I guess I just need any info on said truck. Its my soon-to-be step brothers and our parents want to drive it for the wedding. Its got a 318 that actually runs pretty good but it'll be towing a small camper in the future. He got a edelbreak street performer and a 600 cfm edelbreak carb and shorty headers. Am I going to need a cam with that too? This truck doesn't have to be a hot rod by anymeans! A good cruiser that can spin over a little smoke on the tires is really about all. Thanks folks!!

 

Okay it's a 318. Did I mention that its a 318? Well it is just a 318. Good glad we got that established.

Putting a large port 4 barrel intake made for a 340 or 360 on a 318 with small ports in the head really doesn't make it a racing machine. Nor does putting on headers.

Gort5th ave will no doubt list off all the modifications you can do or you can go read one of his many posts on it.

My advice put the stock manifolds and carb on it and just drive it around it will pull most campers since the rear end gears stock would be 3.55/3.54 depending on which rear end you have in it.

 

Appreciate that Jaclynn_s

it's true you can do a lot
i ran a performer rpm and surprisingly the manifold lines up with the intake
just the other day i was messing with it and a steel gasket perfect alignment.
are the fore mentioned parts installed on the truck?
Whats in it now 2bbl? how many miles?
a cam around 256 duration at the most just for towing if you want to use those parts but you seem uncertain so read all the posts then ask away some more.
jacklynn_s is right it will pull a camper now

 

Change the axle gears to 3.92 and a sure grip/limited slip, you'll lose a little in the top end but it will greatly help out with pulling that camper. That intake and headers are a perfect match as they both will build power from idle to 5500RPM. The carb is a good size too. I'd bolt all that on, run 2.5" single pipe exhaust with a Hooker Max Flow muffler. THrow a HD shift kit into the tranny as well. If you have a manual, get a Centerforce II clutch.

You can always throw in a tow/RV cam later on OR find a 360 to rebuild, throw a cam in and then swap over the intake, headers and carb onto it.

 

X-2
he will loose allot of top end... good towing gear though his 55 mph will be 3000 there about

 

Right now its bone stock. 2bbl carb, factory ignition, factory intake. The carb and intake is a decent choice? The cam I am looking at is High Energy™, 252H comp cam. I'd glady hear any more suggestions. Thanks for the fast response too!

 

Good cam choice and if you are gonna do the intake anyway.. why not do the chain and cam. I would, especially if you are going to tow.. Plus you will then have a rock solid motor and piece of mind.

All your selections are solid. Definitely add a header.

I would caution you to do a simple compression test to check her health. No since in adding HP if she needs a refresh.

 

Put a good set of duals on it, either a 2 1/2 or 3" forget the headers... This is a camper tow package you don't want the header drone that rattles the windows. A small intake and a Edelbrock 600 cfm carb with electric choke and your cam of choice Rear gears ?? What size tires are on it ? 3.54 are probably fine 3.92 would be fine also with a tall tire. OR go with a 518 overdrive trans There are so many things you can do, just depends on your budget

 

I've got just about the same combination in my truck and it works great. If you have a non overdrive trans with 1 to 1 final ratio do not go to 3.91 gears. thats what we ended up with and I'm changing to a 3.55, it always seems like your waiting for another gear after it shifts into 3rd.

 

I appreciate all the help! He doesn't have the camper yet so it'll just be a cruiser. Do yall know where I could get a set of classic looking tires but that are radial? One other thing would be the valve springs, keep the stock ones or throw in a new set?

 

Also, if anybody knows were I could get a new or used hood. There isn't much got rust free parts in frigid norther Minnesota.

 

cokertire.com , You also may want to put a transmission cooler on. How big of a camper are you talking??? I wouldn't go much over 3000# with a D100 unless the trailer has brakes on it. Its all good advise you have to sort it all out and decide what you want to do.

 

New Springs.

252H calls for 901 springs.

