Tell me why not?

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Woody'sScamp

Woody'sScamp

FABO Gold Member
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All,
I want to wake up my '75 Smog 318. I already have 2.5" TTI haust with 340 manifolds, 904 trans, 3.55 sure grip 8/1/4. Looking for more horses with some street manners. And please don't tell me to buy a 360! Thanks in advance, I know nothing about engines, cams, air flow, etc. but I'm trying to learn. Also, someone told me to go with roller rockers and a roller cam if I do upgrades?
Speedmaster PCE281.2149K: Small Block Chrysler Cylinder Head Kit | JEGS

Tell me all the reasons I shouldn't buy this? Plus you get $100 off $1500 or more, and free shipping, this looks like a deal to me?
 
Factory 340 camshaft. Dual plane intake and about a 600 or 650 Edelbrock AVS 2 carb. Get the linkage correct for the kickdown and you will be more than happy.
 
For what you are going to be doing with it , I’m sure it will be fine ! I would add a small perf cam, and something like a 2500 to 2800 stall conv !!! I would also add a dual plane intake manifold as well !
 
All of this will not return much improvement if you have a smog motor with low compression and stock smog heads. That’s where performance starts, more compression and heads that will flow some air in and out.

it’s why a smog 318 is a pussycat and a 426 hemi or max wedge is an animal.
 
First of what is condition of short block. Do a compression test and report psi here. If compression is really low, new heads won't help much.
 
413 said:
All of this will not return much improvement if you have a smog motor with low compression and stock smog heads. That’s where performance starts, more compression and heads that will flow some air in and out.

it’s why a smog 318 is a pussycat and a 426 hemi or max wedge is an animal.
Click to expand...
Not sure I agree "it's subjective" I did this not long ago. Bought a what-turned-out to be a very low miles 318 "of the 70's ran it long enough to see that it ran well, then tore it down and replaced the cam with a mild solid cam a bit smaller than a 340, installed a 4bbl intake and carb, later went TBI EFI. That little gal woke right up. Fun to drive.
 
Get some flat top pistons for that teen and up the compression. Then a stock 4bbl, cheap .484 cam and a Carterbrock. Heads will yeild little with those slugs. Roller rockers are not needed, roller cam and lifters will be >$600....
 
That 74 teener the pistons hit TDC .080" - .100" in the hole. That coupled with the stock open chamber wedge heads gives you about 8.0-1 compression. Smooth running, and can run on rat piss, and run forever. Shitty for performance.

You got the exhaust end figured out. Heres what you need for a fun 318. I am building mine this way as soon as the block and rotating assy is out of machine shop jail. KB167 zero deck flattops with 5cc valve reliefs, 302 heads. Port match the heads to a weiand #8022 stealth intake (Eddy LD4B clone) this intake has 318 sized runners. Use Melling VS-380 340 spec valve springs with inner damper, melling SPD-22 which is a 68 340 automatic cam, and an eddy 600. Use a .040" thick headgasket and you should be right around 9.7-1 compression.

Remember 318s have smaller cylinders than 340s and 360s. They can only draw so much fuel and air on an intake stroke. Make everything too big in regards to intake, cylinder head ports etc, and you will slow port velocity down and actually hurt performance.

Hope this helps
Matt
 
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67Dart273 said:
replaced the cam with a mild solid cam a bit smaller than a 340
Click to expand...
come-on man, that is a different engine.
The Ica on a 340 cam installed 4* advanced is like 62* IIRC, and the overlap is 44*. CCP will be down around 122psi, in a tight true 8/1 engine. That is dog-town until the cam starts working, which with 3.23s, is up around 30 mph, in 2.45 First gear.
The stock Smoggerteen really needs a solid lifter cam where you can control the Ica exactly, and a minimum 2800TC......... But what it needs more than anything is to get pumped up, and to install some decent heads to match the cam.
By the time yur done, the only left of the original engine, is ....
the block/crank/rods....... and the covers;
and then you still have to get a convertor, a "posi" and some street gears, plus all the usual bolt ons.
I vote take a shortcut and go straight to 4.10s, a 2800, and a semi-auto shift-kit. Yur gonna need it anyway
 
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moparmat2000 said:
That 74 teener the pistons hit TDC .080" - .100" in the hole. That coupled with the stock open chamber wedge heads gives you about 8.0-1 compression. Smooth running, and can run on rat piss, and run forever. Shitty for orrformance.

You got the exhaust end figured out. Heres what you need for a fun 318. I am building mine this way as soon as the block and rotating assy is out of machine shop jail. KB167 zero deck flattops with 5cc valve reliefs, 302 heads. Port match the heads to a weiand #8022 stealth intake (Eddy LD4B clone) this intake has 318 sized runners. Use Melling VS-380 340 spec valve springs with inner damper, melling SPD-22 which is a 68 340 automatic cam, and an eddy 600. Use a .040" thick headgasket and you should be right around 9.7-1 compression.

Remember 318s have smaller cylinders than 340s and 360s. They can only draw so much fuel and air on an intake stroke. Make everything too big in regards to intake, cylinder head ports etc, and you will slow port velocity down and actually hurt performance.

Hope this helps
Matt
Click to expand...
I forgot to mention i do have a LD4B and a 600 Edelbrock 1406.
 
3406pk said:
First of what is condition of short block. Do a compression test and report psi here. If compression is really low, new heads won't help much.
Click to expand...
One cylinder compression was 129 when it was tested 5 years ago, it's been parked since then. I remember most were 135 to 138. The mileage is 33,000 miles.
 
Woody'sScamp said:
I forgot to mention i do have a LD4B and a 600 Edelbrock 1406.
Click to expand...

Well perfect then. Go to Rock auto and get the 318 302 closed chamber Reman heads for 500.00 for the pair shipped to your door. You have the LD4B and 4 bbl to bolt on and good to go with the stock cam that is in it.

That's a great first step.
 
Much depends on how many $$$ you have to spend, best bang for the buck & how much disassembly you are willing to do. Changing heads ain't simple if 'you know nothing about engines'.
If you want to feel a noticeable difference & keep costs down, I would use your Edel intake & carb....but change the cam. The cam I would get that will give you street manners is the Isky 264 Mega, #390164. Have your factory lifters re-faced, which guarantees the cam runs with good quality lifters & not today's crapola lifters. I think your factory valve springs might work with this cam, others might know for sure. If not, springs can be replaced without removing the heads.
It makes little sense to me to spend big $$$ on a small engine like a 318 as it is cubic inches limited...& low compression, both performance killers.
 
Woody'sScamp said:
All,
I want to wake up my '75 Smog 318. I already have 2.5" TTI haust with 340 manifolds, 904 trans, 3.55 sure grip 8/1/4. Looking for more horses with some street manners. And please don't tell me to buy a 360! Thanks in advance, I know nothing about engines, cams, air flow, etc. but I'm trying to learn. Also, someone told me to go with roller rockers and a roller cam if I do upgrades?
Speedmaster PCE281.2149K: Small Block Chrysler Cylinder Head Kit | JEGS

Tell me all the reasons I shouldn't buy this? Plus you get $100 off $1500 or more, and free shipping, this looks like a deal to me?
Click to expand...

It is a pretty good deal for all that. If you can afford that, I'd go ahead and get the KB167 pistons and get some real compression in it too. That, plus the heads and "whatever" performance cam you choose could make a really nice power package in a 318.
 
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