high performance 318 build (on 87 octane)

I dont get to build 318s very often so I thought I would post this link to a 2.5 minute youtube playlist showing the 318 I built that ended up in a 68 B-body. The owner was going to put a 440 in it but decided to stick with a 318 so he could keep his exhaust and the rest of his drivetrain etc. I think he underestimated the cost of the full conversion, he had already purchased a 440 core motor and then went with my 318 and sold the 440.

thanks

https://www.youtube.com/watch?v=XppHo3nPYVU&list=PLtmvPP9_MU2PbOPk_fbOt4gaA-hLXUJR3

Nice, but without build specs its like saying go look at the sky, its blue.

So can we get the full build specs?

The description of the first video clip lists most of details and you can see he is using the stock 318 manifolds. As far as the cam I have alot of time invested in it so I dont want to reveal all the specs but it is a flat tappet hydraulic (even though it is a magnum engine) and has a bit over .500 lift but under 230 degrees of duration. Optimal shift point is right around 6K rpm with 318 manifolds and relatively free flowing muffs/pipes.

As you can see, the tach video is informative (even though it looks like it was not so easy to record) It seems to be pulling decent at 6K on the 1-2 shift. He said he has tried 6500 RPM but it felt spent (what I would expect for the overall combination).

That seems like one fine running 318 you built!

318 and 87 octane are not words I would normally associate with high performance.....but the second part of the video seems real enough.
None too shabby.

I had a Grey & white cat just like that one.
Nice pull to 6k rpm!

Me thinks 318 motors and high performance don't mix well together
Of course a good engine builder can make any motor run well

Its posts like these that kind of pushes me in the direction of buying a 318 just to prove that everyone else is wrong Yep im one of those stupid ones who likes to do everything backwards

Not sure why people say the 318 isn't a performance engine.
5.2L of high winding power.

Isn't it the same bore size as a 4.8 and 5.3?

Good heads, cam, intake and you can run it right up to the bottom end limits no problem.

Who wouldn't love a 500+hp street car?

I don't do Magnum stuff........my notion of a 318 is cast iron 2 bbl intakes and 4 door sedans.
They can make some power obviously , but as small blocks go , they are kind of small. LOL

[ Moparts Family Site - Keep it Friendly ] is a 4.8 or 5.3?

GM LS engines. However those (the 4.8 and 5.3) have an even smaller bore than our 318.

Always enjoyed my 318. It was a 67 block and heads. The holdover heads from the 273. Smallish ports. Only thing I did to it was add an Edelbrock Performer and Holley 600. Car had great throttle response and got 20odd mpg. Think it had 2" duals with glasspacks. Great cruiser.

Everyone's idea of performance is different I guess.
And that is fine.
But the bar has been continuously raised with the passage of time.
12 second street cars used to be pretty quick.
Now , they're boat anchors.
I have seen some righteous motors in the 300 c.i. neighborhood.......in Competition Eliminator cars. ;-)

True. My point was to show that even a stock 318 can perform. A built engine is even better. My 340 has W2 heads on it. I was always curious how my 318 would run with them. Put some comp and cam in it to see how it would do.

Sounds great!

Cool stuff Jeff!!!

We did a durability test with one in a 1967 Coronet.
It was heading to the bone yard and we were bored......a couple friends stopped by with a case of beer and suddenly , it made sense to fire it up and put a brick on the gas pedal.
It ran at W.O.T. for a half hour , until it ran out of gas.
The exhaust manifolds were glowing red and it started spitting through the carb at the end.
My best guess would be valve float causing this.
We were expecting something more dramatic........spitting a rod or some other catastrophic failure.
If the car wasn't so rusty , I could have driven it for another couple years I bet.
If this bit were original , I'd be a genius.....but at the end of the day , engines are air pumps.
The 318 would respond to modifications much like any other motor.
Decent heads would make a huge difference.
400 h.p. would be pretty easy with the right parts and you would still have excellent driveability.

Why would you not keep the magnums roller cam?

sounds nice!

Thanks to all for the encouraging words.

"High performance" is relative. In the muscle car era stock 340s or 383 magnums were considered by many to be high performance. 318s were never used in a factory performance application with the exception of the 80s cop cars.

A flat tappet cam was used to keep costs down, I've done a bunch of magnums with FT cams and they have performed well. IMO in the low duration hydraulic realm a FT which has snappy close and open off-the-seat, goes a long way. This motor was done with the goal of "budget performance". Low fuel consumption and cheap 87 octane for someone who is just going to do a ton of cruising and driving.