 

I used those springs with my XE256H cam. New retainers and locks, used thier tool to add positive locks and lower the guide a bit for lift clearance, worked great. My son did a bit of bowl blend and minor port match too. Stock 1.78" + 1.5" valves 302 heads idles smooth tons of grunt and far more top end than I expected.

Tools: http://www.compperformancegroupstore..._Code=VALVETLS

 

One of my buddies is a machinist and he took a look at a bunch for me and suggested the Lunati#638-10200701LK. Said it works with stock springs too. Has anybody used or know about how well the specs would work out?

I REEAALLLLLY don't like cuttin corners on things but I am not going to have a whole lot of time to work on this engine before the due date so if I don't have to tear into the heads that would really be a plus.

 

May have trouble fitting that .475" lift into a stock 318 head, check clearance between retainer and guide seal.

 

Lunati tech support says the cam will work but I just need springs... Ok, the part list is starting to come together! Now I just got to get the truck out of the snow bank and get to work!

 

I keep getting asked the same ?s so I will try to explain the basic principals of cam design & selection. The cam is basically the heart of the engine and controls the power. It is also 1 of the least understood parts of the engine.
There are 4 parameters in the design of cams - duration, lift , overlap, & centerline.
1] duration - this is the most important aspect of the cam as it determines what rpm the cam works at , this is the # of degrees that the valve stays open measured in crankshaft rotation. When selecting a cam this is the first thing to consider determine what you use the engine for & be honest or you will be disappointed with the performance !!
This works as a guide & the numbers are approx as centerline, porting, roller cams etc. will vary the results a bit.
Advertised @.050 RPM
240 - 250* 200 - 210* idle - 4500
250 - 260* 210 - 220* idle - 5000
260 - 270* 220 - 230* 1300 - 5400
270 - 280* 230 - 240* 1500 - 5700
280 - 290* 240 - 250* 2200 - 6000
290 - 300* 250 - 260* 2700 - 6200
300 - 310* 260 - 270* 3000 - 6500
310 - 320* 270 - 280* 3500 - 7000+
The peak Hp will be reached approx 500 rpm before the max rpm & the peak torque will be reached approx 1500 rpm before max rpm, the other secret to making power is to match all the other components such as intakes, headers ,head work converters to work at the same rpm so the whole package works together, you will be disappointed if you match an intake rated for 4500 rpm max with a cam that starts working at 3500 rpm!!
2] lift - this is how far the valve is lifted from the seat, lift does not affect the rpm the engine works at but the more the better at a given duration , Mopar cams use a wider lifter so the valve can lift faster than other makes. UltraDyne , Hughes & Mopar all have cams designed to take advantage of the wider lifters Also the Mopar heads stop flowing more air or the valve becomes invisible to the air flow around .550 lift without port work.
3] overlap - this is the amount of degrees both of the valves are open at the same time & this is done to use the velocity of the exiting exhaust to help pull in the new air/ fuel mix this effect works better with higher rpm which is why the overlap increases with bigger cams, but the increase also hurts idle quailty & causes the lope when the engine is running. Larger headers will also hurt this effect by decreasing the velocity & resulting vacuum.
4] centerline - this is the least understood aspect of cam design & to over simplify the higher the # of degrees the longer & flatter the power band becomes [eg 115*] & the lower the # the shorter & more peaked the power band becomes [eg 106*] for example a 115 cam may give you 300 hp from 3500 - 5500 rpm with a peak of 375 hp where a 106* cam would give you 275 hp from 3500 -5500 rpm & a peak of 395 hp [these figures are arbitrarily made up] I prefer the long flat power band , it works well with the long mopar rods & gives pull everywhere but if you have ideal gearing & 5 speeds in the trans to decrease the rpm drop between shifts the car should run faster with a lower centerline cam.
Generally choosing a smaller cam will hurt you less than choosing a cam that is bigger than you need.

