Degreeing a camshaft for begginners

[wyrmrider]

prove me wrong but I've never seen a Chrysler FSM say checking height for advertised timings and duration is 006
"the assuming the @.006 is the standard of measurement for the cam as the FSM states it is.'
which FSM are you looking at? I think I have a 62 somewhere and a set 67-78
us the SAE translations which I alluded to in my first post
"you can find catalogues that give factory durations and timing and SAE durations and timing" you've been given 3
The SAE are at the valve using (assuming a) 1.5 rocker ratio
BUT it's been pointed out that slant 6 rockers may be closer to 1.35: 1
SAE @ .006 using 1.5 rocker AT THE VALVE is theoretically similar to CRANE .004 at the CAM for hyd cams
a cam measured .006 at the CAM like Jones or Comp would be LARGER at the same advertised duration
looks like your mileage may vary

[1930]

prove me wrong but I've never seen a Chrysler FSM say checking height for advertised timings and duration is 006
"the assuming the @.006 is the standard of measurement for the cam as the FSM states it is.'
which FSM are you looking at? I think I have a 62 somewhere and a set 67-78
us the SAE translations which I alluded to in my first post
"you can find catalogues that give factory durations and timing and SAE durations and timing" you've been given 3
The SAE are at the valve using (assuming a) 1.5 rocker ratio
BUT it's been pointed out that slant 6 rockers may be closer to 1.35: 1
SAE @ .006 using 1.5 rocker AT THE VALVE is theoretically similar to CRANE .004 at the CAM for hyd cams
a cam measured .006 at the CAM like Jones or Comp would be LARGER at the same advertised duration
looks like your mileage may vary

Somehow I made an error, I see now way to edit the post. The FSM does not state this. I was playing around with possibilities, .006.020 and .050 to see which number had me closer.

It should have read ..........he assuming the @.006 is the standard of measurement for the cam ............end of story
Sorry for the confusion.

[wyrmrider]

I just saw an ad for a hyd comp cam for the slant 6
260 @006 212 @.050 .440 valve lift theoretical with 1.5 rockers
compare with Jones above
comp takes more duration to give you less lift

[1930]

1930,

Looked through the massive thread.

Chrysler used .010" lash on the intake (hot) and .020" on the exhaust (hot]. Therein is probably the issue. Just use these as your numbers (cold) since you have the heads off.*

Both of these can be found in the Direct Connection book from long ago written by Chrysler engineers. SL6.org has that chapter reproduced:

http://www.slantsix.org/articles/Slant% ... Manual.pdf

Good luck.

* Remember those lashes are for solid lifter cams. If you go to the end of the article you will see some hydraulic performance cams listed for other engines with zero lash indicated to check their timing events. Try zero lash as well -- that will take some careful slow turning over several trials to accurately determine the point where the cam base circle is reached (no change in reading, i.e. zero lash).

Also, remember that -- with the solid lifter lashes -- since you are measuring directly at the cam without the rocker arm ratio that you will need to calculate back. With hydraulic, unless the camshaft manufacturer instructs otherwise, i.e. a different clearance, 0 lift at cam times 1.5 is still 0.

Theoretical stock 1.5 rocker means .010 at valve = .0067 at cam
" .020 at valve = .0133 at cam

Actual stock 1.35 rocker means .010 at valve = .0075 at cam

" .020 at valve = .015 at cam

Fun, huh? Gives you a lot of appreciation for the work that goes into so-called blueprinting an engine.

Originally Posted by dovercrossing View Post
I saw a article in Hot Rod several years back that said a higher lift rocker arm set was used on certain years of the slant 6 and I am interested in using them I think the standard is 5 to 1 and the ones in question were 6 to 1. Would it be worth the cost versus horsepower gained to use them I have oversize valves!

No, the OEM rocker arms are supposed to be 1.5:1, but they are in reality, more like 1.35:1, so higher-lift rocker arms are worthwhile... if you can find any.

AFAIK, no "high-lift" rockers ever came on a /6 from the factory.

As mentioned previously I have the heads off so valve lash and rocker arm ratio do not come into play here but thanks anyway

[1930]

Bottom line just to cut to the chase, can someone tell me if using the intake centerline method will help me to see if the #1 intake valve is opening at the correct time and if so what is the procedure for doing this?

