View Full Version : Dumb, Dumb, Dumbbbbb

01-04-2012, 12:15 PM
I have said many times " I am not the brightest tool in the shed".
I offer proof.
I am getting dressed to drive my cam down to Isky this morning to have it ground to the E4 grind many have reccomended. I realize I have not yet taken off the cam gear. I quickly pull the bolt, eccentric for the fuel pump, and lock ring. I see, of course, the threaded holes in the gear for a gear puller anchor point, BUT, my impatient "i gotta get to Isky" mentality and lack of apparent brains, I figure "its only fiber and I have a new one to install, I will just tap on it to knock it off of the cam".

So I grab my small rubber/plastic mallet, The kind that has a inch and a quarter diameter rubber button on one side and a same size plastic button on the other side. Small, light, and unobtrusive mallet, right?

Yep you geussed it, 2 light pops to the back side of the gear and it pops right off....my eyes exploded WIDE open as I see the end of the cam still inside of the gear....yep, I busted the end of the cam right off.

Dumb3 {that is 3=cubed}.
Never in my life would I have imagined that the end of the cam would have broken clean off with 2 light pops. I truely mean light too. I was NOT wailing on it. I only hit it about as hard as you would hit a nail just to set it....literally a tap.

So I guess I need to ask, is the cam in my 232 that is sitting here useable for the 289?
Are the cambearings the same diameter? Is the lift and duration close enough to still have it ground to the E4 grind from Isky?

I really had ought to just ride the SHORT bus everywhere and just do finger painting with my IQ.

Thank guys in advance.

ps: I am hoping the reason it broke so easily is there was a flaw and it was actually a good thing I found it now.....right? That would lessen the emotional pain and blow to my faint ego.

01-04-2012, 12:25 PM
Hell Kell, we all make mistakes. Frankly, I'm as surprized about the breakage as you are. And MAYBE it was a good thing if you exposed a weakness NOW - instead of at 70MPH. I've held in my hands - the result of a cam gear coming off at speed. It' isn't pretty! Lemmee see if I've got another candidate layhing around here. Just pay shipping and it's yours - assuming I have one.

01-04-2012, 12:32 PM
Yep, Kelly; what Bob said. I'd be glad it happened as described. Count the incident among your blessings. BP

01-04-2012, 12:39 PM
Found one. I'll need yhour address again.

01-04-2012, 12:50 PM
I will PM my address to you Bob. You, once again, are the MAN. I will send you what ever the shipping is, and a thank you tip of some sort...

Man I LOVE this place. I would accept any taunting and laughing you all want to dish out. I deserve it this time...well I usually do anyway.
Thanks for the support folks.
Kelly "knucklehead" Mac

01-04-2012, 03:10 PM
FWIW, I've seen many people destroy the fiber gear trying to get it off the cam. I've never seen anyone break the nose off a cam tapping it with a hammer. Maybe the mistake was to hit the gear from behind. This puts all the force on one side of the gear and at an angle to the cam

Lacking a puller, it might have been better science to open the jaws of your large bench vise just enough to suspend the cam vertically with the jaws supporting the gear. Using a brass drift, tap straight down on the nose of the cam. This way, when the cam falls out of the gear, it will land directly on your left big toe.

jack vines

01-04-2012, 03:28 PM
That is one of the DUMBest parts...I have a puller. Just got in a hurry and could not imagine it was that pressed on to need it. I thought I would give it a few taps to see if it would slide off before I dug out my puller.
Best part, I turn around really upset, only to see my puller laying 5' from where I busted the cam.
I would be ok with using my left toe as a bumper to cushion the blow of the cam hitting the floor, but I am not even THAT bright.

At least I have some actual experience to share with any noobs who need help...I can speak "from experience" now on cam breakage and the need to use the puller....now if only I can remember this tomorrow....
The bi-polar medication really jacks up my memory....and apparently my better judgement.

01-04-2012, 04:40 PM
Don't throw that old cam away. The end can be cut off and used for one of the roller cams.

01-04-2012, 04:52 PM
Alan, It is your if you want it...the end broke off flush with the gear.

01-04-2012, 07:06 PM
You'll have the "new" one tomorrow. I dropped it at UPS awhile ago.

01-04-2012, 07:37 PM
Don't worry you are not the first one that has done it. Most here won't want to admit it.

