Any 318 Performance tips?

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68383GTS

68383GTS

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Pulling the slant and installing my 318.Is there any cheap performance things I can do to the 318 before I drop it in.I can not afford different pistons or heads right now... Here is what I have a rebuilt 1974 318 with 10,000 miles on it.Stock rebuild with Lunati 284/484 cam, double roller timing chain,weiand intake,650 Holley, Doug's headers,2 1/2 Summit exhaust.Oh and a 4 speed tranny.
Here is what I plan on buying....Summit Racing ready to run distibitor,summit 40,000 v coil,Taylor 8 mm wires,Mopar Performance fuel pump,.028 head gaskets,355 suregrip 8 3/4.I was thinking while I had the heads off I could polish the chambers and ports,but I may be wasting my time since the heads are small valve open chamber heads.

I had two dart sports with stock 318's with 4 bbls ,manifolds and dual exhaust and they ran pretty good.So the Duster should run a little better. I have had nothing but big blocks the last 15 years so I am a little rusty on smallblocks...LOL Thanks,Jim
 
Summit 6900 cam kit and good timing set. Make sure you degree it.
 
Why not try it with the cam that's in it first... then you can compare (I'm assuming this is an engine you haven't run yourself before?). You can always swap it out later. That's almost exactly like my 318 build except I have the 302 closed chamber heads and it was running somewhere in the 13's in an Apsen (I don't recall exactly where). Maybe pick up a cheap set of those. Good luck, can't wait to see/hear it when it's done!
 
The heads are the only thing left to do as far as big parts go. I see no waste of time polishing and/or porting them. IF you had the cash, I'd do a nice new set of valves, 2.02's. Use your heads, skip the 302's.

I feel your cam is a little big for the combo's low compression. Do you know what the exact ratio is? Otherwise, you look good to go.
 
My buddy built the motor and said it had the smallest lunati cam so it may be a little smaller than 284/484.No he told me it had stock pistons so I am guessing 8.5-1 or 8-1. I am going to pull the heads off though and take a look.
 
I agree some bigger valves in those heads may be better, but I suggested 302's mostly because he mentioned cheap, if he could find some real cheap, plus should bring compression up a bit. Not disagreeing with either of the above 2 comments, just another way of looking at it, and potentially an even cheaper move.
 
68383GTS said:
Ok I think it may be more like this cam 256/262 454/475
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If it's this one or something similar, your good to go. As far as a minor cleanup of the heads, if you have time, it certainly wont hurt, but I'm not sure how much difference you'll feel on the street. A good valve job would be just as important from a performance standpoint in my opinion.
 
OldmanRick said:
If it's this one or something similar, your good to go. As far as a minor cleanup of the heads, if you have time, it certainly wont hurt, but I'm not sure how much difference you'll feel on the street. A good valve job would be just as important from a performance standpoint in my opinion.
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That's a nice cam for that combo.A good valve job,will live longer on the street ,long term. That "good valve job,bowl blend " will hit 5-600 bucks,with the existing parts.,upwards if worn . Feel the same tomorrow ,yes. See & feel the same 3 years later,not likely.
 
72Dodge said:
I agree some bigger valves in those heads may be better, but I suggested 302's mostly because he mentioned cheap, if he could find some real cheap, plus should bring compression up a bit. Not disagreeing with either of the above 2 comments, just another way of looking at it, and potentially an even cheaper move.
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In his first post, he states very clearly, no money for Pistons or heads.
The best option at this point is to simply reuse the stock heads well preped. Home polishing of the chamber and exhaust port is what he can do inexpensively.
A well don't valve seat multi angle job should be done.

I only wish I could provide the seat cut angles.
 
rumblefish360 said:
In his first post, he states very clearly, no money for Pistons or heads.
The best option at this point is to simply reuse the stock heads well preped. Home polishing of the chamber and exhaust port is what he can do inexpensively.
A well don't valve seat multi angle job should be done.

