Cam degreeing

[Stangman]

Besides being able to advance or retard the cam (more top end or low end). Is there a big horsepower difference. Almost all the cams I have had I put in straight up because they were advanced 4 degrees from the manufacturer. The short block that I have now was done by Barry Im sure he degreed it. What if it was just straight up would there be much difference.

Sorry Jay I put this in wrong section feel free to move it I would appreciate it.

[My427stang]

Straight up doesn't mean dot-to-dot, it means LSA=ICL=ECL, however, I know that isn't what you were asking.

It matters when it matters.  I have seen some be 4 degrees off, with good parts, and some early non FE Fords far worse when someone slips a retarded timing set in.  So the first thing degreeing does for you is make sure you have the right parts, and the small tolerance window on every part involved, doesn't put you where you shouldn't be

As far as installing 4 degrees advanced versus straight up, depending on the combo, you can have a significant difference in idle vacuum, throttle response, drivability.  In fact, back in 2000 I bought a new Dodge Ram to replace my 1995 Dodge Ram.  Engines were about the same, but the new one was a pig., turns out they retarded the cam to change how it behaved for emissions.   Upon the advice of RJP, a member of this forum, I advanced the cam and the torque came back

On the first version of my Mustang engine, I had low vacuum, 300/250 @ .050 108 LSA on 108 (straight up).  The car ran good, but was very soft down low, I advanced the cam 4 degrees to 105 (it actually came in a degree late as originally installed) and vacuum came up from 7 to 11 inches and throttle response was better.  Now that was a young man's 427, P-sonic, 850 Holley, TRW pistons in the hole, and too big of a cam, but it did help

Hope this helps

[blykins]

Besides being able to advance or retard the cam (more top end or low end). Is there a big horsepower difference. Almost all the cams I have had I put in straight up because they were advanced 4 degrees from the manufacturer. The short block that I have now was done by Barry Im sure he degreed it. What if it was just straight up would there be much difference.

Sorry Jay I put this in wrong section feel free to move it I would appreciate it.

A lot of the time, there is no horsepower difference at all.   There is not always a correlation between which direction makes more power either.  The computer simulations will have you believe that advancing takes away higher rpm horsepower and vice versa.   I've seen it both ways.  Just have to know the combination.   

[e philpott]

Very little difference and more than likely you won’t feel anything

[plovett]

The term, "straight up" has been used to mean both installed dot to dot and also to mean the intake centerline is the same as the lobe separation.  The latter may be correct.  I don't care and for god's sake am not trying to argue something pointless.   

A better solution is to just numerically describe the intake centerline, and the lobe separation angle.  If you say the intake centerline is installed at 106 degrees and the lobe separation angle is 110 degrees, then there is no confusion.   You can call it anything you want and it won't matter.   If you didn't install it yourself, ask your engine builder what the actual installed numbers are. 

pl

[blykins]

The term, "straight up" has been used to mean both installed dot to dot and also to mean the intake centerline is the same as the lobe separation.  The latter may be correct.  I don't care and for god's sake am not trying to argue something pointless.   

A better solution is to just numerically describe the intake centerline, and the lobe separation angle.  If you say the intake centerline is installed at 106 degrees and the lobe separation angle is 110 degrees, then there is no confusion.   You can call it anything you want and it won't matter.   If you didn't install it yourself, ask your engine builder what the actual installed numbers are. 

pl

Well, no one is arguing, just clarifying, but the latter is correct.   If you send in an order to any cam grinder and tell them 110 LSA ground straight up, you will get an 110 LSA with an 110 ICL.  They won't ask you how the gears line up. 

[frnkeore]

Another term, used instead of "straight up" is "split overlap", in application, they are the same. In the olden days ('60's and earlier) you installed a cam, with the lobes at the same height. The way you did that, was with a straight edge across the lifters, on the same cyl, of course. The pro's used dial indicators. You then put the timing chain on, with the piston, at TDC. Recheck and use a bushing or key to correct it, if off.  Of course, a degree wheel, is more accurate. Just a point of history.

Regarding cam advance, using sims, they usually show a little less max hp but, more average hp, as you advance the cam, to some point. It's average hp, in your rpm range, that gets the job done.

I don't know how accurate the sim might be. I guess only some dyno work directed at that feature, with many different engines, would tell.

