What do you builders think these build specs will run like?

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72Dodge

72Dodge

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I picked up a very cheap but fresh 318 from someone I trust. But, not being an engine builder myself, I don't really know what to expect (other than what I was told) after I put the motor in the car. I don't have all the specs, but I have the below.

So, anyone who knows from experience what different parts put together will yield, how do you think this will perform in terms of power, streetability (revs), etc. Opinions are fine I suppose, but I'm looking for more like solid experience or any other tips. "Build a 340 or 360 instead" is not an answer... I have those motors too. This is a cheap 318 to put in a driver, and will be in an auto car (well, maybe).

Motor is pretty fresh.
1973 318 block, .030 over, crank .030 under
cast pistons
302 swirl port heads (stock as far as I know, but freshened up... it was one of the good years for these, don't remember offhand)
double roller timing chain
melling oil pump, new oil pump drive shaft
Mopar purple cam P4120231, 284 duration, 484 lift
compression is a little over 9, I can't remember exactly, but not much over 9.

Apparently there was a different cam put in this to begin with, and it fell on it's face. The builder called MP and told them how the rest was built and they said that choice was bad, but for this build, this cam would work well, and apparently, it did. Was a strong runner, from what I was told.

For an intake I was thinking either a Edelbrock Performer or a Weiland 8007 Action Plus. Any thoughts on that? Also, don't have a carb selected.

Goal is fun street car, nothing crazy (of course).

Thoughts? Suggestions? ... Thanks
 
A lot of cam for a 318.What gears,stick,automatic(what stall converter?)Nice combo,otherwise.Intake should match your cam choice.If you like rowdy,run that cam,add a air gap intake.
 
(On the power brake issue):

OK, see this is the sort of info I need, I would not have thought of that. First of all, I'm not sure at this point what car it's going in. It may go into my 72 Dart, and in that case, it would be a power brake car. Or, I may (likely) just leave that a /6 since it's so nice as is and drive it, and find another car for this motor.

Can you tell me the reasons it might not enough vacuum for power brakes? And is there anything I can do to rectify that?

Thank you!
 
Abodybomber said:
A lot of cam for a 318.What gears,stick,automatic(what stall converter?)Nice combo,otherwise.Intake should match your cam choice.If you like rowdy,run that cam,add a air gap intake.
Click to expand...

Yeah, it sounded like a lot of cam for the 318. The guy I got it from sounded like he was surprised that MP recommended so much, but said it worked. Again, this is someone I trust, but the actual builder wasn't available for me to get more specs from him.

No gears/trans yet selected, and no stall (that would be later once I get the whole combo settled). Would be for auto car if it goes into the 72, or if something else, i don't have a car yet, so who knows. Would prefer 4-speed!!! Oh, I do have a 8.75 with Sure Grip and 3:55, in theory I could use that with whatever car that goes in, but again, this isn't settled. I have a lot of parts with not enough cars to put them in LOL

Rowdy... that's what the guy I got it from said. Good to know, thanks. Air gap, will look into that. Thank you.
 
Big cams have overlap,it isn't streetable,to make power at 6000 rpm.It is a tradeoff.A smaller cam would pop on this setup.A Lunati Voodoo 60400 is a good choice,as is a Summitt k 6900 cam kit.
 
Abodybomber said:
Big cams have overlap,it isn't streetable,to make power at 6000 rpm.It is a tradeoff.A smaller cam would pop on this setup.A Lunati Voodoo 60400 is a good choice,as is a Summitt k 6900 cam kit.
Click to expand...

OK, so it's going to just give good power at high revs, but by sacrificing torque? Is that what you're saying? I'm not an engine builder, I'm pretty new to engines, but with that big of a cam, that was pretty much my guess. Looking into different cams is definitely an option. I could use this cam on a future 340/360 build, or not, whatever.

This is why I ask... pretty much just want to make the right choice of car/setup, since this isn't for any particular car. I have a habit of adopting motors for no good reason.
 
Bump up one cam grind if 3.55s,and 4 speed.Lunati 60401,or Summitt k6901 if on a budget.(I have the same problem,my weakness is small journal 327 Chevys)
 
Gotcha. Good to know. Thanks much. This gives me a great start to making good choices. Any one else with further thoughts by all means.

Thanks!
 
i'd stick with the cam you have, try it out see how it goes. you could always get a vacuum assist if your power brakes dont work so hot... but you will probably be fine. make sure you have all the vacuum ports on your new carb connected properly / capped. your carb will come with instructions / pictures so it's hard to get it wrong.
as far as intakes, get a decent dual plane (i think the ones you mentioned are both good choices) and it will be fine for the street. dont overdo the carb... 600 vac secondary / elec choke would be my guess as a good match.
9:1 is real good compression. this also means good suction in on the intake strokes haha. i'm pretty sure you will do ok.
 
It sound real nasty but won't have much torque under 4000 rpm with that cam and such low compression. It'll require at least 3.91 gears with a tire no taller than 27" and a pretty loose converter or 4 spd. or it'll just be a pig on take off. And as mentioned earlier there's no way it'll pull enough vacuum to run power brakes. Probably be lucky to pull anything over 5" of vacuum. Personally, that's one of the last cams I'd run with a small cube engine and low compression.
 
I hope the REAL compression ratio is over 9:1.....that's what I was worried about too. Cast flat-tops .060 in the hole? I hope not. It'll probably do all right though, in a light enough car with a little converter.
 
Putting all the thoughts together, it pretty much confirms my suspicion, that while it would be possible to drive this setup on the street with the right setup, it'd probably just make a lot of noise and suck a lot of gas. Unless I end up with the right setup for this car, I'll probably get a toned-down cam for it to turn it into a nice street cruiser 318, which is much more likely what I'd want. For a bruiser, I'd rather just go with one of my 340 or 360.

Thanks again for all your input.
 
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