Magnum heads are on, it RUNS! (and well)

[volaredon]

Hey guys, haven't posted much lately. Lurked a bit though.
Well I got my truck back together; 83 318, went from stock 2 barrel and original heads and cam, to EQ heads, a stock replacement 360-2 barrel cam (for $#!ts and giggles you guys might wanna compare the numbers in your FSM for this cam to a COMP 252. Other than 0.015" more lift on the 252 pretty much the same. (and with the 1.6 RR of the Magnum valve train you get that back and more) and the factory stock replacement is a big improvement over a stock 318 cam, at 1/2 the cost of buying the COMP.

I put the stock 83 Manifolds back on. sealed up fine (once I got the correct manifold gaskets; I needed the Magnum ones NOT the LA ones with the cutout for the AIR pump holes) Duals with glass packs is a project for another day.
Also put a standard Performer on for an intake (not RPM not Airgap) and a Carter AFB #9636 625CFM elec choke and my "overkill" ACCEL coil; the big un; new and 25+ years old, still in the orig box, with all its nuts n bolts still sealed in plastic; I don't think $10 was a bad deal there. Air filter housing; found an 80 B van in the yard with a TQ equipped 360 (but it "looks" too small in my truck) I wish I had the dual snorkel one that was on my old '81!Another Tim Taylor "more power" thought there; the "big one" oughtta mean 50 HP, right (ha ha)

What a difference in the way this thing runs! ALOT less pedal to get going!
Good thing I put a chain n gears in; I wonder how it ran at all, with the old (nylon POS) one in there as sloppy as it was! (I could see the old one going bad right after putting the new heads on it, otherwise) all new but bent valves there; I don't THINK so!)

16*initial timing so far and NO ping; it pinged before at 8*!

Only problem I see so far, other than minor tuning, is what seems like a low vacuum reading; I cannot get over 16" out of it. I had almost 20 before. Is this cam big enuf to make THAT much difference in vacuum readings?? It gets 19-20" on a 360 on good shape. (I know Ive had a few)

After 121K, and an untouched original 26 year old shortblock, I have minimal carbon ridge and plenty of factory cross hatch still visible as well. Running on my 18V cordless Milwaukee drill when I pre lubed it to be sure I got iol to the rockers I had 70# of oil pressure with a fresh fill of 10W40 Valvoline! I think this motor's still very solid/lotsa miles left in it.

I did wind up having to pull the oil pan (was not originally planning on it) when I dropped one of my new pushrods into it. Probably a good thing; the end seals were brittle and cracked to Hell. Gave me a chance to glass bead the pan and paint it too. Replaced EVERY gasket and seal in it, except the rear main. Cam bearings looked brand new too. the motor is VERY clean inside sludge wise too.

Would the higher flowing heads (EQ vs stock '83 318 ones) cause the vacuum reading to be lower than I am used to?

[Speed Dragon]

Sweet dude. Good to hear it's doing good after all that trouble you had. I'm actually kinda considering them myself, I still don't like the rocker arm design, but meh, everyone seems to have good luck and says they flow better. Time to quit being stubborn about it I guess :) I have a set or two of 5.9 Mag heads laying around.

And your vacuum reading is probably just the bigger cam, remember your engine is 42 cubes short of a 360. You might try advancing the timing some more, I was running 23 degrees w/ the same intake and carb as you, on '68-74 675-casting 318 heads. Timing affects vacuum also.

[volaredon]

Yeah; I went outta my way, to try to do the most with the least, save money by rehabbing used heads, that wound up being no good, and spent more $$$ on heads that wound up cracked/junk than I did on the brand new ones.

But, I have heard on other sites, of guys that say "so what" run 'em, they all crack and these cracks have no effect on them, but thats a lotta work to go thru for that "1 time" that they leak.(meaning a redo) which is one of my pet peeves. I like this sort of work and I would do the same job multiple times but I hate re doing it multiple times on the same vehicle!

when I was in the dealer the factory wound up telling us just that, on the old Mitsu 2.6's in K cars, and the earliest minivans. Dave Hughes (Hughes Engines) says his earlier experiences said the same about the Olds 350 diesel heads but he also was the one who wouldn't drill these same Magnum heads for an LA intake because of the cracks.

