Degreeing camshaft


http://209.208.111.198/Topic112038.aspx 		Print Topic | Close Window

By slumlord444 - 10 Years Ago
Can't seem to get anywhere near the readings I am supposed to. I have the cam installed at 4 degrees advanced. Not sure how to figure that in as no matter how I figure it I am no way near what I am supposed to be. About 10 degrees off. Have dial indicator set up and degree wheel . Figured TDC without any problem. Measuring off the pushrod with a bracket made to support it. Heads off. Going to cut off an old pushrod and plug it to get a flat surface to measure from. Should be more accurate but don't think that will make that much difference. Could not find a cam degree thread here. Using the instruction sheet that came with my  Isky cam.
By Ted - 10 Years Ago

Without knowing which procedure you’re using to degree in the camshaft, it’s going to be tough to figure out where you are.  If you are using the opening & closing specs, there tends to be some variation in that method and some of that is simply related to the type of lube that’s on the lobes and/or lifters.  Lifter bore clearance can be problematic at times too if the bores have not been thoroughly cleaned or honed during the block machining process.  Do not use cam lube on the lifter bores themselves; use only engine oil.
 
If you’re using the lobe centerline method, then you should be doing both the intake and exhaust lobes.  By also doing the exhaust lobe, you are verifying the checking methodology as used on the intake lobe and also verifying that the camshaft is ground as advertised.  Assuming you are getting a reading that is indeed ten degrees off, then the question comes up “ten degrees advanced or ten degrees retarded?”  If the cam is ten degrees advanced and you already have the sprocket in the 4° advance position, then simply move the crankshaft sprocket to the 2° retard position and recheck the camshaft again.  This is assuming you are targeting for 4° advance for the initial install.  If using the Rollmaster timing set, then also be aware of where the new 'dot' needs to be on the outer row of teeth so you can count off the twelve links correctly.  If the timing events happen earlier than expected, then the camshaft is advanced.  if the cam events are occurring 'late', then the camshaft is retarded.
 
As a general rule, the first check of a new camshaft is with the crank sprocket in the zero position.  Many new camshafts have a given amount of advance built into the camshaft during the grinding operation.  On the Isky cam card or sheet, it will be listed as degrees of cam advance which if it’s listed as 2°, then it will equate to 4° on the crankshaft or degree wheel.

If it’s any consolation, I am putting together a ‘how to degree in the camshaft” article for The Y-Block Magazine.  Once it’s published (targeting for issues 127 & 128), I’ll put it up on my own website.

By Ted - 10 Years Ago
If you’ll send me an email, I can send you the rough draft of the aforementioned upcoming ‘How to’ article.  My email address can be found under the ‘contact’ information at www.eatonbalancing.com .
By lyonroad - 10 Years Ago
Slumloard, I degreed my cam in much the same manner as you described.  In the zero position everything seemed ok but I wanted to advance the cam 4*.  I went through this every possible way I could using instructions on the internet.  I would end up with 8* (as I recall) advance.  Just for my own education I tried 4* retarded and got 8* retarded.  I was using a new timing set that I got from Carshop Inc.  I called them for assistance.  They suggested that I speak to Vern Schumman as it was his timing set.  I couldn't get in contact with him at the time so I bit the bullet and bought a timing set from John Mummert.  Before installing John's set I compared it to the Carshop Inc. set and found that the the advance and retard numbers etched on the outer edge of the crank sprocket were one tooth off.
By slumlord444 - 10 Years Ago
Thanks, I will keep that in mind when I work on it again tomorrow.
By lowrider - 10 Years Ago
I feel your pain. Built a new engine for my 57 a few years ago & wanted to degree the cam in. I had it apart so many times I thought I'd wear the bolt holes out. I followed the instructions on the degree wheel, the Internet, cam installation & cereal boxes. Nothing worked out right. Finally I was going thru it for the umpteenth time one day and it worked out right. Of course I don't remember what I did different ( or right) that time. Ran thru it a couple more times & it checked correct each time. I degreed the cam at different settings of advance & retard & each time the readings checked good. Finally put the cam where I wanted it & finished assembling the engine. I guess you just have to stick with it. I'm sure you'll get it.
By slumlord444 - 10 Years Ago
First I want to thank Ted for the rough copy of his article. It helped me figure it out. I started checking with the cam straight up instead of advanced and found out it was 8 degrees advanced. Re set it at 4 degrees retarded and ended up at 3.5 degrees advanced which is close enough for me. Apparently the multi slot timing gear was way off.  Now I know why I was 10 degrees off the first time.Hence the need to degree the cam. Took a while but I learned a lot. Made a piston stop out of a piece of 1/4" steel I had. Drilled holes to bolt it the block and a tapped hole in the middle for a bolt. used the same piece with another hole as a pushrod guide. Cut off an old solid pushrod just above the plate and used it as an extension from the lifter to the top of the block. Worked well. Needed a tool to fit on the crank to turn the engine over without using the bolt on the front of the crank. Dug up a pipe bushing that went from I think 1 1/2' down to 1 1/4". Had to file the inside out slightly so it slipped over the front of the crank. Filed a slot to match the key in the crank and used a large crescent wrench to turn the engine over. Worked like a charm. Thanks again Ted. The looking forward to seeing the completed article with photo's. Like your method better than Isky's. One big thing, and Ted covered this, is the importance of starting straight up even if you intend to advance the cam.
By lyonroad - 10 Years Ago
Thanks for the tips slumlord.  My problems were exacerbated by the way the degrees are marked on my Mr Gasket degree wheel.  I eventually covered the numbers with masking tape so that I didn't get confused.