Last ditch effort for used 318

-
http://www.summitracing.com/parts/dcc-4452761ae/overview/

This one? I'm with others double checking the cam timing right where it is, and adjusting from there. It looks like it's spec'd out for 1500-5800, so in straight up form, it should be close to what you'd need to see.

Another thing is distributor springs, I'm telling ya man, please grab a HEI advance curve spring kit from the parts store and start playing with lighter springs in the dizzy.. Like the lightest and second lightest... It's like taking 50lb sacks of flour out of the trunk when you get it right.

s-l1000.jpg
 
The advice still stands for the vacuum advance tuning... It will help you with torque off the line AND fuel economy! Ported vs manifold is up to whatever gives you better results.
 
Looks like it.

I just dont want to tear down, advance the cam 4 degrees and find out it doesnt
improve lowend performance much......



Thanks
 
^I don't want to see that either, that's a hard days worth of work on a gamble..

My thoughts are play with the timing, dizzy springs, and once you get that sorted to where it pulls the hardest, add in the vacuum advance and shoot for 8-12 over total timing..

THEN:


I hate to say it, but since your using a Holley, if it has a lean power valve channel restrictor, and/or secondaries, that's running say 14:1 and you run best at 12.5:1, then your giving up 20ft/hp or more...

An educated guess is, the idle feed restrictors/emulsion that run the RPM range from idle to 2300rpm are too fat, like they ALWAYS are in these aftermarket jobs in anything other than a HI-PO big block, your going to see slow down...


You can literally take the main jets out of a Holley and run around on the idle circuit to see what I'm taking about. The mains have no effect until around 22-2500..

Why I also recommend that AFR gauge... And reading this:

http://www.burtonmachine.com/tech

http://ls1tech.com/forums/carburete...t-level-holley-tuning-serious-ocd-tuners.html
 
RAMM said:
See thread here. http://www.forabodiesonly.com/mopar/showthread.php?p=1971138123&posted=1#post1971138123

318's from the smog era are torqueless which equals funless. J.Rob
Click to expand...

Your last post says it all J.Rob. A 268/454 cam can be too much in a low compression 318. It doesn't sound like a very big cam by the specs but small cubes and low compression and you have a low end pooch. I'll bet it sounds good at idle but like you said, it won't get out of its way until 3-4000 r's.
 
The cam may be rated for 1500-5800 but in a 318 got to add at least 300 rpm to those numbers but your running pretty large headers. After its tuned right up your engine still needs CR, heads, stall and gears to make all that work.
 
mycuda said:
I just dont want to tear down, advance the cam 4 degrees and find out it doesnt improve lowend performance much......
Thanks
Click to expand...
4 degrees advance will make it better for sure; I just can't calibrate it to your expectations. But I do know that 4-5 degrees in a low compression /6 makes that engine VERY noticeably doggie. Putting a new chain in for a worn one in a slant 6 and getting that 4-5 degrees back is a REALLY rewarding experience.... makes it feel new: much improved off the line and much snappier partial throttle response in low and mid RPM's.

What you don't know is if and by how much it may be retarded right now. If perchance, it is 2 degrees retarded and you go to 4 degrees advanced....then you will really feel it.... and IMO it needs to be done anyway with the low CR.

You don't need to take the timing cover off BTW to check the cam timing BTW. The prior check with just valve lift at overlap looks retarded. (If I understand what you were measuring.)
 
I've run a 268 duration cam in a 318 with stock pistons, and had all kinds of bottom end power. That cam is not too big for a 318. I used the thin Mopar composition head gasket, so I got maybe a half point compression increase. Did you run a compression check on all cylinders to verify their all within 10%? Either you cam is not properly advanced, you're ignition curve is lazy, or you have a weak cylinder(s). I always degree the cam when installing. I've seen timing chains and cams excessively retarded right out of the box. Valve spring problems are not going to show as low bottom end torque, the motor will breakup on the high end. I suggest you post compression test results (cold motor). If that works out, you need to buy an adjustable timing and figure out your timing curve, not just initial advance.
 