I only wish I could provide the seat cut angles.
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I read the first post. I'm focusing in on the "no money" part. A pair of 302 heads could probably be had for about $50, bolt them on and go. This would almost positively be cheaper than the head work you're suggesting (even if he had to pay more for the 302s, and if I'm understanding what you're saying correctly), which is more in the spirit of "no money for pistons or heads" than spending more money on the heads he has. I know there's a lot of varying opinions about 302 heads just like there is on a lot of things, but there's also a lot of people who say certain things won't work, when in fact they do.

I'm NOT saying that what I am saying is the only way to go or that what you are saying is invalid, but what I am saying does have merit from a different perspective, which I'm offering. Rumble, I always respect what you say and your advise, but I guess there isn't room for any other perspectives or experiences, so I will bow out from offering further input here.

Carry on.
 
The heads have all new valves and springs.So I was just thinking about polishing them up some.Later on I will find big valve heads or have bigger valves put in my heads.
 
rumblefish360 said:
In his first post, he states very clearly, no money for Pistons or heads.The best option at this point is to simply reuse the stock heads well preped. Home polishing of the chamber and exhaust port is what he can do inexpensively. A well don't valve seat multi angle job should be done.I only wish I could provide the seat cut angles.
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15 degree top cut, 45 degree seat, 70 degree bottom cut.
 
68383GTS said:
The heads have all new valves and springs.So I was just thinking about polishing them up some.Later on I will find big valve heads or have bigger valves put in my heads.
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I would not even pull the heads. If it is all sealed up, just put it in and run it. It sounds like a pretty good combination to me.
 
jerry6 said:
just run it for now , might surprise you
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x3. Run it as is for a while. Save up some money, pick up another set of heads to work on, then just swap them out after you have them worked the way you want.
 
When you say "smallest Lunati cam" you need to realize, Lunati has several lines of cams. The smallest one of them all is probably smaller than a stock 318 cam, so it would really help if you could nail it down. Do you mean the VooDoo cams?

For instance, this is their smallest in the High Efficiency line:

http://www.lunatipower.com/Product.aspx?id=2965&gid=258

Here is the smallest Voodoo:

http://www.lunatipower.com/Product.aspx?id=2340&gid=287

It would help us greatly to help you if you can narrow it down.
 
Don't be afraid of a bit of cam. I did the 280 dur cam in my 318 with stock 72 low CR pistons and it was a bit sluggish out of the gate, but guess what, so is a 250 dur cam.

Go big and enjoy that long cam pull winding out on the top end.
Way more fun that a slight bump in low end feel for the first 60 feet.
 
If I were you, I'd add the Magnum timing chain tensioner, degree the cam and run it. While there you could pull the part number off the cam and verify what you have and change if you feel necessary.
 
And be sure you check the spring pressure and have the valves reseated if you can afford it and other simple add ons such as good ignition system and air induction even as simple as a K & N filter will help.
 
68383GTS said:
The heads have all new valves and springs.So I was just thinking about polishing them up some.Later on I will find big valve heads or have bigger valves put in my heads.
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When I had the heads off my 318 to heli-coil stripped exhaust holes, I just could not bring myself to put them back on without doing something. So I did a little pocket porting. And I mean a little. About 1-1/2 hrs total with a Dremel and stones. I just imagined myself being an air molecule rushing through the ports and smoothed things I would bump into. Also replaced the valve seals as some were in bad shape.
Two weeks after, I ran it at Norwalk and ran .5 second faster than my previous best.
CHEAP and dirty.

318+.020, Weiand, Carter AFB, unknown cam, 3.23 SG, 904, street tires, 14.77 seconds.
 
Decided against the 383 eh?
I would just stick the 318 in as is with the parts you have and run it.
If you start opening up the engine to change the cam and do some mild porting, then it usually snowballs into springs, valve seals, shaving the heads for more compression, etc. etc.
Save all of the money you will spend and do it all at once down the road with some better heads, bigger valves, etc.
That's what i would do, i made the same mistake several times.
 
I believe it is a Vodoo cam.I will have to ask my buddy who built the motor.OK I am going to just leave the heads on and change them out later down the road.My buddy who built italso said just drop it in also.
 
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