Build my engine

neptco19

Currently have a 360 in my CJ2A but its smoking like a b*tch. You can see it in this pic...I was barely on the gas

So its time for a rebuild. I already have a edelbrock intake, MSD billet dist/6al set up for it. What I need is cam and piston suggestions. If it matters the jeep has a T18 and 5.38 axle gears and I love high rpm tire smoking 😃 Right now it just has the stock 2bl on it b/c it performs really well off road but the possibility of FI is very possible in the not so distan future. I would like a cam that has a little bit of a lope to it, nothing crazy but just enough so that it sounds like there is a strong engine under the hood....if that makes any sense :?

mkzmomo

I went with a comp cam 268h for my 360, and used sealed power piston stock compression not need to spend the extra $$ for forged piston I had good comments on the 268h, I'll see when the engine's back in one piece

neptco19

What about going up in compression a little bit?

ol' school power

If you're going injection, you need to be real mild on the cam or have one custom ground.

ironman_gq

tell the cam grinder what you use it for and that you might run fuel injection. you want a little more LSA around 112 degrees is good. and you need a cam that will pull good vacuum at idle with FI or the computer is gonna freak out. I have had good luck with Engle cams the guy on the phone is very helpful. I would go for a little bump in compression just because your already in there. 9-9.5 should be good

AMX69PHATTY

If the cam duration is increased, then Static CR should be also
to maintain Dynamic CR affected by intake valve closing angle.

A "middle ground" piston choice to raise compression ratio is to use
AMC 343 V8 2 or 4 barrel cast pistons from www.egge.com
since the 343 is the same bore as a 360.
They are listed on the egge webpage under Rambler not AMC or Jeep.
About ~$350 for a set of eight cast pistons.
2 barrel are _14cc small dish, 4 barrel are _4cc valve reliefs.
They also sell engine kits.
Stock Sealed Power, TRW, etc 360 pistons, about 26cc dished tops & ₈.5:1 CR,
might cost less than the egge 343 pistons, not sure,
but Forged pistons most likely will cost more than the egge pistons.
CR can also be increased by milling the block deck and/or heads
and offset grinding the crank to increase stroke.
Those also have costs associated with them.
But will still be "stuck with" the somewhat large _26cc dish in "off the shelf" cast 360 pistons.
Beyond that it gets a little exotic trying to use 4.125 bore chev slugs.

Someone here last year with a lime green jeep built a 360 using the egge 343 slugs.

Who was that ?

imho would build it with ₁₀:1 static CR, use ign timing to prevent ping.

neptco19

Thanks for the tip. Which one would yield the ~10:1 ratio 2 or 4bl pistons? Hopefully the deck and heads will only require a minimal amount of shaving, just enough to smooth it up and then I can make up compression with the piston.

AMX69PHATTY

All values are Nominal, believed correct but not guranteed, have manufacturing variations, and must confirmed from actual parts. ---------------------------------------- Using 14cc for Egge 343 2V Pistons: 4.110 Bore - stock +.030 3.440 Stroke - stock nominal 9.208 Deck Ht - stock nominal 5.872 Re-Con Con Rod - 0.003 shorter 0.046 Deck Clearance 1.570 Comp Ht - Egge 343 2V cast pistons 14.0cc Dish Volume - Egge 343 2V cast pistons 55.5cc Comb Cham - Stock AMC 58cc heads milled .015 0.045 thk x 4.265 dia FelPro Head Gasket Result: 9.31:1 Static CR - Offset grind crank or mill deck and/or heads more to increase the 9.31:1 CR ---------------------------------------- Using 4cc for Egge 343 4V Pistons: 4.110 Bore - stock +.030 3.440 Stroke - stock nominal 9.208 Deck Ht - stock nominal 5.872 Re-Con Con Rod - 0.003 shorter 0.046 Deck Clearance 1.570 Comp Ht - Egge 343 2V cast pistons 4.0cc Dish Volume - Egge 343 4V cast pistons 55.5cc Comb Cham - Stock AMC 58cc heads milled .015 0.045 thk x 4.265 dia FelPro Head Gasket Result: 10.34:1 Static CR - Unshroud valves in heads to increase volume and decrease the 10.34:1 CR ---------------------------------------- :-|

neptco19

Just an ignorant question here...what kind of power diff. would I be looking at from going from the 8.5 to 9.5 or the 10.5 compression? Any other downsides to bumping up the compression other than needing higher octane gas?

AMX69PHATTY

Cam choice is the driving factor.
As cam duration is increased, the intake valve closes
further and further past bottom dead center.
This reduces the Dynamic Effective Compression Ratio, kills power.
Static CR is a pure ideal figure, total BDC volume / Total TDC Volume.

Am running an AMC 343 block with 360 crank offset .010
dished top _26cc 360 cast pistons, -.007 deck clr (above deck)
'70 heads milled .060 for _47cc's, Torker, Holley 750 DP.
Has ₁₀.2:1 CR Static, Elgin E-1041-P cam, spec'd 5200rpm max
.488/.488 - 218/218 - 284/284
With the 10.2:1 Static CR, can run 93 pump gas all day long.
Dizzy is 15 initial, 24 mech adv, 39 total, all in by ₂₈₀₀ rpm.
No ping or detonation.
Makes ₄₀₇ HP gross IF 25% drivetrain loss is used.
Makes ₃₈₁ HP gross IF 20% drivetrain loss is used.
Not in a Jeep, in an AMX, Auto, 3k stall, 3.73 gears.
Stall and gears are almost too much for this "small" cam.
Car with driver is ₃₂₅₀ lbs, runs 12.6 at 107 mph.
Above HP figures derived from the 3250 lbs and 107 mph.

To make the engine thump and make power and torque,
need to build for ₈.5:1 DYNAMIC Effective CR for pump gas.
Pick the cam first, then can use the Dynamic CR Calculator
on the Keith Black Silv-O-Lite web site to determine what Static CR
will result in 8.5:1 Dynamic CR based on the cam's Intake Valve Closing Angle.

Think about it, how hard the pistons push on the crank after the fire is lit
is where all the power and torque comes from and CR directly effects how powerful the bang is.

Trust me :wink:

Hopefully, others here will confirm what's been said. :-|

Link to recent burnout video, and actually a pretty weak one at that,
compared to what it could do, faith in cameraman was limited
that it was actually getting recorded or not, so was reluctant
to really realy burn it down and masacare the tires.
Did just that on the first attempt, and it didn't get recorded 111!!!
Marks from first attempt are visible in the driveback clip
and going the other way in the final burnout clip.
http://www.youtube.com/watch?v=iYtxM2d5tfw

AMX69PHATTY

Think the user here was "PaintedRat" that did the 360 with Egge Slugs build.
The build used the 343 4V Flat top Pistons.

link to PaintedRat's thread here about it with some pictures :

http://www.bulltear.com/forums/viewtopic.php?t=6620&highlight=360

neptco19

Thanks for all the tips :lo1l: I think I've found a rebuilt 360 with some edelbrock goodies in/on it...so if this deal falls through I'll be back to square 1 rebuilding mine..

neptco19

Well I bought the whole truck that was connected to the 360, pulled the engine today. Got to pull the jeep engine tommorow and install it in the J truck for a fella to come buy. Then I'll clean up the truck 360 and put it in the jeep.

AMX69PHATTY

Sounds like a plan. Really the best way to get a fresh(er) motor in a cost effective way and minimal time. Rebuilds can take months and sometimes can snowball on costs. Great find on the 360 J10.