CL20-224-4 Competition Cam installation question

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Claude C

Claude C

Twin '66 Cudas
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1970 318 cubic inch motor. Bought the listed cam in the title which is for 273 thru 360 1964 thru 2002. The end journal is too big and won't fit into the block. What does that mean? Does it mean the cam that cam out had an undersized journal and had an oversized cam bearing installed? Please advise.
 
Measure the cam journal.
It’s either in spec or it’s not.

I show the spec as 1.9980-1.9990
 
First off, take a caliper and measure the cam journal. Then measure the cam bearing to see what the difference is. check your specs to check clearance. I just installed the same cam with new bearings with no issues

Tim
 
A caliper is not accurate enough, given the tolerance spec. A good 1-2” micrometer is required, preferably checked against a 2” standard. Need a bore gauge for the bearing. A very high end caliper might get you close but is still the wrong tool.
 
Sorry to be a pain...do you know what the rear journal should be... i have 1.15615 with this one.
 
I measured a sealed power rear bearing and came out to 1.5685. I think there should be @ .0015 clearance. Let others chime in more knowledgeable than my self.

Tim
 
If you have access to the rear cam bearing, you could take a set of inside calipers and get a measurement and measure the inside. Make sure the bearing wasnt damaged during installation.

Tim
 
Are you assuming the rear journal is the problem because it won’t go in the last little bit? Definitely measure each bearing journal on the camshaft with a micrometer.

I had this happen twice.
First was with a new Mopar short block. Rear journal would start in the bearing but then the other journals would start and the cam would bind. Very tight. On mine, it was the third or fourth bearing that was too tight. Other known good camshafts were also tight in that block. Mine was on an engine stand, not in the car, so I was able measure everything. It ended up being the bore in the block was small, so the backing for the bearing was getting rolled under when bearings were installed, causing tight spots. Once the bore was honed to correct size, the bearing installed properly and the same camshaft installed and turned smoothly.

Second was a big block. This one known good camshafts installed and spun nicely. The brand new Comp Cams solid flat tappet cam was ordered with nitride treatment, and the bearing journals were oversized compared to Chrysler design specs. Had that cam fixed by Comp Cams warranty dept. That’s when they told me they don’t grind their flat tappet cams any more, they come finished by their supplier. Who knows. Comp is garbage these days.
 
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The spec for #5 is 1.5605 - 1.5615

Does it mean the cam that cam out had an undersized journal and had an oversized cam bearing installed?
Click to expand...

If the old cam fit with no problems, measure and compare the sizes on all five journals.
 
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Long story... bought the 318 15 years ago from a guy who raced it. Finally got it put into my Barracuda last fall. Put disc brakes on front and rear sure-grip drum to drum. The motor has too much cam and hardly idles, smells like unburnt fuel because of the cam overlap, and hardly creates enough vacuum for the brakes to work! So I took to this guy to have this cam put in. When trying to put the new Comp Cam in, it hangs up just before the last bearing goes in and just before the front bearing goes in so wasn't sure which was hanging up. Turned the cam around just to try and put the front bearing in and it wont fit. Took measurements today and all are within the specs that the guys listed in this post. So I am assuming the bore needs to be honed. My mech wants to have all new cam bearings put in to make sure everything is right and fits. He pulled the trans already to install a lower stall converter (old one was 3,200). Since the trans is out anyway, he is pulling the motor and I am having a machine shop do the cam bushings and to clean up the bores. Does that sound like the right thing to do?
 
That sounds like a logical choice. My shop installed new Clevite bearings and I put in the same cam and it slid right into place. May sound dumb but you did remove the dist drive gear.

Tim
 
Claude C said:
The motor has too much cam and hardly idles, smells like unburnt fuel because of the cam overlap, and hardly creates enough vacuum for the brakes to work!
Click to expand...
The stink might not have been, probably was not, anything to do with the overlap. Big cams have special needs regarding the synchronizing of the throttle blades to the transfer slots, and Idle-timing. And some cams will not work properly at idle with a metering-rod carb, without a lot of work.
You may find a similar situation with your new cam, depending on the specs. And depending on your cylinder pressure, you cannot always install a smaller cam without making other changes. I hope your mechanic knows this and is on top of it.
 
Claude C said:
Long story... bought the 318 15 years ago from a guy who raced it. Finally got it put into my Barracuda last fall. Put disc brakes on front and rear sure-grip drum to drum. The motor has too much cam and hardly idles, smells like unburnt fuel because of the cam overlap, and hardly creates enough vacuum for the brakes to work! So I took to this guy to have this cam put in. When trying to put the new Comp Cam in, it hangs up just before the last bearing goes in and just before the front bearing goes in so wasn't sure which was hanging up. Turned the cam around just to try and put the front bearing in and it wont fit. Took measurements today and all are within the specs that the guys listed in this post. So I am assuming the bore needs to be honed. My mech wants to have all new cam bearings put in to make sure everything is right and fits. He pulled the trans already to install a lower stall converter (old one was 3,200). Since the trans is out anyway, he is pulling the motor and I am having a machine shop do the cam bushings and to clean up the bores. Does that sound like the right thing to do?
Click to expand...
My buddy had his cam journal turned down on a laithe. Fit great. Motor has been together for 15 years. Kim
 
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