Has anyone seen a misground camshaft for a 472/500/425/368? MTS #5 here.

[mikanystrom]

Hi Club,

Almost a year ago I took my 1970 De Ville to my local shop because it was making some bad noises (turned out to be the driveshaft..), and ... well they found bad compression on 2 cylinders, not unexpected after 255k miles, including 100k+ on unleaded gas, I suppose.

They rebuilt the heads, and, as the camshaft was worn, I went for a new camshaft at the same time.  I ordered a #5 from MTS in Apple Valley, which sounded like a good match for the engine.  Well, skipping a bunch of irrelevant stuff, I get the car back, and it runs kind of... crappy.  Shop said, it's probably the carburetor.  Indeed the choke pull-off was broken on the carb.  I rebuilt the carb myself using a kit from Ruggles (2nd time I did this), am fairly confident I didn't screw it up.  I ditched the TCS and just hooked up to ported vacuum, set idle to 650 in drive and timing at 7.5 before.  I get some high-RPM pinging but that's not my major issue.

Issues that I see are...

- running hot (was boiling over with a Chevy thermostat, doesn't boil with a Cadillac 195 and brand new cap, but it's borderline)
- dieseling on shutdown now and then
- bad vacuum (11 in. at idle)
- unstable idle
- bad power at low RPM
- good power at high RPM
- no "Quadrajet howl" at WOT, more like a big sucking sound
- hard starting (sounds like the starter can't turn the engine over)

From what I've gathered, these are textbook symptoms of a retarded cam.  I talked to my shop and they wouldn't even consider it.  (These guys are not crooks, maybe not the absolutely most competent.)

Given that the shop had put in the wrong thermostat I figured I needed to delve into this myself.  Well I had no idea it was so much work to get at the cam chain.  Sigh...

Anyhow, I asked MTS for timing details but they only gave me the advertising numbers.  I probably didn't ask the right way.  I *think* this is the cam card for the cam:

http://www.pbm-erson.com/UserFiles/Documents/CamCards/529005.pdf

It matches the naming of the MTS cam lineup and matches the advertised figures for duration, lift, etc.

Key numbers on the cam card are IO @ -1, IC @ 35 (but I verified others). @  .050 lift.  Max lift 0.288.

They don't say the references but I suspect that cam people always use the same reference? in other words, IO @ -1 BTDC = 1 ATDC, IC @ 35 ABDC

So I got myself the cam timing kit and figured out how to set it up.  The piston stop for the TDC-finder had to be ground to fit in the small spark plugs bores in the Cadillac head.

Set the TDC on the wheel using the piston stop: screw it in, reverse the engine, CLUNK, 33 degrees (or so), forward until CLUNK, 33 degrees again.  Adjust wheel so both are same.

Then run a couple of revolutions clockwise with a long breaker bar on the crank bolt.

here is what I measure: base circle looks good, maybe varies max 2 mils.

The way my shop had installed things, I measured:

IO 10 ATDC
IC 43 ABDC
lift 0.294

(measured exhaust too, EC 1 ATDC EO 35 BBDC 0.299 lift)

OK... so from the above numbers, the cam looks indeed about 10 degrees retarded from the card.  And I'll add that... if any cam for a Cadillac had those specs, even if the card is not quite right, it can't be off by THAT much, right?  In any case the specs on the cam grind itself match up just about exactly with the cam card.  The lobe separation, duration, and lift are right on the money.  The only thing that's wrong is the timing.

I repeated the TDC check after degreeing the cam.  TDC marker lines up.

I ripped out the timing set the shop had put in (a stock style) and put in a Cloyes roller set that I had bought just in case there was a problem with the timing set.

To those in the know it should come as no surprise that with the Cloyes set (set for the factory mark, round dot), the timing #s come out exactly the same as the shop had set it up.

So my timing is off by TEN degrees.