Loved my Crane split pattern cam. 272/284 (218/228 or something like that @.050), .454/.480 on a 112. Low compression '79 - 318 did well.
 
middleagecrisis said:
I've run a 268 duration cam in a 318 with stock pistons, and had all kinds of bottom end power. That cam is not too big for a 318. I used the thin Mopar composition head gasket, so I got maybe a half point compression increase. Did you run a compression check on all cylinders to verify their all within 10%? Either you cam is not properly advanced, you're ignition curve is lazy, or you have a weak cylinder(s). I always degree the cam when installing. I've seen timing chains and cams excessively retarded right out of the box. Valve spring problems are not going to show as low bottom end torque, the motor will breakup on the high end. I suggest you post compression test results (cold motor). If that works out, you need to buy an adjustable timing and figure out your timing curve, not just initial advance.
Click to expand...


Not all 268 cams are equal. Look at the stock 340 cam vs Comps xe268h world's apart even Comps xe250h is slightly hotter than a 340 cam.

I don't think its one thing or one major thing but a few little losses that add up headers, CR, gears, cam and maybe even expectations.
 
middleagecrisis said:
I've run a 268 duration cam in a 318 with stock pistons, and had all kinds of bottom end power. That cam is not too big for a 318.


Agreed. I've even installed the 280/.474 MP cam with home ported 360 heads in my brothers stock block 318 Dodge Demon with 2.76 gears/904 stock stall and layed some decent rubber on the pavement by just punching it from a dead stand still.

You have something else going on ....... What rpm does the stall brake torq up to...???
Click to expand...
 
The gears and TC are sorta locking the engine into an ugly operating mode; to in the neighborhood of 20mph.From there to 30ish mph, the engine struggles. At 35mph it finally wakes up, but around 45 it runs out of breath, and by 50 it's time to hit second gear.Then when you hit second the Rs drop to 3000 or a little less, and the engine is struggling again. Does that sound familiar at all?

With that cam; 268/110/in at 104ICL,
the Wallace calculator says 120psi is about 7.7Scr and 6.5Dcr.
So here's my take;
At low rpm,what little charge the pistons are able to draw in, they push a good portion of it back up into the intake until that late-closing intake finally closes(58*ABDC). As the rpm goes up there is less and less time for this phenomenon to occur, and by 2200 or so, the engine is finally getting a decent charge. But at 7.7Scr it will still be soft until it approaches the torque peak.

All figures cited depend on accurate inputs, so your actual results may vary.

IMO,
A band-aid cure for this poor girl, is either a higher stall or a performance gear ratio,or both.
The cheapest is a cam swap.But you are still stuck with that 7.7Scr
The best is a boost in Scr.With a decent Scr that combo would wake up considerably.For instance; at 9.6Scr, the Dcr would climb to 8.0 and the pressure might be 160. That'll burn rubber.
 
AJ/FormS said:
The gears and TC are sorta locking the engine into an ugly operating mode; to in the neighborhood of 20mph.From there to 30ish mph, the engine struggles. At 35mph it finally wakes up, but around 45 it runs out of breath, and by 50 it's time to hit second gear.Then when you hit second the Rs drop to 3000 or a little less, and the engine is struggling again. Does that sound familiar at all?

With that cam; 268/110/in at 104ICL,
the Wallace calculator says 120psi is about 7.7Scr and 6.5Dcr.
So here's my take;
At low rpm,what little charge the pistons are able to draw in, they push a good portion of it back up into the intake until that late-closing intake finally closes(58*ABDC). As the rpm goes up there is less and less time for this phenomenon to occur, and by 2200 or so, the engine is finally getting a decent charge. But at 7.7Scr it will still be soft until it approaches the torque peak.

All figures cited depend on accurate inputs, so your actual results may vary.

IMO,
A band-aid cure for this poor girl, is either a higher stall or a performance gear ratio,or both.
The cheapest is a cam swap.But you are still stuck with that 7.7Scr
The best is a boost in Scr.With a decent Scr that combo would wake up considerably.
Click to expand...

That's a cool analogy. It makes sense!
 
The cam seems to be way retarded as said earlier. If it were straight up it would probably be 45/45 at tdc a guess would be about 4-5 thou per degree .If 4 degrees adv. the int. should be about 20 to 25 thou. higher.Almost sounds like ita a tooth off.
 
I see a bunch of things that all ad up to poor off idle/low end torque but the one thing that grabs my attention the most are 1 7/8 headers. Those are too big for your engine. 1 5/8 would help solve the problem.
 
