Best 273 and 318 builds (NO 360's please)

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dartndodge said:
Mild 273 Build.
273 block 40 over TRW race pistons.
std 273 forged crank 3.31"
Mild Port 340 X heads 2.02x1.60 valve notch in block.
MP 292 x .508" Hydraulic cam pkg.
750 Holley on Strip Dominator single plane.
Headers.
904 trans w 4000 converter.
5.14 gear 8 3/4.
Centerlines and slicks.
All in a std 67 Dart GT, using the original 273 engine.

Performance????
10.80's @ 114mph!!!!!!!!!!! NO nos, blower, turbo, methanol or anything, just Mopower.

Ha ha, all the older members will recognise this build from the "Dart Attack" article about this 10 second Dart GT , back from the early 90s in MA. (Magazine)
"I owe you a 10 second car" ...see that ol 67 Dart over there.....:)

Yes this is a real build, I hope the car is still out there somewhere. Was owned by a Mopar family that had Dusters, Hemi Challengers etc etc.
Click to expand...

:pottytra:


Sorry, the 'mild 273 build' part got me..
 
LOL, while not exactly a mild engine, it is built of parts mostly off the shelf and obtainable.
 
I know this is an older thread but I couldn't resist. We have a 318ci in a 69 Dart (3300 lbs) running a mild tune doing 10.50's @129. 12 psi of boost, 8.1 comp and 575 Demon. No need for big cubes or big tires! Later
Ryan

[ame="http://www.youtube.com/watch?v=qBfcq93Mgl4"]YouTube - 1969 Turbo Dodge Dart 318ci 10.61 @129.34[/ame]
 
Wow thanks for all the input. My little 318 is just waiting to be redone.
Anyone know what the cheapest reliable 350 horse combo would be.

I plan on doing it myself. No expirence so I do not want to get to fancy on this one.
 

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rapidtransit340 said:
Wow thanks for all the input. My little 318 is just waiting to be redone.
Anyone know what the cheapest reliable 350 horse combo would be.

I plan on doing it myself. No expirence so I do not want to get to fancy on this one.
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Try a 9.5-1 max compresion engine with 360 heads (Or bowl ported 318 heads. Your looking for about 220 cfm intake flow and approx. 70% of that for the exhaust flow.) and a Comp Cams XE268H or 340 cam, headers with a free flowing exhaust @ 2-1/2 inchs and a H pipe. RPM intake and a 750 carb.

This should be worth 350 HP (5500) and about 380 lbs of torque. (4000)
 
Also I will need new pistons
should I use flat top or domed?

Wont know really what I can use till I rip the engine apart.
Thanks again
 
1967 273. Steel crank,wiseco 10.5 to 1 pistons.MP .484 hyd cam.MP rocker assembly,and pushrods.Double roller timing chain.Rhodes lifters. LD 340 intake.1.88 j heads. 600 holley carb.Headers.I did not build this engine but it runs really strong and revs like a son of a gun. It is in a dodge colt,and it pulls the wheels.I expect solid 12 if not better in the 1/4 mile.
 
rapidtransit340 said:
Also I will need new pistons
should I use flat top or domed?

Wont know really what I can use till I rip the engine apart.
Thanks again
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Depends on the head used, so once you know what your going to use, a 318 ported or a 360 head touched up, you can go from there. The reason being is the head cc amount will drop the ratio alot with the 360 head.

From a 318 head to a 360 head, the drop can be this much.
9.90 down to 9.12. (.78)
Or the reverse going back to a 318 head from a 360 head.
So if the 318/360 head combo was built at 9.5-1 to start with, then you go back to a 318 head, it would go to 10.28 -1

With the above cam(s) recomended, pump gas could be an issue. Because the cam is small and may not bleed off enuff compresion down low...thus pinging will arrive.

Also, a domed piston designed for a 360 head will not fit into a 318 head with it's smaller chambers.
 
This is my current set-up:
72 318 Block .30 over
79 318 Heads, not sure of the casting number think they are 72 cc chambers
1.88/1.60 valves
purple cam 276/284 .444/.453" 112 degree
LD4B Edelbrock intake
650 Edelbrock carb
windage tray
double row timing chain
Mopar Electronic ignition with and orange ECU box
Dakota Manifolds

it is a 200 hp 275 ft lbs torque motor.

I will pull it and rebuild it next year, zero deck the block etc.
KB167 pistons
Eagle rods
302 castings heads, if I can find them.
May mill my heads to reduce the cc's , not much just enough.
Just want at the least 300 hp, in a 2600lbs car that will be enough fun for me and the car will still be driveable as we take it out of town alot....
 
A few years back worked on a 65 valiant w/ a barracuda front end swap on...I believe it used to belong to a duo called the "barker boys" or "brothers" or something or another. Had 4 speed manual w/ 3.23 8 3/4 rear.

The owner had been running low 15's @ 88-89 mph with an engine of then fairly unknown details.

Brought it into my home garage to help the owner swap in 302 swirl port heads/cam/and a set of spitfire headers.

Once we got the heads off, it was obvious that the closed chamber swirl ports wouldn't work...since the short block had 11.5:1 doomed pistons in it....and the cam was roughly a similar size to what we were swapping in when we checked with a micrometer...roughly a cam similar to a 340 auto cam.

