Choosing a new cam

Discussion in 'General IH Tech' started by Darrell Tuxworth, Nov 19, 2020.


  1. Darrell Tuxworth

    Darrell Tuxworth High Wheeler

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    I currently have an ISKY 256/262 cam and am going to be replacing it.
    ScoutII is a 345 4 speed, 3.73 and 33's used for just about everything, off-road, daily driving, highway travel (to the trails in another state) and remote exploring as well as towing about 4k lbs.
    I am a low rpm type driver, I don't typically rev the IH mill very hi...after all it is a truck motor so I am looking at low RPM cams. Off road I usually drive at 800-1600 rpm and just let the engine lope along.
    I am looking at two Comp Cam grinds:
    252 grind 800-4500 rpm range
    260 grind 1000-5000 rpm range
    The engine will handle the 5k range of the 260 grind but I really don't need that much rpm and the 252 would suit my needs just fine.
    Does anyone have any experience with either cam?
    I do want a little more rpm than a stock cam (3600ish) and since you can't get new that is out.

    Darrell
     
    Last edited: Nov 19, 2020
  2. Dreamingofbinding

    Dreamingofbinding Farmall Cub

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    I’m very interested in this conversation. What are the downsides of these options vs stock?


    Sent from my iPhone using Tapatalk
     
  3. Darrell Tuxworth

    Darrell Tuxworth High Wheeler

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    The stock cam is a great low rpm torque cam but runs out of oomph early and when pulling a steep grade with the 4 speed and the trailer you need to get a bit more upper end rpm to stay in the powerband when you shift.
    That and the fact you can't get a "new" only reground used factory cam it's out for me. I am not sure there is any real downside other than maybe slightly less low, like under 1k rpm-ish torque. But I just guessing as I have never seen any actual apples fr apples dyno tests.

    Darrell
     
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  4. Dreamingofbinding

    Dreamingofbinding Farmall Cub

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    Thanks Darrell, i'm facing a similar situation which is why I'm asking. I like the low end, but am wrestling with leaving the stock cam in, or upgrading the 392 before I land it in the engine bay. I don't want to give up any low end.
     
  5. jeff campbell

    jeff campbell Lives in an IH Dealership

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    Tell them what u want and theyll custom gr ind u cam to fit your needs. A phone call.
     
  6. Darrell Tuxworth

    Darrell Tuxworth High Wheeler

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    They being who exactly? I'm unaware of a company that actually has an IH 345 and does Dyno testing with their grind these days.
    Anything is possible if you have enough money and I'm pretty sure I don't want to spend that much. I'm asking if anyone has either one of these cams in front of a 4-speed and what their thoughts are.

    Darrell
     
  7. steve bridge

    steve bridge Binder Driver

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    Reground might not be a bad thing. I assume Metallurgy has evolved for the better over years. Hard Weld rebuilding of the Lobes is said to make them harder than the original cast.
     
  8. Darrell Tuxworth

    Darrell Tuxworth High Wheeler

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    I guess I figured regrinding a cam was just regrinding the same profile smoothing the cam surface out to get it ready to wear in with new lifters not actually hardfacing it and then grinding back to factory specs. Now that I think about it regrinding a camshaft without first hardfacing the lobes would change the cam profile. And possibly change the torque and horsepower Another concern if the cam wasn't harfaced was making the base Circle smaller and potentially end up having valve train issues due to that fact. Maybe a reground camshaft is not a horrible idea. As you mentioned metallurgy has come a long way in the last 40 years but how much of that carried over into the camshaft world who knows.. Still want more rpm for shifting and keeping in the power band

    Darrell
     
  9. Challengeexcepted

    Challengeexcepted Farmall Cub

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    I definitely feel your want for “shifting rpm” when I built my first Jeep 4.0 I biased everything toward low end toque. That was fine, except for the fact that it fell on its face after 1800rpm. Highway driving was fine, except when you came to the slightest hill at which point the auto trans would shift out of overdrive, unlock the converter, and try to set a new “worlds highest reving I6” record until the topography flattened out. If you end up going the regrind route I recommend delta cams in Washington state. I’ve used them before. They can build up and regrind a cam to whatever you want. Also they seem to have multiple lobe profiles available for every engine ever conceived. Last time I had a cam done it was about $60 plus shipping. Comp makes good stuff too though.
     
  10. steve bridge

    steve bridge Binder Driver

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    At 4800 pounds, I never expected much from my Rallye Scout, but it was no slug either. When I put a 392 in a Scout II, it would bark the tires going into second at 55 mph; that had a standard cam. I was pulling my 220 Bow Rider with it and got stopped by a light. I had my sister and brother in law riding in it for the first time. When light turned green, I gave it just enough throttle to do a slow burnout across the intersection. "Oh, grow up" she said.
     