01-04-2012, 08:53 PM
I am used to admitting to stupid things....I do enough of them.
Thank goodness Rosco is around to save my day....again.
I am very glad to hear I am not the first one to do this.
I really expect someone here to harass me...this site can not be so PC that you wont even tease a well deserving guy like me. lol

01-04-2012, 10:08 PM
Do you know anyone who has broken a cam that way?

01-05-2012, 12:43 AM
This thread is a shining example of why I love this Forum, and Studebaker folks. :) Problem explained, problem solved!

01-05-2012, 12:53 AM
Not all cam technicians are bi-polar; just the half-speed ones. Most are merely eccentric.
You say it broke right behind the frontal lobe? Don't dwell on it.

Sorry, I'm just a cam follower. Didn't mean to be desmo...

Bob Andrews
01-05-2012, 05:19 AM
Not all cam technicians are bi-polar; just the half-speed ones. Most are merely eccentric.
You say it broke right behind the frontal lobe? Don't dwell on it.

Sorry, I'm just a cam follower. Didn't mean to be desmo...

Mike, you shouldn't get weird in the middle of the night. Who can be there to follow your quips with the necessary rim shot?

Kelly- no need to hassle you. I cannot believe a healthy piece would be broken as you describe. I'm betting it was flawed already and would have broken during machining anyway. I've just never seen one that fragile. Of course, if it had broken at Isky, you would have lost the chance to beat yourself up like this:)

01-05-2012, 05:25 AM
What is a cam? jimmijim

01-05-2012, 10:32 AM
Not all cam technicians are bi-polar; just the half-speed ones. Most are merely eccentric.
You say it broke right behind the frontal lobe? Don't dwell on it.

Sorry, I'm just a cam follower. Didn't mean to be desmo...

Baa dum pump....pssshh [rimshots & crash cymbol sounds] 6,6,6 jokes in one....pretty good ones Comatus.

01-05-2012, 10:53 AM
What is a cam? jimmijim

It is that bumpy stick behind that big spoked plastic thingy under that cover, behind that whirly bird propeller whatcha ma call it. ;)

Bob A,
Thanks for taking it easy on me...lol. I got to look at it better last night after I cooled down and started to laugh at it after venting here. It broke pretty cleanly right at the back of the front gear. There is the threaded hole in the end to hold on the gear and the fuel pump eccentric, then after the threads end, there is a small hole that was likely the pilot hole for the tap that is about 1/16" or 3/32". The shaft broke exactly at the end of that pilot hole. In other words, If I hold up the gear, with the busted stubb still in it, you see a small hole all the way thru. Then if you look at the busted end of the cam you see a tiny dimple dead center that is obviously the stop point of that hole in the stub.

It makes me feel like there was possibly a weak spot, but I know it was just the way I hit it must have put an angled, vibrating shot that just popped it off. My bad. Laughable now that Bob has helped me get back on track.

Showbizkid, I feel the same way. I was able to vent here, laugh at myself, hopefully make a few of you laugh, even if it was AT me not with me, and then in very short order the problem was resolved.
I simply asked if my other cam was useable and yet in 10 minutes I had a possible one on the hook, and in 25 minutes it was already in the mail....fixed. Very cool stuff and I GREATLY appreciate SDC and its members. I have some new friends, reconnected with some old friends, and gotten an unbelievable amount of help from all of you who have no reason to help me other than their kindness.
So THANK you all again.

01-05-2012, 11:31 AM
Dave, I busted one myself being in a big hurry probably 40-45 years ago and I have had a few people who will remain nameless that have called me asking for a cam core that have done the same.

01-05-2012, 11:33 AM
Kelly, look at it this way, it was meant to happen like it did, things work out that way don't ask why they just do, you were not meant to spend money on that cam, short story a few years ago and I will not name names but a friend came to California to pick up an Avanti he bought here, when he was here an extra day I gave him my lift for the day to do what ever he wanted with the Avanti, he checked over every thing and some things twice the next AM he and his wife took off driving home and stopped to fill the car with gas after that was done he started heading home and got just down the block and the car starting smoking to no end so he calls me and tell me the story, I tell him to get it to the shop and we can check it out, once he gets there I smell some thing funny and guess what he fill the Avanti with the green handle pump. ya Diesel fuel so I said lets drain the tank and the easiest will be to take off the supply line from the tank to the engine he reaches up to remove the clamp and the old hose breaks, the only thing he did not check and fuel starts running all over, we got it drained and back on his way in about an hour and all I said it was meant to be that you put the wrong fuel in just think if you had been going across the desert and have it let go , the car is so low you could never fix it so count your blessing that it was meant to be that way, if something is meant to be it will be count on it, if the owner of the story want to own up to it he will because he is a man of stature or something like that.

