Crankgear positioning

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VeryValiantVellow

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Hoping to be brief here. Picked up a knock in 416 stroker. 1st thought it was lifters. Moved on to crank and cam. I didn't build engine. Had a pro do it 11 years ago. He and I lost file on details and parts we used. Here's problem at this point. Using crank gear with 3 keyways: zero degrees, plus/minus 4 degree options. So 3 possible positions. The Zero degree key has a dot over. A few degrees to the left (counterclockwise maybe 10 degrees) is another positioning mark (punched dot). Spent a day trying to determine manufacturer. Can't locate. Which dot do I use? By the way the gear is marked as MAP HPR-2A.
 
That could have come in a half dozen different boxes. That’s going to be tough unless someone can cipher the markings on the gear.
 
You should ID the cam brand and using a degree wheel install the cam at the correct center line, which ever key way it is.
 
Closest I have come so far is Mellings. Similar numbers on the cam gear. I'm really stumped at to which mark to use although the timing was set using the mark to the left of the Zero degree keyway. Not running the way I wanted though. Hard to keep idling etc.
 
SGBARRACUDA I don't follow.


You need to degree the cam to the crank. That isn’t lining up the dots. So you need to know the numbers from the cam and then you put the cam has been ground to be installed.

Anything else is a guess. If the builder referenced above didn't degree the cam he damn sure should have.
 
The woodruff key should roughly line up at a 45* angle, around 1:30 location for proper orientation to camshaft dot. Look on the crank gear about 45* counter clockwise from the keyway the crank gear is using. There should be a mark in that area.

If you can easily see the 0 dot, count the teeth back to the mark near the aligning tooth. Do the same with any of the other marks.
 
Ones I've dealt with had 3 keys and 3 unique marks. Whatever symbol is over the crank key you use, match the other like symbol to the dot on the cam cog.
 
Ones I've dealt with had 3 keys and 3 unique marks. Whatever symbol is over the crank key you use, match the other like symbol to the dot on the cam cog.

You'd be surprised at the number of cylinder heads I got to redo when multi-key way crank gears showed up. Hey I'm gonna put it on the triangle, then they lined up the 0 dot... smack smack smack smack... Valve sales were very good!
 
some get confusing, I saw an 8 way Romac that was marked all over the place, and the fact that it was hammered on so the marks were obliterated.
 
The Original Poster should go to a single keyway new cam gear/crank gear and double roller chain set up, and set it back to zero degress on the cam timing.

The performance cam manufacturers grind an advance into their new cams anyway, so the OP does not need to be even more confused by the three slot cam timing set trying to set his own cam timing.

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The Original Poster should go to a single keyway new cam gear/crank gear and double roller chain set up, and set it back to zero degress on the cam timing.

The performance cam manufacturers grind an advance into their new cams anyway, so the OP does not need to be even more confused by the three slot cam timing set trying to set his own cam timing.

View attachment 1715567778
There is no standard advance ground into a cam. That's why you always degree the cam.

He can have it Cam Doctored by any cam grinder and then he will know all the specs.

Yes you can guess and hope the new non adjustable timing set is correct.
 
For one thing if you don't know what it is don't use it. By a Cloyes true roller billet set. And like said, Degree the cam there is no other way to tell where to put it. Evey cam can be different even if its the same part number..

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The dot is for the 0 offset That put the cam in straight up. You use the keyway marked zero. The 4 degrees retarded or advance are also marked and you use the corresponding keyway if you choose to adv. or retard the cam.

Where was it when you started? Leave it there.
 
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The dot is for the 0 offset That put the cam in straight up. You use the keyway marked zero. The 4 degrees retarded or advance are also marked and you use the corresponding keyway if you choose to adv. or retard the cam.

Where when you started?
I'm surprised by the number of posts. Let me qualify some of what I'm dealing with. First of all this Virus thing has put me out of work for months. So I'm trying hard to control what I have to spend. Thus I've looked hard to discover the identity of this gear or to reach someone who recognizes it. The gear and chain are in very good shape. Once again the description of the gear: 3 slots. A dot appears over the Zero degree slot. A second dot appears counter clockwise from it a few degrees and higher up toward the teeth. I opened the engine up and found the gear on the Zero degree keyway and the alignment set up with the other dot. This puts the engine at exactly TDC. Which seems to me to be the proper alignment. BUT why 2 marks? Second problem. And this one could be expensive (at least from my perspective) Used calipers on cam. Its a 564 lift CC. Simply checking height on each lobe I found 14 thousandths variation. Comp Cams says they think the limit should be 2 or 3 thousandths. What do you think? Anybody? I've got more questions. Haven't had to rebuild engine in 15 years. Forgotten a lot of little details for building a stroker.
 
