Small Block versus Big Block (My apologies to AMC purists)

[1986 Woody]

I am getting ready to pull the trigger on the motor for the Cherokee build. Question is: big block versus small block.

I am torn between either a 350ci or 502ci mass flo injection motor. I am looking at enginefactory.com's 350ci/400 hp motor or their 502 FI motor.

Both will have a March or Zoops belt system and the sb will also be upgraded to all forged bottom end. My concern with a big block is getting rid of the heat a bb will generate.

What have you folks who have gone down this road experienced? I am leaning toward the bb as it is only slightly more than the sb. Any input is appreciated.

[JeepinPete]

If you go big block, you are planning on swapping out the rear axle too, right? The D44 in the rear has no chance of surviving a 502. I'm not sure what axle you can swap into a Waggy that will be the right width and not custom though.

Other than that, a TH400 backed by a NP205 would work behind the 502, but you have to do some mixing and matching with some Ford parts to end up with a drivers side drop 205.

[1986 Woody]

I am running D60's front and rear with 4:56 gears and ARB lockers. Transfer case is a NP205 tranny is a TH400 and it is a WT Cherokee.

Sorry about that....

[bushwood44]

I vote for the 350 sb they are tough as a hammer and i have both (not in a fsj)350 and 454.

[El Jefe]

I second the 350. Big blocks are just to much engine in my opinion

[superal30]

I third the small block. Big blocks are too heavy and with today's technology you can make really big small blocks if you want. I build engines for a living, the small block is definately the way to go in my opinion. Of coarse that is the way I'm going.

If you look at the two ads side by side compare positive and negatives. For instance the sbc is an all roller motor (roller cam and roller rockers), the big block is roller cam, standard rockers. That is just what I would do.

Something else you might want to look at is what are you doing with the rig. That will help determine a lot.

I would also call your local engine shops/machine shops and get quotes on what they would charge to do it. That way if you have a warranty claim, it can be delt with locally and not well ship it back and we'll see if you messed up or we did (cough cough). Just do yourself this favor so you don't have a hassle in the end. Look around in the local classifieds and find a core. Have your local engine shop build it to your specs, not some "crate" specs that every joe blow has.

The fuel injection is a definate plus, but remember people make fuel injection for small blocks too.

[mud&metal01]

im trying to decide the same thing. i have buddies with lifted chevys. 1 is running 37 and a built 350 one has a stock 350 and 35s and the other the other is a 454 with 38.5. all have proper gears. i dont see a difference between the 350s but the 454 is a beast but gets alot worse milage

[Jayrodoh]

I say big block, mainly because this will be your toy. All your work is outstanding already, imagine popping the hood to show off the 502, that'll match the wow factor of the rest of the project.

[Topher]

There's no replacement for displacement. Go BIG or stay home. If you want the WOW factor, put a HEMI in it. :thumbsup:

[1986 Woody]

I want the big block but is heat an issue that will consistantly crop up? I want drivability as well. I plan on a custom radiator with electric fan(s) but will this be enough?

[JeepinPete]

Drop a PM to Mark on this forum. He has a big block in his Cherokee.

[JavaJeep]

Go the big block , you will keep dreaming about the 502 when you are driving the 350

Ventilate the engine bay with some hood louvres , a lot of the Jeep overheating problems is from trapped air under the hood

[1986 Woody]

Jeepinpete, done, thanks. He is in NJ too!

[YellowJeep]

I say small block. You can build a pretty wicked small block for reasonable price now as previously stated. I couldn't be happier with the mildly build LT1 in my 94 Camaro. The 383 stroker kits are cheap and plentiful and make a nice motor when you are done.

[Topher]

You can build the snot out of a small block and make lots of noise, but at the end of the day a properly tuned big block will cruise right by that small block while tuning the radio! Not to mention the MOUNTAINS of torque that a bb will create OVER a sb.

[jeepsr4ever]

My god man dont even ask this question ...go big block of course. 350's are for kids!!

[TPICherokee]

I second the 350. Big blocks are just to much engine in my opinion

Is there such a thing as too much?!?!!!

[TPICherokee]

There's no replacement for displacement. Go BIG or stay home. If you want the WOW factor, put a HEMI in it. :thumbsup:

It would only be wow factor when you popped the hood, when you tried to get out of the hole, it wouldn't be very wowie... Drove a new HEMI a little while back and it was a total slug out of the hole, pathetic actually. My 96 Big Block Suburban would do circles around it.

[skeletor]

If you want the WOW factor, put a HEMI in it

i wouldnt put a 230 tornado in it :D


i say amc 327, chevys are nice and all but if your considering a 502 might as well consider an amc bb. but regarding your question 502 for sure vs a 350.

[krek]

Twin turbo Buick 350... you know you want to. :D

[billyrb]

big block. The larger engines work less to get the same amount of work done, meaning the engine should last longer and see less wear over the same amount of time. Not to mention, I'd rather have extra power in reserve when I needed it, than not have it and wish I did.

[Gearhead 1990]

I want the big block but is heat an issue that will consistantly crop up? I want drivability as well. I plan on a custom radiator with electric fan(s) but will this be enough?

