AMC 360 build for low-end torque

[rbdesse]

I am building an AMC 360 for use in a 1980-1986 CJ-7. I am looking for high low-end torque, since I have no need for high-end speed/power in this application.

I have a 1970 or 1971 AMC 360 (old-style flat crankshaft flange, and 3-bolt balancer w/ 3-bolt pulleys), and a set of 58cc heads (casting number 3233344).

I welcome comments on the following parts and suggestions for alternative selections:

(1). Bulltear 9.5:1 forged pistons
(2). Engle #5054H cam
(3). Edelbrock Performer Intake (no EGR valve)
(4). Considering a 650cmf carb with vacuum secondaries

Has anyone used the Engle #5054H cam in a 360? If so, how was low-end torque and idle quality?

Can anyone recommend an alternative low-end torque cam and tell me about your experience with performance and idle quality?

Thanks,

Richard

[jeepsr4ever]

Hey did Dusty use that cam and have good luck? Paging Dusty..

[tufcj]

I run an Edelbrock Performer cam/manifold on my 360. I'm running stock pistons with 291C heads (around 9:1). I ran a Holley 600 w/vacuum secondaries before I went EFI. That was more than enough carb, the EFI is rated around 550, and is still enough.

Mine has enough torque (with a 70:1 crawl) to spin all 4 at idle while rock crawling. It does fall on its face over about 4500 RPM though.

AMC's like to breathe, make sure you have a big enough exhaust. I run stock manifolds to a 3" single exhaust (have to for smog).

Bob
tufcj

[kris]

...I am looking for high low-end torque, since I have no need for high-end speed/power in this application...

I welcome comments on the following parts and suggestions for alternative selections:

(1). Bulltear 9.5:1 forged pistons
(2). Engle #5054H cam

Has anyone used the Engle #5054H cam in a 360? If so, how was low-end torque and idle quality?
Thanks,

Richard

You might not want to hear this, but...
For what you are saying you want for this engine and the cam you want to use, your compression is probably too high unless you are OK with running only premium fuel.

I'm on my second 360 build with an Engle k52/k54 (5052/5054) grind with a 112*lsa, no advance on the intake, and 8.5:1 compression. Ive recommended it to several others including one 401 build that was at 8.75:1 compression. The 401 owner later went to the k54@110* and wished he stayed with the 52/54.

Both the k52 and k54 grinds are short duration/low compression grinds. They are best under 9:1 compression. I did a compression test a few months ago and was in the 140-145 psi range. I havnt dyno'd mine, but Ive had two different people "desktop" it and both came in around 350lb/ft under 3500rpm.

Heres the card from my latest grind...



As of last year, Engle is no longer in Santa Monica or owned by the Engle family. They sold to "SoCal Imports" who specializes in VW's. Ive run a bunch of Engle cams over the last 25 years and mostly in VW's. Growing up in Santa Monica I always enjoyed stopping by their shop, but I dont know if this new company is grinding in-house. I would have a talk with them before ordering and make sure that they are at least being done in a reputable shop locally rather than out of state, or country.
Also, the new catalog is wrong in the CR recommendations, they have 9:1 listed for all the cams up to 298* duration. The old "Engle" catalog had the the k52 and k54 listed as under 9:1 compression, and the longer cams listed from 9.5 on up to about 11:1 for the longest durations.

Oh, mine idles fine. I have about 17in/hg at 700-750 rpm.
k.

[rbdesse]

O.k. I am getting a little nervous about the Engle cam.

I came across earlier posts discussing the following cams:
(1). Edelbrock Performer
(2). Summit K8600
(3). Competition Cam 268H (mild) street cam
(4). Comp Cam 258

Does anyone have any experience with these cams (perferably with 9.5:1 compression and the Edelbrock Performer Intake manifold)? Any comments on low-end torque and rpm performance band is appreciated.

Richard

[jeepsr4ever]

You dont want the Summit cam. Any of the other cams will yeild big big power on the low end for you with that kind of combo.

[kris]

Dont get me wrong... Im a really big fan of the Engle grinds. I just havnt bought from the new company and dont know where they are made. Im picky that way.


Just that with the compression you are wanting to run you should have an intake duration around 268-272*. The shorter duration Engle grinds are great for low end torque. You dont need the compression to build that torque if you are running the k52 or k54 grinds...

I was just suggesting you go with a lower compression ratio to match those cams... Only a suggestion...

Cams...
The Edelbrock Performer is wimpy. I ran one before going to the 52/54 grind. Ive heard its fine in a 304, but it wasnt much more than a stock grind in my 360.

Lots of people have run the k8600, and because of that theres been more talk about premature failures. Im not sure thats the cams fault and the people that have them like them. The duration is probably still too short for 9.5:1, you might look at the k8601 if thats the route you decide to go.

The Comp 268 would be the best in that list based on your compression ratio. The lift is a bit mild and the 110lsa a bit tight. It may build peak torque higher than you'd like.

The Comp 258 is putting your duration just behind the Engle k54. There are a few on IFSJA that run the Comp 258 in stock (8.5:1) 360's and like them.


Is there a reason you want 9.5:1 compression in a low end grunt jeep engine ? Im not saying its wrong, but its not really necessary for what you've said you want.



k.

[rbdesse]

o.k. I think I understand the issue: match cam with compression ratio.

My idea was to increase the compression ratio to improve overall engine efficiency and enhance low-end torque. I was thinking of 9.5:1 CR mostly because bulltear sells a set of 9.5:1 pistons for my application.

It is my understanding that most replacement pistons have a smaller compression height, which will actually slightly reduce CR unless some decking/milling is performed. I suppose this is done to allow for some decking/milling in case there is warping?

I am not opposed to limiting my compression ratio to something under 9:1 for better matching to the Engle K52/54 cam (and some of the others listed), but I do not know where I can get the parts that I need (pistons and/or thinner gaskets)?

Can anyone suggest where I can get parts to achieve a CR somewhere between 8.5:1 to 9:1 with 58cc heads? Maybe I am not going to get much improvement for my application by this small CR bump anyhow? If so, how about a set of replacement pistions that has the same compression height as the stock pistons?

Thanks.

[jeepsr4ever]

You dont have to limit your compression ratio for this type of build. You will find more power in increased compression using a RV type camshaft. MFGs call out minimum compressions for camshafts because you loose compression when your exhaust valve is open for too long.

[msalaba]

I run the Summit K8600

I have the edelbrock performer intake #2131, Duraspark dizzy w/ MSD 6AL box & SS coil and stock CJ exaust manifolds w/ 2.25" duals.

Engine is a 360 from a 78 Wag, 0.000" block deck, 0.045" head shave and factory pistons (no overbore) This puts me ~9:1 compression ratio.

Runs on Propane.

BW T15 Manual, 5.86:1 Gears w/ 42" Iroks

I really like this combo. It runs smooth on propane. Tons of low end torque. I can idle down to 500 RPM when crawling. Mash the skinny pedal off the line and you are in the seat till about 5000 RPM. I have never run out of steam on a vertical hill climb either.

The best part is the look on all my friends faces (who told me to put a chevy in it when I build it) when I fly by them on the trail!

The biggest downfall to the Summit cam (from what I've read) is quality control.

This thread from a while back discusses it:
http://www.bulltear.com/forums/viewt...ighlight=k8600

I've had mine in for 4+ years now with no problems.