3-Bolt Cam worth the investment...Check out these pics of the Stroker 505-OUCH!!

[Mfr426]

Well folks, I learned that the 3-bolt cam is a smart choice for anyone building a motor. This was a lesson that I was encouraged to pass on. I've had a tough few weeks with my 505 stoker motor performing very poorly and many weekends spent trying to figure out my problem. Thanks to Ron (firefighter) for working with me to find this problem over countless emails and phone calls. Ron, you're a good man!! I think I'm now up to (2) cases of beer at Carlisle! :-)

My car problems started at the end of last driving season. While hammering the Charger the one day I lost power and it began to break up over 1,500 RPM. My oil pressure was fine as was temperature but the motor shuddered over 1,500 RPM and the idle was not smooth. Clearly something had gone wrong with my bullet proof stroker 505 and I was sick. Fortunately it was litterally the last drive for the year for the car last year and I limped it home and parked it for the winter. I figured it was something simple like a carb adjustment or vacuum leak that just developed and that I could resolve this issue quickly once I had the time. Boy was I wrong. 

Over the last few weeks I worked to resolve my problem and swapped out my coil, reset the float level, swapped out my ECU, pulled plugs and checked spark, checked compression, replaced the oil drive gear with a new pinned gear, rechecked timing and did a ton of other items with no luck.The car still ran like a bag of crap. Frankly, I was out of ideas and pretty depressed about the whole thing considering that this motor dyno'd 509 HP/592lbft at Ray Barton about this time last year and performed flawlessly all last summer.

As a last resort yesterday I pulled the front end of the motor off after more failed attempts to fix the problem. I noticed that it seemed that my once quiet motor was also noisy towards the front end of the motor since my issue developed last summer. Frankly, I was just out of ideas and got sick thinking I could have internal problems with my $$$$$$ stroker build. I figured if I opened up the front end of the motor and did not find something out of the ordinary with the timing gears, chain, balancer, etc. I would not know what to check next. Well, I found my problem.

As you can see the three bolts that hold the timing gear on had ALL loosened allowing the gear to back off of the stud and move. This changed my timing enough to cause big problems and really CRAPPY performance. The bolts had actually gouged out the inside the new timing cover that I had installed as well. Apparently my machinist neglected to use 1) good timing gear bolts, 2) washers and finally...3) lock tight. The noise that I had been hearing was the bolts rubbing up against the timing cover. You can see the marks from the OUTSIDE of the cover so the bolts had pushed placing quite a bit of pressure on the cover from the inside. The heads of bolts were all worn down.

I was lucky to have found this. Had my Engle K60 cam been a single bolt cam the cam stud would have most likely broken off forcing me to buy a new cam and lifters. That would have been a $300 problem. Fortunately I'm only out about $75 for a new timing cover, gaskets, oil filter and new ARP timing gear bolts. The lesson learned is buy the 3 bolt cam AND check your machinists work. I should have seen the cheap hardware and lack of washers on the timing gear but I didn't. Rest assured I was lucky that this was not A LOT worse. Thanks to Ron for the help and the suggestion for the 3-bolt Engle cam.  Now I can get this thing back together and and ready for spirited spring drives. Ron, YOUR beer is on my Carlisle list.

Mike R in Reading PA
69 Charger RT/SE 505

[bull]

Yikes! That was a close one. Good catch.

[mauve66]

i thought all 3 bolt cams had a thrust button to prevent the cam from walking, don't they also prevent the bolts from backing out?? i always thought the thrust button was on the bolt side of the timing chain and i don't see one there at all, i've never had a 3 bolt cam just read about them so i could easily be wrong

[Chryco Psycho]

Glad you found the problem if it had been a 1 bolt you might be replacing a bunch of valves as well

[RD]

i thought all 3 bolt cams had a thrust button to prevent the cam from walking, don't they also prevent the bolts from backing out?? i always thought the thrust button was on the bolt side of the timing chain and i don't see one there at all, i've never had a 3 bolt cam just read about them so i could easily be wrong

that is what i was assuming too.

[firefighter3931]

i thought all 3 bolt cams had a thrust button to prevent the cam from walking, don't they also prevent the bolts from backing out?? i always thought the thrust button was on the bolt side of the timing chain and i don't see one there at all, i've never had a 3 bolt cam just read about them so i could easily be wrong

that is what i was assuming too.

Mopar flat tappet cams are designed with tapered lobes and crowned lifters which pull the cam towards the back of the block. Most BB Mopar cams are available in both single bolt and 3 bolt designs so if you think about it ; if a 3 bolt cam requires a thrust plate and button, why wouldn't a single bolt cam ?  The answer is neither of them needs it. 

Now on a roller cam there is no taper ground into the cam lobe so the thrust button is needed to keep the cam from walking too far forward. There is an acceptable endplay and often the timing cover needs to be tweaked a little to set that endplay. 


I asked Mike to post those pics as a learning tool and a good reminder to check and double check things over. In this case there were a couple of mistakes made by the machineshop ; incorrect bolts with no washers and no loctite.  Fortunately for Mike the 3 bolt upper gear attachment saved a catastrophe. With a single bolt cam the pin would have sheared off the cam core and possibly wiped out several valves as well as the cam itself...and the lifters which would be junk since they are forever mated to a broken camshaft. 

