Slant Six Forum :: Can I adjust cam timing without pulling the oil pan?

I'm now confident that my cam timing is off a tooth.

I see no reason to try and reduce oil flow if switching to solid valve train from hydraulic

Actually if the cam is on a earlier blank the oil will be reduced automatically

Quote:

I'm now confident that my cam timing is off a tooth.

You just can't move it a tooth. It may be off just as bad the other direction. Your going to have to figure out how to degree it if you want it in right. Before you pull the damper and everything off, mount your degree wheel again and check where it is at before you pull it apart. We'll help you!

Rick's right. And in complete sympathy with your difficulties, I quote John Jerome: "You can't get the cam timing right until the cam timing's right". That's from Truck, his excellent 1977 book (also available to read for free on the Internet Archive here and here).

Yes, you can change the cam timing without dropping the oil pan. You'll have to pull the timing cover, and you'll still have a fight with parts of the oil pan gasket—the notoriously-difficult-to-seal "Bermuda Triangle" at the right front corner, its corresponding left front corner, and the rest of the gasket area sealing the bottom of the timing cover to the front of the oil pan.

I see adjustable rocker arms, so I guess you've either built a pre-'80 (solid-lifter) motor for this truck, or you've converted an '81-up (hydro-lifter) engine to solid lifters. That's fine as long as you have all the correct valvetrain parts, including camshaft, not a mashup of some hydro and some solid parts—and if you've converted a hydro-lifter motor, you've taken steps to reduce oil volume to the top end.

Speaking of oil to the top end, that looks like an aftermarket valve cover. Those usually don't have baffles in, which will mean high oil consumption, fouled spark plugs, and pinging. Read up on this and how best to fix it (other than installing a stock valve cover with baffles, which is probably the best/easiest/least costly way) here.

Oof…that Comp cam. I fervently hope you have better luck with it than others have.

For engine info, look for a stamping on the block deck, below the frontmost spark plug—visible with the head installed. If the block has been heavily decked it will have been erased, but if you find a stamping there it'll help figure out what this engine (or at least the block) came from.

Enough-more-than-one instances of the engine not running satisfactorily/not up to expectations, no matter what was tried. In general I dunk on Comp because last time I checked (admittedly, quite awhile ago) they just more or less use Chevrolet lobe profiles on everything they offer. Everything relevant to us, anyway. That by itself doesn't make their products poopy, but it does mean their cams don't take account or advantage of the larger-diameter Mopar lifter, nor the other Chrysler-specific engine characteristics. That 0.012" exhaust tappet clearance spec is rather small; you might find yourself wanting to open it up.

I've done some cursory skimming on the 'net and through my books and I've not seen anyone degree a Slant Six cam with the head on. I need to study the process again in detail, which I will do when I have some time to dedicate to it, but I'm not sure why it wouldn't be possible to do, albeit not ideal. I do see vids where people accomplish this on other makes (E.G. LS motors). I really don't want to be pulling the head again if I don't absolutely have to. Have you done it?

Quote:

I have done it several times. You need to use a piston stop in the #1 spark plug hole, to find TDC. Remove the valve cover, Best to remove the rocker assy. and use the dial indicator on the #1 intake pushrod. Or you can do like I did and "glued" three lifters together and put these in the #1 intake lifter hole the dial indicator on these. The hardest part is fitting a degree wheel to the engine while in the car.

I happen to be running the same spec cam myself, which I bought used... from Charlie S. So hopefully there's enough collective knowledge about that cam in this thread to get you sorted! The one I have turned out to be timed exactly according to its cam card and I was able to install it with the timing chain at its default location.

I see you're using a conventional set of sprockets, not something like the Roll-Master chain with the multiple keyways. The picture you posted shows the timing chain installed properly and all the markings lined up. So if it's still installed as in the picture, and if everything about the cam and timing chain are made to tolerances, everything will be lined up as it should. The bad news is if you have something out of tolerance, it will be tricky to adjust. If it's not too far off, you can use an offset crank key, but you may end up needing to get the Roll-Master chain if you can't get things right with the chain you have.