If you have more ??s , ask!!


he main reason I stick with Lunati is Harold , he was the one of the first to take advantage of the wider Mopar lifter & increase the ramp speed accordingly although I am sure Mopar engineers understood the advantages in the 50s when they designed the V8 engines . Harold started UltraDyne & I could see the advantage of using UltraDyne cams years ago , but UltraDyne went out of business & I printed their online catalog before it was removed from the internet . Hes was hired by Lunati at the time he closed his own business , Ulradyne . Since then many have copied him with Mopar specific grinds having more lift at the same duration . Most Comp Cams designs for Mopar are copied from the small block Chev, you can find the exact same grind in both the Mopar & small block sections although they are starting to change , the SBC has a very short rod ratio & needs a totally different cam than the Mopar , it is just lazy to copy the SBC design for Mopar . Harold has created a whole new series of cams for Lunati for all makes of engines which is sold as VooDoo as well most of the UntraDyne profiles can be found in the Lunati catalog still . There is a section around pg 185 with various lobe profiles in Hyd & Solid lobes specifically for the 904 lifter Mopars & AMC

Further to this is the Chev is a short rod engine with a 1.45 rod ratio
Mopar is typically in the 1.7 - 1.8 range with much longer rods .
This changes a number of things , @ both TDC & BTC the piston moves much slower & actually stops for a longer period of time this does 2 things it allows more time for complete burn of the fuel & moves away slower allowing more time for the pressure to work on the piston which results in increased torque & decreased fuel consumption ! If you have driven an older GM pick up you are lucky to get 9 MPG while a 440 can get into the teens & sometimes into the 20s , the best I have done so far is 24 mpg in a 440 Challenger on the highway & 512 " strokers pushing high teens on the highway even with dynoed stupid power .
The downside to long rod engines is the intake , the piston moves away slower so the engine tends to pull less hard on incoming air flow . Ever notice that the 440 Port is only slightly larger than the Chev small block while the 454 , 455 , 460 even the 351 boss have Huge intake ports ? The trick is velocity , by using a smaller port the air speed in the port is higher so the air flow is kept moving even when the valve is closed building pressure behind the valve & creating a mild supercharging effect . conversely the short rod engines pull air better so having a bigger port with more air available makes sense .
Back to the cam choice do you really think a cam designed for a short rod engine is ideal in a long rod engine ?

 

Pretty good 318 thread here: https://moparforums.com/forums/f81/d...ust-yet-14437/



I'd slap in a 256h cam for some more low end grunt and call it a day. Head work would be real nice, but that can get pricey.

 

Ok, my step brother is back home and had a chance to talk to him more about what he really wants this truck to do. The gross weight is right around 2,000 lbs of the camper and just haulin odd and end stuff. As I said, he thought the truck ran pretty good already. He already has the intake, carb and headers. There won't be any head work as far as I know so I guess the real question is... Spend the money on a cam and the time throwin it in or just run the few aftermarket parts I already for a mild upgrade? I can always do more work later too...

 

Dont go to much over a 600cfm carb. I would put a mild cam & double roller timing chain set. Along with the other stuff you mentioned, And call it a day.

 

hey pal, 318s are one the best engines out there.you want to hop it up a bit?
get good cam, dual pattern cam would be great with a automatic or stick. Crane makes some great grinds,so does Lunati and Comp Cams,dont forget Isky Cams. stick in the neighborhood or 260 to 268 duration and dont go over .460 lift.also watch the centerlines you want something with 110-112 degree centerline. as far as a intake look for a old Edelbrock street master or a 340 Torker, a good dual plane intake is the LD340 or the factory cast iron 340 4 barrel intakes, bolt on a 600 cfm car, tune the carb to the motor dont just bolt it on and expect it to run. get yourself a good double roller timing chain while your changing the cam. Headers are great but a pain, you dont need anything exotic.some 2inch to 2-1/4 in exhuast and a pair of glass packs and youre all set. good luck

 

a small cam in the 250 - 262 good choose for a 318
as for intake the regular perfomer is awersome it matchs the ports
flows well. i would stick with a 500 carb headers do help i had 2/14
duels on my ole r/c now mopar has a 248 cam awersome tq cam
if ur running stock tires 3.55 are ok. if ur runnin an auto tranny find a
huge tranny cooler