The mighty 318

I got the 318 on the dyno and fired up this afternoon. So far naturally aspirated it's pumping out 229hp@5135&267.5@3722rpm. It's a bit rich yet and I'm going to lean the secondaries out about 4% tommorow morning and make another pull before hooking up the turbo.
It's a big improvement over the bone stock motor a few years ago when it pumped out a stump pulling 160hp.

Can't wait! Ought to be very interesting!!

I have to pull it a little higher too Greg. I only went to 5135 rpm and the hp was still going up. Also have to pull a valve cover and check the pushrods. The last stock set gave up and bent. I have a bit more spring pressure than the old motor. Interesting too the motor was only using 372 cfm@5135rpm. The f/a ratio was at 12.00 at the end of the pull so I'm going to try and lean it out to 12.5/12.75.

A 318 with proper machining, stock internals and the right cam will make 320HP with the wacky TQ..

Would extra fuel be better? My Saleen blown Mustang makes great power at 11/1 ,7.5 psi, cast pistons, 55,000 hard miles on it.

I did not screw it together trying to make maximum hp naturally aspirated. There is a GT-45 turbo hung on it.
Greg, I'm jetting it for Max hp naturally aspirated to see what it makes without the turbo. After that the secondaries get rejetted so it's high 10's low 11's for the turbo. It will be interesting to see how much the turbo increases the output and how much more cfm the motor sees.

Fun stuff!!

The 318 2bbl was rated at 230hp for a long time.

Well it didn't go very well today. I found a mouse had camped out in my phase convertor and I had to do some backyard engineering to get my water pump running. All the while my phase convertor was smoking and sparking.
Anyway, naturally aspirated it didn't really gain anything so I richened up the secondaries and hooked up the turbo and dropped the timing back to 20°. It ran great until the clamp on the tube between the carb hat and the turbo said uncle at 4252 rpm. I also blew an O-ring on the blowoff valve.
Anyway, it was at 423.1hp&517.4ftlbs@4152 rpm and still going straight up. Boost was at 15.07psi.(I should add that all pulls were done on C14)
I'll have to rewire the phase convertor and pick up some better clamps before I explore the outter limits of the 318.

Cool deal! I think a turbo is calling my name.

How low do you have boost, and what A/R is the turbo?

Jeff, the turbo specs are at work but it is sized for this motor, on the dyno it's at 2lbs. by 2500 rpm.

Therefore: good choice

What are the particulars on this beast? I'm curious about heads, cam, pistons, manifolds, etc.

R.

Stock short block, 8.9-1 (deck O-ringed with Clark copper head gaskets), 302' heads with 1.88/1.60 valves, summit house grind cam, .441 lift, 218/228@.050 114C. Performer intake, Eddy 600cfm carb.

The 229hp is with ex manifolds?

Yes, it's not the nicest exhaust system, it's junk off the garage floor. Also it's exhausting through one 3" pipe.
And at the same time I don't get to hung up on numbers, I look at the amount of change seen.

When your learning there is no need to ruin parts shooting for the moon

I wonder if the power were better to begin with, if the percentage of change/gain would still be the same, with the same amount of boost per rpm point.

I mean, it should be pretty easy to get close to another 100hp out of that 318 with some head work, headers, faster cam, etc.

If you made 500hp with xx boost from your 229hp starting point, that’s 2.18 times the original power output.

If you started at 330hp, would that same xx boost still increase the output 2.18 times(719hp)?

I definitely don't want to try and push it that far with stock parts. The first one I did went from 160hp to 536hp with just a 800 Thermoquad and 26 lbs of boost.
I may drop the pipe off the turbo just to see how much restriction it's causing. Also, about 550hp is about as far as I dare push on this thing. I've got 3 sets of trashed pistons already and I am getting tired of unzipping this thing.

160 > 536....... 335%!!

Single 3" exhaust on a 2.2/2.5 turbo car is a restriction so imagine it's quite a bit on yours.

Any pics of the engine bay?

The motor goes in my "Blue Creampuff". 1981 W-150. It's been rolled, turned into a farm sprayer, and abused to within an inch if it's life. I paid 2 cans of diet Coke for it. It's only got 50 some thousand original miles on it and it looks like it's got 500,000. I've surprised a few sports cars with it though.

I don't want to try and run 26lbs of boost on the street and that what it took to generate those numbers. All I've got to work with at the pump is 87 octane, that and a snow alky injection system under the carb.

A Snow is on my 2-do list, but they were a little vague on what kind of advice they could give me for my PT6466 equipped 2JZ. I'm trying to add knock suppression via methanol to dodge running really big (1,000cc) injectors, but not sure what pump gas A/F to try vs. how much volume via Snow.
Did they help?

Can't really tell you yet but I did buy 2 different jet sizes. My first try with failed due to operator stupidity.(I under fused the circuit.)

Keep us posted on your progress, it would be interesting to know what numbers you are getting.
At this time I am running two turbos on my 318 truck and I can tell you that it is holding up the 500+ HP and I'm only at 8 pounds of boost. Bottom end is stock but I am running a bigger cam and same as you 302 heads with 360 valves but I've done quite a bit of Port work oh yeah and I'm running dual quad throttle bodies on a tunnel ram.
I have no intentions of pushing my luck with it though, until my new motor is ready to go in.

Inspiring topic.
Makes me want to start to play with the watercooled Raptor V Supercharger I've got, although I'm sure results won't be that spectacular as with a turbo.
The constant S/C drag won't help MPG either I would think.