With headers and carb I wanted to approach or exceed the power of a stock 440 magnum or 5.7 hemi (while enjoying the benefits of a lighter engine/904 trans). I love building motors like this. There isnt a high dollar part to be found anywhere in it. The owner loves it BTW.

318, 340, 360, 408 etc. My problem is I love them all.

I figured that is way you went with the ft cam...I just bought a lunati magnum roller and just the cam was $500 here in Canada.
Do you run adjustable rockers? Thanks and great build!

No aftermarket rockers. Again, a budget build. The next step up would be a higher compression piston with a tight quench that would allow pump premium. Guaranteed gain across entire RPM band (as well as MPG)

Jeff, is that a Procomp HEI distributor?
Wondered how you guys liked working with it.
Thx
Rich

During the last year I've built three 318's that I took to dyno. Nothing special, or at least special in a sensible way, but real world build ups with low budget and probably medicore results.
1) A 1980 318. New bearings and rings, hone job. Double roller timing chain. Stock heads with stock valves, milled .040" and homeported. Comp Cams 260 HE cam, factory distributor with quick and short advance, performer intake, 1850 Holley and shorty headers with 3" exhaust and mufflers. 265 hp between 4500-5000 rpm.

2) a '73 318, .030 oversize, KB hupereutectic pistons,302 heads with 1.88" intake valve, homeported. Cam was a comp cams XE275HL and the intake an old Offenhauser 2 x 4 with twin 400 cfm carters. Distributor unknown electric, same shorty headers and exhaust as in 1). 335 hp at 5500 and still raising, the owner didn't want to wind it higher. Might have produced a few more.

3) a '71 318. '030" overbore, old TRW dome pistons with the dome shaved a lot, just over 10:1 cr. polished 360 rods with ARP bolts. mid 70's 360 heads with 2.02/1.60 valves, homeported. Lunati Voodoo 30200741 solid cam, 273 pushrods and rockers. Torker 2 intake, 1850 Holley, 1 5/8" cheapo headers, 3" exhaust with mufflers, MSD pro billet distributor. 391 hp at 6000.

A Strip Dominator, a good 750 double pumper and 1.75 headers and that last build you've posted would have been close to 450 HP and not lost one iota of driveability. A nice, current 4000 street converter in an A body with a 3.73 gear and you are looking at a very low 12 second car. If you screwed with and got some bite to it, it would go in the 11's all day long.

Probably true, it was just built for fun from parts laying around. It's still a very strong 318.

I haven't personally used the Chinese HEI distributors but a couple guys I build motors for have. Not sure if they even fit in an A-body car (its tight in a B-body so I kinda doubt it). This guy used it mainly because everything is self contained so all he needed to do was connect 12V.

I like stock looking stuff. The buyer had a choice of an old style mopar M1 dual plane intake or this airgap. If it were me I would have used the M1(it is basically a slightly enhanced stock 340 4bbl intake cast in aluminum) and a mopar ignition along with some stock valve covers (stock LA valve covers can be used on magnum heads with very little work. The five bolt holes line up perfectly) Paint the whole thing red and you have a stock looking 318.

You can fit an HEI in an A body, but like you say, it's a tight mother. I have a Mallory Comp 9000 I'm going to install and that's a tight mother.

No doubt that 318 would catch many off guard. All you have to do is go to the local drag strip and see how many 500 HP guys are running 12's to know they've never even seen a dyno, let alone had anything on one.

Good info. Seems like the Procomp HEI works well enough for him. I had to go back and watch it again to make sure I was seeing what I thought I was seeing.

Interesting thread.
In the spring I will be refreshing my 73 Waygun's 318 (with 3 on da tree)
It already has 800CFM Thermoquad,1971 340 intake dual exhaust with factory logs.Recurved distributor with Summit ECU.
I do haul with the waygun and being 3 on da tree in a heavy car I would like some suggestions on camshaft specs
Thanks in advance

Call Jim at Racer Brown for a cam.


That is one damn fine car and cool as hell. I wouldn't change much.

Thanks!
Not going crazy with it.Just making it more fun to drive and better to run on today's gas. A modern update so to speak.
Today's cam modern cam grinds are much more efffiecent.
All parts ar bolt on so it can be reversed back to stock if need be but she is a keeper.

What a cool car.

Absolutely cool.
I have an 80 Volare wagon in the driveway that is the next project , but even that lacks the cool factor of the Satellite.
That's a Road Runner hood away from incredible.