Daily driver small block build

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remytherat

remytherat

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I am hoping to eventually have a warmed over small block in my daily driver 69 dart. This is not something I am in any rush to get done: I'd like to start collecting parts soon so I can have everything ready by next summer. Just trying to get advice on a starting point. Some main goals:
- Spending less than a few grand total
- 300 HP
- Solidly double digit gas mileage
- Solid low end torque
- Runs on 89 octane

Some questions:
- 318s are a dime a dozen where I live. $300 for complete motors left and right. 360s are a bit harder to find and a little bit more expensive, but would it be worth it to find one?
- Is a roller camshaft worth it at this level?
- Which heads should I look for?
- Compression ratio?
 
if you're talking straight up easy and cheap-- 5.2 or 5.9 magnum, snap on a 4bbl intake send the cam to oregon and have it reground, thin headgaskets to bring the compression up and roll.

if you're even thinking of going roller cam on an LA, start with a roller block. or, again a magnum.

300hp out of 318 is cake all day. bump the compression a bit if needed, don't over cam it, some decent heads (302's or 360 2bbl) and top it with dual plane and you're set.

you already have the intake and carb, so you're set there.

machine work eats up budget, oddball set ups (magnum heads on an LA) eat budget, fancy pistons and cams eat up budget. keep it simple and keep it reliable, you'll also keep it cheap.
 
I don't think the 5.2 would even need thin head gaskets. Remember, the Magnum engines have a shorter deck height, so they have higher compression already. IMO, if he finds a good low mileage 5.2 (they are still out there) all he needs do is put a chinesium Air Gap, a 650 DP, a good distributor with a hot advance curve and a set of long tube headers and he's so close to 300HP he'd never feel the difference.
 
RustyRatRod said:
I don't think the 5.2 would even need thin head gaskets. Remember, the Magnum engines have a shorter deck height, so they have higher compression already. IMO, if he finds a good low mileage 5.2 (they are still out there) all he needs do is put a chinesium Air Gap, a 650 DP, a good distributor with a hot advance curve and a set of long tube headers and he's so close to 300HP he'd never feel the difference.
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i always forget that the 5.2 has a hair more compression.

the yards out here are absolutely rife with 5.2 and 5.9's so it's easy pickins. if you could snag a low mileage piece that just needed rings and bearings that'd haul the budget way in. worst case reman short blocks are like 8~9 hundy with a warranty.

with the right combo of parts, some judicious shopping and a little work, i don't think knocking on 400/400 wouldn't be out of the question.
 
It really comes down to the heads, 318 vs 360 vs 5.2/5.9 magnum stock head to make 300 hp
A magnum basic does that stock, 360 needs a mild cam and 318 needs a fair amount of cam.
 
318 magnum, see post #4, have the heads checked for cracks. Or 318, 360 heads, factory intake, decent carb, 340 valve springs, custom cam, Double roller timing set, pistons, ARP rod bolts, balance, speed pro rings, windage tray, high pressure oil pump spring, and a quick curve distributor. I personally don't like 360's, but I like a high winder not a low end torquer.
 
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Just check the Magnum heads very close, they have a tendency to crack. The better heads, if you can find them are the RT heads.
 
remytherat said:
Some main goals:
- Spending less than a few grand total
Click to expand...
with my interpretation a few G's is 2~3 and that, to me, is going to be the biggest hurdle to clear.

300 horse is a fairly low bar to clear, but with the 5.2 you'd still need to add about 70hp to get there.

i *think* the stock compression will support that, and with the right cam and intake and maybe justttt breathing on the heads makes it happen; and unlocks a boat load of torque, and likely all done by 5K or so.

with the 5.9 that goal is achieved a little easier.

either way, the whole operation hinges on getting an absolutely stellar core that needs practically nothing.
 
For a daily driver or street machine you need lo rpm torque. A high hp 318 will be lacking low
rpm power where you'll do 95% of your driving. Hold out for a 360. With a small cam, 14" tires
and a 3.23 or 2.94 gear you will get your 20mpg and break the tires loose easily.
 
Just a thought... Considering the tight budget, if are you starting with a /6 you'll have to factor in a trans swap and engine mounting.
 
The bone stock factory 5.9l Magnum swapped to a 4bbl and headers was the actual MP 300hp crate engine. Get one of those and bolt it in. Tuning is the key to mileage and in my opinion very few can do it well anymore so maybe a self learning efi for it would help.
 
junkyardhero said:
with my interpretation a few G's is 2~3 and that, to me, is going to be the biggest hurdle to clear.

