I was curious i lost timing on my cam shaft when i replaced my chain. But the motor is already at top dead center do i just need to make the cam shaft dot and the crank gear to line up to have it in the correct spot for my distributor im not really sure what im doing

something like this but the picture below i had the cam gear off

 

On these you align the indicators on the cam and crank gears. Crank at 12' cam at 6'

 

Yes. As described, put the cam sprocket on the cam without the chain, turn it until the dots line up, take the sprocket back off, and reinstall it along with the chain.

Note that your crank sprocket has 3 possible positions you can install it in, and 3 marks around its circumference, which are probably different shapes (like a dot, a triangle, and a square, or some such; or maybe something like "0", "+", and "R" to match the keyway marks). You install that sprocket to the crank with the crank key in either the "0" (straight-up, as the cam was designed) slot; or the "+" one, or the "R" one, to either advance the cam or to retard it with respect to its normal timing. You have it in the "advance" position in the photo, whether that's what you intend or not. You'll need to use the corresponding "+" mark to align to. Note that the crank keyway is EXACTLY in line with the #1 rod journal, therefore when it points EXACTLY at 1:30 (EXACTLY toward the left-bank cyl centerline), #1 is EXACTLY at TDC. If you use either of the positions OTHER THAN "0", including where you have it now, the marks will align at some crank & piston position slightly OTHER THAN exactly #1 TDC; that being "the point" of cam timing adjustment, namely, changing the cam position's relationship to crank/piston position.

Installing the timing set in the "advance" position the way you have it will tend to move all of the engine's power production downwards in RPMs compared to the cam design, and of course the inverse for retarding it. Advancing will also tend to raise the peak torque but lower the peak HP, and will tend to make the engine spark knock more easily which sometimes isn't a factor at all but other times is crippling. Without knowing what cam you have other than it looks used, what motor you have, what gears you have, what converter you have, what the rest of the vehicle is, etc., it's hard to say whether that's really the best thing to do. Being a 207 block casting, that's a 350 block, from maybe 80 to 85 or thereabouts; no way to know from the photo what heads are on it; butt I would recommend installing it in the "nominal" or "0" position, unless you are deliberately and consciously making that change after already knowing what it acts like at "nominal" and are re-tuning it.

Note well also, this position is NOT #1 firing. It is the other instance of #1 & #6 TDC. This is #6 firing and the point at which the #1 exh valve is closing and the #1 int valve is opening. We assemble engines at the point where the dots are together NOT because it's #1 firing, but rather, because it's easy to see and get lined up right at that spot. Once you have it all put together there, rotate the crank exactly one full revolution to get to #1 firing. The #1 & #6 pistons will again both be at TDC, butt this time, #6 will be at the valve changeover spot and #1 will be at firing. You can watch the motion of the valves to verify: as you turn the crank, #1 intake will open, reach its peak, and then close at roughly half of the above-described full crank revolution, ending the intake stroke; then the #1 valves will both remain closed during the 2nd half of that revolution, which when complete, #1 will be at the end of its compression stroke and beginning of the power stroke, aka "firing".

 

FYI... If you're installing a new GM timing chain, be aware that some of these chains come with 4 deg of retard in the cam timing.

I found that out when I was trying to degree in an aftermarket cam and couldn't get my valve events to match the cam card.

The timing chain I was using was 12552129.

Ended up getting a Cloyes timing chain set which then allowed me to dial the cam into the cam card specs.

If you're using this particular GM chain and if your previous GM chain also had that 4 deg retard then you won't know the difference. However if not, you may notice a little loss of bottom end torque.

 

Indeed. NEVER EVER EVER FOR ANY REASON use a GM timing set in a "performance" motor unless you TRULY understand what it is.

At the beginning of the "emissions era", sometime around 71 or 72, GM changed the timing set to retard the cam by 4° (cam° that is... 8° crank). They used the same cam (the infamous 929) from the mid 60s up through the early 80s in nearly ALL motors with only a few notable exceptions, unchanged, and made the adjustment they wanted by way of the timing set. Retarding the cam gave 2 emissions benefits: it reduced cyl pressure which lowered NOx emissions, and, gave a certain amount of built-in exhaust gas recirculation by way of the late intake closing. Typical aftermarket cams and timing sets restore the valve event timing to roughly the pre-72 standard. The chain wasn't what changed that; it was the sprockets. Not sure whether it was the crank one, the cam one, or both. The chain is just a chain, a linked belt with however many pieces. Can't change the timing by changing the chain (assuming its length stays the same); only by changing the sprockets, specifically where the sprocket teeth are WRT the shafts, which is to say, the crank key groove or the cam dowel pin. Pretty sure all GM did was to change the crank sprocket, butt even back in the 70s when I was lazy butt building lots of motors anyway, I never bothered to actually measure one to nail it down. I just threw the stock s*** in the trash and put in ones I knew what they measured.

I would note also, in your photos, it looks like you have a "double roller" chain setup. Be aware that any "roller" chain that costs less than around $60 is NOT a "roller" at all, but rather what we call a "bushing roller" or "truck roller". That chain type wears ALOT, and REAL FAST, such that it "stretches" 3 or 4 times as much as a stock Link-Belt chain like the one in your 2nd photo. That type of chain will "stretch" (wear) and thereby retard the cam timing by 12° or more, the exact amount being TOTALLY unpredictable, within acoupla hundred miles after startup, rendering any "setting" or "measuring" you pretended to make during your build, null and void. Obviously a "true roller" chain is not nearly as susceptible to this, butt I have no way of knowing what you ACTUALLY have, since it's not mentioned nor is it in the photo. Details matter.

 

I have found just the opposite, the $60 single roller chain is ifinitely better than the complete pile of dog doodoo link chains. The single rollers last 200-300K without stretching even with heavier valve springs and more aggressive cams. There was a reason GM used them rather than the wear prone link chain in heavier GVW trucks, marine, and industrial engines and they filtered over to crate engines like the ZZ4. The GM single rollers last better than the make you feel good aftermarket $200+ dual rollers and have less stretch over time.

 

As opposed to, the $28 ones. Big difference.

I'd rather have a stock Link-Belt style than a cheeeeeep "bushing roller".

 

I guess I have never messed with the bushing style ones. I use a Cloyes 9-1157 or the identical GMPP Cloyes sourced unit. Generally go with whichever one is cheaper. I bought a spare Cloyes in the Summit Bargain cave a while back for $30. They use a hardened open barrel roll pin looking roller that is crimped into place.

 

You're lucky. They're what you get when you go to AutoZone or the like and get a "roller" setup that costs $30 for the set.

I don't really know how to look at them from the outside and spot a difference... both the bushing type and the "true roller" type have an axle pin through the center that's sort of peened over to retain it over the links. The bushings or rollers are hidden up in there. I've always just looked at part #s and whatnot, if I didn't already know what it was.