'69 Coronet Engine Dilemma

[FranksCoronet]

Hey guys,

A few months ago I acquired this 69 coronet sedan for pretty cheap and I've tried to make it a low buck driver. The 318 runs but has a few burnt valves and other issues from abuse over the years. I'm on the fence between fixing up the 318 or swapping it with something else. I want to make a fun sleeper sedan but keep it on the budgeted side. I've explored a big block swap like a 400 because they're on the cheaper end, or maybe a 5.9 magnum swap. I've even considered a modern hemi swap but that's a little too expensive for this. I was wondering if I could get some opinions on what path I should take or some ideas. Ideally the budget is ballpark $2k for the swap or build, and the horsepower goal is near 400. Thanks

Also any links to other budget builds would be appreciated

 

[origcharger]

Thats a tight budget. Probably going to limit you to sticking with a small block of some sort.

 

[Kern Dog]

I have a 318 in the shop that I have been pondering about...
I have considered a 4.0 crank and a .030 overbore. That makes a 390 cube engine that looks like a 318!
Another thought: Engine Quest heads in the Magnum pattern. They flow a LOT better than any LA 318 head.
One of the 318s shortcomings is the cylinder head flow. The cam and valvesprings are pretty weak too. These engines run a long time but can be made to run strong without compromising the durability.
The big block gets the glory but a strong 318 can be a lot cheaper and still make great power.
In 1992 or so when the 318 was changed to be called the 5.2, they made a few changes including the heads. This improved the HP ratings from approx 150 to 230. That was huge and much of it came from the heads.
Good luck.

 

[toolmanmike]

https://www.forabodiesonly.com/mopa...-making-hp-with-a-318-so-why-is-it-so.464921/

You can get 300 horse out of a teen pretty easy and with good heads and some compression (and all the rest of the goodies) 400 horse isn't out of the question.
There are tons of 318 threads over at FABO.

 

[PRHeads]

If that’s really the budget, I’d def keep it very simple and very basic.

DIY re-ring job on the current motor, have the heads refurbished, small cam, 4bbl carb and intake, headers, dual exhaust, electronic ignition.

 

[toolmanmike]

If that’s really the budget, I’d def keep it very simple and very basic.

DIY re-ring job on the current motor, have the heads refurbished, small cam, 4bbl carb and intake, headers, dual exhaust, electronic ignition.

Here's a similar combo for a Charger. Pretty much stock short block. Has a very mild cam, 4 barrel and headers for the dyno test. 283 horse, 355 tq. That would work in a B body.

 

[FranksCoronet]

I have a 318 in the shop that I have been pondering about...
I have considered a 4.0 crank and a .030 overbore. That makes a 390 cube engine that looks like a 318!
Another thought: Engine Quest heads in the Magnum pattern. They flow a LOT better than any LA 318 head.
One of the 318s shortcomings is the cylinder head flow. The cam and valvesprings are pretty weak too. These engines run a long time but can be made to run strong without compromising the durability.
The big block gets the glory but a strong 318 can be a lot cheaper and still make great power.
In 1992 or so when the 318 was changed to be called the 5.2, they made a few changes including the heads. This improved the HP ratings from approx 150 to 230. That was huge and much of it came from the heads.
Good luck.

A 390 would be sweet! 5.2 heads can be bolted onto a 318 LA right? The oiling system is just different on the newer motors right?

 

[FranksCoronet]

https://www.forabodiesonly.com/mopa...-making-hp-with-a-318-so-why-is-it-so.464921/

You can get 300 horse out of a teen pretty easy and with good heads and some compression (and all the rest of the goodies) 400 horse isn't out of the question.
There are tons of 318 threads over at FABO.

Thanks! Theres a bunch of good smallblock threads on FABO.

 

[FranksCoronet]

If that’s really the budget, I’d def keep it very simple and very basic.

DIY re-ring job on the current motor, have the heads refurbished, small cam, 4bbl carb and intake, headers, dual exhaust, electronic ignition.

It has a pretty interesting dual exhaust already, but definitely would do all those other modifications

 

[PRHeads]

If you could pick up a complete 360 core for the right money....... you could apply the same plan to it and end up with a little more “umph”.

That’s probably what I’d do.

 

[Kern Dog]

A 390 would be sweet! 5.2 heads can be bolted onto a 318 LA right? The oiling system is just different on the newer motors right?

The "Engine Quest" heads are available to fit either engine as I recall. They have better ports and allow for more compression without the risk of detonation. In many engines, the power is found in the heads. Look at the 3rd generation Hemi for example. 345 cubes in the 5.7 engine yet in 2002, it replaced a 360/5.9 and made 100 more horsepower. 245 vs 345.
I have come around to where some guys have been for most of their lives: Big cubic inch engines are great but you can still find power and have fun with the smaller engines.
I'm not quite ready to accept a slant six car but who knows!

 

[forphorty]

I believe the EQ heads are no longer in production.

 

[PRND21]

If you could pick up a complete 360 core for the right money....... you could apply the same plan to it and end up with a little more “umph”.

That’s probably what I’d do.

That was my first thoughts...

 

[493 Mike]

Junk yard turbo /6?
Mike

 

[FranksCoronet]

Junk yard turbo /6?
Mike

If anything I was considering a junkyard turbo 5.9 magnum but I'd have to do a lot of work with the computer and plumbing everything in the engine bay

 

[GrabberOrange69]

2k budget, I like the 5.9 Magnum Idea. Probably pick one up in a wrecking yard with around 110k miles for cheap out of a totaled truck or van. Easy 200k trouble free miles. Metallurgy on these modern engines has been all worked out - hardened seats, lighter tension narrower rings, tighter machine tolerance, roller cams, etc. Slap a 4bbl on it and with the $$ you save, buy nitrous kit.

 

[FranksCoronet]

2k budget, I like the 5.9 Magnum Idea. Probably pick one up in a wrecking yard with around 110k miles for cheap out of a totaled truck or van. Easy 200k trouble free miles. Metallurgy on these modern engines has been all worked out - hardened seats, lighter tension narrower rings, tighter machine tolerance, roller cams, etc. Slap a 4bbl on it and with the $$ you save, buy nitrous kit.

I found one in a running truck for like 400obo complete. Only issue I have is swapping over pulleys and accessories to make it work without spending too much. Also the heads usually crack apparently. But that's currently #1 on my list of options, seems like fun