360 build plans

rockjeep

I need a good guide to build a 360. Can't find a 401 for a decent price. It is going in rock crawler with a tf727. I had a 304 but it keeps eating the lifters and cam. I need something reliable yet want to make close to 400 ft/lbs. Any suggestions on how I should build it? I'm going to be running rockwells with 6.72 gears and 47-49" tires. Thanks Bobby

dbesade

PM "mudrat" he made a 360 with some good numbers. Do a search for a while there was a lot of 360 builds going on.. Best of luck -Dave

AMX69PHATTY

There's always the $1000 drop in Crane Hyd. Roller Cam option.

jeepsr4ever

Rock buggy a simple RV camshaft and a bump in compression would give you all of 400 in torque. Put a edelbrock performer intake and carb on as well. It doesnt take much to get the low and mids from a AMC V8.

rockjeep

I want to get it built but don't want to just go to the local shop and tell them to build it. All they will want to do is build it to stock specs. Thanks bobby

jeepsr4ever

Bobby you dont need much more than stock. Tell them you want a RV camshaft and a performer intake on it (which is a simple request) and you should hit those numbers.

AMX69PHATTY

Was just saying a way to avoid cam lobe break-in concerns is to use a roller cam, not that it's cost effective or appropriate. MC, have built any AMC motors with the Crane Roller Cam set-up ?

jeepsr4ever

Crane stuff is great for a roller street application but if your doing a full on race bushing the lifter bores is the only way to fly.

1980_Cj7

jeepsr4ever wrote
Bobby you dont need much more than stock. Tell them you want a RV camshaft and a performer intake on it (which is a simple request) and you should hit those numbers.

Hmmm, now you really have me wanting to put our new 401 on a real dyno. We're .040 over, have a 220/220 .488/.488 (@.050) cam, 9.5:1 KB354 pistons, an Edelbrock Performer intake, and an Edelbrock Performer 750 CFM carb. When I punched everything into Desktop Dyno, including the stock 6090 head flow numbers I got off this site, I am only getting something like 362 HP and 412 ft. lbs. (I don't have the actual numbers in front of me). Don't get me wrong when I say ONLY, that's not that bad, but you're saying you should be able to hit those numbers with a 360. Is Desktop Dyno any good?

The max HP was at like 5500, and max torque came in at 2500 (NICE!).

jeepsr4ever

Because the stroke and bore are smaller the 360 will have to have a higher point of power in the rpm range and it will using the same camshaft that is used in a 401. Alot of this is depending on the overall condition of the short block that you start with (If used). Desktop dynos are decent but cannot take in all the charateristics of a motor that may or not be tuned. The rate your secondaries open up for example and the amount of vaccum you achieve are things that greatly effect performance at various RPMs. Desktop dynos are fun and a decent tool but real world numbers are usually up or down from the DD.

1980_Cj7

Just looked up the numbers on our engine. My memory was off a little. Actually got 356HP @ 5500, and 404 ft. lbs. @ 3500.

82Waggy

1980_Cj7 wrote
Hmmm, now you really have me wanting to put our new 401 on a real dyno. We're .040 over, have a 220/220 .488/.488 (@.050) cam, 9.5:1 KB354 pistons, an Edelbrock Performer intake, and an Edelbrock Performer 750 CFM carb. When I punched everything into Desktop Dyno, including the stock 6090 head flow numbers I got off this site, I am only getting something like 362 HP and 412 ft. lbs. (I don't have the actual numbers in front of me). Don't get me wrong when I say ONLY, that's not that bad, but you're saying you should be able to hit those numbers with a 360. Is Desktop Dyno any good?

The max HP was at like 5500, and max torque came in at 2500 (NICE!).

Don't mean to hijack this thread, but, 1980_Cj7, are you having any detonation problems at that CR - and on what gas? What deck clearance didyou end up with?

rockjeep

I'm picking up the stock 360 saturday. Should I have the machine shop assemble it too? It doesn't seem to be to complicated to assemble it as long as i torque everything in sequence and proper amounts.

CJim7

rockjeep wrote
I'm picking up the stock 360 saturday. Should I have the machine shop assemble it too? It doesn't seem to be to complicated to assemble it as long as i torque everything in sequence and proper amounts.

That's going to be up to how you feel about your own mechanical abilities.

Im takeing my 401 in to have it cleaned up and machined, crank turned, and new cam. While it's there, im going to have them install the crank, cam, and timing gears/chain. I dont feel real comfortable with cam bearings and main bearings just yet.
Im haveing them go through the heads also...install new valve guides and seats. 3-angle. from there i can re-assemble the heads.
Im hopeing that will save me some money by doing a good portion of the assembly myself, i could be wrong though.

1980_Cj7

82Waggy wrote
Don't mean to hijack this thread, but, 1980_Cj7, are you having any detonation problems at that CR - and on what gas? What deck clearance didyou end up with?

We're running 93 octane pump gas, and no detonation problems, just goes thru gas like nobody's business. Just replaced the sending unit in the gas tank last night in fact. The fuel gauge has never been close to accurate and it has always been a guessing game. Would only go to like 5/8 when full, and consequently you hit empty way before you actually were. Could get away with it with the 258, but with this thing, there's not much leeway for guessing.

I think we are running too rich. If you stand behind the exhaust pipe, you can feel "moisture" hitting your legs (wearing shorts) and get little black dots all over them. This if even like 5 feet away from the pipe. Experienced this on a cold start. Didn't check to see what is going on once it's warmed up. No choke on it. We have the Edelbrock Performer 750 carb set to the richest settings with the rods and jets.

1980_Cj7

Oops, missed your one question. We ended up with 0 deck clearance and therefore just the thickness of the gasket for piston to head clearance. I think the Felpro is something like .043 to .045. We haven't tried anything but 93 octane yet, as we are really paranoid about detonation after what happened last year, even though that was caused by a poor excuse of an engine builder. The engine/Jeep is so loud, it's hard to hear pinging, so we're playing it safe and sticking with 93 octane for now, and being conservative on the timing. Running great. Normally runs under 180 degrees and worst it gets up to on really hot and humid days is a hair over 200. We were worried about going .040 over, but so far so good. Only had it "offroad" once so far, on a rock course at the PA Jeeps Show 2 weeks ago, but the difference in torque is unbelievable over the tired old 258. You don't even have to give it any gas, it just climbs right over the big rocks at an idle.

rockjeep

well i picked the motor up yesterday! now to tear it apart.