Moving the darn A/C cooling fins! I am in the middle on a cam change. I took the rad. and shroud out so I'd have enough room to take and replace the cam. Well the cam hit the A/C cooling fins. I needed to move it 1/2 an inch!! Well now that I have that loose and hanging. I might as well replace it with the one I need to correctly work with the R-34 I have in the system. I was told that my air is not going to get cold enough because the original fins are not cooling it enough. But that was some time ago. Can anyone help me remember what kind of cooling fins I should be looking for? A 4-core somthing? Thanks......This cam thing has turned into a monster. = chrome water pump,timing chain,chrome oil pan, and so on!!

 

What you are refering to is the A/C condenser coil. It doesn't matter if you are using R-12 or R-134a the condenser coil is the same. the only difference between the two refrigerants is the oil used in the system. R-12 uses mineral oil and R-134A uses polyolester oil. Unless the coil is damaged beyond straightening some fins, there is no need to replace it. Good luck with your top end rebuild.

 

???
I've replaced cams on my 69' SBC without even removing the radiator?
Not sure how you managed to hit the A/C condenser?

 

Dan - I think you may be referring to a cross flow or parallel flow condenser.

John

 

Dave, One thing is for sure you are not afraid to get in there and get after it. Keep us posted on how the cam works out.

Scott

 

Thats what I am refering to! Parallel flow condensor!!! I remember that in order to get the R-34 COLD enough you need to get a new 4-core? one. I will post pic's of my work so far, hold on.

 

Ok, as of now I am half way thru this process. Everything has been removed or taken off. Now it's time to clean and start replacing and putting back together. Pleas look at the two pics of the OLD timing chain. Notice where my fingers are? That is "EXACTLLY" how it was when I took the cover off. I thought on GM there is suppose to be a "dot" over "dot". Mine wasn't so!!!

 

Had you turned the crank before removal, the marks would have eventually lined up.

You need the largest parallel flow condenser you can fit in there.
They are rated at least 30% more efficient than same size oem tube and fin and 134 uses it.
Save your hoses for the compressor fittings to be recrimped.
If you were happy with your a/c, then you can use a "fin comb" to straighten the original condenser.

 

I have it at TDC now, shouldn't they have lined up? As for the air, it was never cold enough for me down here in south fla, I got it to 65, when I ran the garden hose over it it went down to 59. So I know I need a new updated one. Thanks

 

Needs to be #1 at TDC on compression stroke... and yes the marks should have been in line with each other. Even if the PO had advanced the cam the marks should have been closer than shown. Now you need to determine if #1 is indeed at Top Dead Center, and if not get it there. Not certain how that could be verified now without reassembling most of the front of the engine... perhaps someone more versed can offer a way???

 

With the drivers side valve cover off rotate the engine clockwise until the intake valve opens then closes. Continue rotating until the dot on the crank timing gear is at 12:00. This is TDC on the compression stroke. Leave it there untill you reassemble and when you install the cam rotate it without the chain until the dot is at 6:00. Remove old crank gear and unbolt cam gear and reinstall new gears and chain with cam gear dot @ 6:00 and crank gear dot @ 12:00 and your good. On a max performance build you would degree the cam but it is usually right within a degree or two if you follow this method.

 

I know it was at TDC. I had the compr. valve screwed into the plug hole, and distrib. cap off. Making sure the rotor was pointing to number one, also had the intake removed. I also have the oil pan off now, and can see where the piston is. When I first got the car, it ran like a dog. I tried timing it, but found out the Harmonic Bal. had turned. I bought a new one, but could never really hit it on the head with the timing. I even had the distr. turned all the way both ways till it would not turn anymore. The car still ran with it like that. Not great but it would start. The chain was VERY LOOSE. I could pull and push in on it about an inch of play. I'm thinking it must have jumped, and somebody took the distrib. out and replaced it so it would run. And has been that way since. Funny thing, at one time I had the car tuned and it ran awesome spinning the tires up and down the street. But when I started adding intake/then headers/ then mufflers/ and so on, I could never get that feeling back. Thats why I wanted to do this cam change.

 

With the cam out, and putting on a new crank gear, it wouldn't matter where it WAS at prior. Because when putting the crank gear on IF THE KEY WAY was not at the top center, you could move it there. Then when you put in a new cam the gear on the cam you would then line up with the crank. This should be TDC. am I right in this thinking???

 

Yes.

 

The timing mark on the cam gear should look alot like the mark on the crank gear. I'm pretty sure that casting bump is not the timing mark. If the cam was that far off it would have not run and more than likely have damaged valves and pistons from contact. Doesn't matter now though since you are installing new stuff. You can use a piston stop in No 1 to determine TDC with your cam out.

 

Does you crank gear have a "0" over the key way and another under a tooth a half inch or so away? This would simply indicate which slot in the gear goes over the keyway and the other is used to line it up with the cam gear. The key way should be at the 1-2 o'clock position with the "0" at the 12

 

Does the keyway line up with the timing dot on the crank gear? It didn't on the original. Looks like the new gear has both 4 degree advanced and retarded slots also.

 

Should be something like this

 

Yes the NEW gear has three positions, stock/retard/advance. The old did not. The "dot" on the old was two teeth left of the keyway. Ther is no other mark on the old cam gear. Just that triangle.

 

To install the new set, forget about TDC and align the dots (with pushrods removed or rockers loose) to meet at 12 and 6 oclock as palmbeachvette76 pictured and 63mako described. This position is not #1 TDC on the firing stroke.
To get the #1 firing stroke after gear set installation, continue to rotate the crankshaft another full turn so the dots are both at 12 o'clock and install the dist so the rotor meets #1 on the cap. No need to check the piston position for TDC when you can see the gears.

Here is a pic (not mine) of the relative position of the 0 mark and the crank key and cams gear at install position.
(Notice that it is also a couple teeth from the keyway as you described yours)

Just for fun, you can rotate your new install to simulate the gear positions in your first pic.



You are correct about the arrow.
Here is a nylon set that uses an arrow like your did.
Notice the dowel location is close to 90° from the timing mark and when installed by the "matching method" the dowel is always close to 3 o'clock.



It's common to have the same amount of slop in the chain as you have found in the oem setup. I doubt it ever skipped. I have never seen a tooth skipped without serious damage to the original plastic cam gear.

I put a .0240" hole in the galley oil plug to help lube the chain, but that's for another discussion.