300 horse is a fairly low bar to clear, but with the 5.2 you'd still need to add about 70hp to get there.

i *think* the stock compression will support that, and with the right cam and intake and maybe justttt breathing on the heads makes it happen; and unlocks a boat load of torque, and likely all done by 5K or so.

with the 5.9 that goal is achieved a little easier.

either way, the whole operation hinges on getting an absolutely stellar core that needs practically nothing.
Click to expand...

Factory rating for 5.2 Magnum is net so that's with single exhaust and 1990s (restrictive) catalytic converter and beer-barrel intake that runs out of steam by 4500 RPM, plus factory EFI tune which needs to be emissions-friendly and minimize knock. Swapping on a 4-bbl intake and carb, distributor ignition with performance advance curve, and 2.25-2.5" true dual exhaust will free up a ton of power. Maybe not quite 70 HP but still a lot.

Most Magnum cores need zero machine work if they weren't totally abused, not uncommon to find 150k+ mile short blocks that still have cross-hatching on the cylinder bores and no ridge at the top. I found one at a junkyard a few years back in a 2000 Ram 2500, truck looked like it had been in a derbycross race but the engine was mint inside. I put new rod bearings in it and left everything else in the short block alone; bolted on a good top end (ported Edelbrocks and RPM intake) and put in a custom-grind hydraulic roller cam, reused the factory roller lifters and sent it. It's been in my '70 Duster for about 5 years now and still runs like a top.

If I had to do it again I'd still rather buy 3 5.9L Magnum cores and pick out the best of the bunch than find a crusty old worn-out LA 360 and do a full rebuild.
 
This might seem like a bizzare comment
but i have found that in many cases upping the static CR, to what it should have been i.e 10:1 or just over... getting a good ignition and the right curve, headers. no bigger than standard sized pipes and running a decent carb that is 1 size down from the one everyone else says is the carb to have....

not porting out anything just keep runners standard size .... keep the air speed up and the head ports standard
produces a motor that is a joy to drive with lots of torque right where you need it for street gears and driving
which in most cases makes for an economical but fun motor

performance means different things to different people
if a roller cam means preparing the block for a roller cam new oil pump drive etc and sleeving the lifter bores. in my opinion No, not worth it.
if it means buying a magnum well maybe

Dave
 
Pretty well covered by others so I'll just add a couple thoughts. If you go the magnum route check the cam bearings. Having the cam reground is a budget friendly hp option. I would not be afraid to run magnum heads that are cracked unless they show signs of leaking water. More than half of them on the road are cracked and run fine but no one notices until the engine is torn down.
 
mgoblue9798 said:
Pretty well covered by others so I'll just add a couple thoughts. If you go the magnum route check the cam bearings. Having the cam reground is a budget friendly hp option. I would not be afraid to run magnum heads that are cracked unless they show signs of leaking water. More than half of them on the road are cracked and run fine but no one notices until the engine is torn down.
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Yes cam bearings are usually flaked and pitted, should've replaced mine but I didn't and haven't had any problems... yet. Like the LS guys say, "the cam bearings are fine unless you look at them" hahaha
 
LA vs Magnum, you'll have to think what your whole package will be when you drop it in your Dart; and it's going to be the little things that add up and drive up your costs.
Things like:
Do you want an electric fuel pump, or do you want to stay with a mechanical pump? Magnums can be converted to mechanical, but you will need to source LA front components (timing cover, water pump, pulleys, accessories and brackets, and an early Magnum balancer with the bolt-on pulley) to do it; adding to the cost of the Magnum.
A Magnum, any Magnum, is going to require you to get a Magnum-compatible 4 bbl. manifold and a 360 passenger car oil pan, pickup, and dipstick/tube in order to fit your Dart, along with a non-EFI distributor.
Granted, most of this is a drop in the bucket if you can avoid having major machine work done by scoring a good condition Magnum, but it is something to keep in mind. The little things add up fast.
As far as HP, either Magnum or LA will get you there. With LAs/Magnums you can basically fart on them and make 300 hp, but as previously mentioned it's the 360/5.9's torque that will make you smile with a daily driver. Avoid the pitfall of thinking "bigger is better" with your build, and you'll be fine either way. Avoid the "bling" that doesn't add to performance or drivability (fancy cast valve covers and chrome thermostat necks don't add 1 single horsepower or mpg) to keep costs down.
Your build will ultimately hinge on what kind of deal you come across at the right price, That LA 360 needing a full rebuild at a premium price will pale in comparison to the 5.2 Magnum that some guy is selling dirt cheap because he pulled it out of his Ram to put in a Cummins...
My recipe?
Find an early/mid 90s van, 2wd pickup or Dakota with a 5.2 and a 32RH.
Front drive, fuel pump, and accessories from an LA, oil pan as mentioned.
LA roller block 360 cam, stock. (the cam's specs are enhanced by the Magnum's 1.6 rocker ratio vs. the LA's 1.5, and has the long snout to drive a fuel pump. No custom pushrods needed like a reground cam would require.)
Get HalifaxHops to curve you a distributor.
Chinese 4 bbl manifold with whatever flavor 600 cfm carb you prefer.
904 kickdown linkage to the 32RH.
Cheap azz generic Summit or Jeg's headers and exhaust kit.
You'll be breathin' on 300 easy, and the mild cam and lockup convertor of the 32RH will have you well over 20mpg all day long.
 