I have all the figures now just not sure which I should be using to answer the one seemingly simple question I still have and that is given above and below.

If not than is their a procedure to determine whether or not the #1 intake valve is opening at the correct time with the numbers/info I have given?

At this point I am still assuming the only way I can check this opening figure is by comparing opening closing events I have gathered from other engines I have mapped out. In my case the 81-87 hydraulic engines since they all appear to have used the same camshaft.
Posts 4, 9-12 on second page were very helpful, still working on getting a better understanding of everything mentioned though.
Thanks

[Kevin Johnson]

As mentioned previously I have the heads off so valve lash and rocker arm ratio do not come into play here but thanks anyway

No, you need to pay attention to the source of the information. If you are reading a FSM, for example, and it is explaining how to check cam timing at the valve then if you alter that and check the timing at the cam lobe directly with the head removed then you must adjust the clearance because of the mechanical ratios involved.

For example, in the Direct Connection racing manual the values of .010 and .020 valve lash in a hot engine are given. This means the head is on the engine and to compare the data to measuring directly at the cam lobe you must use the rocker arm ratio.


The other comment I should make is that I think you should have someone demonstrate this to you first hand. People learn in different ways and it appears clear that after reading the answers people have given to you here and on other forums that explaining it via words is not working. When I was in tech school I was a tutor for someone with dyslexia and he needed to have someone read the textbook to him and then answer questions that he had. Remember that reading and listening use different parts of the brain. I am not trying to be a smart-ass -- just pointing out that people do learn and/or process information in different ways.

[1930]

As mentioned previously I have the heads off so valve lash and rocker arm ratio do not come into play here but thanks anyway

No, you need to pay attention to the source of the information. If you are reading a FSM, for example, and it is explaining how to check cam timing at the valve then if you alter that and check the timing at the cam lobe directly with the head removed then you must adjust the clearance because of the mechanical ratios involved.

For example, in the Direct Connection racing manual the values of .010 and .020 valve lash in a hot engine are given. This means the head is on the engine and to compare the data to measuring directly at the cam lobe you must use the rocker arm ratio.


The other comment I should make is that I think you should have someone demonstrate this to you first hand. People learn in different ways and it appears clear that after reading the answers people have given to you here and on other forums that explaining it via words is not working. When I was in tech school I was a tutor for someone with dyslexia and he needed to have someone read the textbook to him and then answer questions that he had. Remember that reading and listening use different parts of the brain. I am not trying to be a smart-ass -- just pointing out that people do learn and/or process information in different ways.

Now I understand what you were getting at in mentioning valve clearance, makes sense and thanks.

Yes, its no problem. I do understand that everybody learns in different ways. I will admit that I am not the brightest bulb in the box and it does not bother me to admit that. I have talents that other people only dream of having and so life goes on.

Its a simple question that I asked though, would the answer be yes, no or figure it out for yourself.

My question is will using the intake centerline method with the figures shown above in previous posts tell me if the cam is opening the intake valve at the correct time in relation to the crank?

I have had alot of answers answered and alot of additional info that I did not ask for provided to me and so it gets confusing. I am pretty sure that no-one learned this stuff overnight and so I am trying to cram many years of people experiences/knowledge into a short period of time.

If no-one has an answer to that seemingly simple question than so be it, Ill keep searching. I dont want any problems and so Ill just make this my last post and move on. Thanks for the information given thus far. Alot of it helped me to understand alot of things better and I have printed and saved much of it cause eventually it will all fit together like a jig-saw puzzle

[DrillDawg]

You have to know the method that was used to get the numbers your using to check your cam. Once you find out and understand that method then you can go about checking the numbers using the same method.

May I ask why it's so important to degree a stock cam?

[1930]

You have to know the method that was used to get the numbers your using to check your cam. Once you find out and understand that method then you can go about checking the numbers using the same method.

May I ask why it's so important to degree a stock cam?

Ok this is understood now, this is what I had thought from what I have been reading and thanks for confirming this.

It is so important for me because I spent 1500 dollars to have the engine re-built , the engine was VERY difficult to start from day one, once it had been started and dialed in as best as I could it had poor manifold vacuum ( 13 inches ) and continued starting/stopping issues.

