What valve springs should I use?

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CordobaDart

CordobaDart

318 SLANTMAN
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I have a 1973 model year 360 short block out of a camper with 80k miles on it that I put a Summit 50052 cam in. I am using the heads on another engine and got ahold of some magnum heads off of a 98 318 that I would like to use on this 360. The new lifters have holes for pushrod oiling and I know I will need custom length oil-through pushrods. Lift of this cam with 1.6 magnum rockers should be around .484". This is a for fun budget build and I was wondering if the stock springs on these heads would hold up to this combo on the street as a flat tappet cam can have less spring pressure than a roller I have read. If not, what springs would be sufficient? I have not called anyone on this yet.
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I went with the 1110 springs and matching retainers/locks from Hughes. Looking foreward to putting this engine in the Dart to test it out:) Thanks for the replies.
 
Might want to do a double take on that cam lift.
I think that's pretty close to valve guide seal/retainer contact on the Magnums.
Hughes sells a spring, retainer and lock set just to solve that, but I think Magnummopar on here can make you a better deal on them.
Pretty sure I remember him saying that, but I could be wrong

The stock springs are sissy's. :D
 
MOPEkidD-3 said:
You get those Magnum heads checked for cracks?
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Yes, I checked them while ejoying a Hamm's beer after work. :). In all seriousness, the heads were free, I got 2 free sets for helping clean out a guy's old shop. I did not see any visible cracks or any signs of coolant leaking, just typical carbon.
 
TrailBeast said:
Might want to do a double take on that cam lift.
I think that's pretty close to valve guide seal/retainer contact on the Magnums.
Hughes sells a spring, retainer and lock set just to solve that, but I think Magnummopar on here can make you a better deal on them.
Pretty sure I remember him saying that, but I could be wrong

The stock springs are sissy's. :D
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Dang, I wish I would have known about magnummopar before I ordered from Hughes today.

As for my cam, it is a Summit 50052 with .454" when used with 1.5 rockers. So it should be around .484" with the magnum heads.
 
CordobaDart said:
Yes, I checked them while ejoying a Hamm's beer after work. :). In all seriousness, the heads were free, I got 2 free sets for helping clean out a guy's old shop. I did not see any visible cracks or any signs of coolant leaking, just typical carbon.
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Not to be a party pooper but get them checked by a machine shop, I'm willing to bet at least 2 have cracks between the valve seats...

EDITED nvm saw you got springs already
 
Why are we worrying about cracked Magnum heads? Seems like 80% of all Magnum engines are running around with cracks and operating just fine. I've got a set of ported cracked Magnum heads on a 420HP 360, thousands of miles of hard use with no problems. How many of you 'cracked head worriers' have ever experienced any water leaks from the cracks between the seats or any engine damaged from those cracked heads? Aren't the cracked heads coming off running engines for the most part. I've pulled a lot of 'em off wrecked cars/trucks and they had to be running to get in those wrecks. Just saying....cracked Magnum heads have never caused me a problem.
 
RustyRatRod said:
The Comp 901 spring would work well.
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I would have loved to go this route, but unfortunatly these springs have an outside diameter of 1.494" and both sets of mag heads I have measure 1.440" on the valve seat, I have a new set of Sealed power 340 replacement springs that I tried only to find they did not fit, measured them at 1.5" wide. The Hughes 1110 springs are a perfect fit at 1.440". LA's do have a larger and cheaper selection of valve springs I have noticed.
 
Opened up the pushrod pinch, blended the bowls, got rid of some casting flash in 2 exhaust ports, smoothed out exhaust port roof, lapped the valves, gave it a wash and fresh paint. Ready for my springs to show up tomorrow. My second budget(ish) build 360 is coming along. I did install a swap meet sourced windage tray and an HV oil pump I bought in high school and forgot on a shelf in my parents basement.(i would have gone standard volume if I knew then what I know now). Used magnum timing set with new timing tensioner. But plenty of new parts as well. I got my other 360 together for around $350, I am probably over double that with this one. The 318 in the Dart runs great, but needs to be regasketed badly, so I want to try more cubes:)
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IQ52 said:
Why are we worrying about cracked Magnum heads? Seems like 80% of all Magnum engines are running around with cracks and operating just fine. I've got a set of ported cracked Magnum heads on a 420HP 360, thousands of miles of hard use with no problems. How many of you 'cracked head worriers' have ever experienced any water leaks from the cracks between the seats or any engine damaged from those cracked heads? Aren't the cracked heads coming off running engines for the most part. I've pulled a lot of 'em off wrecked cars/trucks and they had to be running to get in those wrecks. Just saying....cracked Magnum heads have never caused me a problem.
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Dang I was not aware it was that minor of a problem, machine shops and such had told me it was a no-go but if that's the case then hell yeah... I was worried I'd crack the factory Magnums on my 360 but if what you say is true I'd love to stop caring lol

CordobaDart what head gaskets you gonna use? I would use the thinnest (steel shim??) you can find with those dished pistons. I am also running the Hughes 1110 springs on my 360 with their retainers and locks, the engine has at least 20k since I put it together and it still runs great. I should probably pull the valve covers at some point though and check it out, I can't say exactly the condition of the parts but I run it hard and it never makes noises or skips a beat.
 
Just the word "Cracked" next to heads has everybody freaking out as if there junk and you now need, sorry, I ment "NEED!" New heads.

Everyone acts like it is the end of the world and you have the cooties!