I am surprised with 120# comp it even starts. Perfect example of a bad combination of parts. Higher than stock stall with no gears, big tube headers(top end power) and cam trying to make power down low. Over carbed and under timed.

Even with pistons way in the hole and open chamber heads it should have more than 120#'s. The engine is probably worn out, bad rings and valves not seating means no compression which is made much worse by to big of a cam(for engine condition), headers for stroker w big cam, throw some overly rich air in there and try to light it with too little/too late timing.

Since it was in a police car, I cant imagine that after 32 years it doesnt have more miles than mcdonalds has served. And we all know cops never rev the crap out of their cars :D

If this were a horse, it would be 35 years old, no teeth, bum leg, bad hips, stomach problems and you just put a brand new saddle on her and expect it to do what?

Do the people you are selling it to and install something in better shape, 318's in good condition are a dime a dozen, get one and sell them something worth owning, charge $500 more to cover engine cost and you will have a happy customer instead of somebody cursing you every time they sit in the seat.
 
My bad, typo, 1 5/8" headers.

AJ, sort of what I was thinking.Thanks

This engine didnt cost me much and will keep it that way, not worth it.

Can find a decent shortblock/engine with compression.quite reasonable.

The car is for sale, if It doesnt sell as a cruiser with potential,
Time for for my initial plan for the car. B/RB, the car deserves it. Will also help the pricetag.

But for now, I will mess with cam advancement and report back the find/results.

Thanks for all responses.

Dave
 
Here it is.
Marks look right on to me.
How many degrees is a tooth??

One tooth right or left of mark on cam gear?

Thanks never had to do this before.


Thanks Dave
 
Here
 

Attachments

  • 20160220_142053_resized.jpg
    85.3 KB · Views: 189
  • 20160220_142224_resized.jpg
    72.5 KB · Views: 196
Well, it looks good in the pix with a straight edge, with the caveat that it is kinda tough to be sure the crank sprocket dot is properly lined up with the crank centerline in a pix like this. Looks like a stock chain, and there is some fair slack on the non-drive side (passenger side) so that would easily put the cam easily 2-3 degrees retarded (if not a bit more). Going from that to 4 degrees advanced would be a big change.

I was expecting you to put a degree wheel on it. That is the thing you need to do next.

Being off one cam tooth is about 14-15 degrees so that would be a pretty gross problem. So no, you just can't jump a tooth.....did you say the chain had been replaced or not?

Were your cylinder pressures pretty even across all cylinders at 120 psi, or was there some larger variation? If pretty even, then I'd think the cylinders are pretty decent.

Edit to add:
Ideally, you'd get a kit with a new chain and the adjustable crank sprocket. You could also move a few degrees with a new offset woodruff key in the crank or cam sprocket too. But your chain looks kinda sloppy worn so if you want to get to 4 degrees advanced, I think you need a new chain and then as a minimalist approach, try the offset keys. You'll get more change with the offset key in the cam. You can find cheap Dorman ones at Advance Auto or any hot rod store.

If you want to degree it (which you really should do) so you can see how much slack there is even with a new chain and then pick the right timing slot or offset key, you can print off a degree wheel and paste it on some thick cardboard to use, so you don't have to drop the $$ for a degree wheel:

http://www.machinerycleanery.com/DWUniversal.htm
 
mycuda said:
Here it is.
Marks look right on to me.
How many degrees is a tooth??

One tooth right or left of mark on cam gear?

Thanks never had to do this before.


Thanks Dave
Click to expand...

Whether the marks are lined up is not what your answer is, here. You need to figure out IF that cam is workable, and WHERE it should be degreed to make it work. I'm no expert on "all the cams". People like Rusty and Crackedback are.

Earlier, I pointed this out to you. Did you read this?

67Dart273 said:
The cam could be timed "by the marks" but that does not mean that's where it needs to be to run good, especially in a "torque" street engine. One of the members on here and I had to advance the CRAP out of a purple shaft.

You need to find out WHAT exactly cam that is. Then ask here where (several good people on here) think it should be timed. At least some of these purple cams don't run well 'straight up' in a street engine.

Read this for some insight.

http://www.forabodiesonly.com/mopar/showthread.php?t=244033
Click to expand...
 
You must log in or register to reply here.
-

Back
Top