Good deal on your cam being installed straight up, that is all you need to know at this point to get it running right.

If you have your engine opened up far enough check the lifter bottom on the lifter from the short - .014 ths cam lobe and see if it is starting to dish out.

Heck, check all the lifter bottoms for dishing they shoud all be flat. Keep the lifters in order to their respective cam lobes also if you plan to use them again.

Did not tell us if it has hydraulic or solid lifters ? Do you have the adjustable rocker arms or the factory mopar bolt on rocker arms ?

The camshaft could be going flat, high lift, high pressure valve springs, and using today's regular engine oil with out the zinc additive in it can all lead to cam failure.

Can also easily cut the can off your oil filter and see if there is any steel floating around there in the bottom. Can take a magnet to the paper filter too, if there is any steel in it it will jump to the magnet.
 
The rockers are adjustable Comp, flat tapped cam, hydraulic. He also put a new set of lifters in less than a week ago.
 
Dad, post the pics you sent me, it will help everyone understand what yoUr trying to say.
 
Hoping to be brief here. Picked up a knock in 416 stroker. 1st thought it was lifters. Moved on to crank and cam. I didn't build engine. Had a pro do it 11 years ago. He and I lost file on details and parts we used. Here's problem at this point. Using crank gear with 3 keyways: zero degrees, plus/minus 4 degree options. So 3 possible positions. The Zero degree key has a dot over. A few degrees to the left (counterclockwise maybe 10 degrees) is another positioning mark (punched dot). Spent a day trying to determine manufacturer. Can't locate. Which dot do I use? By the way the gear is marked as MAP HPR-2A.


Read through this thread:

How to Assemble the Front of a Small Block
 
A41C6DF8-8761-4DEA-B3F9-513691222B96.jpeg
The cam is lined up with the small dot, straight up and down.
 
^^^ your correct ^^ you should have a smaller dot over the next keyway clockwise. There can be no other option for your dots to match each other.


You got new lifters, good. Good lifters are not flat on the bottom, they are convex (slightly domed) and will rock back and forth on each other slightly. If they are FLAT (no light between 2 lifters base to base) then they are used and should be replaced as they are probably not spinning anymore on the cam and have (started to) wipe the lobe. Measure base to tip of lobe across every one and check for variance, pay attention to INT and EXH as they may have different designed lift. It not uncommon for a used cam to have a few lower lobes but its just worn out, get it reground or pitch it. As for your lower timing gear. Does it have 3 keyways? Simple: the key points right up #1 cylinder (~2:00) at TDC, the "dot" of the cam gear points straight down. So its safe to say that the key and matching mark are about 45 degrees apart. If you got 3 keys, you should have 3 marks ~45 to left from each keyway. Those are your 3 sets of options, -4,0,+4 most likely. Sometimes a dot, a circle and a triangle are used on the crank gear to show the other timing options. you can figure out what is what (8 degree difference) by looking at the distance to the first keyway to the right of the ^ or O mark

(on a cell phone, touch the area you want to focus on before taking the pic so as to control the depth of focus)
 
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post 15
0 may or may not be "straight up"
most likely 4 degrees advanced ground into the cam
YMMV
get out the degree wheel
 
It is the correct way of installing your camshaft to know it matches the recommended install by degrees. Google camshaft decreeing.


THIS

Those code marks must match the marks on the matching gear. Degree the cam and see where it sits.

You should be able to lay them out on a flat surface with a straightedge and figure out what is what. lay them out with the chain. Pencil inside the sprocket shaft holes. Line them up with a straightedge on one set of timing marks and make a reference mark on the large sprocket. Mark that sprocket mark also on our background, cardboard or paper. Then set up another set of marks, and reference your cam sprocket mark on the paper again, and note which set of timing marks, square, triangle, etc. You should be able to see which markes put the cam where on your background paper

When you line up the marks, use a straightedge to get the marks centered on the shafts centers
 
I take it that the engine has been running fine for the last 10 years or so?
When Dad and I did the top end on our 273, we ordered everything from Comp. The crank gear had similar(3) markings. I installed it and when we turned it over by hand to set valves, discovered(thanks to @Badsport and fabo) I had installed it wrong.
Thankfully it was on engine stand.
The 3 markings as mentioned are for "advanced", "retarded" and "zero/straight up"
Post pics of all 3 markings in relation to each other.
Fyi we didnt degree our cam either. Yes it should be done but it ain't the end of the world.
 
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