318 Rebuild: Looking for some parts & build suggestions for a more hp street-able (fun when needed) ride.

[nktrnljerms]

Well it's finally happening.
Pulled my 1968 Stock 318 (Cracked passenger side head) out of the barracuda.

Scheduled to go to the machine shop early Sept. and to begin a parts list.
Looking for some parts suggestions for a bit more than mild street build.
Not apposed to an aftermarket aluminum heads.

Have a decent budget to pull from because this will continue to be a family car and will not be being sold anytime soon.

Drivetrain upgrades as well will be happening too to help accommodate the engine upgrades and some better drivability n safety.
- Transmission Rebuild
- New Brakes & Suspension
- 8 3/4 rear end swap
- Wheels n tires

 

[273]

Heads is where the power is at, A 9:1 cr 318 with a 600/650 carb, dual plane, manifolds or headers and duals a 210 to 225 ish cam and a good tune. The heads will mainly decide how much power 250 to 400 + hp, basically stock 318 heads 250 to 300 hp, ported 318 or stocker 360 heads 300 to 375 ish hp, well ported stockers or aftermarket heads 375 hp +.

318 needs more rpm than a similar hp 360 (400-700 rpms) which means higher stall (2500-3500) and deeper gear 3.55 (at least) are your friends.

First question what's stall and gears your willing to run will decide how much cam etc.. you can go?

 

[TT5.9mag]

Look up the recent build by @NC Engine Builder and duplicate it. It should be close to 400hp (we’ll know soon as he’s going to dyno it) and be reliable as a hammer. Or buy his because I think he’s going to list it for sale after dyno.

318 build with dyno session

 

[Jim Kueneman]

Compression, compression and compression... then some heads that flow some air. Same recipe for the slants. Only the first 2 years of the LA 318 had good compression then they were detuned (probably so the new 340 would look better) with less compression height on the pistons. Lucky to get 8:1 out of a later 318 and the 225 I have done where about 7.2:1..... if you don't get compression first any cam, other than the factory short duration, will kill low end daily street torque.

 

[273]

I agree compression is important and since the engine gonna be a rebuild there's no real reason not to build the required amount of CR for the cam and fuel type, but thinks saying low end torque will be killed is a little extreme and seen little evidence to support it.

 

[Jim Kueneman]

I agree compression is important and since the engine gonna be a rebuild there's no real reason not to build the required amount of CR for the cam and fuel type, but thinks saying low end torque will be killed is a little extreme and seen little evidence to support it.

If you run a model in Performance Trends it is clear. Your dynamic compression goes in the toilet at low RPM with low compression and a longer duration cam. I have never proven it since if the model says it's bad why spend the time to convince yourself it is true. Just up the compression as it is better for everything.

 

[273]

Here's a couple of articles and a video to give you some ideas, I know it's 360 but a 318 will respond similar just at higher rpm's.

3-8-Teen Dream
Stock low CR 318 long block Mod1 xe262h cam 4 bbl and headers Mod2 spacer.

TORQUE SUPERFLOW 901 DYNO-TESTED AT WESTECH
RPM	BASE	MOD 1	MOD 2
2,000	292
2,500	287
3,000	287	338	336
3,500	272	335	340
4,000	248	326	330
4500	218	309	319
5,000	188	285	296
5,500		250	258

HORSEPOWER SUPERFLOW 901 DYNO-TESTED AT WESTECH
RPM	BASE	MOD 1	MOD 2
2,000	112
2,500	137
3,000	164	193	192
3,500	182	224	227
4,000	189	248	252
4,500	186	265	274
5,000	179	271	282
5,500		262	270

Chrysler 318 Engine - A Powerplant To Brag About
318 10:1 cr EQ heads stock vs ported 4bbl headers and xe275hl cam

