318 questions...

-
D

DBrown

hold my beer...
Joined
Jul 5, 2006
Messages
72
Reaction score
0
Location
Bowling Green, KY
I am running a stock 318 from a 73 dart sport that was rebuilt at some point about 7 yrs ago. I am wanting to upgrade to the 360 4bbl cam. the motor seems to have plenty of pep and it is not smoking or giving any type of whorn out feel so I think I will be ok to run this motor for a while. my question is this: I am not sure if the stock valve springs can handle the 360 cam. has any one ran that setup?

I installed a stock 360 4bbl intake a few years ago, and was thinking to pull off the heads while I got it down and gasket match the heads and run a thinner head gasket. does any one got a part number or recommendation on a set of thin gaskets that will work well?

sorry if it was covered before but I searched and didn't see anything...
 
360 4 bbl cam
will need stronger springs.

do you have dual exhaust yet?

what rear gears?
 
yeah, I got dual exhaust and long tube hedders. I also have a 2.73:1 rear gear but plan to run a 3.5x:1. I am also running a 904 auto but plan to go manual in the future. I figured the 360 cam would be a good choice with using a dual plane 360 4bbl intake and the other upgrades I am using. I don't want to change my power band to much because I don't realy want to have to change the converter to match if I am going manual in the future.

I am not wanting to go too extreme on the budget and realy just want something decent untill I realy decide to build a motor. for now I think I can live with a mild budget 318 build.

can I just order a set of stock 360 springs or should I get a better set of springs?
 
It would be my opinion to ethier get a Comp Cams High Energy cam rated @ an advertised 260 duration or the Wxtreme cam that is very close, the duration being the XE256H. It's a split duration cam that should provided alittle more power with the longer exhaust duration on stock heads.

HI energy @ .050 is 212/ .454
The extreme is 212/218- .447/.455
Both cams on a 110 for a little thump sound.
Get the springs for it while your at it.
Better than a stock 360 cam.
 
ok, I did some totals and crossed your numbers and I think I found a cam set up to work:

dur. - 268/268
lift - .454/.454
lobe sep. - 110
dur. @.050 - 218/218
1,500-5,500 RPM

the cam comes in a kit that has everything...cam, lifters, springs, timing chain, and retainers for $299.95 I am pretty happy with that price.

these numbers are pretty close to what you had, do you think this will work good with what I am trying to do?
 
D with the gears you have now and the automatic it may be a little sluggish off the line but you did say you are going to switch to a 3.55 gear and 4 spd. so with that it sounds like it would work good at higher rpm's.

Just curious what brand cam are you looking at there? The reason I ask is if it isn't a Comp cams you can't really compare specs exactly unless you have ALL the specs. I ran into that with the cam I have in my Cuda. There are overlap, and rate of lift to consider also.

But to be honest I'd still look into the Extreme Rumble mentioned. Since your running on the street with full exhaust the extra duration it provides on the exhaust will help you with your stock heads. I think it would give you a little more torque that your little 318 can use.
 
That would work. Compare the price on a Extreme cam. Also look into the possible "Head work" needed (Possible is the key word) for the comp springs.
 
that is a comp cam's high energy kit. I priced it at summitracing.com. cca-k20-212-2

when you say that it will be slugish off the line, do you think I will need a new stall? I realy don't want to go that far...
 
Sluggish only by compare. It's not like a dead dog being kicked to get out of the hole. Just the intail. The cams rated to begin @ 1500 wheres stock is idle, 700. It is something your likely not going to be bothered by at all.
Should you feel a problem with it, a purchase of Rhoads lifters will absoultely fix it.
 
another question I had was should I be able to use stock push rods with this cam?

the kit doesn't supply them and I don't want to take this thing apart again...

also does any one have any opinion on the head gasket size? or what is the smallest gasket I can get away with to give me a little more compression?
 
Yes, you can re-use the pushrods. The thinnest head gasket you can use is the stock unit. If you need a tad more compression, mill the head.
 
man, thanks for all your help. I plan to order everything either today or wed. I took everything apart yesterday, so the cleaning and painting will probably get done on thrus or fri and hopefully I can get her back on the road by next week.

I talked to a friend that used to do some port work so I might clean up the casting bumps on the heads and match everything up while they are off this week. I will let y'all know how it all turns out!

thanks again everyone!
 
:thumbup: Leave the floor of the head alone.
 
