Pre-fitting cam bearings ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

[skip68]

The new cam bearings will be in today.   I've read that they sometimes need scraping to fit.   Can we slide the new bearings over the cam before it's installed and make sure they fit good and if need be, shave the bearings so they fit better and are not to tight before we put the bearings in the engine ? ? ?    

[TylerCharger69]

I've never heard of that myself....maybe someone will chime in on this one...But I think that cam journals come in a standard size.  Unless of course there is a "racers secret" that I don't know about.   And cam bearings....all 5 are different sizes...with number 5 (rear) being the smallest

[John_Kunkel]

Sliding the bearings on the cam won't be the same as when the bearings are driven into the block, installing the bearings into the block causes the inside diameter of the bearing to shrink.

[firefighter3931]

Chuck, the bearings needing a scrape (clearancing) is often due to cam bore alignment problems....which has nothing to do with the bearing itself.....it's an issue with the block (cam tunnel not 100% straight)

Ron

[six-tee-nine]

Sorry to go further on this Ron, but how should this clearance be determened? I mean how you guys know when scraping is needed  or when the fit is ok.......

[LeadfootBob]

Just make sure the cam turns freely, usually they bind in a spot or two when you spin it by hand
Another fun fact is that every cam bearing is different in size in the big blocks, they're numbered and packed in sequence in the box.

[TylerCharger69]

Exactly....As was posted above....once the cam bearing is installed into the block, correctly of course, with the proper tool....you should have no issues

[firefighter3931]

Sorry to go further on this Ron, but how should this clearance be determened? I mean how you guys know when scraping is needed  or when the fit is ok.......

As mentioned above....the camshaft must turn freely in the block with little resistance. 


Ron

[Doright]

No follow up by Chuck?

Well They worked frantically Chuck and VegasMike and she runs again seen it myself.

Didn't run too bad either But I would have went with a Hydraulic cam myself


Solids = Too much maintenance for a daily driver for me any way.

[firefighter3931]

Personally, i prefer the upper rpm stability of a solid flat tappet....no need to worry about lifter pump-up or valve float when you rev that badboy ! 

Valve lash takes ~30-45 minutes and from my experience....once a year is enough unless you're daily driving the beast....then twice a year would be sufficient. 



Ron

[Doright]

Personally, i prefer the upper rpm stability of a solid flat tappet....no need to worry about lifter pump-up or valve float when you rev that badboy ! 

Valve lash takes ~30-45 minutes and from my experience....once a year is enough unless you're daily driving the beast....then twice a year would be sufficient. 



Ron

I like a Flat tappet in a race engine sure but the street? I dont think so sure I can knock out an adjustment that fast and I'm sure he will learn too.

Keeping an adjustment for that long? Not in a street motor that is driven regularly not with the rockers he has any way I just wouldnt trust them myself just me though. .

I would say an adjustment or check should be done at least at each oil change maybe every second oil change  having to bend over those Big fenders is going to get old. 

If I was going to go through this much hassle I would have went with a roller cam  now that would be worth it

[firefighter3931]

Keeping an adjustment for that long? Not in a street motor that is driven regularly not with the rockers he has any way I just wouldnt trust them myself just me though. .

The cam is middle of the road in terms of lobe velocity....nice and stable. The rocker arms are descent as well and will hold lash for a long time.  

For example ; a buddy uses the same rockers with a very agressive .904 lifter profile Ultradyne solid in his street car and lashes once a year. Some of the time one or two valves might be out a few thousandths....most of the time they are fine. Keep in mind that this is a pretty radical grind (.600 lift at the valve)....waay more agressive than Chuck's stick !

I picked this cam because it makes descent power and is not anywhere near the ragged edge on ramp speeds. The primary focus was reliability (mild spring pressures) and no beating up on valvetrain parts. The high rpm stability (solid lifter) is a bonus so there's no spring surge, valve float or lifter pump-up to worry about. Chuck can wind it up to 6k all day long and not worry about breakage.  

