SBE 318 basic rebuild +CAM , INTAKE, HEADS, expectations?

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Sebambam

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Hi team
lets me start with thanking all of you for the patience and the knowledge you provide.
great stuff.

so i had a couple other posts where i mentioned the 74 Duster 318/904 car i got and the different possible routes that i considered to go.

i checked on the OEM engine and its a runner with good compression ( all Cylinders are max 8psi apart and between 107-115psi , with a generic compression tool which i believe is not the most accurate ).
I am in the process of pulling the motor and trans and "REFRESH IT" with new gaskets a good clean. and i want to throw some "performance " parts on it.
i will do :
-dual plane intake
-a Summit cam kit ( since i live 10 min from a summit ,it is easy) SUGGESTIONS? https://www.summitracing.com/search...10RPaH8Xo5ULd6G0s4ZbAGija3CBgsV2p9FQ8rXqB0vND
- Carb: most likely a Holley Vac Sec. 650 or 750

and the Heads:....
Yes i understand that the OEM heads can be rebuild and upgraded, however by my experience i will run into , Cleaning , valve job , Springs, seals , milling , probably loose guides etc...
+ i would consider Port work since i have the "plug" in the Neighborhood ( elliotsportworks) so its a BILL of 600 + $ no matter what and its still CAST heads.
by that time and $ , out of the box alu heads become reasonable i think

So the questions is basically
what performance gains can i expect from simple SPEEDMASTER or PROMAXX as cast heads for FT Cams ?
I would use the stock Shaft rockers

I have a set of longtubes on the car already that i can most likly refurbish as well and use..
 
Thanks for keeping the 318! Wise choice :) One thing i will mention is don't forget you can get thinner head gaskets to get that compression up a bit.. not sure on the promaxx or SM chamber size but with trickflows (60cc i believe) i ended up at 155psi on a stock '85 bottom end..

BTW.. what is your end goal for the car? is it just a cruiser for fun? keep it how it is and freshen it.. **** will snowball fast.. i did it to myself.
 
Sebambam, I have used both the Summit K6900 and K50052 in 273 and 318's
Great cams for budget builds. With your choice of heads you may consider the K50052.
I agree with Icetech and the small chamber heads to boost compression.
 
Icetech said:
Thanks for keeping the 318! Wise choice :) One thing i will mention is don't forget you can get thinner head gaskets to get that compression up a bit.. not sure on the promaxx or SM chamber size but with trickflows (60cc i believe) i ended up at 155psi on a stock '85 bottom end..

BTW.. what is your end goal for the car? is it just a cruiser for fun? keep it how it is and freshen it.. **** will snowball fast.. i did it to myself.
Click to expand...
End goal is always as much bang for the buck.
But essentially its a 90% street driven HotRod
 
Sebambam said:
End goal is always as much bang for the buck.
But essentially its a 90% street driven HotRod
Click to expand...
Then as a 318 owner myself.. i will say... go on market place and find a 360.... you will have much more torque and power for much less money.. on a good day you can find one for $300ish.. put in a cam and intake and you will probably be in the same range as the 318 with heads/cam/intake... would be a better bang for the buck.
 
If you decide on the aluminum heads, take them to a machine shop and ask them to check guide clearances and such before slapping them on. It will be money well spent. It has been reported in the past that guide clearances have been found a little wonky on them here and there. Get your machinist to help you figure the compression with the CC's of the heads you buy. It can be adjusted with head gaskets and surfacing the heads to get it to a desired range. (within reason) Good luck to you.

:thumbsup:
 
Probably low to mid 300 hp.

Here's a stock low cr 318 with comp xe262 4bbl and headers makes 282 hp, add better heads and probably a cr bump should at least be around 1 hp per cid depending on cam choice.

https://www.motortrend.com/articles/mopp-0312-318-long-block-bolt-ons/

HORSEPOWER SUPERFLOW 901 DYNO-TESTED AT WESTECH
RPMBASEMOD 1MOD 2
2,000112
2,500137
3,000164193192
3,500182224227
4,000189248252
4,500186265274
5,000179271282
5,500262270
 
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Icetech said:
Then as a 318 owner myself.. i will say... go on market place and find a 360.... you will have much more torque and power for much less money.. on a good day you can find one for $300ish.. put in a cam and intake and you will probably be in the same range as the 318 with heads/cam/intake... would be a better bang for the buck.
Click to expand...
Can I switch over the oil pan+ pickup, mounts, acc, from the 318 to a 360 LA?

Are there any differences in 360 LA, lers say foe example the MoHo 360?

Wouldn't a 5.9 roller engine be better then?
 
Sebambam said:
Can I switch over the oil pan+ pickup, mounts, acc, from the 318 to a 360 LA?
Click to expand...
would use a 360 oil pan, they are different sizes on the end.. the rest should bolt up.. driver side motor mount might need a spacer made but not a major thing.... i believe everything else is bolt on. Nothing wrong with a 318 if you have realistic expectations.. but you are gonna end up with $2800 into a 318 to make 330hp....
 
The oil pan won't work, but everything else will. You would need to space the drivers side motor mount with some washers, and get a B&M flex plate to use the existing 904 neutral balance converter.
 