Author:	doubleclutch [ Mon Sep 09, 2024 5:16 pm ]
Post subject:	Can I adjust cam timing without pulling the oil pan?
Last year, I did an engine and tranny rebuild and re-installed everything back into my '85 D100. Since then, I haven't had a lot of time to work on it..but you know, life happens. I've been chipping away at troubleshooting ignition gremlins, and thanks to the assistance received in a previous thread on this forum, I have that taken care of. With the ignition system working again, along with everything else, I'm now confident that my cam timing is off a tooth. Regardless of ignition timing, it always runs a bit rough and doesn't want to idle at a reasonable rpm. While assembling the engine, the ONLY step in re-assembly that I wasn't confident with was that damned timing chain installation. The reason I couldn't find any confidence is that regardless of who's illustrations, instructions or video I followed I was left wondering about accuracy. We did the degree wheel thing, along with other methods to try and find some accuracy but just couldn't. This re-assembly step was over a year ago, so I can't offer specific problems we had at this moment but it's obvious now that I'm one tooth off. I recall a frustration I had was the timing chain has so much slop. I'm confident I'll have more questions later once I tear into it again since I was befuddled trying to get the cam chain right, with it being so loose and all. The bible for us in rebuilding this engine was Dutra's book, "Chrysler Slant Six Engines How to Rebuild and Modify" - it's an excellent guide and we did try the instructions within about the degree wheel. On that note, I do have an initial question so I can prepare for a tear-down of the front of the engine bay: I have no reason to pull the engine, if I don't have to. So, my plan is to pull apart the front of the engine bay (rad, trans cooler, fan, pulleys, etc). My question to those that might have been in this position is: With that awful disjointed oil pan gasket design, is it possible to leave the oil pan on and just take apart the cam cover portion of the gasket/seal to adjust cam chain timing? If I'm forced to pull that oil pan, the project gets a lot bigger in this vehicle since the K-member is in the way. I'm attaching pictures from LAST YEAR, after we had ultimately found ourselves guessing on cam timing. You can see our marks on the sprockets. I've also posted a picture of the engine bay, with the engine installed BEFORE we pulled it and overhauled it. It looks nice and painted, but it was worn to pieces inside.. Attachment: timingChain.jpg [ 83.27 KiB \| Viewed 2031 times ] Attachment: build1.jpg [ 59.15 KiB \| Viewed 2031 times ] Attachment: IMG_20230414_143432.jpg [ 64.35 KiB \| Viewed 2031 times ] Attachment: IMG_20230205_151545.jpg [ 76.04 KiB \| Viewed 2031 times ]

Author:	Rick Covalt [ Mon Sep 09, 2024 5:42 pm ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: I'm now confident that my cam timing is off a tooth. You just can't move it a tooth. It may be off just as bad the other direction. Your going to have to figure out how to degree it if you want it in right. Before you pull the damper and everything off, mount your degree wheel again and check where it is at before you pull it apart. We'll help you!

Author:	SlantSixDan [ Mon Sep 09, 2024 8:53 pm ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Rick's right. And in complete sympathy with your difficulties, I quote John Jerome: "You can't get the cam timing right until the cam timing's right". That's from Truck, his excellent 1977 book (also available to read for free on the Internet Archive here and here). Yes, you can change the cam timing without dropping the oil pan. You'll have to pull the timing cover, and you'll still have a fight with parts of the oil pan gasket—the notoriously-difficult-to-seal "Bermuda Triangle" at the right front corner, its corresponding left front corner, and the rest of the gasket area sealing the bottom of the timing cover to the front of the oil pan. I see adjustable rocker arms, so I guess you've either built a pre-'80 (solid-lifter) motor for this truck, or you've converted an '81-up (hydro-lifter) engine to solid lifters. That's fine as long as you have all the correct valvetrain parts, including camshaft, not a mashup of some hydro and some solid parts—and if you've converted a hydro-lifter motor, you've taken steps to reduce oil volume to the top end. Speaking of oil to the top end, that looks like an aftermarket valve cover. Those usually don't have baffles in, which will mean high oil consumption, fouled spark plugs, and pinging. Read up on this and how best to fix it (other than installing a stock valve cover with baffles, which is probably the best/easiest/least costly way) here.

Author:	Charrlie_S [ Tue Sep 10, 2024 3:18 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Solid lifter head. Spark plug tubes in the photo. I see no reason to try and reduce oil flow if switching to solid valve train from hydraulic. Actually if the cam is on a earlier blank the oil will be reduced automatically by the different oil metering of the rear cam journal. Solid cam has two intersecting oil holes in the rear cam journal, where the Hydraulic cam has a full groove. But many "new" solid cams are ground on hydraulic blanks and have the groove. PS: I add a groove to all my slant six cams. Just not as wide or as deep as the factory hydraulic cams.

Author:	SlantSixDan [ Tue Sep 10, 2024 10:47 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: I see no reason to try and reduce oil flow if switching to solid valve train from hydraulic I might agree with you if not for that valve covr; the combination of excessive top-end oil and a no-baffles valve cover will have too much oil entering the intake tract via the PCV. Quote: Actually if the cam is on a earlier blank the oil will be reduced automatically Yes; I raised the issue to check if the OP knew/verified all compatible valvetrain parts.