I had a big block 454 in my cherokee and only had the stock radiator and a small flex fan with no shroud. It would stay pretty cool going up trails and stuff cause I think the fan would pull more air. When I'd go mudding and stay at high RPMs it would only heat up a little bit cause the fan would flatten out. I think you should be fine with an aftermarket radiator and electric fans :thumbsup:

So I say go with a big block :D

[AlsChopShop]

unless its a small block that looks like this:

http://www.expressdistributing.com/00_all_share/banks/TwinTurbo-engine.jpg

go with a big block. :thumbsup:

i'd have put one in mine but i couldn't find a TBI 454 anywere for a decent price.

Al

[YellowJeep]

i'd have put one in mine but i couldn't find a TBI 454 anywere for a decent price.
230hp and 385torque is pathetic for a big block. Consider yourself lucky you didn't find one.

[TPICherokee]

230hp and 385torque is pathetic for a big block. Consider yourself lucky you didn't find one.

Those, of course, are starting numbers, once you remove all of the smog crap, they get a lot happier and add headers.

If you are going fuel injected big block, the Vortec (96-99) 7.4L Big Blocks are the way to go, start with 290 hp and 410 torque, plus you add a quality set of headers (banks or Doug Thorley) and they come alive. The Banks kit shows 33 hp and 43 torque at the rear wheels, makes them a lot more fun to drive.

[superal30]

plus you add a quality set of headers (banks or Doug Thorley) and they come alive. The Banks kit shows 33 hp and 43 torque at the rear wheels, makes them a lot more fun to drive.

Remember those "kits" claim "up to" 33hp and 43 torque

[superal30]

if your gonna waste "cough cough" spend your money on the big block you might as well get an LS7 instead, you'll be much better off. Lighter, more dependable, won't have to worry about heat, these are all good things.

http://www.webdesignetc.net/Merchant2/graphics/00000006/LS7a.jpg

[TPICherokee]

Remember those "kits" claim "up to" 33hp and 43 torque

Come ride in my Suburban and then ride in a stock one, you'll feel the difference....

I test drove a ton of these and I ended up buying this one because it ran the strongest, after I bought I realized what had been done. My friends like to call it the Honda killer, if I had a nickel for everytime I had 4-6 people in it and raced a Honda and won, I would have about a buck. I love watching their faces as they get owned by a big purple (yeah, I thought it was maroon) Soccer mom Suburban...

[TPICherokee]

if your gonna waste "cough cough" spend your money on the big block you might as well get an LS7 instead, you'll be much better off. Lighter, more dependable, won't have to worry about heat, these are all good things.

http://www.webdesignetc.net/Merchant2/graphics/00000006/LS7a.jpg

x2.....

[PlasticBoob]

My friends like to call it the Honda killer, if I had a nickel for everytime I had 4-6 people in it and raced a Honda and won, I would have about a buck. I love watching their faces as they get owned by a big purple (yeah, I thought it was maroon) Soccer mom Suburban...
Hey hey now, I've had my stock Civic up to 130ish. Just need to race on a longer road ;) :p

[mud&metal01]

The owner of a local speed shop around here is also big in 4x4s he is a chevy truck guy and says that the vortec 350 converted to a carb is the best way to go for an easy reliable engine swap with all the power youll need. i just cant find one

[TexTJ209]

The owner of a local speed shop around here is also big in 4x4s he is a chevy truck guy and says that the vortec 350 converted to a carb is the best way to go for an easy reliable engine swap with all the power youll need. i just cant find one


People convert TO carbs?

[mud&metal01]

around here all the time. he accually has the manifolds in stock he uses the 670 holley truck advenger. whats so bad about a good carb motor. u aint gotta worry about computers and setting up all that stuff in the truck. and i like my electrical on an offroad rig to be as simple as possible so do the rest of us. or mabey its because my friends like old chevys?

[Gearhead 1990]

230hp and 385torque is pathetic for a big block. Consider yourself lucky you didn't find one.

Wow thats all? My TBI 454 feels like it has WAY more power than that!!

.......maybe its also because a have an aftermarket harness and chip and headers and dual flowmasters :cool: :p

[Gearhead 1990]

around here all the time. he accually has the manifolds in stock he uses the 670 holley truck advenger. whats so bad about a good carb motor. u aint gotta worry about computers and setting up all that stuff in the truck. and i like my electrical on an offroad rig to be as simple as possible so do the rest of us. or mabey its because my friends like old chevys?

Fuel infection is the way to go if you ask me. Starts nice every time, runs at any angle, tunes itself, better mileage, and tells you when something is wrong with it.....

I know you usually can get more power out of a carb but I'd rather have all the other benefits of EFI.....

My 2 cents

[billyrb]

People convert TO carbs?

Yeah, they're called "electrically challenged" :)

[Jayrodoh]

Back to the original heat issue, I wouldn't think that it would be too big of an issue. Obviously people are running the 502 in other applications. Since you are doing a groud up build, you can plan for the extra cooling capacity needed (fans, controllers, rad, etc.). Additionally, you'll be miles ahead with the FI, if the engine is running in tune all the time, you won't have to worry about excess heat generated by a lean condition etc.