So here is where I need help.  Dear Club members, can anyone tell me if this is even possible in any way other than the cam being ground off by 10 degrees?  Has anyone seen this before?

The factory set is basically idiot proof (although they say they invent a better idiot every day).  There is only one way to install the gears.  And there are 18 teeth on the crank sprocket, so if you're off by a tooth, that's 20 degrees of crank angle (10 of cam angle, but we're measuring based on crank angle).

The Cloyes set is also 18 teeth on the crank with keyways for -4, 0, +4.  So the only angles you can get are -4, 0, or +4 plus some multiple of TWENTY.

Just to make sure I didn't misunderstand I put in the gears off by a tooth and yes, now the cam is 10 degrees advanced, as expected (from 10 degs retard to 10 degs advance---I'm getting really quick at setting the TDC on my wheel now!).  Closest I could theoretically get is 6 degs retard or 6 degs advance from specs (if I can figure out how to get the Cloyes crank sprocket off without breaking it the way I did to the other crank sprocket).

Turning over the cam gear, maybe?  But no, by design, the cam gear has an even number of teeth (since it must rotate exactly half the speed of the crank).  So swapping it so the false dowel is covered will again only give the same choices of timing angles (the gear is symmetric by design).

I conclude that the leading hypothesis is that the camshaft is ground 10 degrees of crank rotation (5 degrees of cam rotation) off. 

Any other suggestions?  Any experience with this sort of thing?  MTS could have sold a bad batch?  (I had to wait forever because they were backordered, I remember that.)

[Bobby B]

Mika,
Hi..Did you take all the readings @ the .050 mark on the dial indicator? Most cams you buy today are basically ground with 4 degrees already built in. According to what your getting on your readings you would be more like almost 15 degrees off then. Make sure the P/N of the cam matches what they put in, and also corresponds with the timing card. I have heard stories of cams being ground that far off, but we're going way back here. Nothing would shock me anymore in the aftermarket. All the symptoms you're experiencing are of the Cam being retarded. Did you check it on every lobe to make sure you don't have a few bad ones or ones worn down immediately from improper break-in protocol? I would call the manufacturer ASAP and see if they have any insight before you lose your mind with this. When you say "New" cam, was it reground (lobes built up with metal spray and reshaped), or brand new cut from stock? Nowadays, hydraulic cams are real sensitive to correct break-in. Pontiacs will eat these things up if not broken in properly. I've switched to roller design cams on the last few 400 motors due to dealing with the break-in nonsense. Too difficult to be getting everything perfect on start-up, and having to worry about the hydraulic cam break-in process. Keep us posted....
                                                                            Bobby

[mikanystrom]

Yep I was real careful to get .050 off the base circle.  If I couldn't hit it within a mil or two I would go two more revolutions and start over.

Only checked #1 so far.  As I mentioned... it looks perfect except for being 10 degs off, the cam itself matches the card precisely.

I'm just thinking that there would even be no reason to grind a cam with the profile I'm measuring.  It's a low-RPM high-torque grind that can't be made to line up with the crank.  Not some crazy racing cam.

MTS has a reputation for reliability and customer service, that much is clear from reading about them on this site...

[mikanystrom]

Actually my understanding about the "4 degrees advance ground in" is that it should still match the "checking numbers" on the cam card precisely, not be off by 4... is that right or am I confused?  If the cam card says "checking numbers @ .050 IO -1" that means I should see the intake valve cross .050 at 1 ATDC in the real world and the 4 degs advance have already been taken care of.  Or???

