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Advice on cam choice - is it too big - AMC 401

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Halvard View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Halvard Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2020 at 12:32am
Thank you for the time spent on those graphs WesternRed. 
The HR224 is definately looking strong, but I wonder if the HR232 is in fact looking even better... It is at least making me think that it is worth making a call to discuss custom grinds, to tweek the cam to fit my application... 

i6cj7:
Good to meet a fellow jeeper on here. Sounds like a solid setup you have there. 
I hear your points, and I agree with most of them. First of all, I love the SM465 both for the extremely low first gear and the fact that it just feels unbreakable. But it is also the achilles heel as a street application. The few and wide gears makes it hard to downshift in to some appropriate RPM range when you need it. I am also questioning how happy it will be shifting from 2nd to 3rd at 6500 RPM the way it is built (twice as big and heavy as my original T-176). That gear shift would be the only time this engine will rev past 6000 RPM... If I still had the T-176, with a normal 2nd and 3rd gear, the desired RPM range would probably look a bit different. 
My cruising RPMs in 4th gear (50-70 ish MPH) will range from 2000-2800. I would like the cam to perform well in that area and up to 6000 for some highway shenanigans without having to drop down a gear.
In any ways I will reach my pucker factor top speed of 100 MPH at 6000 RPM in 3rd and 4000 RPM in 4th, so no need to shoot for cams with duration moving the curves too far to the right. 



Edited by Halvard - Jan/16/2020 at 7:31am
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WesternRed View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2020 at 2:52am
The HR232 doesn't appear to give up much on paper, plus you do have a few extra cubes to help things along, so maybe bigger is better in this instance. On the flip side, your heads are ported, so you should be able to do more with less cam.

The charts are just something I had laying around from some previous investigation, otherwise it would have been good to plug in a couple of the smaller cams for comparison.

Edited by WesternRed - Jan/16/2020 at 2:55am
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Halvard View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Halvard Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2020 at 3:54am
Thought I'd show (off) what I'm working with

copy+paste links into browser. 

https://drive.google.com/open?id=11jmCSFtNE85UjaKkyLCHPv_ipf-76Tbh 
Launch in second and shifting to third. Doing about 60 when passing the camera man

https://drive.google.com/open?id=11wNtJrdm6xr1NbxkuqE20DF-A-bjYcQ_ 
Crawled that hill and those boulders without using any pedals. EFI working great and idle set to 750. 


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Post Options Post Options   Thanks (0) Thanks(0)   Quote i6cj7 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/16/2020 at 10:45am
Sounds like you drive like i do.. Maniac.. You need a sequential 6 speed.. Lol, I'd like one too but $20k ain't in the budget right now.

That 2nd to 3rd upshift is a loooong throw in the SM, [and the gear change 3.58 to 1.70] is a big drop as well... Having a broad torque range will help keep the engine in its power band for that shift. I'm not even sure the SM synchros will like shifting at 6500rpm.. Its a truck trans, not a race trans unfortunately. Look into redline synthetic oils for a lighter/slicker gear lube. I've been meaning to change mine. And change it every few years. Mine shifts and goes into gear alot nicer with fresh fluid.

As for downshifting, I've started rev matchin,  heel/toe downshifting. It's easier on the synchros, and actually goes into gear with less effort. As you're going from 3rd to 2nd especially, clutch in, toes on the brakes, and blip the Throttle with your heel.


Man.. That's a beast of a CJ, great video! Where do you live? I'm out in Virginia 


Edited by i6cj7 - Jan/16/2020 at 10:47am
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WesternRed View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2020 at 1:42am
I'm sure somebody on here posted some dyno figures for a roller cam engine around the 224 duration mark, possibly jcisworthy, but I can't find the thread.

I see the XE291HR-10 was the cam used in the car craft 440 AMC build, so I gather you have read that article.

Would be worth comparing the dyno numbers and build specs for the two.

Also thinking that as some point your performer intake might be a limitation at higher RPM and that the airgap might be a better choice.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2020 at 7:47am
Your definitely out for the extreme. Have you thought of adding one of these:
That or a little nitro's will give you the tire squealing boost at the upper end.
I,ve seen a electric clutch/ intake "gate" added to these that's cool. Supercharger is switched on when wanted - otherwise know one knows. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Halvard Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2020 at 2:30pm

So I emailed both Crane and Bullet, and Bullet was the first to come back with a cam suggestion.

The say:

.520/.520 lift 296/301 adv 238/242 @.050  111 C/L + 4 adv Rpm 2000 to 6000 

I would have thought more lift, less duration and 112 LSA. Wrote that back to them and waiting on a response. 

Right now I think the off the shelf cams from Crane are looking better, even though I don’t understand why they have narrowed the LSA on the 232 cam… Also, my heads are advertised good for .580 lift. Will .584 fit?

HR-224/339- 2S-12  .542 .563 286 294 224 232 112

HR-232/352- 2S-10  .563 .584 294 302 232 240 110

WesternRed:

I found something about a 208 cam at work, but lost it again. A 343 with lots of torque. Was that the one? 

i6cj7:

Thanks. It is definitely getting there :) I bought my SM from Novak Adapters, and it has been flawless. I have not experienced any of the shifting issues I have read about from the states. Don't see them much over here as we don't get as many full size trucks as you do. I from Norway, so quite a way aways ;) 


Trader:

I have seen that thing. But I am pretty sure I am stretching the limits of u-joints, general drivetrain and what not as it is already...  


 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote PROSTOCKTOM Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2020 at 4:26pm
After looking at Darren's (WesternRed) dyno chart I would have to go with the HR232. If you were only rock crawling I would go with the HR224, but since you want the best of both World's it has to be the HR232. Plus it's a stocked shelf grind and easily available. Buy one and let us know the results.

Tom
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Halvard Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2020 at 4:30pm
How about the lift? 
Is it room to pass the advertised limit by .004?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2020 at 6:03pm
I think you will be fine with the lift limit as far as the heads go, but you will need to check piston to valve clearance. That can be one of the reasons LSA is reduced in the bigger cams.

Do take on board that the comparison chart I posted is just a simulation, so actual results may vary. Though in hindsight I do wish I had chosen the 232 over the 224. My engine makes peak HP at about 5300 rpm, but in a car application that is heavier than the Jeep, never had an issue down low with 2.87 gears and stock stall other than tearing up the transmission twice.
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