I put up on Moparts that anyone who wanted them and would give me better than scrap price could have the 5 cracked Magnum heads I have sitting here piling up. I had a few responses along the lines of "if you were closer".... so maybe there is some truth to it; the same offer stands here. (if no takers soon, they will be hauled to scrap)

this was somewhat of a Tim Taylor "more Power" excercise, somewhat of a "I have them I might as well use them" (but that line of thinking blew up in my face, when I found out they were cracked) then it became "Well I have everything ELSE I need, I might as well get a set of known good heads" and I was initially gonna just do a chain and gears (damn good thing I did, as sloppy as my original nylon one was) and being I had to replace the lifters anyway for the center oiling hole, I figured I might as well put a new cam in as well. Those "might-as-wells" will kill ya every time. but I certainly cringed at the thought of putting these brand new heads on and the timing chain giving up and bending the valves so that was a no brainer.

[Speed Dragon]

Yeah, usually if the cracks are little ones between the valves, you can run them w/ no problems. 2.2/2.5 heads are like that, almost every set you find has those little valve seat cracks, in fact the head on the 2.2 in my Daytona has them, never has given any problems.

As far as those heads go, I'd take them also - if I were closer lol. Problem is, it costs about 100 bucks to ship a set.

[volaredon]

yup. between the valves; 2-1/2 sets sitting here. I robbed the valves (but don't need THAT many laying around) for my EQ heads. as far as my timing advance, I think I'm at the max (which is a huge improvement over the engine in stock form) since if I do get into the secondaries, I get ping; but driven normally, I don't. I just want to know if that vac reading is the best it can be or if you guys think the cam might need some advance.

I no longer own a degree wheel (loaned it out and it never returned) so I did the dot to dot thing, with the new timing set. 3 keyway set I used the "0" slot. I can idle it down below 600 dead smooth, if I so desire; (I have it at 700) as spring comes, I plan on dialing in the carb as I have 2 Strip Kits here and maybe playing with the adjustment in the advance can too. I may try pulling my dizzy out and puttin' the stock original one back in once I rebuild it (sticky advance weights) I have a Summit-brand, that looks IDENTICAL to the MP one which from what I understand is now made by Mallory. but there are a few little details that scream "CHEEP" in the way its made. the arm on the orig dizzy said "11R" the Summit one as well as the "Standard" brand, replacement advance can I have sittin here are "8.5R" but the Summit came set at like 3-1/2 turns out; the OE one was only 3/4 turn out, so it was not advancing much. I seriously doubt the geezer that had my truck originally would have even known that was adjustable (Hell I didn't and I'm a former ASE Master tech, having worked on cars for a living for 18 years; thats probably because I was primarily an alignment guy)

[3834B]

I would run full manifold vacuum to the can minus the restriter and see where you are at. With initial timing set at 10 degrees.

When you connect the full manifold vacuum hose up you should jump to about 20-22 advance which is where you want to be at idle. You may then have to re-adjust your carburetor and then see what kind of vacuum you are pulling.

[impuresoul2k3]

If you could tell me a list of the parts you needed to convert it to the Magnum heads, that would be great :D Part numbers would be fantastic too, but only if it isn't too much trouble.

[volaredon]

Most of what I used is listed in previous posts in this thread; though I admit the info isnt "arranged" well, (I'm not a tech article writer, after all) as far as a list, but you can pick it out of there w/o too much trouble. I can come up with most of the part numbers but I gotta dig out all my receipts and the boxes I still have sitting here, (waiting for garbage day, to get rid of it all) I'll try to over the next couple days.