RPM	TQ	TQ	HP	HP
	BASE	PORTED	BASE	PORTED
3,000	335	335	192	192
3,200	342	340	208	207
3,400	351	356	228	231
3,600	365	369	250	253
3,800	374	379	271	274
4,000	379	384	289	293
4,200	378	383	302	306
4,400	375	383	314	321
4,600	376	382	329	335
4,800	375	386	343	353
5,000	372	384	354	366
5,200	367	383	363	378
5,400	361	379	371	390
5,600	355	374	379	399
5,800	350	371	386	409
6,000	345	365	395	418
6,200	341	360	402	425
6,400	329	345	401	421

Low CR 360

 

[273]

If you run a model in Performance Trends it is clear. Your dynamic compression goes in the toilet at low RPM with low compression and a longer duration cam. I have never proven it since if the model says it's bad why spend the time to convince yourself it is true. Just up the compression as it is better for everything.

When people do cam shootouts on actual dyno's I'm just not seeing this torque in the toilet scenario.

A stock low cr 2bbl 318 makes about 280-300 lbs-ft @ 2,000 rpm show me one built 318 that makes (looks like it may make) way less @ 2,000 rpm ?

 

[George Jets]

1968 318 factory 230 hp 9.2:1 compression ratio. Flat top pistons .040 down in the hole.

Let's hope that engine has had good routine oil changes and you can save that factory short block.

Light free floating factory rods as an added bonus.

Awesome


☆☆☆☆☆

 

[Jim Kueneman]

Here's a couple of articles and a video to give you some ideas, I know it's 360 but a 318 will respond similar just at higher rpm's.

3-8-Teen Dream
Stock low CR 318 long block Mod1 xe262h cam 4 bbl and headers Mod2 spacer.

TORQUE SUPERFLOW 901 DYNO-TESTED AT WESTECH
RPM	BASE	MOD 1	MOD 2
2,000	292
2,500	287
3,000	287	338	336
3,500	272	335	340
4,000	248	326	330
4500	218	309	319
5,000	188	285	296
5,500		250	258

HORSEPOWER SUPERFLOW 901 DYNO-TESTED AT WESTECH
RPM	BASE	MOD 1	MOD 2
2,000	112
2,500	137
3,000	164	193	192
3,500	182	224	227
4,000	189	248	252
4,500	186	265	274
5,000	179	271	282
5,500		262	270

Chrysler 318 Engine - A Powerplant To Brag About
318 10:1 cr EQ heads stock vs ported 4bbl headers and xe275hl cam

RPM	TQ	TQ	HP	HP
	BASE	PORTED	BASE	PORTED
3,000	335	335	192	192
3,200	342	340	208	207
3,400	351	356	228	231
3,600	365	369	250	253
3,800	374	379	271	274
4,000	379	384	289	293
4,200	378	383	302	306
4,400	375	383	314	321
4,600	376	382	329	335
4,800	375	386	343	353
5,000	372	384	354	366
5,200	367	383	363	378
5,400	361	379	371	390
5,600	355	374	379	399
5,800	350	371	386	409
6,000	345	365	395	418
6,200	341	360	402	425
6,400	329	345	401	421

Low CR 360

Tough to armchair design an engine build but the stock CR and the XE274 cam is not that big 218°/224° (I think) not much bigger than the stock cam (can you show me a stock 318 curve and how it relates to this table?)..... I would like to see the XE275 (231°/237°) cam with stock compression numbers. The answer is do the math with the selected cam and CR and see where you are. If you are not in the 180-190 PSI cranking range for a reliable street engine you are leaving torque on the table. HP numbers are thrown around but in my opinion torque numbers are what make you smile in the drivers seat on the street.

 

[273]

Tough to armchair design an engine build but the stock CR and the XE274 cam is not that big 218°/224° (I think) not much bigger than the stock cam (can you show me a stock 318 curve and how it relates to this table?)..... I would like to see the XE275 (231°/237°) cam with stock compression numbers. The answer is do the math with the selected cam and CR and see where you are. If you are not in the 180-190 PSI cranking range for a reliable street engine you are leaving torque on the table. HP numbers are thrown around but in my opinion torque numbers are what make you smile in the drivers seat on the street.

Those were for the OP for build ideas not to prove one way or another about low cr low end torque.

