I recieved my new JP roller timing set in the mail today, and I must say, it's very nice. Putting it next to the factory one I pulled off the truck really shows how dinky the "silent" stock set is. But I have a few questions about it's installation. I did a search and couldn't find a specific answer to my question



But first, the engine in question is a stock 1982 slant six that's in my truck. It has the "tame" factory hydraulic cam and everything else on the engine is the same as it left the factory. I plan on ditching the lean burn and doing the HEI mod as soon as the timing set is installed. Later on I will put the super six on it once I get it running well with the new ignition system.

My question is, I was looking at the advance marks on the crank sprocket and planned to advance my factory cam 2*-4*. I'm afraid to go over that since I don't know how far off the factory tolerances are. I don't have a degree wheel, or a dial indicator and have always just lined up the dots on the other engines I've worked on.

With that being said, do you guys think that 4* advance is good for the factory cam, or should I back it down to 2*. This is a slow revving truck that does a lot of towing, so I don't care about losing anything over 3500 RPM (it never had anything there to begin with).

Advice would be appreciated, all the other threads that mentioned the JP set involved a hotter than stock cam. I just know the hydraulic cam is a single pattern cam with milder specs than the earlier mechanical cam. I have no clue what the LSA is on the factory cam either, or if it had any advance or retard ground into it.

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Get a degree wheel and degree the cam... no "guess-work" with this... just learn how to do it... it is not that hard... & yes, set it at 4 degrees advance. ( 2 of those 4 degrees is likely to be ground into the cam already)
DD

Will this degree wheel set work? I have no clue on how to do this, but I'm not going to learn any younger...

http://www.summitracing.com/parts/PRO-66787/

BTW how do I degree a cam that I have no specs on?

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Try this technique. It's a surefire way to learn almost anything... And from that, you'll discover that magazine articles are often useful. As of this moment, Car Craft has a pretty good article.

You're right about having no spec card. But if all you want to do is advance a factory cam 4* from wherever it is now, why not simply measure it as accurately as you can (centerline is probably the easiest measurement to find) and use that as your reference point?

- Erik

_________________
Lots of early Valiants and Barracudas have crossed my path.
Also a handful of other toys for variety now and then.

Well, I just set it at 2+ and left it there. Used a combination of watching the rocker arms and the 1# piston to make sure nothing was horribly off. Turned it over a couple of times by hand forwards and backwards and the marks still lined up.

Would have liked to had degreed it, but my oil pan gaskets, timing chain cover gaskets, and damper repair sleeve were $120. Kind of gobbled up the budget for a degree kit.

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

well thats not where it is... when i installed my JP set i had to retard the set 4* to get a true 4* adv number... with the set @ 0* the cam was @ 98 lol

you have to remember that with a chrysler made cam, JP timing set, not everything is set where it should be... just to many hands in the pie...

so setting it @ 2* it could be anywhere... thats why you need to degree it

_________________
1965 Plymouth A/FX 512ci (under construction)
1968 Dodge Dart SL6 14.25 @ 91.5 1.91 60'
1973 Dodge Dart SL6 Stock
Killer Bee's Member Since 09'
http://www.forabodiesonly.com/mopar/sho ... p?t=128702
http://www.youtube.com/user/805moparkid

Well that's great, if somebody doesn't mind I would appreciate some links on degree wheel parts that are known to work on a slant, and don't cost a fortune.

BTW tried the google thing, found one good article, and it mentions a piston stop. Will a V-8 piston stop work on a slant six?

Does anybody have ANY specs on the stock chrysler hydraulic cam? I've been trying to find the lift specs. I know it's a single pattern cam, but that's about it.

EDIT: Dug this nice article up on the stock cam.

http://www.slantsix.org/forum/viewtopic ... m&start=15

Even better, found this too in that article:

http://www.flickr.com/photos/13718356@N ... 884804468/
Says that the factory cam was ground 3* retarded. I'm still going to degree it anyway.