As far as the heads go, I spent way too much $$$$$ on OE Magnum heads that wound up as junk (as in cracked), buying them, having them hot tanked and magged, one set that I have that is good, and has already had a fresh valve job, just sitting in the garage, I screwed up on, by taking them to a local machine shop and told them to drill them for an LA intake; but I told them the wrong angle to drill the holes at! (I can still use them with any intake drilled for a stock Magnum engine) I should have taken THAT set to Hughes in the 1st place; "money saved" locally, turned out not to be!

I was originally gonna just buy a carb'd intake that's made for Magnum heads, but this snowballed into a "comedy of errors" and experiments, that wound up costing me way more than that would have. I decided not too far into the process, that I wanted a set of heads that I could put LA intakes onto, because there is such a bigger selection than there is for Magnum bolt-parttern ones. (and I may keep those heads beyond the life of the truck for something else) I started out with the "keep it simple" attitude, but in the end, I over complicated things. In the interest of simplicity and less cost than I spent, I should have just bought that carb'd Magnum intake and still used the original set of heads that I had planned on; but from there to completion, I wound up somehow taking a "back way around" to finish it up. I sure didn't plan it that way at the start.

There are alot of things I could have (and probably should have) done different along the way; I mean, in the end I got where I wanted to be, (at least I think I did; driving time with the truck will tell for sure) but it wound up costing me way more than it could (and should) have, to get there; but winding up with brand new heads, it's the least likely way to have problems down the road, I guess.
I just wish that if it had to end there (with new vs. used OE Magnums) I'd have done that from the start; THAT would have even been much cheaper than it turned out; instead of all the money I spent on the other used Magnum heads I had here that turned out as junk.
but still more expensive, than either just buying the right intake for the way those heads were originally designed, and using what I had here, like I originally intended; OR taking that same known good set of heads to someone that knew what they were doing and having them drilled for the other intake correctly)

[Speed Dragon]

What I'm interested in finding is flow numbers on the stock 302- and 587-casting heads and stock Magnum heads, just to compare for kicks, and to document it. I've asked around on other sites for 302 flow numbers, but they are always like, "just upgrade to Magnums, they flow better", but I want to know how much better :D Everyone says that, but I still see lots of hi-power engines still running 587's and J's and such. If it's so easy to swap to Mag's and they flow that much better, why does everyone use them? It's not like it costs that much more, especially when building and engine from scratch.

[volaredon]

that's just it; more people ARE going to the Magnum heads. there was an article I've seen quoted in different places on the internet recently, with just the comparison you seek, stock Mag's, EQ Mag's R/T's, even an LT1 Chevy head thrown in for the hell of it (stock OEM Magnums outflowed the LT1s BTW) I think it was Mopar Muscle or Mopar Action that did this; there have been a few 400HP 318 builds documented in magazines lately; one mag used the '302 heads another mag did theirs with the EQ Magnum heads. IIRC they put the respective flow numbers in their articles; but flow numbers taken from different flow benches don't really amount to anything (unless you are using the exact same set of heads; but then youd be comparing flow benches, not different heads)

[volaredon]

well it's been ~1600 miles and the oil is still clean and at the same level as when I put it together; meaning no more oil consumption; have not noticed the blue cloud I used to get, either. Got my headers and duals on, so it sounds better, the exhaust was good for another seat of the pants improvement. Next to rebuild the TQ that i have here and experiment with that instead of teh AFB. (also have a 500 AFB here to play with as well) so far MPG is real comparable to OE stock 2 barrel config but power is up. Kickdown linkage is close but not quite right. Fine for everyday but I very occasionally gotta manually put it in "2" to get passing gear.
My MSD box puked about 10 days ago so I am running the OE Blue electronic ign box once again. No diff there if anything surprisingly a touch smoother. Sure starts easy! Choke is a bit funny on the AFB; Runs great stone cold and if I'm steady on the gas as the truck warms up, fine again once totally warm but sputters a bit "1/2 warm" if I gotta stop and take off again. (I seem to catch this one light "red" all the time, I think maybe the truck just don't like that one intersection)