Even though it kind of does, I just haven't seen any real evidence of it, even though people say it does all the time, I imagine the OP will build some CR so it's probably a moot point, as long he don't go the opposite direction and try to build too much cr

 

[junkyardhero]

Here's a couple of articles and a video to give you some ideas, I know it's 360 but a 318 will respond similar just at higher rpm's.

[redacted]

 

[junkyardhero]

Well it's finally happening.
Pulled my 1968 Stock 318 (Cracked passenger side head) out of the barracuda.

Drivetrain upgrades as well will be happening too to help accommodate the engine upgrades and some better drivability n safety.
- Transmission Rebuild
- New Brakes & Suspension
- 8 3/4 rear end swap
- Wheels n tires

i'll say the same thing i say to everybody i do work for: what are you expectations? what are you looking for and be realistic about it. how much gear are you willing to run? how much stall? are you going to bellyache about running premium?

how do you want to really want to use the car and how would you like it to drive? you need to be truthful with yourself on this, otherwise you're just setting yourself up for disappointment.

you don't need 400hp to have an enjoyable ride that'll light 'em up and kick some *** light to light. i generally find everybody that says i want "X" horsepower has never driven a car with that much power and don't have the slightest idea of how specific motors react when built to that very narrow specification.

also, the 318 might not be the right base to build from. you can throw good money after bad if the components are wack or if it doesn't suit what your end goal is.

anyway, this all starts with those questions and taking apart what you have and seeing what you've actually got to work with.

 

[PRH]

OP mentioned having a decent budget for the build, and aluminum heads.

I’d suggest a 4” crank to go with the new heads.

 

[273]

I'd also add where do you want to make (rpm) the power ?

Eg.. say shift at (pulls to) 6,000 rpm probably making peak around 5,500 rpm making 1st gear drop to about 3,500 rpm and 2nd 4,100 rpm plus some convert slip.

Around 1.2 lbs-ft per cid = hp estimation

318/323 x 1.2 x 90% x 5500 / 5252 = 365 hp
360/365 x 1.2 x 90% x 5500 / 5252 = 413 hp

 

[Illahe]

Well it's finally happening.
Pulled my 1968 Stock 318 (Cracked passenger side head) out of the barracuda.

View attachment 1716443496

Scheduled to go to the machine shop early Sept. and to begin a parts list.
Looking for some parts suggestions for a bit more than mild street build.
Not apposed to an aftermarket aluminum heads.

Have a decent budget to pull from because this will continue to be a family car and will not be being sold anytime soon.

Drivetrain upgrades as well will be happening too to help accommodate the engine upgrades and some better drivability n safety.
- Transmission Rebuild
- New Brakes & Suspension
- 8 3/4 rear end swap
- Wheels n tires

Call Delta cams in Wa. He grinds a nice 4bbl stick for a 318. I think mine was 125 bucks. 112 lsa under .440" lift and 211/218 I believe. Great torque, slight exhaust tone and it runs a Rochester 800 well on a cast spread-bore with oem exhaust.

 

[nktrnljerms]

i'll say the same thing i say to everybody i do work for: what are you expectations? what are you looking for and be realistic about it. how much gear are you willing to run? how much stall? are you going to bellyache about running premium?

how do you want to really want to use the car and how would you like it to drive? you need to be truthful with yourself on this, otherwise you're just setting yourself up for disappointment.

you don't need 400hp to have an enjoyable ride that'll light 'em up and kick some *** light to light. i generally find everybody that says i want "X" horsepower has never driven a car with that much power and don't have the slightest idea of how specific motors react when built to that very narrow specification.

also, the 318 might not be the right base to build from. you can throw good money after bad if the components are wack or if it doesn't suit what your end goal is.

anyway, this all starts with those questions and taking apart what you have and seeing what you've actually got to work with.

Great points and I agree.

It just needs to stay/be a nice driver / family legacy car with some more punch when needed.
It a really nice stock survivor convertible that needs some upgrades in the powerplant and drivability front.
Sure a 318 might not be the way to go, but it is what it is there.

