Replacement for C grind cam

[bob_e95482]

 I removed the 84ci motor from my '73 last week, took it to a motor guy. I had bought new lifters and tappet blocks, thinking I had lost a lifter roller. The guy said the C grind cam had the front cylinder exhaust lobe wrecked. I like the way the C grind makes power, and I'm thinking of getting another one, or one similar. I also have Jims roller rocker arms on the way, and I have S&S heads clearanced to .550 lift. I might like a little bit more bottom end, but I can handle a lot of lift.
He also is going to repair my left case Timken bearing insert, and said the S&S flywheels were set up really tight. He also said the wristpins were trying to lose the keepers on one side from a sideload on the wheels. This guy used to be an engineer for the MoCo, seems to know his stuff.
I got about 8 years from the lower end, done by a local indy I don't have much faith in anymore.

[flhswingarm]

Bob............what manufacturer is the cam??

[Hillside Motorcycle]

That cam is pretty damn big for your engine.
I'd set it at about 9.5-10.1 and install a Wood 6. .510 lift/240 dur.

[bob_e95482]

The C grind is an Andrews cam.

[flhswingarm]

Bob thanks.....  not to steal your thread........but anybody direct me to where i can find the specs on my Crane "C"cam ? Been in there since 01 and if memory serves me it has a .488 lift.

thanks again

[bob_e95482]

.550 lift, 278 duration.

[Dogbone45ACP]

Andrews #6 would work good in that size motor. 510 lift 268 duration.

[flhswingarm]

Bob......... thanks again for the info
Although I been running this  "C" cam for 8 years........ and it scoots along just fine...........what could I expect from a less tall cam with a shorter duration?? Like the Wood cam Hillside mentions.  Better mileage??......  71 flh .040 over ...9.5/1 , super E, s 'n s solids, black diamond valves. Or should I just ride the ol "stump jumper" an fuggitaboudit................  

[monty101]

www.nightrider.com is a good place to look up the andrews c cam specs. Its got a .525 lift

[bob_e95482]

The S&S stroker kit came with an S&S 514 cam. The bike had better roll-on at 74" than at 84" with the 514. When the Jims big axle lifters went out, they took the 514 with 'em. The Andrews C grind went in, the bike flat out RIPS! It's just I'd like to gain maybe a bit more on the bottom, without much loss on the top end. I've been on the road, working my butt off, buying parts, I think the lifters I bought may be hydraulic, I haven't checked yet. I'll be using a Thunderheader exhaust, and I turned my adjustable S&S pushrods upside-down, so if I stay with solids, I'll be able to adjust tappets without removing the exhaust.

[stroker800]

   Check out th ratio of your new roller rockers before buying a cam,,,,I have found that S&S rollers have changed the ratio from 1.42 to 1.5 ,,,this in turn gives you greater lift  ie...412 becomes.485 . If goin to a high lift you might want to space up your rocker boxes to correct some of the push rod angle,,,,just food for thought.
Dave

[bob_e95482]

The cut sheet with the roller rockers says they are 1.5. The J&P sticker on the box says 1.43. 1.43 was used from '66 to '80, 1.5 from'80 to '84. I'll get together with my builder, we'll figure out what cam.

[bob_e95482]

Going with a new Andrews C grind. New pinion gear. The S&S heads are fine, the Jims roller rockers should take a load off the valve stems and guides. The wheels had to be taken apart, rebuilt. New USA made solid lifters. STD does not sell the left case bearing repair part anymore, JR had to send it to STD instead of doing it in-house. The bore was about .009" clearance, was set up way too loose. Have to go to .050 over instead of .040. S&S cast pistons are 8.25:1; forged are 8.5:1. Looked into getting custom pistons made to get around 9:1, cost is prohibitive. JR's gonna cc the combustion chambers, then machine the heads to get the 9:1 with cast pistons. S&S oil pump looked good. Crane HI4 plastic case was broken, getting another one. Should end up around 85-86ci.
Got new chrome spoke wheels, Progressive 440 shocks, Santee beveled wrap-around oil bag, Thunderheader, 32A charging system, RevTech 5in4, chain, sprockets, seat, powdercoat the frame, do sheet metal work on the fenders, etc, etc.
Have a pic from the last build, 8 years ago. Frame up, had an altercation with a garbage truck. Got a lot of miles out of it.

[attachment removed after 60 days by system]

[Hybredhog]

   As said before, thats a small motor & pretty low compression for a C grind, and your power band probably feels like its ALL up on top. Installing a c grind damn near ruins a set of heads, as you have to sink the valves so far into the seats so that they won't colide during overlap, and the stem protusion is way out there! With only 8.5 compression, I'd use an Andrews #1 or #2 if its a lighter bike. But if you like the feel of high RPM power, a #6 on the very outside of practical cams...Jeff

[crazycanadian]

I removed the 84ci motor from my '73 last week, took it to a motor guy. I had bought new lifters and tappet blocks, thinking I had lost a lifter roller. The guy said the C grind cam had the front cylinder exhaust lobe wrecked. I like the way the C grind makes power, and I'm thinking of getting another one, or one similar. I also have Jims roller rocker arms on the way, and I have S&S heads clearanced to .550 lift. I might like a little bit more bottom end, but I can handle a lot of lift.
He also is going to repair my left case Timken bearing insert, and said the S&S flywheels were set up really tight. He also said the wristpins were trying to lose the keepers on one side from a sideload on the wheels. This guy used to be an engineer for the MoCo, seems to know his stuff.
I got about 8 years from the lower end, done by a local indy I don't have much faith in anymore.

Umm on the crank that totally contradicts itself.. if the crank was to tight it would take out the bearings.. not the wristpins.. the crank would have had to have been to loose and moving back and forth forcing the rods into the pistons.  Also the pins are free floating and the rod would bind into the piston.. the pins would just freely float.. sounds like bs.

[Hybredhog]

    And if the Left main bearing is loose/ blown, a leading cause is running them at to high of RPM for to long (I.E., C grind's power band in such a motor), Engine life is counted in seconds after 6000rpms....Jeff

[hotham]

That Andrews cam is pretty big for that size motor.  You would want to run near 10-1 CR to make that cam work well.  An Andrews B or 6 I think would be a better choice.  I have a 93 " Shovel with $1500 worth of headwork, roller rockers, Velvatouch lifters and a Leineweber .520 lift cam.  It is to big.  I have great power from 3200 on up, but it needs a smaller cam to gain bottom end back.  The "C" in your motor does the same thing.  I have run probably 10 different cams over the years and like many of us, I try to convince myself that bigger is better.  Wrong!!!!  Best of luck with your new build

[MBSKEAM]

I have the A grind in my 88", it rips pretty good, but is a pain to start, so now I am going to a LEINEWEBER
L2 cam, hopefully this will let it start a bit better....

mbskeam