The duration and LSA are well matched to Chucks stall speed and soon to be improved gearing. Ideally i'd like to see a 3.55-3.73 suregrip in this car for improved acceleration & performance. The cam swap was a HUGE step in the right direction, inmho  





Ron

[Doright]

I think he would have been money and performance ahead too have properly tuned the carb first and put gears in it and maybe headers as well before changing that cam out.

Any good Hot rod guy worth his salt always squeezes out all the performance he can out of a cam first before changing it.

I am not putting your experience down or any thing like that It sounds like you know what the heck your talking about but Other things should have been done first before going with a diffrent cam Because he still needs gears and headers to make this new cam work.


Heck Headers alone would have given him 20+ HP right off the bat and would have made a heck of a change in the way the engine performed 

[firefighter3931]

Dennis, i have to agree....that old cam could have been made to work with some tweaks but those tweaks would have been expensive ; new carb, bigger converter, headers etc...and you're still stuck with a high rpm engine that won't be too happy cruising around on the street. The tight lobe (108* lsa) and big duration don't work too well at lower engine speeds. I've ran that cam in the past and know all too well how much of a PITA it is to tune. The increased overlap is certainly not manifold friendly....waay too much ex gas reversion diluting the intake charge. It definately works much better with headers. 

The 274S is a 110* split pattern grind and does work with a restrictive manifold exhaust. Sure it will make more power with a set of headers so when Chuck decides to go that way he's all set....but for now he's OK as well. The stronger vacuum signal will also make carb tuning much easier. The old cam would have needed a pretty agressive fuel curve to work properly, something along the lines of an HP series holley carb due to the weak vacuum signal at the booster. This one will should run fine with his 750 Demon carb once the jetting is dialed in. 


Hopefully Chuck posts some vids soon !   



Ron

[skip68]

To make that old cam work would mean making the car less fun for the street.   I did some messing with the timing and carb and let me tell you this is a new car.  Now it screams.   I bet I gained 70-80 hp.             With the old cam I would need to run around at 2500 to 3000 rpm just so it would run clean.       I will be doing the dyno very soon.      Dennis, I need to bring you a 12pk and since you love the old cam so much, I'll bring it over today...       

[firefighter3931]

I did some messing with the timing and carb and let me tell you this is a new car.  Now it screams.   I bet I gained 70-80 hp.
     

That's about what i expected to hear.....right on Chuck ! 

What you gained was a LOT of low end torque & throttle response without losing much up top....if anything. 

Amazing what the right cam will do for performance. 
 
You'll be even happier once a set of deeper gears and suregrip are installed.....be prepared for lots of burning rubber. 


Ron

[Doright]

I agree the cam needs to be matched to the combo its being put it and the new cam is a dang good cam but before it was changed is what I am saying you know?


Chuck I will be out in the shop all day Wet sanding that car bring the Beer! trash the cam

[skip68]

 

[firefighter3931]

I agree the cam needs to be matched to the combo its being put it and the new cam is a dang good cam but before it was changed is what I am saying you know?


Chuck I will be out in the shop all day Wet sanding that car bring the Beer! trash the cam

Sometimes, the cam is just poorly matched and making it work is just band-aiding the build. We went through this with Vegas Mike's 440 a few years ago. I had originally specced out the build but some "genius" got involved and everything got fubarred. Mike ended up tearing it down and fixing the issues while installing the original cam i had specced for his motor.  

The end result was a 130-140ftlb torque increase at 3500 rpm and a car that would idle at 850-900 instead of a loading up/plug fouling 1300 rpm. Transformed the car from a gutless pig into a screamer !

Here's a good read complete with dyno sheets of the before and after results. This is an excellent illustration of overcamming and mismatched parts....and how it was fixed.   Same dyno & operator so the results are valid  

http://www.dodgecharger.com/forum/index.php/topic,6000.0.html


Ron