If all things are still in decent enough shape to rebuild that's the platform.

I have a '73 Swinger w/360 build in the works to scratch the more HP/race part side of the garage.

 

[273]

A 318 is just like building any other engine, just remember it will like more gear and stall than a similar 360 and slightly less cam can't hurt for streetability.
A good set of heads with a reasonable cam should get you the power you need.

Look at this thread what can be accomplish with only 224 degrees of cam,
unfortunately there's a bunch of BS argument you got to scroll past
Good Streetabe Power

 

[toolmanmike]

unfortunately there's a bunch of BS argument you got to scroll past

Typical 318 thread.

 

[273]

Typical 318 thread.

True, lol.
But it wasn't meant to be a 318 thread, but that's what the people wanted it to be

 

[Illahe]

A 318 is just like building any other engine, just remember it will like more gear and stall than a similar 360 and slightly less cam can't hurt for streetability.
A good set of heads with a reasonable cam should get you the power you need.

Look at this thread what can be accomplish with only 224 degrees of cam,
unfortunately there's a bunch of BS argument you got to scroll past
Good Streetabe Power

Having built several 318 for A bodies and pick up trucks the underlying issue is Asthma. The 204/214 works okay for heavy vehicles with 360 heads, but lacks any top end. Its capable of 16mpg with a large primary spread-bore.

The 302 heads with 1.88 intake and some mild clean up produced 11hg with the Sum-K6901 cam and sounded like a jet boat with turbo mufflers.

The third combo was the most all around functional package with the mid eighties cop car pistons, I believe they were about .045 below the deck along with early 1.78 318 heads and under 212 @.050 on the intake duration. 224@ .05 will require some 3.55 gears and a looser converter to be fun with a small cubic inch engine and less then 9:1 compression.

I have no hatred for the little engine that can, but conservative combinations bring the most smiles per $ with the "teen."

Good luck with your project.

 

[volaredon]

Don't let the haters talk you out of building your 318

 

[273]

Whatever the OP wants to build that's what people should be trying to help with, as long the OP reasonably knows the Pro's and Con's and isn't asking the impossible then who cares if they want to do a 2,2l /6 273/318 383 or any so called other less desirable engines.

Is there more reasons to probably start with a 360 sure, but that's up to the OP, I don't think he's even stated what he's trying to accomplish, could be only 250-350 hp, even a 273 could handle that.

 

[Ant]

Whatever the OP wants to build that's what people should be trying to help with, as long the OP reasonably knows the Pro's and Con's and isn't asking the impossible then who cares if they want to do a 2,2l /6 273/318 383 or any so called other less desirable engines.

Is there more reasons to probably start with a 360 sure, but that's up to the OP, I don't think he's even stated what he's trying to accomplish, could be only 250-350 hp, even a 273 could handle that.

100%
I think people also forget that the current used engine market can vary depending on location. Heck, I bought a 318 because that's what I can get my hands on for dirt cheap. Sure I would love a 360, but over here sellers want too much money for a junk engine filled with water.

Sometimes the best option is to build what you have. The OP already has an engine, just crack it open and see if it's good on the inside.

 

[92b]

Well it's finally happening.
Pulled my 1968 Stock 318 (Cracked passenger side head) out of the barracuda.

View attachment 1716443496

Scheduled to go to the machine shop early Sept. and to begin a parts list.
Looking for some parts suggestions for a bit more than mild street build.
Not apposed to an aftermarket aluminum heads.

Have a decent budget to pull from because this will continue to be a family car and will not be being sold anytime soon.

Drivetrain upgrades as well will be happening too to help accommodate the engine upgrades and some better drivability n safety.
- Transmission Rebuild
- New Brakes & Suspension
- 8 3/4 rear end swap
- Wheels n tires

Cubic inches is a good economical way to make good streetable power without the down side of having to run deeper gears or a higher stall. But if you don't mind running deeper gears or a higher stall more cubic inches will be even better. Do the math for dollars spent for hp gained and streetable horsepower. Good luck on your project.