Degree cam in car

[brotherGood]

Trying to hype myself up for this challenge, but really kinda struggling to do so..but I'll try to make it short.

Engine builder did not degree cam upon install, just installed everything "straight up". Once the engine was in the car, I started having issues. Through off and on troubleshooting (off and on because it just really irritated me knowing I paid so much money to try to avoid the issues) the determination has been made that my multiple problems are due to the cam having not been degreed properly. (Severe lack of vacuum, compression lower than it should be, inability to tune, having to run shorter plugs due to what appears to be detonation, poor performance)

It was a struggle putting the engine & trans in the car initially. My home garage floor is a disaster so the hoist didnt want to roll, and it's also not big enough. So pulling everything back out isn't on the table. The other kick in the pickle is, I cannot find a cam degree kit for an Oldsmobile with the heads still on.

Per the engine builder who sold me the cam (also an Erson rep and highly regarded Oldsmobile builder) I know where the cam NEEDS to be, but my question is..without the kit (and without pulling the head) how do I figure out where the cam is installed?

In a perfect world, all I'll need to do (assuming I know where the cam is) is just use a 9-keyway gearset and align it on the proper degree and move on. But nothing with this car has been perfect.

Thanks in advance, and sorry for the novel.

[cstmwgn]

OK, so I know nothing about Oldsmobiles BUT on a Ford I might try the following steps.

1. Get a sparkplug TDC tool - it screws in the sparkplug hole and has an inner screw that can be set to different depths to stop the piston before it gets to TDC.
BE GENTLE when turning the engine over by hand (don't use the starter motor) so you don't damage the piston.

2. Now you can turn the engine in clockwise direction until it stops on the stop - note the degree or mark the balancer. Next turn the engine the other direction (anti-clockwise) until it stops - note the degree or mark the balancer. The middle of those two marks is your TDC.

3. ASSUMING your not pulling the intake manifold, you'll need to set up a dial indicator on the top of your rocker arm where the push rod pushes it up from the cam. Try very hard to match the angle of the pushrod with the dial indicator probe to improve accuracy.

4. Follow COMP Cams (and other manufactures) method of measuring intake centerline. I have no idea how Erson grinds their cams - COMP typically grinds their shelf cams 4* advanced so when it is installed straight up it is actually 4* advanced.

5. Adjust as needed.


Now, being the skeptic I am and having more faith in engine builders than they deserve, I might check all this BEFORE removing the balancer and timing cover unless you are more than sure that the cam timing is the issue.

Unless your balancer has degree marks for all 360*s your going to need a degree wheel which will most likely require you remove the radiator and fan at a minimum. It might be possible to get a degree wheel to clear the water pump IF you can come up with a long enough crank bolt to use a spacer to space the degree wheel away from the water pump driveshaft.

GOOD LUCK - lots of utube videos that might explain this a little better - or come back and ask questions as you encounter stuff your not sure about.

[anotheridiot]

Never really though I learned anything with the degree wheel. If you are turning an adjustable rocker engine by hand to degree, is it safe to bury the lifter so you are not guessing that .050-.080 it will move without opening the valve?

[fatguyzinc]

ive pulled a timing cover to advance a cam 4 degrees, made MAYBE 1/4 pound difference on vacuum....
are the rockers adjustable? degreeing a cam is just double checking that its machined correctly.
if youre using a flat tappet hydraulic, you need to substitute a single solid lifter while checking where
its sitting at. ive also disassembled an old hydraulic lifter and flipped cup/glued in upside down to
use for checking.

i hate to rain on your parade, but checking by degreeing, then advancing (more bottom end) or retarding
(more top end) your cam probably isnt going to fix your issues.

[brotherGood]

Rockers are not adjustable, however it does have hydraulic lifters. While the balancer was new upon assembly (completed August '22), the assembly shop informed me I new have a "new zero" on the timing tab..which is approximately 8°BTDC. This was verified last winter when resetting the distributor from being installed 180° out (based on finding TDC of cyl 1 and boating position of marker on balancer)

As much as I'd love to say that would show me the cam being installed at "zero" when the new "zero" is 8° retarded would tell me the cam is actually 8° retarded..I can't expect that be true.