  11. jordandoc

    jordandoc Binder Driver

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    Why not go with what you now have...it's a great towing and low end cam although it puts the torque in a slightly higher RPM range than the stock cam. The Comp 260 and 252 are higher RPM cams if you look at the specs. I've run both of those and, after numerous years and motors, I settled on the Isky 256/262. I run it in 4 Scouts and 3 IH pickups. I do, however, have a special grind Isky 258 and am real pleased with it. You won't find it listed but if you call Isky, I'm sure Rod would grind one for you. I also run one Isky 262 in a relatively potent 392.
     
  12. jtorre4272

    jtorre4272 High Wheeler

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    I run a comp 260/260 in my 392 IC.

    1. Lousy idle vacuum. Won’t even idle properly unless my base timing is at 10 deg.
    2. Great sound at idle. Nice lope.
    3. Bad fuel economy at very low load conditions.
    4. Better performance? Doubtful in my case. I don’t run the engine higher than stock max rpm. Plus, I did not raise compression ratio when adding the cam. Big downfall and huge mistake. These cams need higher compression to work effectively.

    If I could do it over again I’d stick with the stock grind. Especially if I intended to tow routinely.
     
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  13. Darrell Tuxworth

    Darrell Tuxworth High Wheeler

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    Thanks for your input but I have to completely disagree.
    Imo this is a horrible towing and low end cam with a very narrow power band. The Isky cam is spec'd for 1800 to 5000 rpm (and it really is weak under about 1600 - 1800 rpm where it finally hits) where the Comp Cams I listed are spec'd for rpms as low as 800 and 1000. Not sure where you are seeing the opposite info. So Comp Cams are definitely much much lower than the Isky version I have. It might be OK for and auto but definitely not a manual trans.

    Darrell
     
  14. Darrell Tuxworth

    Darrell Tuxworth High Wheeler

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    4800? WOW I scaled mine on a certified scale and it weights in at 6120 lbs with a 16 gals of fuel, a 90 lb dog and me in it. That's it's everyday weight before camping of hunting gear go in. But tools, spares and recovery gear in that never come out.
    I imagine it would be quicker if I could shed 1300+ lbs

    Darrell
     
  15. Darrell Tuxworth

    Darrell Tuxworth High Wheeler

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    I think stock CR is 8.1 and mine is 8.7-8.8 so it is a bit higher than stock but not high by today's standards.
    So maybe the 260 is to aggressive, the 252 might be the better chance.
    I don't tow routinely but enough to know this cams sucks at towing, especially compared to my friends that have stock cams with 4 speeds and tow more weight than me.
    Interesting points you make. Here's my experience with the 256/262 using your comment structure
    1) low idle vacuum with severe overlap which causes a vacuum needle to vibrate rapidly assuming from intake staying open too long. will idle poorly at 10 deg BTDC but is much much happier at 20 deg and forget 0 deg that IH used for base.
    2) Idle sound is fine smooth with no lope in open loop but forget closed loop, but rich no matter what you do. 11.5 -12.5 :1
    3) City mpg not great but better than my friends in all conditions towing, off-road, highway, trail etc....
    4)I do have higher CR...Enough? Don't know.

    Darrell
     
  16. steve bridge

    steve bridge Binder Driver

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    Took it to the local grain elevator along with my other daily drivers at that time. Weighed empty and it was an XCL if that makes a difference. My '74 TA with lots of options and one full tank weighed 5,700. My '68 Triumph Spitfire with a TR6 six cylinder, weighed 1,580.
     
  17. Scoutboy55

    Scoutboy55 Farmall Cub

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    Any of the companies offering IH cams (Comp, Isky, Schneider, etc) start with new blanks. Then they plug in the profiles needed and the machine goes to work. They can put whatever specs together for you. I had Comp do a RV grind that copied lobes from a Chevy High Energy grind. I'll have to look it up, but it was a mild grind. More than stock IH, but like .440/450 202 deg. if I remember right. You can definitely go nuts on this subject. In the end, less is more. These motors just are what they are. Pushing them outside the original envelope really needs to be a system-wide endeavor. Cam, heads, compression, intake, exhaust, gears, the whole enchilada. Picking any of the Comp/Isky etc grinds won't disappoint on a basically stock motor.
     
  18. Robert Kenney

    Robert Kenney Binder Driver

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    The problem is that the blanks are made by CWC and they don't have any supply. Chances are they obsoleted them like they did on the 4 cylinder blank. About month ago I bought a brand new (stock replacement) cam as a kit by Elgin.
    This was after I got word of the shortage. Looked up the kit on Elgin's site. They are out there but going fast and may never be available unless some one coughs up the money to have a run made before they scrap the tooling IMG_5068.JPG IMG_5069.JPG IMG_5070.JPG
     
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  19. kevingweq

    kevingweq Y-Block King

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    Robert , Could you share the pricing ? Great link :clap:
     
  20. Robert Kenney

    Robert Kenney Binder Driver

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    I recall $299 and through Ebay.. I see 2 still on there as CL-415K
     
    Last edited: Nov 20, 2020

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