B Camshaft

George D

George D

Member
Hello I have a B cam in excellent condition that I would like to use in my model A engine. I also have new single lock tappets that measure 1.120" at the base. Are these compatible or do I need to find tappets with a larger bace? Thank you
 
I have been using adjustable tappets from Snyder's with no problems. Be sure and check the diameter of the cam center bearing and also the bearing journal in the block. Any wear more than 0.005" "slop" may create a tap-tap noise. Not good! Most camshafts are worn, best to buy a new one.
 
1.120" will work fine with the A or B cam. FYI, there were 3 different B cams produced. Most had .302" cam lift. A few had .315" cam lift and some .339". The last was the best performer, but all were an improvement over the A cam.
 
The B cam I have is like new with right size bearing diameters haven't measured the lift, did not know there were three different B cam's. I have nothing against a new one but the one I have dosnt need replacing
 
If a used "B" cam has a little rust pitting on the journals, will it necessarily have to be turned down by a machinist? Extra slop (over. 005) would causes tapping or knocking someone wrote. Would a minor amount of rust pitting on the cam journals would be enough reason to reject spending $50 for a used "B" cam? Yes, a Stipe 330 cam would be great, but how much do they cost in comparison to a $50 used cam?
 
I have often wondered what can be done about the cam bearings in the block. If you turn down the journal on the cam to that the slop is unacceptable how do you bush the block? Also how do you measure the cam bearing surfaces in the block? Does the cast iron not wear for some reason? Jack
 
jhowes said:
I have often wondered what can be done about the cam bearings in the block. If you turn down the journal on the cam to that the slop is unacceptable how do you bush the block? Also how do you measure the cam bearing surfaces in the block? Does the cast iron not wear for some reason? Jack
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Hey Jack,
A machinist who knows and has proper equipment can use bronze bushings in the stock (worn) block bearing areas(3). After the bushings are pressed in, they must be reamed to fit whatever the cam specs are. The block is measured with inside caliper / mike. I do not think that this is a job for amateur, but wouldn't be surprised if someone has done this job. I only knew J Steele to have offered this service. Sure the cast iron wears. Compensated for by building up cam bearings or bushing blk as said.

Oh, and if you buy a Donovan alum 4 cyl block, they used chev 350 cam bushings for that purpose, I've been informed.
 
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Hardtimes; thanks, it is nice to get replies. Other makes that I have do not reply with the technical information on their site like this one does. Again, thanks. Jack
 
jhowes said:
Hardtimes; thanks, it is nice to get replies. Other makes that I have do not reply with the technical information on their site like this one does. Again, thanks. Jack
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Welcome Jack !
I've gotten help here and on Early V8 side, since first day old days, when the other owner had this site. I've even learned to negotiate HAMB :eek:.
Just like you, most are here to ask questions and to help others. As no one was born with this knowledge, that is why we ask each other. Ryan, owner, has improved his domain for our benefit and I thank him :)
 
southfork said:
If a used "B" cam has a little rust pitting on the journals, will it necessarily have to be turned down by a machinist? Extra slop (over. 005) would causes tapping or knocking someone wrote. Would a minor amount of rust pitting on the cam journals would be enough reason to reject spending $50 for a used "B" cam? Yes, a Stipe 330 cam would be great, but how much do they cost in comparison to a $50 used cam?
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IMHO, a little pitting shouldn't be a problem. After all, the job of oil is to prevent the two surfaces coming into contact. No contact, no problems.
A while ago, I had an A crankshaft that had standard journals but had been sitting for years, so long that there was a line of corrosion where the main bearing cap met the block. After asking around, I decided to leave it for the reason I have outlined above.
 
Ed H. said:
How does one tell the difference between A and B distributors?
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Here is a "B" distributor I just installed. No arm for retard advance rod to mount to. Small lock screw on carb side to adjust and set advance. Plus centrifugal weights.
 

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hardtimes said:
Hey Jack,
A machinist who knows and has proper equipment can use bronze bushings in the stock (worn) block bearing areas(3). After the bushings are pressed in, they must be reamed to fit whatever the cam specs are. The block is measured with inside caliper / mike. I do not think that this is a job for amateur, but wouldn't be surprised if someone has done this job. I only knew J Steele to have offered this service. Sure the cast iron wears. Compensated for by building up cam bearings or bushing blk as said.

Oh, and if you buy a Donovan alum 4 cyl block, they used chev 350 cam bushings for that purpose, I've been informed.
Click to expand...

Schwalms Babitted Bearings in Pennsylvania installs bronze bushings in the block and align reams them to the correct clearance. I had this done for my new Stipe cam.
 
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