1987 318 rebuild [Archive] - DodgeTalk : Dodge Car Forums, Dodge Truck Forums and Ram Forums

: 1987 318 rebuild


chessman21
12-20-2009, 10:50 PM
My old engine has 300k on it. I would like to replace the cam with a better high lift cam while i have it apart. I was looking at the "12-242-2 - Comp Cams 'Xtreme Energy' Hydraulic Flat Tappet" and was wondering if it would work with my stock push rods and rockers?

bikerlarry50
12-24-2009, 10:05 AM
Talk With The Cam Manufacturers Reps On Thier Help Line, They Will Point You In The Right Direction

Speed Dragon
12-24-2009, 08:07 PM
Talk to Hughes Engines, they make real Mopar grinds.

chessman21
12-27-2009, 04:53 PM
Ok, Iv got my engine apart for the exception of the crank shaft. My plan is to re-hone the bores and re-ring the factory pistons Swop the heads to a set of 4323302"s. I also will will be installing the cl-xe268h comp-cam along with the Edelbrock 2176 proformer intake, hooker headers and a Edelbrock 1405 carb 600. Does this sound like a good combination?

1987 d-150
cast on the engine is 4104230-318-5 5/3/79 (ar127902 on id plate.)

Speed Dragon
12-27-2009, 10:15 PM
Should all work good together, you'll have to swap out the valve springs for that cam though. IIRC the stock 318 springs bind up around .450 lift. You need to get some spring that are good up to .500 lift, that will give you plenty of clearance for that cam's lift. If you don't, you'll bend your pushrods first start.

chessman21
12-27-2009, 11:30 PM
":318 springs bind up around .450 lift." ....bind up,, u mean the stock springs wont compress far enough? Anyguess on about how much hp/tq this combo will make?

Speed Dragon
12-28-2009, 02:03 PM
":318 springs bind up around .450 lift." ....bind up,, u mean the stock springs wont compress far enough?

Correct. It'll probably make around 230-250hp.

chessman21
12-29-2009, 10:13 PM
Thxs for the info,, I would,nt have figured that out till it was to late:cool:

What "could" I do to get 250-275 hp? Bigger valves in the heads, or maybe bore the block 30 over?

And what type/brand of rings are best to use on the stock pistons?

bikerlarry50
12-29-2009, 10:34 PM
if you bore it out, you'll have to go to custom pistons, maybe mill the heads & raise the compression ratio. recomend you contact hughs engines & discuss your plans. they will point you in the right direction, peace, larry

Speed Dragon
12-31-2009, 01:55 AM
Thxs for the info,, I would,nt have figured that out till it was to late:cool:

What "could" I do to get 250-275 hp? Bigger valves in the heads, or maybe bore the block 30 over?

And what type/brand of rings are best to use on the stock pistons?

Don't bore it any more than necessary, it doesn't add much power. Just enough to clean up the bores is what you want.

For 250+ hp, I'd probably do something like this:

Keith Black 9.5:1 pistons http://chucker54.stores.yahoo.net/3185ctop6495.html

Hughes camshaft (w/ matching springs) http://www.hughesengines.com/Index/products.php?browse=category&level0=U21hbGwgQmxvY2snTEEnIDI3MywzMTgsMzQwIGFuZCA zNjAgZW5naW5lcw==&level1=Q2Ftc2hhZnQ=&partid=21848

Crosswind intake http://www.spiderautomotive.com/powerplus55026.html

Edelbrock or Holley carb

Port match the intake to the head

Mildly port the head, debur and polish the chambers, install 360 valves (1.88 int/1.60 exh, as opposed to the stock 318 1.78/1.50)

Hedman or Hooker headers

chessman21
01-03-2010, 11:02 PM
Thank you for this info. I dont plan to bore but to hone only for new rings. The cylinders look to be in perfect condition, the truck didn't ever smoke but i figured with 300k+ on the rings they should be replaced...I dont know one piston type from another but I have "flat" top pistions, the "Keith Black 9.5:1 pistons" are "not" flat in the "picture" on the link, what is the indention on the combustion surface and wouldn't that add volume and lower compression? or is that just a random picture?

Another thing that concerns me with this project is the valve spring bind issue im gonna have after replacing the camshaft. Will ill need to decrees/incress rocker ratio from what i believe to be 1.5? the push rods in the engine im rebuilding are 7.5" x 0.360" with a Push Rod Guide Hole Diameter of 0.50 inches
... the pushrods out of the pre magnum rollor engine that I got the swirl port 302 heads are 6.78" x 0.3125" with a Push Rod Guide Hole Diameter of 0.66 inches.
Hows this gonna work will i need special length rods? or will the stock none roller 7.5" rods work? And if so what about the Push Rod Guide Hole Diameter difference?

B-300
01-04-2010, 11:20 PM
"Flat-top" means not dome or recessed pistons, the majority of the top is flat with valve reliefs when needed.
7.5" is the correct length pushrods for a flat lifter cam. The shorter 6.78" pushrods are for the roller cam engine which uses taller roller lifters and both use 1.5 ratio shaft rockers.
The larger pushrod holes in the 302 heads are used to clear the different angle of the pushrods do to the taller roller lifters.