01-05-2012, 12:18 PM
So this has made me start thinking about a few things.
If this cam had busted, say when I am showing off the Stude power while doing a nice little smokey burnout....somewhere LEGAL of course, and the cam had popped at high RPMs, Is the Stude motor an Interference motor?
The pistons are quite dished so I am curious if the valves would hit the pistons if the cam stopped rotating and the pistons did not?

Also, since I have decided to have the cam reground at Isky, as some have recommended the E4, AND I am currently doing a mild port job myself, mostly cleaning up the ports and smoothing them out not HOGGING them out like some race motor, How much can I mill the heads?
I have a really good machinist here locally who has done some Stude stuff in the past and was excited to hear someone still building a Stude motor. He is going to surface both heads for $70.00 and will cut as much as I want.
I would like to bump my compression a bit just to add to the cam lope a bit. Yes I know lope does not neccesarily add horsepower or performance, I just LOVE that ra ta tat tat of a nice cam lope. I also know I am not building a race motor, just a nice little driver but I want some thump.

How much is safe to mill off without causing any trouble?
I dont want some 11:1 race gas motor.
What is the stock compression ratio of a '63 289 2bbl motor? and, what do you folks think is a safe ratio to bump up to? and, about how many thousandths do I mill off to achieve that?

It is a stock standard bore that I am QUITE sure has never had the heads off or been milled before. It is low miles and in fantastic shape and I have freshened it up with new rings, all new bearings, seals, gaskets, resurfaced tappets, and everything honed, cleaned and mildly ported.
I know you will all reccomend heavier valve springs....slippery slope....

01-05-2012, 01:11 PM
I can say from experience with another fine old design that, if the stop is quick enough, the valve will end up inside the combustion chamber, and from there, they are all interference engines. I managed to save a head once after that happened, but, really, not the piston.

I wonder, now that many others have 'fessed up, if there could be any correlation between a brittle spot on the cam and an engine that has had a critically hot run at some point, or a long-ago temporary oiling issue? Could be a case of it "losing its temper." No joke intended on that one.

01-05-2012, 01:22 PM
If you are building for any kind of performance, go for the Isky ST4 regrind.

The Stude engine has some old school benefits and one is the valves can't hit the pistons with any of the normal street cam/rocker arm setups.

Depending on the head gasket, your engine should be 8:1 or 8.5:1 compression. Using the thin head gasket and milling the head .060" is pretty common and some have gone .125". That much causes the intake manifold to get out of alignment with intake ports.

Consider blocking the intake manifold heat riser ports while you're in there. They're not needed in El Lay.

jack vines

01-05-2012, 01:33 PM
The storied engine that I had rebuilt - it ended up in my hands because of a cam thathad it's nose (and gear) snap off. While I've heard of the fibre gears stripping in high-mileage instances, this one was an aluminum gear on an engine with not too many miles on it. The engine was revving when the gear/cam let go. There was enough inertia for the gear to chew ugly gashes in both side of the gear cover. It was impossilbe to discern whether the gear had shed a tooth and caused the cam to snap, or the cam had snapped and let the gear loose.

As I said, stripped fibre gears ARE known to develop in high-mileage engines (very high-mileage). No doubt, that's what inspired Heavy Duty engines getting fitted with aluminum gears - what with commercial applications tending to see more overall lifetime RPMs endured.

01-05-2012, 02:14 PM
First, thanks for the help and better cam suggestion. Second, my head gaskets are from the SI minor engine rebuild kit. They are a fiber gasket with the metal rings around the cylinders and are a silver meatlic feeling coating on them. They feel like lead, not that they are, they just feel that way. They have one marking on them and it says- Best Gasket 598 - and measure 0.049 with a caliper.

Do you know if that Is the normal thickness or the thin?
If they are the thicker gaskets { they feel fairly thick to me} then what do you suggest I mill off the head so I do not mess up the intake alignment, but still gain some compression?

01-05-2012, 02:36 PM
You have the thicker gasket. Suggest getting the thin steel shim head gasket and milling .030"-.060" off the head. The longer duration of the ST5 should enable you to run 9.5-10.0 compression.

