r block cam

i have a r block 48 degree std la cam tunnel ,and i have a cam 48 degree with the same journals all the way threw ,is it best to grind the cam down or bore the cam tunnel to size

I would think cutting the cam down would go threw the hardening on it. Don't know but I would call Bullet, lsm or predator cams.

I would bore the cam tunnel out and put roller cam bearings in it.

Get the right cam blank... if you have to go
with the one you have, have the cam ground down
and get it nitrited
EDIT
after thinking about it... bore the tunnel out and
change it to a roller tunnel... the blank you have
is it a flat tappet or roller blank.. they are diferent

Big cam core+less cam deflection ====more HP

cam is a callies cam core 1.988 babbit bearing .is there a good aftermarket cam bearing that will last with solid roller spring pressure 280 on the seat 650 open ,i will see on boring the cam tunnel .what are the pros and cons of turning it in to a roller tunnel ,is that a different cam again

Durabond bearing would be fine. I had a 50mm cam ground for around 450. Indy ripped me for 750 to bore the tunnel since I already had a 500mm cam. Been running roller cam bearings for a few yrs now, no problems.

are the cam cores the same size for the babbit bearing and the roller bearing

No. Roller bearings have a bigger diameter. I don't remember the size.

Plain bearing is larger than roller bearing cam.
So plain bearing mains can be ground to run on roller bearings.
Can't use roller cam 50mm in plain bearing block.

Thinking about picking up a 9.2" deck 48 degree R block. Is there anywhere I could bone up on the cam bore/bearing differences?

Was thinking about doing a short 3.7-ish inch ( for me, lol) stroke turbo motor.

Might not be up for a $500.00 cam core that's gonna be hard to come by...lol

Then a r block might not be the right choice, as all came out their are designed for NA motors. You would have to run a custom core to get the proper cam for a power adder car. You can make something work like I did, but it won't be close to ideal.

Bore the tunnel Ian, you will struggle finding 48* cam cores with factory bearing configuration. The babbit journal size is 1.998" or 50.75mm, so be mindful of that. I remember being told that a durabond bearing was available that fit into the 50mm roller bearing bore, but allowed a 55mm core to be used.

i will mate,the cam i have is a 1,998 babbit bearing cam ,which is a better bearing the babbit or durobond and are they the same size as the front bearing on a la block .crankshaft rebuilders are going to bore it ,clive cams said you can turn the jurnells down and the do not need to be heat treated

Predator cams has Babbitt ugl cams in stock. It's where I got mine.

Have them quote you on doing the cam tunnel, it might be a wash when compared to grinding the journals on the cam down. Saliba's in Springvale can do the cam tunnel if Cranky's can't, but Charlie isn't quick.

can the r block tunnel be bored out to handle 60 mm roller cam .i have sitting here too

Yes.

anyone ,have a part number on the babbit bearings or durobond thanks

If you're going to go to 60mm, go with the roller bearings. Do you still have those 60mm cams your got off Craig?

yes mate i have one 500 lobe 275/289 @ 050 on a 116 with 1.85 rockers 925 lift lol

Not the best idea.

You can run plain bearing and save lots of block integrity
No real performance advantage to roller bearings and some top guys even think plain bearings deal dampens harmonics.

If your taking about the first-generation R block ??? What you do is use a 50mm roller cam
You Machine out the block The first 4 mains from Front to back to the bearing size I can get that # if you need it and that last main can only go to 40mm so you have to turn down the cam on the last Journal
There's not enough mean on the block For a 50mm bearing

Pictures below are of a 48° First-generation R block