Scott78

By this coming winter my '78 will have in excess of 115K on the original L48 engine and a change is in order.
I've rebuilt several engines in the past so thats the route I'll take rather then a crate engine. Besides the solitude in the garage is therapeutic for me :yesnod: .
I've got a seasoned SB allready .030 over, the taper isn't bad but it'll need at least to go .040. This is sitting on a stand in my garage, came out of my suburban because of a cracked head. This choice 1 rebuild it as a 350 or (2) stroke it.
Now I REALLY want to put a BB in my car and I've found locally a 454 with a flat cam lobe for $600. This is from a locale guy who runs a auto reclaim lot, it's not out of the lot but out of his truck(a '79). I've dealt with this guy before and I'd rate him an 8 out of 10 on truthfullness.
I've also got a 396 out of a 70 Chevelle available for $250, it was running when pulled just burning oil. This is from my neighbor, it's his buddy's motor and it's about 3 hours away. This guy(neighbor) works in a body shop and has a '74 Trans am with a 500+ cubic inch Oldsmobile motor in it and has 600 RWHP. Runs 11.25 to 1 compression and solid roller cam, he also turned me on to place that sells 110 octane gas at 2.90 a gallon out of a pump :D Believe me you know when it's running and he lives 5 houses down :eek: His take on the motor is that it just needs to be gone thru, he doesn't think there should be any surprises(ie cracked block or heads).
What do you folks think, BB and the associated headaches that come with the swap or SB stroked or not. And what's your opinion of the 396, is a small cubed BB worthwhile or is that a stroker candidate too.

Scott

Gordonm

The small block would be the cheapest because you already have all the small block stuff. I would go the stroker route. If you decide on the big block get the 454. The 396 is a very small big block. You can easily build a 396 small block. Get the 454 and get the most cubes for the buck. Why not stroke the 454 if you go that way. If you decide on the big block you will need all the other brackets and such to go along with it. My .02

Scott78

I'd have to search thru the archives to be sure, but I thought I read it's about $200-300 for the brackets to do a BB swap. Now the SB has no heads so I'd have to get heads, both BB come with heads that are supposedly rebuildable.
Scott

Techno

My choice if I had to do over is a 500 ci caddy engine with chevy guts. Its connecting rod diameters are too big for the chevy rod so you stroke it to a minimum of 510. Hot rod or some other did an article on this. Just under 500 hp and torque and was streetable. The engine weighs 60 lbs more than a chevy small block. Everything can be bought including the plate to the tranny. The casting is different than the other detroit engines, different metal so its lighter. It also lasts longer and has better oiling system. No 4-bolt mains but doesn't really matter if your not drag racing. Much easier engine to work on too. There is at least one web site that does parts or whole engines.

I know you don't like that so the next is the big block.
Whichever you do just remember that most of this horsepower is never going to be used. Speed limit kicks in no matter what you do to the engine.

The torque of big cubes is very very nice, much better than high revving small cubes. If you have a manual the engine braking is nice too. I would stay away from high octane fuels and high compression. Its too expensive to make ponies this way unless thats the only goal. Imagine filling the tank for a cruise!

Scott78

I only mentioned the 110 gas as an oddity, I didn't know it was available outside the track. Any engine I build I'll shoot for a compression ratio between 9 and 10 to 1. Some of the things on this motor that I've never done on others I've built is to get the quench at .040. And to have the heads ported and flow balanced(equal flow at each port) or get a good set of aftermarket heads. I'd really like to get some feed back on the 396, I don't have much literature that talks about it. I thought it was a Hi-Po motor chevy used and it has close chamber heads. Can anyone elaborate further or correct my misconceptions?
Your Caddy engine idea has it's merits but that does sound radical. I do have a Pontiac 455 with 11:1 Arias pistons in it sitting in the garage too Hmmm...

Scott





[Modified by Scott78, 7:10 PM 7/30/2002]

Carl in LA

I like the 383 rebuild on the L-48... works good in my car. The 383 on the overdrive tranny is a fantastic fit for driving in LA... power when you need it and easy on the gas when you just want to get there. Going big block would also be cool and I agree with others... If you go radical - don't stop at stock... go over 500 ci.

73 LS-4

An easy thing to forget on Chevy engines between the big block and smallblocks is that the performance big blocks often had two advantages over most of the small blocks, displacement and their head designs. For example my 049 castings with a 253cc intake port will flow 250cfm on the intake at .500 lift and that's with a stock head. It takes a fairly healthy aftermarket small block head to come close to those flow numbers. So don't discount the 396 just becouse of it's displacement especially if it has decent heads on it, of course there is always the big blocks disadvantages over the small block, weight and cost of parts. The 454 out of the truck will require some different heads to make serious power, since it will most probably have peanut port heads which don't flow very well.

:cheers:
Pat Kunz

Techno

I personaly don't think big engines/ small engines have much to do with fuel milage. Compare any modern truck and they get the same milage as both of my big blocks. I have 4 gears in the Vette and 3 in the Caddy. A modern Vette has How many gears and what rear ratio? Most cars got the milage with the rear end. Trucks have stump puller rears so their milage sucks. Any of the later 70s rear ends have anemic gears compared to the early 70s Change those rear ends and your milage is going to suffer.

But thats just my O-pine.