JDMopar said:
The oil pan won't work, but everything else will. You would need to space the drivers side motor mount with some washers, and get a B&M flex plate to use the existing 904 neutral balance converter.
Click to expand...
Dont' get the B&M plate... 440source sells the same thing for $50 instead of $150 :)

360's are external balanced so they use a torque converter with a weight on it... the flexplate you would need has metal removed to keep the balance and use a normal converter..



1723647491948.jpeg
 
I expect it to do a burnout from one side of town to the other or untill the rear tires pop whichever comes first...:thumbsup::poke:
 
On the other hand if you wanna not mess around and get the best bang for the buck.. you can still get motorhome 440's running for well under 1k.. only major expense putting that in would be headers.. with a cam/intake you would have a killer a-body..
 
Check out 318willrun's 318willrun he shows what can be done with basic hop ups on the track, he's got a mild 318 & 360 dusters.
 
Icetech said:
On the other hand if you wanna not mess around and get the best bang for the buck.. you can still get motorhome 440's running for well under 1k.. only major expense putting that in would be headers.. with a cam/intake you would have a killer a-body..
Click to expand...
the Moho 440 is bretty much ready... it has a cam , intake and a bunch of new parts... i should get the heads from the machine shop end of this week.

definitly a cool motor ...If i sell this engine i can probably fund the whole DUSTER build incl the engine (if i use the 318 )
 
Compression is consistent. I certainly wouldn't call it "good".
 
Sebambam said:
the Moho 440 is bretty much ready... it has a cam , intake and a bunch of new parts... i should get the heads from the machine shop end of this week.

definitly a cool motor ...If i sell this engine i can probably fund the whole DUSTER build incl the engine (if i use the 318 )
Click to expand...
Summer almost done, I do the 440 swap over the winter and have a badass car for spring, there's no way I'd pick a 318 over a 440 if that was the choice, I've have nothing against 318's but to me that's a pretty easy choice, even would choose the 440 over a 360.

For a street car, most self impose a rear gear limit say 2.76-3.55 which ever one you choose, those gears are almost always gonna be more optimal for larger engines aka 440.

A 318 gonna need about 1 full ratio deeper than a 440 eg.. 3.73 vs 2.76 to put similar torque the ground.

A 440 gonna need less gear, stall, rpm than a similar powered 318/360 and will make the most idle to 2500 rpm power, good for daily driving.
 
273's graph showing the 318 mods shows the 318's basic problem...lack of lo end hp and torque which is what you need for the street. You will be far happier with the 360.
 
I think making almost 200 hp @ 3000 rpm ain't bad but yes generally a similar built 360 will make like 20 hp more there and a 440 probably make around 40 hp more than the 360 there.

Hp is 57% of torque at 3000 rpm.
 
Here's a 9:1 350 (I know) with a small xe 256 cam that should be a little less torque than a similarly prepped 360.
Look at the torque at 2500 or 3000. They are good lo rpm numbers and the cam i would recommend for the street
or the Xe262. Just don't put 27560R15's on the rear no matter how bad you want it to look like a dragster.
This is from Comp cams website.

xe256.JPG
 
ir3333 said:
Here's a 9:1 350 (I know) with a small xe 256 cam that should be a little less torque than a similarly prepped 360.
Look at the torque at 2500 or 3000. They are good lo rpm numbers and the cam i would recommend for the street
or the Xe262. Just don't put 27560R15's on the rear no matter how bad you want it to look like a dragster.
This is from Comp cams website.

View attachment 1716289253
Click to expand...
Lol.. 275/60/15 are on it already, ...came like that.
 
ir3333 said:
Here's a 9:1 350 (I know) with a small xe 256 cam that should be a little less torque than a similarly prepped 360.
Look at the torque at 2500 or 3000. They are good lo rpm numbers and the cam i would recommend for the street
or the Xe262. Just don't put 27560R15's on the rear no matter how bad you want it to look like a dragster.
This is from Comp cams website.
Click to expand...
Almost felt like a personal attack.. my 318 has P295/65-15s :)
 
Icetech said:
Almost felt like a personal attack.. my 318 has P295/65-15s :)
Click to expand...
Do they fit with stock rear suspension? 8-1/4 rear end?
On a 8" steel wheel?

Further
my headers are a PITA to take off the driver side routes under the steering and there is no way the big old starter could be removed, I assume it's a older long tube design.
They are in bad shape and I think I have to replace them

So what SB header does clear a 74 duster with power steering ..
Long or shorty headers?
No guess work
 
ir3333 said:
Here's a 9:1 350 (I know) with a small xe 256 cam that should be a little less torque than a similarly prepped 360.
Look at the torque at 2500 or 3000. They are good lo rpm numbers and the cam i would recommend for the street
or the Xe262. Just don't put 27560R15's on the rear no matter how bad you want it to look like a dragster.
This is from Comp cams website.

View attachment 1716289253
Click to expand...
The 350 is making about 30 hp more at 3,000 rpm then the 318 pretty good gain, but the 350 also has better flowing heads.
 
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