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Print this:

http://img20.echo.cx/img20/4583/degreewheel9dg.jpg

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Thanks, I just need to find something to glue it to that will be a good backing and get a dial indicator and the base.

mpgfanatic, if I get a centerline to use for a reference measurement then what do I have to compare it to? According to the chart which took measurements from another camshaft (we all know how the factory was about consistency ) I should have an intake centerline of 108. How do I figure out if my cam was retarded from the factory?

As you can tell, I enjoy tuning but not cams. All the articles keep mentioning that damn "cam card". The only one of those I have is for the cam in my chevy.

According to my chevy cam card, my chevy cam (comp cams XR270HR-10) has 106* ICL and 110 LSA. Is that were the "4 degrees advance ground in" comes from? Totally unrelated to the slant but I'm just trying to get an idea on how this works.

So if the ICL is less than the LSA, does that mean it's advanced?

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

you go off the intake center line. so lets say you cam as designed has a 108 intake center. if it was a perfect world installing the timing set @ 0* would make it straight up @ that 108 center line. so due to many component it could be @ 100 or 112... you just dont know unless you degree.

now ICL and LSA are related but not in terms of having to degree a cam (unless you are looking for that last hp and making sure every lobe is perfect compared to another).

so a ICL is where the cam was designed to be installed and is the main number you need to know for degreeing.

LSA or Lobe Separation Angle gives you a good idea of what the cam is and will do, a big LSA like 112 or 114 is a low over lap (the valves arn't open @ the same time very much) so you can expect a smooth idle and less "sound". a narrow LSA like 106 or 104 has alot of overlap, so more mid-thru top end designed cam cuz you get scavenging.

_________________
1965 Plymouth A/FX 512ci (under construction)
1968 Dodge Dart SL6 14.25 @ 91.5 1.91 60'
1973 Dodge Dart SL6 Stock
Killer Bee's Member Since 09'
http://www.forabodiesonly.com/mopar/sho ... p?t=128702
http://www.youtube.com/user/805moparkid

So I'm currently waiting on my dial indicator and stand to arrive. In the meantime I've glued the paper degree wheel to an old sawblade so it will have a stable backing, made a piston stop out of an old spark plug (which was surprisingly easy), and done some more research on degreeing cams.

That is what leads me to my next question, the majority says not to degree a cam with a hydraulic lifter installed. Is it really necessary to install a mechanical lifter even though you know for a fact that your hydro lifter has leaked down? If I get the same readings from the dial indicator 3-4 times in a row with no variations does that mean the hydraulic lifter is ok?

I can pull the lifters on this engine easily, I just don't have a mechanical lifter lying around to drop in it.

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

you can always just go off the edge of the body if you get different readings... which you should cuz they have a spring in them i believe...

_________________
1965 Plymouth A/FX 512ci (under construction)
1968 Dodge Dart SL6 14.25 @ 91.5 1.91 60'
1973 Dodge Dart SL6 Stock
Killer Bee's Member Since 09'
http://www.forabodiesonly.com/mopar/sho ... p?t=128702
http://www.youtube.com/user/805moparkid

I'll try it and see what happens. If I get different readings I'll see if I can scavage a solid lifter out of my duster.

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Tired using the crankshaft bolt and two nuts to locate TDC this morning. Turned out to be a nightmare. Even after locking down the nut on the crank the compression from it coming up on #1 would make the bolt slip. So everything is postponed until my crankshaft socket and an actual degree wheel arrive from summit. I figured this is something that's worth spending the money one, and anything that can make degreeing the cam easier with the engine installed is worth it.

In the meantime, I currently have my timing set at 2* advanced. Do I need to set it back at 0* before degreeing the cam? Also, do I need to only screw the piston stop in until it barely touches the top of the piston? I'm trying to figure out how presice the relation of the piston stop to the piston has to be.

Am I overcomplicating this?

_________________
82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

start @ 0*...

and you need to pull all the spark plugs...

_________________
1965 Plymouth A/FX 512ci (under construction)
1968 Dodge Dart SL6 14.25 @ 91.5 1.91 60'
1973 Dodge Dart SL6 Stock
Killer Bee's Member Since 09'
http://www.forabodiesonly.com/mopar/sho ... p?t=128702
http://www.youtube.com/user/805moparkid