This was a first for me...i've never seen 3 cam bolts back off like this but seeing how it was assembled it's not difficult to understand why it happened.

Good work Mike....keep us up to speed on your progress. 



Ron

[six-tee-nine]

Yikes, You got away ok here....

But if it were my engine i'd change the oil too (dunno if you did). Looks like the bolts scraped away some metal, I woiuld'nt like to have those slpinters in my oil/engine.

Anyway, glad it was an easy fix, now when the sun is out there you can hammer it some more again....

[tan top]

   good find ! wonder whats caused them to do that think i would fit some kind of locking tab ,  like com cams sell with off set bushing kit

[Mfr426]

i thought all 3 bolt cams had a thrust button to prevent the cam from walking, don't they also prevent the bolts from backing out?? i always thought the thrust button was on the bolt side of the timing chain and i don't see one there at all, i've never had a 3 bolt cam just read about them so i could easily be wrong

Here is another shot. The bolts backed out enough to allow that stud (thrust button?) to walk out of the hole in the gear. The end result was horribly inaccurate timing.

[FLG]

WOW nice catch...atleast is wasnt any worse...lesson learned the much cheaper way 

I think EVERYONE is buying beer for ron, poor guy is going to be blasted at carlisle LMAO 

[Just 6T9 CHGR]

Wow those look like grade NONE bolts as well

I used a single bolt Engle cam BUT I assembled the motor myself triple checking everything....5 years & 10k+ miles so far so good

[RECHRGD]

Wow!! scary looking.  I used a three bolt comp cam on my build last year.  I used the ARP bolts and lock washers from Mancini with lock tight, so I guess I can breath easy.  Good catch!   Bob

[Mfr426]

The ARP bolts were ordered yesterday (along with the new timing cover, etc.). 

[Nacho-RT74]

Off topic

I thought the oil slinger ( sp? ) was just to SBs.

who's the best seller ( cheaper ) for those ?

My Mopar catalog doesn't ilustrate it on diagrams

[firefighter3931]

Off topic

I thought the oil slinger ( sp? ) was just to SBs.

who's the best seller ( cheaper ) for those ?

My Mopar catalog doesn't ilustrate it on diagrams

Mancini & 440 Source both carry the slinger 


Ron

[67_Dodge_Charger]

Wow!! scary looking.  I used a three bolt comp cam on my build last year.  I used the ARP bolts and lock washers from Mancini with lock tight, so I guess I can breath easy.  Good catch!   Bob

I have the same on my setup.  ARP bolts throughout the engine and double check all torque specs......  I would be leary using the motor with the metal shavings....  If it was mine I would pull it and throughly clean and reassemble.  A set of gaskets is all you would be out..

Robert

[dpm68]

It's nice to be kept aware of these things. Glad you're okay.

[mauve66]

i thought all 3 bolt cams had a thrust button to prevent the cam from walking, don't they also prevent the bolts from backing out?? i always thought the thrust button was on the bolt side of the timing chain and i don't see one there at all, i've never had a 3 bolt cam just read about them so i could easily be wrong

that is what i was assuming too.

Mopar flat tappet cams are designed with tapered lobes and crowned lifters which pull the cam towards the back of the block. Most BB Mopar cams are available in both single bolt and 3 bolt designs so if you think about it ; if a 3 bolt cam requires a thrust plate and button, why wouldn't a single bolt cam ?  The answer is neither of them needs it. 

Now on a roller cam there is no taper ground into the cam lobe so the thrust button is needed to keep the cam from walking too far forward. There is an acceptable endplay and often the timing cover needs to be tweaked a little to set that endplay. 


I asked Mike to post those pics as a learning tool and a good reminder to check and double check things over. In this case there were a couple of mistakes made by the machineshop ; incorrect bolts with no washers and no loctite.  Fortunately for Mike the 3 bolt upper gear attachment saved a catastrophe. With a single bolt cam the pin would have sheared off the cam core and possibly wiped out several valves as well as the cam itself...and the lifters which would be junk since they are forever mated to a broken camshaft. 

This was a first for me...i've never seen 3 cam bolts back off like this but seeing how it was assembled it's not difficult to understand why it happened.

Good work Mike....keep us up to speed on your progress. 



Ron

so i was thinking of a roller cam......... thanks for the info

[firefighter3931]

so i was thinking of a roller cam......... thanks for the info

No problem....hope that clears things up. 



Ron

[aifilaw]

Yep, I installed a cam button to keep mine from walking on a hydraulic roller. Never had use for one before this.

[Belgium R/T -68]

Mike and Ron,
Is it the fluctuation in timing that caused the poor performance because the approx 1 gear difference with a loose bolt/bolts should be
adjustable on the distributor? 

Per

[FLG]

Belgum,

It probably moved alot more then 1 tooth. Also 1 tooth means alot with timing.

[aifilaw]

You are referring to two different types of timing, cam timing and ignition timing
Cam timing is the relative position of the cylinder to when the intake and exhaust valves open and close.
Ignition timing is the relative position of the cylinder during the compression stroke to when the spark occurs.

[firefighter3931]

Aiflaw is right...cam timing and ignition timing are two different things. Both or either will hurt engine performance if setup incorrectly. 


Ron

[Charger-Bodie]

505-ouch Is that a phone number for a bad porn line? or what?