The unknown is how good a carb and ignition tuner you are and how much if any your heads have been milled previously. The original spec is 3.5625" deck to rocker rail.

jack vines

01-05-2012, 02:50 PM
When Mike started the roller cam project, I cut a couple of extra cams to send to him. One of the camshafts still had the fiber gear on it and I picked up a hammer to try and knock the gear off of it. I beat and banged, tore up the fiber gear and it never came off. Needless to say, when I cut the back of the cam, the rest of it and the fiber remnants went in the scrap pile.

01-05-2012, 04:49 PM
Jack, Thank you so much for that help. I will look into it and verify the heads dimensions price the better gaskets.

So I am hoping that your comments means that there may have been a minor flaw that my mallet brought to the fore before it cost me a catstrophic future failure.....that is my NEW story and I am sticking with it. ;)

01-05-2012, 05:41 PM
Is the thiner shim gasket part number 1545072?
Who sells them and how much are they?
How thick are they?


01-05-2012, 06:26 PM
I have been doing a bit of research today and found the Studebaker info site also called Bob's resourse site..(?)

I found I have heads cast with number 1557570 and they had the thin shim head gaskets and dished pistons. I measured my old head gaskets, glad I did not just chuck them out now, and they measure 0.016 thick (+ -) so I think that puts my motor at a 9.0:1 motor stock.

It looks as though the graphite gaskets that come with the SI kit I bought are set up to compensate for a 0.030 head mill. If you use the thicker head gaskets and no mill, it looks as though that combo gets you 8.25:1 and if I milled the head 0.060 and ran my gaskets it would put me back up to the 9.75:1 (ish) based on the basic figures I have found....Not a perfect mathamatical calculation obviously, just a low educated guess. It may even be more because as you mill the head the combustion chamber gets slightly smaller as you get farther in, slightly dish shaped or conical for a lack of a better word.

If you were to deck the block it would be a pretty simple calculation of volumn because it is perfectly cylindrical where a combustion chamber is sort of conical or dish shaped with many contours in it, so I think that would be a much tougher calc.

I will guess that most of you will recommend the thinner gaskets because of the higher compression. The graphite gasket makers insist that these are superior and definately seal easier than a thin piece of tin....

As always, thank you in advance for all of your input.
Just to explain something, I am never meaning to doubt anyone, nor argue, I just always like to formulate the WHY's. Once I learn why, then I usually get it. As long as my brain is saying "why Not?" then I just dont see it clearly. lol. I guess I am like that 80s band...the Simple Minds...

01-06-2012, 05:01 PM
Were you getting a full race grind?? Or a 3/4 race cam.................


01-06-2012, 05:57 PM
I'll get even with you someday Frank.....You just wait:p.
I stared at that pic for a full minute before I got it:rolleyes:

Were you getting a full race grind?? Or a 3/4 race cam.................

01-06-2012, 06:10 PM
Very Funny Frank. I not only like the V6=3/4 race...but the fact that you got Jeff makes it even funnier.
I am imagining him with a caliper trying to measure the lobes on the screen to see if it is 3/4 race lift and duration....

01-06-2012, 06:40 PM
After all the cams were cut for the roller project, we had a whole bunch of 3/4 cams!!

01-06-2012, 06:44 PM
I wonder how many of our younger members would even understand the "3/4 race cam" reference??? I do recall that it was always the Chevy guys who had the "full race", "3/4 race" and even the "1/2 race" cams in their engines. They could never answer the question of what the lift and/or duration of their cams were. duh. The machine shop that does my work also does a lot of work on V6 turbo Buick mills so I KNEW they would have a cam to help visulaize what a "3/4 race" cam should look like! LOL

01-06-2012, 06:57 PM
That is not a Buick V6 cam in your photo. I think that is a GM 4.3 V6 like they have in an S10 or some half ton trucks.

Here is a Buick V6 turbo 3.8 cam:


You pic looks like a standard SBC cam and the 4.3 cam which is very close to a SBC with 2 middle cylinders missing. GREAT design in my opinion. I had 2 of them and they were great motors. Rods, rockers, push rods, almost everything interchanged with a V8. Smart engineering to me.

01-06-2012, 06:59 PM
I thought a 3/4 race cam was #3 and 4 plug wire crossed.