Speed Dragon
01-05-2010, 12:02 PM
If you're not going to change the valve springs, don't get that cam, get one w/ less lift. Any kind of rigamarole you do to try and make it work, is not going to work well. The springs must be able to handle the cam lift w/ at least .030 of spare travel to be any kind of safe. The general rule of thumb is .050 to spare IIRC.

If you're going to buy a big cam and then reduce it's lift, what's the point of get a big cam? You'll just end up w/ a low lift high duration cam, not a good combo. The springs aren't that much more money. Usually they sell a cam kit anyway, w/ matched lifters and springs. You are planning on using new lifters also, right?

The indents in the piston are valve reliefs for higher lift cams. Yes your pistons are flat tops, they are also down in the hole about .120. The KB pistons sit nearly level w/ the block deck.

chessman21
01-05-2010, 06:00 PM
Lifters,, no, i wasnt gonna change them but buy the way you put that I think will:D. Ok so, Im gonna need new springs. About the pistons, The KB pistons sit nearly level w/ the block deck. I will assume this creates more compression? I dont want have to use high octane, mid grade is what Id like to beable to run.

Speed Dragon
01-05-2010, 06:58 PM
Lifters,, no, i wasnt gonna change them but buy the way you put that I think will:D. Ok so, Im gonna need new springs. About the pistons, The KB pistons sit nearly level w/ the block deck. I will assume this creates more compression? I dont want have to use high octane, mid grade is what Id like to be able to run.

Good man :) Yeah lifters normally wear to fit their original cam. I have never really tried it, but they say old lifters don't work right w/ a new cam. New lifters on an old cam works, but not a new cam on old lifters. Something about the wear pattern on the bottom of the lifter. You could maybe get away w/ it (I have re-used lifters on different cam when the lifters had less than 10k miles on them, no visible wear pattern), but it's one of those thing that I just don't really want to take a chance on. It would be a shame to go through all the work of building the engine, just to have it tick due to some old failing lifters and have to rip the intake, valve covers, rockers etc back off to swap the lifters.

You may want to call KB and verify, but those pistons should give you a 9.5 comp ratio, even w/ the 302 heads. IIRC the chamber cc is about the same as the old 318 heads, just a different shape. However, IIRC the facory compression ratio on a 318 TBI is somewhere around 9.0-9.5:1, so using your stock pistons should be fine.

Lol I've posted about the comp ratio several times, and I can't for the life of me find it now :o I have used allpar as a source for info, but going through their site I've found a few discrepancies and incorrect specs, so I'm not really sure about some of the specs found on there anymore. Lot of their info just seems to be copied and pasted from other sites w/o double-checking it for errors. And 88-91 LA V8 specs seem to be scarce as hen's teeth :) One day soon I hope to have my own site up where I can post verified specs and info.

B-300
01-06-2010, 01:32 AM
New cam must have new lifters. It will wear out quick without.
Cams have a slight tapper and lifters have a crown on them (they will rock when put face to face) this turns the lifter as the lobe contacts it and rolls oil on the point of contact. As these wear the lifters become flat or even concave and the cam taper becomes flat and then the lobe wears rapidly.
Also check to be sure the spring retainers clear the guides at full lift with room for the stem seals and then some. (0.050")

vaquerorngr
01-10-2010, 04:09 PM
I would also just go with a hughes cam. They are more taylored for mopar engines then comps. Comp basically designes their grinds for chevys and then adapts them to mopar. Hughes designs their grinds specifically for mopars to capitalize on their bigger diameter lifters then gm and fords. If you go on hughes engines web site they have some good tech articles on cams and how to pick the right one for your combo.

chessman21
01-12-2010, 08:56 PM
hughes cam...,, thanks for this info vaquerorngr. Thats makes allot of since.

vaquerorngr
01-12-2010, 09:11 PM
yeah hughes makes best cams for mopars. basically in a cam for a heavier 4x you want a cam that's not to high in duration at .050. That way you keep your usable power in the lower rpm range. But you still want a higher lift. Mopars are the best at this because they have a bigger lifter diameter so the lobe doesn't fall off the end of the lifter. To get the same thing chevys and fords have to run rollers. But you have to go with someone who builds cams specifically for mopars. Speedragon is right though you are going to have to change your springs and your springs need to match your cam for the right cylinder pressure.

chessman21
01-12-2010, 09:31 PM
Ok iv looked at the hughes cams and ran across some youtube videos of the "whiplash cam" in a 340 engine.. It sounds great, but i don't see that cam with those specs for the 318 la,, Which one from the 273-360 page would have that good choppy sound with good low to mid power,,?

vaquerorngr
01-12-2010, 10:34 PM
If you want some rump in you idle I would go with this cam

HUG HEH2328AL

If it were me though my first choice would be this one

HUG HEH1019AL

this one would give you more low end torque for 4 wheeling or towing.