???????????????????
Hate to sound like a Dick, but I know that. I have a good idea on how a head works and what works on head and where to apply them. I just made a mention on what not to do. Like a no brainer thing not to touch.
Now just don't label me a head port or genius or something. Any head questions I go to BJR.
He has a flow bench and tests heads, ports them for customers, and helps a bunch when your lost.
 
yeah ,I talked to my friend about where to clean up and we kind of agreed that the bottom of the head sould be left alone so I don't kill the compression of the motor. we did talk about removing the valves and cleaning off all the casting bumps and shifts then gasket matching everything in the intake and exhaust ports. he worked at Total Engine Air Flow here in Bowling Green. they did race heads for every walk of life so I trust his judgement when it comes to port work. I think that will give me some nice results for a case of beer...
 
Well I was only agreeing with you. That's all. And just adding that port matching and taking out the bumps will help too. If it came accross any other way I didn't mean it too. I didn't label you anything. I'm not that way.

Since you seem to get offended easily don't worry I won't quote you anymore.
 
Since you seem to get offended easily don't worry I won't quote you anymore.
Click to expand...
Sorry to come off as offended. I'm not. Hope your not. Quote me away if you wish. I promise I'll be quoting you. It beets saying "Yea, what he said" all the time. :thumbup:
 
well I pulled the heads apart...now I am kinda bummed. the exhaust valves are not looking to good. there is quite a bit of material missing around the bottom of where it rides on the guide. kind of like the metal was chipped away. I guess that is what they call burnt. so now hear is a question for y'all...can I just go buy some exhaust valves and throw them in or am I going to have to get them completely redone?
 
Bummer D. I've seen guys just install valves and run them but that's not a good way to do it. The seats really need to be ground for proper sealing. How many miles on the engine? Not to bum you out more but it's not really a good thing to do a top end job and install a bigger cam and not do anything with the rings if they have alot of miles on them. Puts alot of strain on them and they usually don't last long.
 
rumblefish360 said:
Sorry to come off as offended. I'm not. Hope your not. Quote me away if you wish. I promise I'll be quoting you. It beets saying "Yea, what he said" all the time. :thumbup:
Click to expand...

No problem Rumble. Sorry if I misunderstood you. Not offended here.:thumbup:
 
yeah, I have always heard that too. I am not 100% on milage, I know it was around 7 years ago and the cyclinder walls "look" clean. is there a way I can check for slop to see if I will be in good shape? or is there a way instead of doing a complete valve job I might be able to get away with just doing the work to the exhaust valves?

at this point I am just looking at options...
 
Fishys right. If the bottom end is in good shape, you probably skate on it. I have seen guys just do there top end over and it seems to be like, "Blowing the bottom end out" kind of thing.
 
I agree with fishy68, better look at the cylinder wall and see how much lip you've got at the top of the cylinder. If you've got much more than what you can catch with your finger nail, then you've got a good amount of wear. Also look at the lifter valley and see how much sludge has accumulated, that's a pretty good indication of how well the engine was taken care of. Good running used smallblocks are fairly easy to find if you want to go the cheap route. If your going to do a rebuild, you may as well go the 360 route. Just remember that a truck and car motor have different oil pans and exhaust manifolds. For the record, I have a stock bottomed 318 with ported stock valve heads, 268/480 cam, headers, intake, 600 Holley DP, 904 trans w/2800 stall & 3.90 gears in a '75 Dart Sport. The motor runs fine on 87 octane and seriously gets with the program.
 
well, I talked to several people about my problem and the common opinion is that where the valves are showing wear is not that big of a problem. the shop that is doing my head work said that as long as there is no damage where the valve rides on the guide and the part of the valve that seats on the head it should be ok as long as it is not to savier.

so I am going to clean them over the weekend and check them out before I get to upset. when I disassembled the heads, and when I did there was no play between the guide and the valve with out the spring and they slid out with a small amount of resistence but did not need to be cleaned up to get out or anything. everything looks seasoned on the inside but not to dirty. I spent all yesterday cleaning the rockers, timing chain cover and everything else that I could remove and get away with.

I ran my finger over the cycl. wall at the top and you can feel a small amount of a ridge but it wasen't enough to "catch" my finger nail on. like I said the walls look pretty good. I think I probably need to just pull the block and check everything in the bottom end for some cheap insurance, well that and so I can clean a bunch of grime and paint the engine bay...
 
You must log in or register to reply here.
-

Back
Top