If it were off by 15 degrees that would be great, because I could actually match that by advancing it 16 degrees!  (advance a tooth and set the Cloyes for -4)

[Jeff Rosansky CLC #28373]

Are you to the point where you can easily pull it out or do you have everything buttoned back up?
Maybe just pull it and have a shop check it or shoot it back to MTS and have them check it.
May be a pain but at least it will keep you from pulling your hair out

Jeff

[Bobby B]

Mika,
  You can usually get an adjustable crankshaft sprocket also to get you in the ballpark. You can juggle the adjustments around until you get it right, but I honestly wouldn't go there yet. I would call the manufacturer first, or even send the cam back , like Jeff said, to make sure that it's not something on their end. Usually the Tech's in a company like that are pretty sharp, and the will know exactly what's up if you explain it to them like you did here.
                                  Bobby

[mikanystrom]

It's pretty well apart.  Would have to take off the intake to get at the lifters but I guess that's small potatoes compared to all the junk I already removed... I figure the cam probably has to come out at this point unless I've really missed something but I don't think so.

Sigh.  Maybe MTS can check-measure a cam and ship it to me crossing mine in the mail if they have something on the shelf.  I have time to work on it next weekend... I'll ask when they are back at the office tomorrow.  Or if they have a better idea.  I already emailed them basically the same story as I posted here.

[Dr. John T. Welch]

To eliminate all uncertainty and settle all speculation around this matter as it pertains to your engine and its camshaft installation, you must "degree" the camshaft.  This is a very standard procedure undertaken when any replacement camshaft (especially one with lift and duration that differs from the OEM camshaft) is installed. The protocol and materials necessary to properly "degree" a cam are readily available. Failure to "degree" a replacement aftermarket cam during an engine rebuild is like buying a new piano and playing without tuning it. Until you "degree" the cam there is no way of knowing if the cam even conforms to the spec card as it is installed in your engine with the timing chain and gears you are using.

[Bobby B]

To eliminate all uncertainty and settle all speculation around this matter as it pertains to your engine and its camshaft installation, you must "degree" the camshaft.  This is a very standard procedure undertaken when any replacement camshaft (especially one with lift and duration that differs from the OEM camshaft) is installed. The protocol and materials necessary to properly "degree" a cam are readily available. Failure to "degree" a replacement aftermarket cam during an engine rebuild is like buying a new piano and playing without tuning it. Until you "degree" the cam there is no way of knowing if the cam even conforms to the spec card as it is installed in your engine with the timing chain and gears you are using.

Dr. John,
I think from his above post he already went back and checked it a few times with a degree wheel and it's not jiving. Whether it was degreed in or not when it was installed, he went back and re-checked everything thinking the poor running condition was related to it being off. Obviously , he knows now that something isn't right. I agree with you  about taking nothing for granted any more during installation. I check everything with a fine tooth comb. Nothing worse than going back and pulling things apart, especially an engine that's already in. MY next investment is  an engine run-in stand........
                                                                               Bobby

["Cadillac Kid" Greg Surfas 15364]

Mika,
I suggest you pull the cam, throw it in the trunk (of a running car) take a drive out to Apple Valley and talk to Paul.  If there is an issue with the cam not being correct I am sure he will make it right.
Greg Surfas

[TJ Hopland]

I had a similar experience with an MTS Erson #5 cam.   On the first build of my engine we were stuck on the whole degree thing.  I was working with a guy with lots of engine experience but not much Cadillac specific.  We tried it on several different lobes and had the Cloyes roller set with multiple slots and no matter what we did we just could not get it to match the card.   Around 10 sounds right using the 0 slots.   We finally found a combination that got us down in the 3-5 range and just went with it.   Had a lot of tuning issues plus it turns out a defective oil pump that sized in a couple thousand miles so engine had to come out and apart for new bearings and a few other repairs.   I did finally get it running pretty good with a carb and then switched to EFI.  Odd things like the timing marks said it was happy at 5* after but it was running decent so I didn't knock it till I lost oil pressure on the highway.  The key slot on the crank sprocket got worn apparently from the extra load of the dragging pump so in my parts order all from MTS this time I asked for another Cloyes timing set. 