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Author:	doubleclutch [ Tue Sep 10, 2024 1:59 pm ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: Quote: I'm now confident that my cam timing is off a tooth. You just can't move it a tooth. It may be off just as bad the other direction. Your going to have to figure out how to degree it if you want it in right. Before you pull the damper and everything off, mount your degree wheel again and check where it is at before you pull it apart. We'll help you! I appreciate it! Attachment: 2024-09-10_16-58.png [ 13.09 KiB \| Viewed 1972 times ]

Author:	doubleclutch [ Tue Sep 10, 2024 2:24 pm ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: Rick's right. And in complete sympathy with your difficulties, I quote John Jerome: "You can't get the cam timing right until the cam timing's right". That's from Truck, his excellent 1977 book (also available to read for free on the Internet Archive here and here). Yes, you can change the cam timing without dropping the oil pan. You'll have to pull the timing cover, and you'll still have a fight with parts of the oil pan gasket—the notoriously-difficult-to-seal "Bermuda Triangle" at the right front corner, its corresponding left front corner, and the rest of the gasket area sealing the bottom of the timing cover to the front of the oil pan. I see adjustable rocker arms, so I guess you've either built a pre-'80 (solid-lifter) motor for this truck, or you've converted an '81-up (hydro-lifter) engine to solid lifters. That's fine as long as you have all the correct valvetrain parts, including camshaft, not a mashup of some hydro and some solid parts—and if you've converted a hydro-lifter motor, you've taken steps to reduce oil volume to the top end. Speaking of oil to the top end, that looks like an aftermarket valve cover. Those usually don't have baffles in, which will mean high oil consumption, fouled spark plugs, and pinging. Read up on this and how best to fix it (other than installing a stock valve cover with baffles, which is probably the best/easiest/least costly way) here. You bring up some valuable questions, none of which I've read about in any of my manuals. I'm glad you brought them up, since I can share my shallow knowledge and learn something! 1) I purchased the truck and it was running, but it was smoking like a BBQ and the inside revealed it had been rebuilt numerous times before. From researching the block, I found it's a very early 225 with 3 frost plugs, spark plug tubes, and a serial number that is before any sort of meaningful numbering scheme. From what I could find out, this means it's probably very early sixties but apparently you can't determine a year on the early ones. So, with that being said, it's solid lifters under there. The cam is a new cam with a mild profile - here is the cam card: Attachment: Cam Card.jpg [ 225 KiB \| Viewed 1970 times ] 2) I had no idea it was a mismatched valve cover. From what I know about the truck, I suspect it was assembled by a diesel shop to be used as a parts runner and they probably used what they had. So, it isn't surprising that it didn't come with the original cover. I'll read up on your reference and determine what to do to make sure the cover gets corrected in some way. Update: After reading the reference material and and doing minimal Google-foo, I determined that the valve cover on mine is a generic after-market that can be found on eBay or Amazon. It is no more than a stamped sheet of metal and has no baffles. Very luckily, I found a listing on eBay where someone is refinishing stock Chrysler slant six valve covers (with proper baffles) and so I ordered one. Thanks for the additional reference to the '77 book! I found a cheap copy on eBay so it's on the way.

Author:	SlantSixDan [ Wed Sep 11, 2024 9:17 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Oof…that Comp cam. I fervently hope you have better luck with it than others have. For engine info, look for a stamping on the block deck, below the frontmost spark plug—visible with the head installed. If the block has been heavily decked it will have been erased, but if you find a stamping there it'll help figure out what this engine (or at least the block) came from.

Author:	doubleclutch [ Wed Sep 11, 2024 10:19 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: Oof…that Comp cam. I fervently hope you have better luck with it than others have. For engine info, look for a stamping on the block deck, below the frontmost spark plug—visible with the head installed. If the block has been heavily decked it will have been erased, but if you find a stamping there it'll help figure out what this engine (or at least the block) came from. What experiences have you heard of regarding this cam? I should probably know what to look out for.

Author:	SlantSixDan [ Thu Sep 12, 2024 10:38 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Enough-more-than-one instances of the engine not running satisfactorily/not up to expectations, no matter what was tried. In general I dunk on Comp because last time I checked (admittedly, quite awhile ago) they just more or less use Chevrolet lobe profiles on everything they offer. Everything relevant to us, anyway. That by itself doesn't make their products poopy, but it does mean their cams don't take account or advantage of the larger-diameter Mopar lifter, nor the other Chrysler-specific engine characteristics. That 0.012" exhaust tappet clearance spec is rather small; you might find yourself wanting to open it up.