moper said:
The bone stock factory 5.9l Magnum swapped to a 4bbl and headers was the actual MP 300hp crate engine. Get one of those and bolt it in. Tuning is the key to mileage and in my opinion very few can do it well anymore so maybe a self learning efi for it would help.
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THIS ^^^^^

The curve in the distributor and vacuum advance will get you the mileage and 89 octane capabilities.
 
With similar goals I did a warm-up rebuild on a 5.2 Magnum short block I picked up for $125. For the the block I went .030 over with flat top pistons on stock re- conditioned rods , align honed, and squared up the deck, crank inspected and polished. Magnum heads had a complete valve job done and square up mating surfaces, stock rockers with Hughes 1110 spring kit with Trend .080 pushrods. I sent the cam to Oregon Cam Grinding for their #1280 grind at 212/[email protected] .485/.506 lift 110LSA, I'm using stock replacement lifters. I used thin 1121G head gaskets for a little more compression. After measurements and calculations I'm getting 7.6:1 dynamic compression ratio
Edelbrock Performer RPM airgap intake and 1405 carb, long tube 1-5/8" x 3" headers. Stock electronic ignition bought and curved from @halifaxhops. Machining totaled $2200.00 parts (many FABO sourced) all in at about $1300, self-assembled. I love it! Plenty of tire burning power, sounds awesome, pulls good to 5000 RPM (afraid to go farther). 17 miles per gallon in my '67 Dart and that's with foot in it from stop signs a bunch.
 
Yeah all the goals are in line and easy except for the fuel mileage part..."solid double digits" are you talking 12mpg or 22mpg?

The keys to that will be
1. Put an egg on the throttle pedal
2. Get an O2 sensor and tune idle and cruise values as lean as you can while maintaining response and idle quality.
3. Run low gears and better yet an OD trans with a lockup converter.
4. Stick with very mild cam timing. I.e. stock.
5. Ideally go with EFI this will help with the lean mixtures
6. Run a properly curved vacuum advance distributor.

I'd be looking for a 5.9 magnum. It doesn't have to be super low mileage. I'd be fine with a sub 150k mile engine, up to 200k. It may need some basics like a head gasket/valve job/valve seals. The bottom end will probably be fine ifnit was horrendously abused. They're easy to find and not expensive. I personally wouldn't bother with the 5.2. Many here will disagree with me on that point. But dollar for dollar the 5.9 will be up on torque literally everywhere in the curve and the only way to close that gap with the 318 will require sacrifices and money.
 
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Mean416 said:
Yeah all the goals are in line and easy except for the fuel mileage part..."solid double digits" are you talking 12mpg or 22mpg?

The keys to that will be
1. Put an egg on the throttle pedal
2. Get an O2 sensor and tune idle and cruise values as lean as you can while maintaining response and idle quality.
3. Run low gears and better yet an OD trans with a lockup converter.
4. Stick with very mild cam timing. I.e. stock.
5. Ideally go with EFI this will help with the lean mixtures
6. Run a properly curved vacuum advance distributor.

I'd be looking for a 5.9 magnum. It doesn't have to be super low mileage. I'd be fine with a sub 150k mile engine, up to 200k. It may need some basics like a head gasket/valve job/valve seals. The bottom end will probably be fine ifnit was horrendously abused. They're easy to find and not expensive. I personally wouldn't bother with the 5.2. Many here will disagree with me on that point. But dollar for dollar the 5.9 will be up on torque literally everywhere in the curve and the only way to close that gap with the 318 will require sacrifices and money.
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Agree with you about the 5.9 with the exception being if fuel mileage is the top priority. I have never had a stock low compression 360/5.9 get anything resembling good gas mileage.
 
i think mid-teens are achievable with a light throttle foot and might even tickle 20's on the open road if he's got some freeway flyer gears and keeps out of the 2ndaries on the TQ.

but city daily, probably 12

what sucks is that you can't easily go straight up fuel mizer status and find something like a SP2P or a 2bbl setup because of the magnum heads. the only way around that is money: drilling an intake and port matching it, or the EQ(?) heads that have both bolt patterns. or, again, EFI. but i don't see that returning massive gains over a well tuned carb set up.
 
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