I was not around for the whole process but my mechanic friend called when the parts arrived and asked if I wanted the stock type chain.   I forgot to specify I wanted the roller set again so I got the stock type with no extra slots.   Figured that was going to be a problem and was looking at overnight freight on another set because it was taking up space in my friends shop.  By the time I called him back to say I found one I could get down there he said he decided to just try it and said it came out perfect.   We didn't change the cam, only took it out to inspect it and the bearings.    We were both kinda stumped but figured we must have just been doing something wrong or over thinking things the first time.  When it got back together timing went back to normal numbers and I had to completely re do all my fuel maps so we had to have it off originally somehow. 

We never tried going back to the original set to see if it was off again or if it was just us screwing something up.   Both my sets were Cloyes.   Have not heard of them having a bad batch and you are having the same issue with presumably 2 different brands? so it seems unlikely unless they were both poorly made at the same factory.   

[mikanystrom]

Yes I think the procedure I described was degreeing it.

At the same time... the stock setup is basically idiot-proof.  If you're not off by a tooth, there's no adjustment to be made.  It's installed and that's that.

The Cloyes of course is a bit more involved, but still... I guess I could install the cam 6 degrees advanced.

Yes the two timing sets are from different manufacturers.  One is Cloyes the other is stock-type.  And they look to be to spec.  Very confusing.

Apple Valley isn't that far, I guess...

[The Tassie Devil(le)]

I had no trouble with the MTS # 5 which was a Lunatti Cam.

Bruce.

["Cadillac Kid" Greg Surfas 15364]

I am running a #5 in one of my cars with absolutely no issues. It's a great cm, but Mika at least call Paul at MTS and see what he says.
Greg Surfas

[mikanystrom]

Greg, I'm going to do that tomorrow.  I already emailed him...

By the way, did you degree your cam? 

Or has anyone else running one of these cams degreed it in their engine and gotten more sensible figures than I am seeing?

[TJ Hopland]

First time on mine we did it using the tool that fit in the lifter bore.   Second time the heads were on so I think he did it with a more typical dial indicator on a lifter.   

[mikanystrom]

That looks good enough.  And I take it the numbers were close to the cam card....?  Not 10 degrees off like for me?

[TJ Hopland]

That was several years ago now so some of the details are a little fuzzy but I think what it shows in the pic which is like 8 or 9 is where it came up with the timing set installed at 0.  I think that was why I took the photo.   We ended up flipping the crank sprocket upside down and using one of the offset slots and getting it down to like 3? which didn't make sense either but it was as close as we could get matching the card.  I did get it running decent but it never seemed right then after the oil pump went for some reason the next non adjustable set went on fine and it matched the card and ran better.   

This was an Erson #5 too.  I kinda have a fuzzy recollection that my guy said the way the cam card was written was a little different than usual so we were wondering if we were overthinking it.  It may have had to do with the 'built in' offset or something along those lines.  I do remember we spent several hours on it checking and re checking and checking other lobes and with and without lifters.  I think at one point we were going to remove the alignment pin and slot the holes in the cam sprocket but I don't think we went that far.   

I wish I had an answer for you but we never really figured it out the first time and I was not around for the assembly the second time so just took my guys word for it that it all went fine.  The ignition timing made more sense the second time so I assume he was correct. 

[Bobby B]

 I'll admit that I really don't know the specifics of this particular engine, but just out of curiosity, why is there controversy surrounding this particular Cam/Grind?  It seems that a few people have had issues regarding setting it up correctly. Are there no other manufacturers that make a modern day "High-Energy" style cam for this specific engine? Again, not being facetious, just curious......
                                                                                                                                                   Bobby

["Cadillac Kid" Greg Surfas 15364]

Mika,
Have MTS check out the cam.  I have gotten several cams from them and they have all been right on the money.
I did check the first cylinder on the #5 cam just for fun and it was right on what the cam card said.
I have a 350 degree (at .0.050) roller cam in one of my engines and I did also degree the first cylinder to verify it was as the cam card.
In your first post is seem there might be a few issues to getting your car running well, so first things first and have MTS verify the cam.
Greg Surfas