SO, came up with a plan B:

Ported 360 heads retaining the 1.88 valve arrangement.
MP 284 camshaft (284 degrees duration, ~ 243 @ .050, .484 lift, 108 lsa)
swapped the old school torker single plane intake for a eddy rpm.
Spitfire headers (there were minor issues w/ the z-bar...but nothing unsurmountable)
650 cfm double pumper carb.
recurved the ignition so that pretty much all timing was in by 2200rpm, initial 18 btdc, total 38btdc...swapped the orange box to a silver.

This really woke the car up...to the tune of 13.3's/13.4's @ 104mph! A very healthy improvement.

What was holding the combo back were obviously the stockish 318 heads that had been on there. However, changing pretty much all the breathing components, and having the advantage of stout compression really let us push the engine a bit. Car ran great on the street and at the strip.

Never could persuade the owner to make the next mod, which was to go with steeper gears b/w 3.90's to 4.30's....with something like that, he'd have had a 12 second beast of a stock cubed 318.

Still, had issues w/ clutches due to the small size...even went to a custom clutch with little avail.
 
63dartman said:
BaDart no cussing in this thread. You said the "360" word twice in your previous post:-D You might be getting a nasty gram from the mods soon.
Really though I am happy to see this thread. Not everyone wants to or has the option to just build a______(fill in the blank). Some have to get the most out of what they have. I like to see people that do good with very little. It promotes innovation and ideas for everyone. I wish I knew more about squeezing performance out of a 273 or 318 or any engine for that. My 318 builds have never met my expectations but, I really haven't put in the effort to learn and understand what it really takes. I'm kinda like the guy that wants the super duper killer engine by just using more cubic inches and relying on hear say for my builds. Don't get me wrong I have learned more from this site than anywhere else:cheers: I'm in the process of building another and this thread has opened my eyes to start digging deeper to understand what it really takes to build a really reliable performance engine. Good luck finding the info you need and I look forward to reading this thread.
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I thought you were referring to that 5 letter word.....chevy
 
Great thread full of info i've been looking for... rebuilding my 318 in my demon this summer and have been looking for performance info
 
hey new here. here is my 318 build
71'318 block bored .030
older forged 318 crank 10/10
KB167 pistons .003 in the hole
318 reszed floating rods
fully ported 302 heads with 1.88/1.60 valves w/61cc chambers
lunati 230@50 .480@50 BM2 cam
weild action plus dual plane intake
650VS holley
comp push rods
mopar 509 springs with damper
9.73to1 comp
i did not really want that cam but i got a 318 that was built and never ran cause it somehow got water in cylinder and frose and busted it. it had the whole rotating assmy cam,intake headers and ARP bolts top to bottom in it and got it for 180 bucks. never even turned over,cam still had assmy grease all over it.

i had a fresh block that been machined and a set of 302 heads i ported to put on it so i figured i could not go wrong. but i might change the cam later
so what do yall think about it?
 
I'm the original poster for this thread. It's been a while since I've checked in on this post, and I'm thrilled to see how much it's taken off! There really have been a lot of good postings. I do feel like I need to clear the air as to the postings original intent though. I've seen a lot of people arguing over the "RULES" of the thread. So hopefully I can put some of the argument to rest. The only real rules for the post were 273 or 318 block, and no dogging anyone for their choice of a 273 or 318. The goal was to create a safe place for people to ask about 273 or 318 builds without being attacked with the usual "just ditch it and start with a 360!" line.
Some people just want to build up a 273 or 318 period. I personally have always admired the 273 since my older brother took me to a Mopar only drag race when I was 16 and I saw a WILD Valient with 18" numbers down the side reading "273CI" running 11's and beating car after car.
With that said, this really has turned out to be an awsome post. Keep up the good work!
 
I forgot to mention that I do have some personal experience with modded 318's. Before my duster got it's 360, I ran a 318 with a m/p cam, gear drive, eddy manifold, holley 600, and a set of 302's milled and fitted with 2.02/1.60 valves. It was a blast! (until it blew up!) It was so much fun that it made me rethink 318's.
 
'71 318:grin: block, Scat cast 4" STROKER crank and I-beams, Icon 846 forged flat tops with total seal rings.
Custom 252 degrees@ .050" hydraulic roller with Hughes lifters.
Will use ported RHS/Indy heads with 67cc chambers for 10.9:1 compression.
Custom 1000HP carb on Performer RPM intake.
ATI Super Damper, Charlie's Oilpan and CSR Electric Water pump.


Heres a link to get you here cheaply; http://www.google.com/aclk?sa=l&ai=...8&cl=ie&p=go&cid=yes&nm=3&clkt=156&nx=89&ny=6
 
Sweet!!! I can't wait to hear what the final numbers are!
Did you have to notch the cylinders to avoid valve shrouding?
 
jeremiah2146fa said:
Sweet!!! I can't wait to hear what the final numbers are!
Did you have to notch the cylinders to avoid valve shrouding?
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Actually, could probably get away with skipping notching but as I'm not exactly short on static compression I'm doing it anyway. If I pick up a few numbers at peak lift then its worth the little effort.
 
jeremiah2146fa said:
So have you already had the machining done, or are you still in the parts gathering phase?
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A bit of both...Block is away being machined at the moment. Ordered the cam and lifters a couple of days ago. I have everything else to complete the short block, except a few sundry items (gaskets and cam/main bearings). Rotating assembly has been balanced and the damper is due tomorrow. I need to have the lifters to check for link bar clearance before I piece it together though.
 
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