With a proper low rpm bypass valve to go around the supercharger, it isn't too bad.

Thanks for the particulars on the 318.
Interesting that you saw 229hp from 372cfm, that's really close to the 0.6hp/cfm that I use as a rule of thumb.

An actual 229hp would be a big improvement over the 120 or so hp the truck may have come with. In this day of seemingly unlimited horsepower figures, those small numbers seem like peanuts but the percentage gain is what's important to how the car feels.

I'd be leery of taking a 318 block over 500hp but then again 318s are nearly free.

Fast68, I think the biggest thing holding this combination back is the dinky ports. It takes more pressure to jam air through a small hole. Other dyno tests of turbo engines have shown that intake port flow is very important to achieving max horsepower. If the airflow was increased to increase baseline power, then it'd probably follow that hp would increase proportionally. I'm not so sure if a larger cam and more compression would translate the same, though.

R.

With it being a boosted combination, I’d have just gone with some 360 heads for the bigger runners and added flow, and not worried about any loss of velocity, but it’s easy to sit at my desk and spend other people’s money.

I agree, those 302 heads are about the wors choice for this, I would say even the open chamber 318 heads would be a good upgrade as they flow more and will drop the compression a hair.

I have several sets of 360 heads I could have used. With the cam I am using and the fact that most of the time it is not under boost I didn't want to loose any port velocity and kill more bottom end.

Im going to order up some 3-1/2" tubing and redo the exhaust right off the turbo and see how much that improves things too.

Well I got the 3-1/2" tubing and made up a head pipe off the turbo. The problem now is keeping the hose between the turbo and the carb hat from blowing off, I need to pick up better clamps.
The highest rpm I've been able to pull to is 4356 and them the clamps give up.
The numbers so far are; 489.1hp and 589.8ftlbs.@22lbs. of boost. The numbers are still going straight up, I don't know how much harder I dare push this poor thing with stock cast pistons.

Have you tried these?

https://www.amazon.com/Breeze-Constant-Torque-Stainless-Worm-Drive-Diameter/dp/B009SD07IK

Kevin

Yep, in fact I have one right off the turbo, I need a couple more the right size.

Maybe try the T-bolt style with the spring. That's the style on my C15 Cat and N14 Cummins. I think they are 4" and hold 40psi.

Kevin

Well I got it to pull to 4350, made a few minor changes and here are the numbers.
520 hp and 633.4 ftlbs. at 22.44 lbs of boost. I put the air turbine on it and it was pulling 1024 cfm through a 600 Edelbrock. I wonder how it would respond to a 750?
That's about as hard as I dare lean on 100,000 mile cast pistons. Engine is still intact.

Dave, with pistons being the first thing to go, have you considered stock bore hyper replacement pistons with the ring gaps opened up a bit? Did the failed pistons show signs of the rings butting?

Cool build!

keeping the hose between the turbo and the carb hat from blowing off, I need to pick up better clamps.

The clamp isn't the problem (been there, done that), you need a bead rolled into each end of the tube.

I’m reading this to my 15yo son and he is smiling ear to ear thinking about the possibilities with his 72 318.
Good work and results!!!

Once I read your response Jeff I realized that a bead makes perfect sense, thank you.
Greg, I file fit the rings and opened them up to .035+. All the pistons I have hurt have been destroyed by detonation. One set broke Every skirt off every piston. I'm still trying to figure how it can rattle a piston that hard in a properly clearance bore
Sometime this week I'm going to try a 750 Eddy on it.

Wrist pin offset. It's great for preventing piston slap in low performance engines but...

just listened to the pod cast from " uncle tony's Garage" that you were on.

Yep, that was me the funny sounding guy. If you've ever seen the movie "Fargo" some of us really do talk like that. I grew up and still live about 50 miles nort' of Fargo.

you don't have any wood chippers around, right ?

Nah, too messy, feed 'em to the hogs.

What size rotary convertor are you using for the dyno and what type of dyno. I recently got a 20 HP motor to build convertor for my SF 901. I may try a 7.5 HP to run my machine shop I'm setting up as I don't think the 5 HP I have now will run the CK 10 properly, I'll find out in a few weeks.

The phase convertor just runs the motor for the water pump that feeds the absorber. It's a bank of capacitors that kickstart a 3 phase motor. I've done the same thing just spooling up a 3 phase motor with another single phase motor.
The dyno is a L&S 13" dualrotor water brake. It's good for 2000 ftlbs of input torque.

Well I finished testing and tuning. The motor is still in one piece and ready to go back in the truck.
I'm a bit disappointed as I couldn't get it past 520hp and 633ftlbs. The wastegate and blowoff valves wouldnt allow me to go any higher.
I backed the boost down to 14 lbs. The 600 Eddy made 376.1hp@4390 rpm and 459.5ftlbs at13.9 lbs of boost. The 750 Eddy made 409.5hp@4587rpm and 485.7 ftlbs. at 14.04 lbs of boost.
To get the carbs rich enough I ended up removing the secondary jets entirely. I could have drilled and tapped the airbleeds to richened the carbs up but I'm running out of time to screw with it and this worked.
I made about 35 pulls and probably could have made another 35 but there comes a time to say good enough. So the motor went from 229hp naturally aspirated to about the same level as a 413 maxwedge with a little help of a cheap Chinese turbo. If at some point I feel a little 'gamey' it's just a spring change away from another 100hp.