[mud&metal01]

voice of experience with my old xj. after about a year of muddin in it the electronics including the fuel injection had some issues. but back to the origanal issue i think the 502 if u can afford it and the gas is best. im looking to go cheap and still have a good motor

[Elliott]

If you aren't going 401 then 502 or better yet, the Indy Cylinder Head AMC 500... if they have a version that will run on pump gas;)

[1986 Woody]

Jayrodoh:

I agree with you. If I use a full aluminum radiator and electric fans, tranny cooler, etc. I think I will be fine. There has been no outstanding issue posted so far that clearly identifies cooling as an issue with this swap.

[mjself]

If I had unlimited resources, I would go for the 5.7L Hemi. Otherwise I would go with the most cubes you can fit between the frame rails.

[Topher]

It would only be wow factor when you popped the hood, when you tried to get out of the hole, it wouldn't be very wowie... Drove a new HEMI a little while back and it was a total slug out of the hole, pathetic actually. My 96 Big Block Suburban would do circles around it.

You drove a punk Hemi, not a real one. I'm talking about 426 cubic inches of mind blowing performance. My buddy has a 66 Hemi Charger that makes my lil ole 383 look like a Furd Pinto! His engine still has the stock pistons and bore in it. He did install a hydraulic cam, which makes it much more nicer to drive since the v/cs don't have to come off every couple of weeks for adjustment.

I see the old small verses big "discussion" is as strong as it ever was.:dancingbanana:

[cu4whln]

What about the width of the engine? Will a big block fit OK?

Will it hit the heater box? Brake booster? exhaust clearance to the firewall?

Just thinkin' out loud . . . I prefer fuel injection any day of the week - and no carb vapor lock issues !! :D

[TPICherokee]

You drove a punk Hemi, not a real one. I'm talking about 426 cubic inches of mind blowing performance.

I was comparing apples to apples, I didn't want to get into the old and real (best) HEMI's, no comparison, that would be like comparing a Honda to an original 427 Corvette. I was just making a point that the new 5.7L HEMI's leave quite a lot to be desired in the low end power dept from what I saw....

[thomastenn]

go with a stroked small block 383,388, or 406 for chevy or if you want chysler you can take a 360 to 408. the key to power is efficiency not just size. the 5.7 hemi isnt bad just to many electronics and you have to go with carburation unless you convert to drive by wire

[sungoesdown]

go with a stroked ford 460 on juice! Cant beat 557 cubic inches and a 200 shot!

[billyrb]

BB btt :)

[addicted]

BB would get my vote since mileage is not of any concern. But I would go with a dual quad 440. :cool:

[Gearhead 1990]

You should make a poll.... :thumbsup:

[Topher]

I was comparing apples to apples, I didn't want to get into the old and real (best) HEMI's, no comparison, that would be like comparing a Honda to an original 427 Corvette. I was just making a point that the new 5.7L HEMI's leave quite a lot to be desired in the low end power dept from what I saw....

Of course you can take a 6.1, and throw in a stroker crank and have 426 cubes + 650 ponies WITHOUT touching the heads. Oh, and that's with a carb on top. I would definately go with injection IF you're going to go at anykind of an angle, but if yer just street screamin a carb is the ticket.

[bushwood44]

SBC:whistle:

[wickedwagon767]

Wether you go big block or small block I reccomend

1)hood louvers
2)large aluminum 2-core, or copper/brass 4-core radiator
3)A big single, or dual electric fans
4)add oil capacity to your engine via a remote dual filter system and cooler

Remember stock Oldsmobile 455's,Buick 455's, 396/402/454's and mopar 440's from the muscle car era put out great power in stock form and if you were to pick one up and perform a stock rebuild with a fuel-injection upgrade you would probably be very satisfied and spend alot less than a FI502

unless you just need/want all that neck-snapping POWER!:p

[originalrecipekenny]

i have a sbc in my wagon and i love it. it riiiiiips! i really wish i had gone fuel injected in the first place. i would also recomend electric fan, remote oil filters, bigger proper swap radiator (i had the stock one modified) power steering fluid cooler, ceramic coated and wraped headers. advanced adapters headers and mounts are awsome very heavy duty easy to work with and affordable.

[JavaJeep]

For cooling this belly heat exchanger louvre from a Boeing 727 is going on the hood of my J20

You can also see the 3 round side vents I put into the fender in the background of the 1st photo

Originally we were looking at using 2 units , 1 on each side but now the decision has been made to use one in the centre

http://www.nusantara-sky.com/website_photos/Indo%20FSJs/DSC05043.JPG

http://www.nusantara-sky.com/website_photos/Indo%20FSJs/DSC05049.JPG

http://www.nusantara-sky.com/website_photos/Indo%20FSJs/DSC05048.JPG

(Guys in the photos are some of my staff getting some weekend overtime)

[originalrecipekenny]

that vent is awsome. :eek: you going to set up a cable acctuator to open and close it?

[JavaJeep]

that vent is awsome. :eek: you going to set up a cable acctuator to open and close it?

Cable or air cylinder