[Stangman]

So it’s to make sure that I’m getting the cam that’s let say is in the box, and the power difference will probably be minimal depending on application. I’m not a rocket scientist but I’m not going to pick a cam that is way out of the ballpark. And I will ask for help before I get one. One of the main reasons that I asked this question is I don’t have a degree wheel. Don’t get me wrong I can afford a degree wheel I was just wondering if it was absolutely a must these days. Was thinking of going to a small solid roller but that is something that’s been rolling around in my head.

[GerryP]

Is it a must?  Depends upon to whom the question is being asked.  A professional builder whose reputation is on the line and everything must be measured and proven, then yes.  For them it's an absolute.  The further you get from that, the less vital it is.  Most people stab in a cam, line up the dots and call it good.

The question is if you do degree the cam and you find that it's three degrees out, what do you do about it?  How do you put it in spec?  That's easier said than done and is why most don't fool with it.

If you aren't inclined to want to degree the cam, then it's more important to check your piston to valve clearance.  An engine with a retarded cam might be pretty lazy down low, but an engine with bent valves is going to be lazy everywhere.

[Stangman]

Thanks GerryP

[blykins]

I have seen both instances of cams getting mixed up in the order queue and also the entire timing set/crankshaft/camshaft combination being off about 8°.  If I hadn't degreed it, I never would have caught it and both instances could have caused some pretty big issues. 

As for a small solid roller, unless it's a non-drilled block, I see no need for them.   A "small" solid roller would indicate lower rpms and there's no reason to risk lifter failure or have to go with higher valve spring pressures for no benefit.   It is true that you could go with a small solid roller with a pretty aggressive lobe and may sneak ahead with a few ponies that way, but I personally can't see the logic in that.   A solid roller in and of itself doesn't necessarily mean it will make more horsepower than any other camshaft, be it a hydraulic roller, solid flat, etc, etc. 

[plovett]

The term, "straight up" has been used to mean both installed dot to dot and also to mean the intake centerline is the same as the lobe separation.  The latter may be correct.  I don't care and for god's sake am not trying to argue something pointless.   

A better solution is to just numerically describe the intake centerline, and the lobe separation angle.  If you say the intake centerline is installed at 106 degrees and the lobe separation angle is 110 degrees, then there is no confusion.   You can call it anything you want and it won't matter.   If you didn't install it yourself, ask your engine builder what the actual installed numbers are. 

pl

Well, no one is arguing, just clarifying, but the latter is correct.   If you send in an order to any cam grinder and tell them 110 LSA ground straight up, you will get an 110 LSA with an 110 ICL.  They won't ask you how the gears line up.

I understand.  Thank you.

pl

[Stangman]

Brent it is a 63 center Oiler. I was just thinking out loud. I have a small solid cam now and I was going to step up to the next size or so but I was just thinking about a solid roller for the non break in troubles.

[Yellow Truck]

Stangman - based on your posts over the years I think you are will ahead of me in terms of knowledge on engines and the FE in particular. I've only built one, and I had a lot of help to build it.

I don't really remember how we installed the cam as I had a friend who is a diesel mechanic (and a pretty good one) do it while I watched. The intention was to install it as the cam card called, but I can't remember the technique. I do remember having a timing wheel on the front of the engine, but if it was just dot to dot or if he measured TDC by cam events etc. I don't remember. The cam card says it has LSA of 110 and ICL of 108.

What I do remember is that I was having a really tough time getting it to run well and someone on this forum (possibly Howie who seems to have disappeared) suggested that my cam may have been retarded. I bought a piston stop, a degree wheel, and a dial indicator and took the valve train, oil pan, and timing cover off and got to work. It took me probably 20 measurements before I was confident that I was getting the cam events correctly identified, and what it told me was the cam was 4 degrees retarded. Luckily I had a Ford racing timing set and could move the timing gear to set positions. Sadly I didn't have Jay's adjustable timing set - I don't think I'd do another engine without it.

I advanced it 2 degrees (actually 6 degrees from where I started) for the simple reason that I was told on this forum that it would probably improve vacuum and help with low end torque, and with the engine in the truck I didn't want to take off the pan and timing cover a second time to experiment with different timing gear positions. It was a few years ago and I'm not very good at recording what I did, but my recollection is that the cam was retarded.

My point is that I should have had a degree wheel and checked all this to begin with, but it was my first and I let someone else do it, rather than doing it myself. Advancing it did wake the engine up and improved the vacuum.

[blykins]

Brent it is a 63 center Oiler. I was just thinking out loud. I have a small solid cam now and I was going to step up to the next size or so but I was just thinking about a solid roller for the non break in troubles.

I do a lot of engines like that.   I will either run a nitrided solid flat tappet cam with tool steel lifters or a solid roller.