Author:	doubleclutch [ Thu Sep 12, 2024 3:13 pm ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: Enough-more-than-one instances of the engine not running satisfactorily/not up to expectations, no matter what was tried. In general I dunk on Comp because last time I checked (admittedly, quite awhile ago) they just more or less use Chevrolet lobe profiles on everything they offer. Everything relevant to us, anyway. That by itself doesn't make their products poopy, but it does mean their cams don't take account or advantage of the larger-diameter Mopar lifter, nor the other Chrysler-specific engine characteristics. That 0.012" exhaust tappet clearance spec is rather small; you might find yourself wanting to open it up. Ah - understood. I don't recall why I selected this cam since it's been awhile since I purchased it. I vaguely recall finding a well-rated cam across the board wasn't especially easy or possible, but I'm not sure why I settled on this one. I've done some cursory skimming on the 'net and through my books and I've not seen anyone degree a Slant Six cam with the head on. I need to study the process again in detail, which I will do when I have some time to dedicate to it, but I'm not sure why it wouldn't be possible to do, albeit not ideal. I do see vids where people accomplish this on other makes (E.G. LS motors). I really don't want to be pulling the head again if I don't absolutely have to. Have you done it?

Author:	Charrlie_S [ Fri Sep 13, 2024 4:29 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: I've done some cursory skimming on the 'net and through my books and I've not seen anyone degree a Slant Six cam with the head on. I need to study the process again in detail, which I will do when I have some time to dedicate to it, but I'm not sure why it wouldn't be possible to do, albeit not ideal. I do see vids where people accomplish this on other makes (E.G. LS motors). I really don't want to be pulling the head again if I don't absolutely have to. Have you done it? I have done it several times. You need to use a piston stop in the #1 spark plug hole, to find TDC. Remove the valve cover, Best to remove the rocker assy. and use the dial indicator on the #1 intake pushrod. Or you can do like I did and "glued" three lifters together and put these in the #1 intake lifter hole the dial indicator on these. The hardest part is fitting a degree wheel to the engine while in the car.

Author:	doubleclutch [ Fri Sep 13, 2024 7:59 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: Quote: I've done some cursory skimming on the 'net and through my books and I've not seen anyone degree a Slant Six cam with the head on. I need to study the process again in detail, which I will do when I have some time to dedicate to it, but I'm not sure why it wouldn't be possible to do, albeit not ideal. I do see vids where people accomplish this on other makes (E.G. LS motors). I really don't want to be pulling the head again if I don't absolutely have to. Have you done it? I have done it several times. You need to use a piston stop in the #1 spark plug hole, to find TDC. Remove the valve cover, Best to remove the rocker assy. and use the dial indicator on the #1 intake pushrod. Or you can do like I did and "glued" three lifters together and put these in the #1 intake lifter hole the dial indicator on these. The hardest part is fitting a degree wheel to the engine while in the car. Excellent info, and very good news. Thanks!

Author:	MadScientistMatt [ Fri Sep 13, 2024 8:04 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
I happen to be running the same spec cam myself, which I bought used... from Charlie S. So hopefully there's enough collective knowledge about that cam in this thread to get you sorted! The one I have turned out to be timed exactly according to its cam card and I was able to install it with the timing chain at its default location. I see you're using a conventional set of sprockets, not something like the Roll-Master chain with the multiple keyways. The picture you posted shows the timing chain installed properly and all the markings lined up. So if it's still installed as in the picture, and if everything about the cam and timing chain are made to tolerances, everything will be lined up as it should. The bad news is if you have something out of tolerance, it will be tricky to adjust. If it's not too far off, you can use an offset crank key, but you may end up needing to get the Roll-Master chain if you can't get things right with the chain you have.

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Author:	doubleclutch [ Fri Sep 13, 2024 8:18 am ]
Post subject:	Re: Can I adjust cam timing without pulling the oil pan?
Quote: I happen to be running the same spec cam myself, which I bought used... from Charlie S. So hopefully there's enough collective knowledge about that cam in this thread to get you sorted! The one I have turned out to be timed exactly according to its cam card and I was able to install it with the timing chain at its default location. I see you're using a conventional set of sprockets, not something like the Roll-Master chain with the multiple keyways. The picture you posted shows the timing chain installed properly and all the markings lined up. So if it's still installed as in the picture, and if everything about the cam and timing chain are made to tolerances, everything will be lined up as it should. The bad news is if you have something out of tolerance, it will be tricky to adjust. If it's not too far off, you can use an offset crank key, but you may end up needing to get the Roll-Master chain if you can't get things right with the chain you have. That's valuable info - thanks much. It is put together now exactly as pictured. I guess we shall see about the cam timing! I have some work to do and some orders to place, so there will be some posts coming up..