factory 273 cam .. Isky E-4. #390144
So with the 627-16 one half of the keeper is 2 groove and the other half is 4?? Or it gives you an option of getting complete sets with either the 2 or the 4??
Im wondering if the silver 7* ones(if thats what they are) are causing the valves to sit lower...thus the different installed heights of the valve springs?? This in combination with the retarded timing on the crank will cause valve to piston slap.
73abodee, I cant believe we put enough tension on the ratchet to cause bent push rods!! Weird, we didnt just reef on it, I aint a 'tard, I know enough to stop when something jams. Engine is on the stand, so everything is accessible easily enough...oh hey....I just thought of something....take a look at the pics where I show how close the rocker shaft is to the spring...I cant remember if that valve is the one with the new or old keepers, but if it is the old keeper, then the valve would be sitting lower right?? With the valve lower, the rocker arm has to come down further which would put the rocker arm closer to the valve spring right?? New keepers in there, would lift the valve up a bit.... Ok im going to bed now cuz my head hurts :banghead:.... dad is just about ready to give up and send the engine to a machine shop...this is disappointing as I feel like I let him down...its a simple frickin cam swap....my god I took apart my 383 sandblasted the heads, did a newfie valve lap on them, re-assembled it and it ran perfect..
67Dart273
Well-Known Member
Steve, I'm wondering if you changed the valvetrain geometry enough that the pushrods are rubbing the sides of the holes?
Also remember that your cam drive multiplies whatever torque you apply on the crank X2 at the cam
Also, the website posted earlier IS in effect "the cam card"
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=665&sb=2
Also remember that your cam drive multiplies whatever torque you apply on the crank X2 at the cam
Also, the website posted earlier IS in effect "the cam card"
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=665&sb=2
Hey Del, I will chk pushrods closer but i dont believe they are rubbing. I knew that the website is the same as the cam card, where my concern lies is that there is no cam card.. Maybe someone had previously purchased and returned it due to issues?? I kow I have made mistakes on replacing the cam, but maybe there are issues with the new cam?? Dad is going to machine shop tomorrow, so i will see if he will take the cam in to get checked.
67Dart273
Well-Known Member
Ya know, I never thought that MAYBE it was MIS BOXED
But you can check that within reason, right in the engine with a degree wheel. Just "estimate" duration, you'll have to transfer .050 lift from the 1.5X rocker ratio, but you could measure that with no pushrods. That would be .033 at the lifter which "ain't much" so just to estimate duration, just go by "the lifter just moved" and read your degree wheel.
Lift is also easy, just measure the lifter height on the back of the cam against the top of the lobe, and multiply that by 1.5 rocker ratio
How about markings on the cam itself? (Not familiar with comp cam markings)
But you can check that within reason, right in the engine with a degree wheel. Just "estimate" duration, you'll have to transfer .050 lift from the 1.5X rocker ratio, but you could measure that with no pushrods. That would be .033 at the lifter which "ain't much" so just to estimate duration, just go by "the lifter just moved" and read your degree wheel.
Lift is also easy, just measure the lifter height on the back of the cam against the top of the lobe, and multiply that by 1.5 rocker ratio
How about markings on the cam itself? (Not familiar with comp cam markings)
Ive never used a degree wheel, so I could see it taking hours for me to figure out. I figured on just taking the new cam to the machine shop and get him to measure the valve/lobe lift on it. Im hoping to get there early enough to talk to the machine shop guy and get his take on everything
dbl post...its late LOL
Bulldozer
free ice cream sandwiches
Steve i posted the isky info just in case you decide to send that comp cam back. toolmanmike had posted that info as a alternative to the comp cam 273 grind. and i think even if the valves were sitting lower, that would not change how much they open. i just dont feel good about the cam. we have done enough cams to know how to do it, and with these basically factory ground cams, it is pretty much a no-brainer. we would have to work at screwing them up lol.... i have done my share of SB and BBs, but i will admit i have never put together a 273.
Just for reference I never got a "cam card" when I bought mine either. Now that I look closer at the head, notice the spring seat being raised it is possible you are getting coil bind especially on the valves that stick up through the retainer more. 67 may be on to something there. My spring seats on my teen were not raised like that.
This fix might just be getting those springs up on the valve. Notice the difference between the coils in this pick.
PS. I wouldn't use the old retainers with those springs.
This fix might just be getting those springs up on the valve. Notice the difference between the coils in this pick.
PS. I wouldn't use the old retainers with those springs.
Badsport, in that pic, the valve on the left if I remember correctly is exhaust. And all the exhaust got the new keepers. Am I right here in thinking that the installed spring height should be the same in all the valves? I see a difference in the coils, but in my opinion that is because the valve is sitting up higher, therefore putting more tension on that spring???
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