Even the older heads crack. 308's, 302's, X-J-U, Poly heads, HEMI heads, 906, 452's, they all crack. Not every head cracks, but you would never know unless it leaks water and they normally crack where there is no water. And that is part of the reason they crack.
 
CordobaDart said:
I went with the 1110 springs and matching retainers/locks from Hughes. Looking foreward to putting this engine in the Dart to test it out:) Thanks for the replies.
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CordobaDart said:
Opened up the pushrod pinch, blended the bowls, got rid of some casting flash in 2 exhaust ports, smoothed out exhaust port roof, lapped the valves, gave it a wash and fresh paint. Ready for my springs to show up tomorrow. My second budget(ish) build 360 is coming along. I did install a swap meet sourced windage tray and an HV oil pump I bought in high school and forgot on a shelf in my parents basement.(i would have gone standard volume if I knew then what I know now). Used magnum timing set with new timing tensioner. But plenty of new parts as well. I got my other 360 together for around $350, I am probably over double that with this one. The 318 in the Dart runs great, but needs to be regasketed badly, so I want to try more cubes:)View attachment 1714964354View attachment 1714964356
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Sounds like a good solid,budget build....
 
MOPEkidD-3 said:
Dang I was not aware it was that minor of a problem, machine shops and such had told me it was a no-go but if that's the case then hell yeah... I was worried I'd crack the factory Magnums on my 360 but if what you say is true I'd love to stop caring lol

CordobaDart what head gaskets you gonna use? I would use the thinnest (steel shim??) you can find with those dished pistons. I am also running the Hughes 1110 springs on my 360 with their retainers and locks, the engine has at least 20k since I put it together and it still runs great. I should probably pull the valve covers at some point though and check it out, I can't say exactly the condition of the parts but I run it hard and it never makes noises or skips a beat.
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Good to hear you are getting good service out of your springs. My buddy has a 01 Ram 5.9 he put the Hughes air gap fi intake on and a towing regrind cam in, along with this same spring-retainer-lock kit and a tuner. His truck has far more power but he plans on headers and a modified throttle body next. Has treated him well even with towing a trailer of snowmobiles and a bed full of gear up north.

The head gaskets I am using are the standard fel-pro blues that came in my la kit for when I was originally going to just re-gasket this engine and cam it. They lined up good, hope everything seals up nice.
 
Had to set the intake and valve covers on to see how it looks even though I need to install the valvetrain and pre-lube it. Pretty excited, I will need to burn off the 10 year old BFG's and get fresh rubber when it gets in.

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IQ52 said:
Why are we worrying about cracked Magnum heads? Seems like 80% of all Magnum engines are running around with cracks and operating just fine. I've got a set of ported cracked Magnum heads on a 420HP 360, thousands of miles of hard use with no problems. How many of you 'cracked head worriers' have ever experienced any water leaks from the cracks between the seats or any engine damaged from those cracked heads? Aren't the cracked heads coming off running engines for the most part. I've pulled a lot of 'em off wrecked cars/trucks and they had to be running to get in those wrecks. Just saying....cracked Magnum heads have never caused me a problem.
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I've experienced added heating from a cracked Opel CIH head in racing. They cracked between the valve seats. It was totally common for the early year induction hardened Opel CIH heads. The cracks would allow a minor amount of combustion gas to seep into the water jacket. I ran it for several long endurance races with nothing but moderately elevated coolant temps, but I finally replaced it.

So, based on that, with tiny head cracks, keep an eye on water temps. The hard part IMHO is to know which tiny cracks will leak enough combustion gases to cause heating issues. Good experience with one set of heads is fine, but does not strike me as any sure indication that the next set of cracked heads will perform as well. Sounds like a crap shoot...
 
Lot of good heads are tossed because of the stress relief crack.
If it ain't leaking don't worry about it.
 
Update on this engine. It rocks! Does not seem to like more than 33 degees btdc total timing. Tried vacuum advance, hates it, I even welded a washer on my vacuum advance pod to limit travel, still no likey. I put 2 factory light springs in a distributor that I welded the slots to limit mechanical advance. So my magnum headed 360 with this mild cam likes 15 initial with 18 mechanical advance for 33 total. Really motivates my Dart Sport. Pulls righ off idle, has an awesome midrange, and seems to not want to stop pulling even at 5500 with this 216 duration cam. Idle is rather smooth, kinda sounds like a factory big block.
 
How does the engine behave when it does not 'like' too much advance?
What pistons are this engine? Stock ones? Head gasket thickness or PN? Cam installed straight up or advanced? Tnx: I just like to relate this to numbers....
 
You should hook the vacuum advance to ported vacuum.
 
RustyRatRod said:
You should hook the vacuum advance to ported vacuum.
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I tried both ported and manifold vacuum. At first if I hooked up to manifold, it would stumble at idle. And if I hooked it to ported(passenger side of the edelbrock carb) it would stumble when throttle was applied off idle. I used a piston stop to verify true top dead center and applied timing tape as the mark on the converter was a degree off. What I did after that was weld in a 1/4" washer(.062" thick), to limit vacuum pod travel by that much. What I will likely do is pull the vacuum advance pod and tack weld another washer to the backside of the vacuum pod to take a bit more travel out of it. Then I can set the Allen wrench back at most sensitive vacuum advance and reduce from there. It was so close to operating well with it, off idle was more crisp and felt a bit more powerful. The symptoms were random sputters/missfires between 2500-3000 on the highway, that went away above 3000 and 70 mph. After disconnecting the vacuum advance, this went away. I had the the pod turned 6 turns out from full advance at this point as well as the. 062" of travel removed from a 11 vacuum canister.
 
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