Working with some very knowledgeable people on the internet the cause for this problems I was faced with has not been found. Step by step things were tried different tests and it finally came down to removing the head and seeing if the cam was out of phase with the crank.

It has been assumed that because it was out of phase than it could be causing the issues I had been having.

All I really wanted and still want to know is if the #1 intake valve is opening at the correct time but evidently there is no way to tell if that is happening ( cause I dont know how the stock cam was originally measured ) so Ill just have to buy another new camshaft and of course this time I will have a cam card.

EDIT: I also did a ground up ( every nut and bolt ) restoration on the truck as can be seen here if anyone is interested. http://ramchargercentral.com/vehicle-help/1986-dodge/

[DrillDawg]

Just a suggestion, the next time you have a problem, please let everyone know that you have a problem and what it is and what it is you want to achieve.

If you have an early year engine and you install a later model timing chain in it you might have your problems. At some point just about every car marker install timing chains that retarded the cam for emissions reasons, that would be the first thing to check, the next would be to make sure the valves are adjusted right and that you have the right length of pushrods (most hyd and solid lifter pushrods are differnet, the third would be to check to be sure the intake manifold is sealing right, the forth would be to make sure your distributor is not installed one tooth off. If you have done all this and it's all fine and still have your problem, then you have a mystery.


Here's a link that might be useful, good luck.

http://www.slantsix.org/forum/viewtopic ... 2c63a956a7

[Force Fed Mopar]

Silly question, but you have checked that the timing gear marks are correct, right? I have seen instances (IE '78 318 w/ a factory double row chain) where the original timing chain gears had both dots pointing straight up (12 o'clock position), and the new replacement (single row from Advance Auto) had them point at each other (12 o'clock on the crank, 6 o'clock on the cam).

[DrillDawg]

The second post on my link shows the correct way to line up the dots.

[1930]

Just a suggestion, the next time you have a problem, please let everyone know that you have a problem and what it is and what it is you want to achieve.

If you have an early year engine and you install a later model timing chain in it you might have your problems. At some point just about every car marker install timing chains that retarded the cam for emissions reasons, that would be the first thing to check, the next would be to make sure the valves are adjusted right and that you have the right length of pushrods (most hyd and solid lifter pushrods are differnet, the third would be to check to be sure the intake manifold is sealing right, the forth would be to make sure your distributor is not installed one tooth off. If you have done all this and it's all fine and still have your problem, then you have a mystery.


Here's a link that might be useful, good luck.

http://www.slantsix.org/forum/viewtopic ... 2c63a956a7

I did not want to confuse things. No valve adjustments to be made on these hydraulic lifter set-up, yes push rod length is different when talking about solid lifter engines versus my hydraulic, checked manifold sealing but eh, who knows and dicked around with dist till I was blue in the face.

Ill check out the link, thanks

[1930]

Silly question, but you have checked that the timing gear marks are correct, right? I have seen instances (IE '78 318 w/ a factory double row chain) where the original timing chain gears had both dots pointing straight up (12 o'clock position), and the new replacement (single row from Advance Auto) had them point at each other (12 o'clock on the crank, 6 o'clock on the cam).

Yeah the FSM manual shows the dots lined up right next to each other, this newer style chain has one at 10 o clock ( on the cam ) and the other at 5 oclock ( on the crank )

Thanks, I am going to get the timing cover off ( again) and continue to look into this as well.

[1930]

Just a suggestion, the next time you have a problem, please let everyone know that you have a problem and what it is and what it is you want to achieve.

If you have an early year engine and you install a later model timing chain in it you might have your problems. At some point just about every car marker install timing chains that retarded the cam for emissions reasons, that would be the first thing to check, the next would be to make sure the valves are adjusted right and that you have the right length of pushrods (most hyd and solid lifter pushrods are differnet, the third would be to check to be sure the intake manifold is sealing right, the forth would be to make sure your distributor is not installed one tooth off. If you have done all this and it's all fine and still have your problem, then you have a mystery.


Here's a link that might be useful, good luck.

http://www.slantsix.org/forum/viewtopic ... 2c63a956a7

I think this link looks like it may be useful, thanks for showing it too me.