However, between the 8° retarded on the balancer, plus the 2° advance not being acknowledged (2° called out on the card) it raises plenty of concerns..but at the same time I don't know how it'd run as well as it does being so far out.

the fact that countless Oldsmobiles have run this cam, or similar grinds with no low end issues, no vacuum issues, etc and yet I've experienced pretty much every symptom of retarded cam timing is unbelievably frustrating.

[silver_bullet]

I found this article and am not sure if it will lend any insight.... Wishing you ositive vibes and best of luck!

https://www.motortrend.com/how-to/oldsmobile-cam-big-gonna-fix/

[Captain]

Just a idea ....
when I had the 390 FE engine at the machine shop, they "Trued" all the faces. The heads, and the block, and match the intake as well. And a Torque Cam Shaft grind. (It is going into a pickup)
Well .005 here, .005 there and before I realized it, I was .015" under. So the stock push rods were TOO LONG! Just enough to let air squeak past the valves. I got under sized push rods.

[DanStokes]

Just a idea ....
when I had the 390 FE engine at the machine shop, they "Trued" all the faces. The heads, and the block, and match the intake as well. And a Torque Cam Shaft grind. (It is going into a pickup)
Well .005 here, .005 there and before I realized it, I was .015" under. So the stock push rods were TOO LONG! Just enough to let air squeak past the valves. I got under sized push rods.

I was about to suggest he check pushrod length. Great mimes think alike!

[brotherGood]

I'll take a look at that article for sure.

Regarding pushrod length..as much as I'd love to say the assembly shop checked/corrected rather than just ordered stock sizes..I dont know what to trust at this point considering the issues.

I do know he tried to say he couldn't degree it as I didn't supply the correct timing chain..but at the same time the bearings that came in the rebuild kit provided (from the machine shop) were for a Pontiac..so I'm not sure why he couldn't just get what he needed to do the job correctly.

I mean heck..the machine shop mounted/balanced/reconditioned the factory rods that were bent. So the assembly shop had to wait weeks while I tried to find rods/pistons.

[anotheridiot]

.
.015 is not alot to move a head. The range of most non adjustable hydraulic lifters are .050-.080 preload. That is the number you have to figure out from the manufacturer before trying to find pushrods that are .015 shorter. If you cant find that, then find zero lash with a push rod and leave the rocker there, (even if you shim the rocker, then measure how far it takes for the lifter to actually start opening the valve, so dial indicator on the pushrod side. That should get you in a range of the preload. If you are still at .050 because it used to be .065, I think you are OK. I would even go as far as just suggesting to put a shim under the rocker stands before trying to find more pushrods. .

[Captain]

The 390 FE as single rail rockers. And I ordered two under size push rod sets that Ford offered.
there is some size difference over the years of manufacture, and Car/Truck engines variables.
We have not really installed either set yet. I have had other things come up.
But it is on the "To Do List" punch card.
The heads are from a '67 T-bird. The block was from a "Good Neighborhood", but the casting numbers matched the original T-bird block that had a internal crack in the water jacket.
Now I will have to "Put My Best Man On It"
Right after Turkey Day Weekend

[cstmwgn]

...I do know he tried to say he couldn't degree it as I didn't supply the correct timing chain ...

Well that certainly would concern me. I might do some research to understand exactly which timing set your engine needs and try to figure out which timing set came in the kit! I was a little surprised by the alignment pictures in the link Patrick posted. Again, not an Oldsmobile buy so maybe that is the way it is supposed to be.

[brotherGood]

Well that certainly would concern me. I might do some research to understand exactly which timing set your engine needs and try to figure out which timing set came in the kit! I was a little surprised by the alignment pictures in the link Patrick posted. Again, not an Oldsmobile buy so maybe that is the way it is supposed to be.

Sorry, it was correct..just non-adjustable.

[anotheridiot]

Sorry, it was correct..just non-adjustable.

the adjustables have different marks on the crank gear, so you either line up a dot, a circle a square or a triangle. They make it confusing from the get go because you are not really adjusting the cam, you are changing the position of the crank.

[brotherGood]

Right. So I'm assuming (I truly don't remember what the machine shop ordered other than a double roller) it was a single key-way set.

I need to go ahead and pull the trigger on the 9-keyway..that way it's here when I'm ready for it.